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Sample records for monkey striate cortex

  1. Interlaminar and lateral excitatory amino acid connections in the striate cortex of monkey

    International Nuclear Information System (INIS)

    Kisvarday, Z.F.; Cowey, A.; Smith, A.D.; Somogyi, P.

    1989-01-01

    The intrinsic excitatory amino acid pathways within the striate cortex of monkeys were studied by autoradiographic detection of retrogradely labeled somata following microinjections of D-3H-aspartate (D-3H-Asp) into different layers. The labeled amino acid was selectively accumulated by subpopulations of neurons and, to a small extent, by glial cells, the latter mainly in the supragranular layers. Immunocytochemical detection of neurons containing GABA showed that, apart from a few cells exclusively in layer I, GABAergic neurons do not accumulate D-3H-Asp. Several lines of evidence suggest that D-3H-Asp uptake occurred only at nerve terminals; thus, the pattern of perikaryal labeling allowed the delineation of interlaminar and lateral projections. Neurons in layer I probably project laterally, and layer I receives wide-ranging projections from layer IVB and layer V from cells up to 1300 microns laterally. Some neurons in layer II send a focused projection to lower layer VI. Some neurons in layers II/III project up to 1 mm laterally within their own layer, but relatively few neurons can be labeled in these projections. Similarly, in layers II/III few neurons can be retrogradely labeled from layers V and upper VI, and this projection is organized such that cells closer to the pia project deeper in layer V/VI. The connections of layer IVA could not be revealed separately because of the difficulty of confining injections to this thin sublamina. Neurons in layer IVB project up to 1300 microns within IVB itself. A small number of cells from IVB also project to layers III, IVC-alpha, V, and VI with much more restricted lateral spread. Neurons in upper IVC-alpha send axons to layer IVB with at least 600-800 microns lateral spread. Neurons in lower IVC-alpha/upper IVC-beta project to layer III with at least 300-500 microns lateral spread

  2. Interlaminar and lateral excitatory amino acid connections in the striate cortex of monkey

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    Kisvarday, Z.F.; Cowey, A.; Smith, A.D.; Somogyi, P.

    1989-02-01

    The intrinsic excitatory amino acid pathways within the striate cortex of monkeys were studied by autoradiographic detection of retrogradely labeled somata following microinjections of D-3H-aspartate (D-3H-Asp) into different layers. The labeled amino acid was selectively accumulated by subpopulations of neurons and, to a small extent, by glial cells, the latter mainly in the supragranular layers. Immunocytochemical detection of neurons containing GABA showed that, apart from a few cells exclusively in layer I, GABAergic neurons do not accumulate D-3H-Asp. Several lines of evidence suggest that D-3H-Asp uptake occurred only at nerve terminals; thus, the pattern of perikaryal labeling allowed the delineation of interlaminar and lateral projections. Neurons in layer I probably project laterally, and layer I receives wide-ranging projections from layer IVB and layer V from cells up to 1300 microns laterally. Some neurons in layer II send a focused projection to lower layer VI. Some neurons in layers II/III project up to 1 mm laterally within their own layer, but relatively few neurons can be labeled in these projections. Similarly, in layers II/III few neurons can be retrogradely labeled from layers V and upper VI, and this projection is organized such that cells closer to the pia project deeper in layer V/VI. The connections of layer IVA could not be revealed separately because of the difficulty of confining injections to this thin sublamina. Neurons in layer IVB project up to 1300 microns within IVB itself. A small number of cells from IVB also project to layers III, IVC-alpha, V, and VI with much more restricted lateral spread. Neurons in upper IVC-alpha send axons to layer IVB with at least 600-800 microns lateral spread. Neurons in lower IVC-alpha/upper IVC-beta project to layer III with at least 300-500 microns lateral spread.

  3. Interlaminar and lateral excitatory amino acid connections in the striate cortex of monkey.

    Science.gov (United States)

    Kisvarday, Z F; Cowey, A; Smith, A D; Somogyi, P

    1989-02-01

    The intrinsic excitatory amino acid pathways within the striate cortex of monkeys were studied by autoradiographic detection of retrogradely labeled somata following microinjections of D-3H-aspartate (D-3H-Asp) into different layers. The labeled amino acid was selectively accumulated by subpopulations of neurons and, to a small extent, by glial cells, the latter mainly in the supragranular layers. Immunocytochemical detection of neurons containing GABA showed that, apart from a few cells exclusively in layer I, GABAergic neurons do not accumulate D-3H-Asp. Several lines of evidence suggest that D-3H-Asp uptake occurred only at nerve terminals; thus, the pattern of perikaryal labeling allowed the delineation of interlaminar and lateral projections. Neurons in layer I probably project laterally, and layer I receives wide-ranging projections from layer IVB and layer V from cells up to 1300 microns laterally. Some neurons in layer II send a focused projection to lower layer VI. Some neurons in layers II/III project up to 1 mm laterally within their own layer, but relatively few neurons can be labeled in these projections. Similarly, in layers II/III few neurons can be retrogradely labeled from layers V and upper VI, and this projection is organized such that cells closer to the pia project deeper in layer V/VI. The connections of layer IVA could not be revealed separately because of the difficulty of confining injections to this thin sublamina. Neurons in layer IVB project up to 1300 microns within IVB itself. A small number of cells from IVB also project to layers III, IVC-alpha, V, and VI with much more restricted lateral spread. Neurons in upper IVC-alpha send axons to layer IVB with at least 600-800 microns lateral spread. Neurons in lower IVC-alpha/upper IVC-beta project to layer III with at least 300-500 microns lateral spread. The bottom 50-80 microns of layer IVC-beta contains neurons with a very focused projection, apparently exclusively to the layer III

  4. A difference in [14C]deoxyglucose autoradiographic patterns in striate cortex between Macaca and Saimiri monkeys following monocular stimulation

    International Nuclear Information System (INIS)

    Hendrickson, A.E.; Wilson, J.R.

    1979-01-01

    Since the apparent absence of ocular dominance columns (ODC) in some New World primates could be caused by deficiencies of the transsynaptic autoradiographic technique, such as spillage of label in the poorly laminated dorsal lateral geniculate nucleus, the authors have examined this question using a functional autoradiographic tracing technique based on the uptake of [ 14 C]2-deoxyglucose ([ 14 C]dG) by active neurons. When only one eye is stimulated, this innovative method graphically demonstrates a repetitive pattern in Macaca monkey striate cortex which has been interpreted to be the ODC driven by the open eye. They now report on the results of a comparative study of Old World Macaca and New World Saimiri monkeys using [ 14 C]dG autoradiography in which evidence is found for repetitive patterns of [ 14 C]dG in Saimiri for layers above, but not in, layer IV. (Auth.)

  5. Suppression of metabolic activity caused by infantile strabismus and strabismic amblyopia in striate visual cortex of macaque monkeys.

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    Wong, Agnes M F; Burkhalter, Andreas; Tychsen, Lawrence

    2005-02-01

    Suppression is a major sensorial abnormality in humans and monkeys with infantile strabismus. We previously reported evidence of metabolic suppression in the visual cortex of strabismic macaques, using the mitochondrial enzyme cytochrome oxidase as an anatomic label. The purpose of this study was to further elucidate alterations in cortical metabolic activity, with or without amblyopia. Six macaque monkeys were used in the experiments (four strabismic and two control). Three of the strabismic monkeys had naturally occurring, infantile strabismus (two esotropic, one exotropic). The fourth strabismic monkey had infantile microesotropia induced by alternating monocular occlusion in the first months of life. Ocular motor behaviors and visual acuity were tested after infancy in each animal, and development of stereopsis was recorded during infancy in one strabismic and one control monkey. Ocular dominance columns (ODCs) of the striate visual cortex (area V1) were labeled using cytochrome oxidase (CO) histochemistry alone, or CO in conjunction with an anterograde tracer ([H 3 ]proline or WGA-HRP) injected into one eye. Each of the strabismic monkeys showed inequalities of metabolic activity in ODCs of opposite ocularity, visible as rows of lighter CO staining, corresponding to ODCs of lower metabolic activity, alternating with rows of darker CO staining, corresponding to ODCs of higher metabolic activity. In monkeys who had infantile strabismus and unilateral amblyopia, lower metabolic activity was found in (suppressed) ODCs driven by the nondominant eye in each hemisphere. In monkeys who had infantile esotropia and alternating fixation (no amblyopia), metabolic activity was lower in ODCs driven by the ipsilateral eye in each hemisphere. The suppression included a monocular core zone at the center of ODCs and binocular border zones at the boundaries of ODCs. This suppression was not evident in the monocular lamina of the LGN, indicating an intracortical rather than

  6. Prenatal Co 60-irradiation effects on visual acuity, maturation of the fovea in the retina, and the striate cortex of squirrel monkey offspring

    International Nuclear Information System (INIS)

    Ordy, J.M.; Brizzee, K.R.; Young, R.

    1982-01-01

    In the present study, foveal striate cortex depth increased significantly from 1400 μm to 1650 μm by 90 days, whereas prenatal 100 rad exposure resulted in a significant reduction of foveal striate cortex thickness at 90 days of age. From birth to 90 days, cell packing density decreased, whereas overall neuropil density increased in both control and 100 rad exposed offspring. Regarding the effects of prenatal radiation on Meynert cells, there was a significant difference in the time course of early postnatal spine frequency reduction on apical dendrites of Meynert cells, particularly in laminae V and IV. It seems possible that the significant differences in the time course of perinatal increases and subsequent decreases of spines and synapses on such pyramidal neurons as Meynert cells in the deep layers of the striate cortex may play an important role in the development of binocular acuity. Future follow-up studies will be essential from 90 days to 1 and 2 years to determine the extent of recovery from, and persistence of visual acuity impairments in relation to structural alterations in the foveal projection of the retino-geniculo-striate system of diurnal primates. (orig./MG)

  7. Normalization of cell responses in cat striate cortex

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    Heeger, D. J.

    1992-01-01

    Simple cells in the striate cortex have been depicted as half-wave-rectified linear operators. Complex cells have been depicted as energy mechanisms, constructed from the squared sum of the outputs of quadrature pairs of linear operators. However, the linear/energy model falls short of a complete explanation of striate cell responses. In this paper, a modified version of the linear/energy model is presented in which striate cells mutually inhibit one another, effectively normalizing their responses with respect to stimulus contrast. This paper reviews experimental measurements of striate cell responses, and shows that the new model explains a significantly larger body of physiological data.

  8. Interpretation of the function of the striate cortex

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    Garner, Bernardette M.; Paplinski, Andrew P.

    2000-04-01

    Biological neural networks do not require retraining every time objects move in the visual field. Conventional computer neural networks do not share this shift-invariance. The brain compensates for movements in the head, body, eyes and objects by allowing the sensory data to be tracked across the visual field. The neurons in the striate cortex respond to objects moving across the field of vision as is seen in many experiments. It is proposed, that the neurons in the striate cortex allow continuous angle changes needed to compensate for changes in orientation of the head, eyes and the motion of objects in the field of vision. It is hypothesized that the neurons in the striate cortex form a system that allows for the translation, some rotation and scaling of objects and provides a continuity of objects as they move relative to other objects. The neurons in the striate cortex respond to features which are fundamental to sight, such as orientation of lines, direction of motion, color and contrast. The neurons that respond to these features are arranged on the cortex in a way that depends on the features they are responding to and on the area of the retina from which they receive their inputs.

  9. Altered figure-ground perception in monkeys with an extra-striate lesion.

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    Supèr, Hans; Lamme, Victor A F

    2007-11-05

    The visual system binds and segments the elements of an image into coherent objects and their surroundings. Recent findings demonstrate that primary visual cortex is involved in this process of figure-ground organization. In the primary visual cortex the late part of a neural response to a stimulus correlates with figure-ground segregation and perception. Such a late onset indicates an involvement of feedback projections from higher visual areas. To investigate the possible role of feedback in figure-ground perception we removed dorsal extra-striate areas of the monkey visual cortex. The findings show that figure-ground perception is reduced when the figure is presented in the lesioned hemifield and perception is normal when the figure appeared in the intact hemifield. In conclusion, our observations show the importance for recurrent processing in visual perception.

  10. Metabolic activity in striate and extrastriate cortex in the hooded rat: contralateral and ipsilateral eye input

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    Thurlow, G.A.; Cooper, R.M.

    1988-01-01

    The extent of changes in glucose metabolism resulting from ipsilateral and contralateral eye activity in the posterior cortex of the hooded rat was demonstrated by means of the C-14 2-deoxyglucose autoradiographic technique. By stimulating one eye with square wave gratings and eliminating efferent activation from the other by means of enucleation or intraocular TTX injection, differences between ipsilaterally and contralaterally based visual activity in the two hemispheres were maximized. Carbon-14 levels in layer IV of autoradiographs of coronal sections were measured and combined across sections to form right and left matrices of posterior cortex metabolic activity. A difference matrix, formed by subtracting the metabolic activity matrix of cortex contralateral to the stimulated eye from the ipsilateral depressed matrix, emphasized those parts of the visual cortex that received monocular visual input. The demarcation of striate cortex by means of cholinesterase stain and the examination of autoradiographs from sections cut tangential to the cortical surface aided in the interpretation of the difference matrices. In striate cortex, differences were maximal in the medial monocular portion, and the lateral or binocular portion was shown to be divided metabolically into a far lateral contralaterally dominant strip along the cortical representation of the vertical meridian, and a more medial region of patches of more or less contralaterally dominant binocular input. Lateral peristriate differences were less than those of striate cortex, and regions of greater and lesser monocular input could be distinguished. We did not detect differences between the two hemispheres in either anterior or medial peristriate areas

  11. [Raman spectra of monkey cerebral cortex tissue].

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    Zhu, Ji-chun; Guo, Jian-yu; Cai, Wei-ying; Wang, Zu-geng; Sun, Zhen-rong

    2010-01-01

    Monkey cerebral cortex, an important part in the brain to control action and thought activities, is mainly composed of grey matter and nerve cell. In the present paper, the in situ Raman spectra of the cerebral cortex of the birth, teenage and aged monkeys were achieved for the first time. The results show that the Raman spectra for the different age monkey cerebral cortex exhibit most obvious changes in the regions of 1000-1400 and 2800-3000 cm(-1). With monkey growing up, the relative intensities of the Raman bands at 1313 and 2885 cm(-1) mainly assigned to CH2 chain vibrational mode of lipid become stronger and stronger whereas the relative intensities of the Raman bands at 1338 and 2932 cm(-1) mainly assigned to CH3 chain vibrational mode of protein become weaker and weaker. In addition, the two new Raman bands at 1296 and 2850 cm(-1) are only observed in the aged monkey cerebral cortex, therefore, the two bands can be considered as a character or "marker" to differentiate the caducity degree with monkey growth In order to further explore the changes, the relative intensity ratios of the Raman band at 1313 cm(-1) to that at 1338 cm(-1) and the Raman band at 2885 cm(-1) to that at 2 932 cm(-1), I1313/I1338 and I2885/I2932, which are the lipid-to-protein ratios, are introduced to denote the degree of the lipid content. The results show that the relative intensity ratios increase significantly with monkey growth, namely, the lipid content in the cerebral cortex increases greatly with monkey growth. So, the authors can deduce that the overmuch lipid is an important cause to induce the caducity. Therefore, the results will be a powerful assistance and valuable parameter to study the order of life growth and diagnose diseases.

  12. Contrasting effects of strabismic amblyopia on metabolic activity in superficial and deep layers of striate cortex.

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    Adams, Daniel L; Economides, John R; Horton, Jonathan C

    2015-05-01

    To probe the mechanism of visual suppression, we have raised macaques with strabismus by disinserting the medial rectus muscle in each eye at 1 mo of age. Typically, this operation produces a comitant, alternating exotropia with normal acuity in each eye. Here we describe an unusual occurrence: the development of severe amblyopia in one eye of a monkey after induction of exotropia. Shortly after surgery, the animal demonstrated a strong fixation preference for the left eye, with apparent suppression of the right eye. Later, behavioral testing showed inability to track or to saccade to targets with the right eye. With the left eye occluded, the animal demonstrated no visually guided behavior. Optokinetic nystagmus was absent in the right eye. Metabolic activity in striate cortex was assessed by processing the tissue for cytochrome oxidase (CO). Amblyopia caused loss of CO in one eye's rows of patches, presumably those serving the blind eye. Layers 4A and 4B showed columns of reduced CO, in register with pale rows of patches in layer 2/3. Layers 4C, 5, and 6 also showed columns of CO activity, but remarkably, comparison with more superficial layers showed a reversal in contrast. In other words, pale CO staining in layers 2/3, 4A, and 4B was aligned with dark CO staining in layers 4C, 5, and 6. No experimental intervention or deprivation paradigm has been reported previously to produce opposite effects on metabolic activity in layers 2/3, 4A, and 4B vs. layers 4C, 5, and 6 within a given eye's columns. Copyright © 2015 the American Physiological Society.

  13. Monkey cortex through fMRI glasses.

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    Vanduffel, Wim; Zhu, Qi; Orban, Guy A

    2014-08-06

    In 1998 several groups reported the feasibility of fMRI experiments in monkeys, with the goal to bridge the gap between invasive nonhuman primate studies and human functional imaging. These studies yielded critical insights in the neuronal underpinnings of the BOLD signal. Furthermore, the technology has been successful in guiding electrophysiological recordings and identifying focal perturbation targets. Finally, invaluable information was obtained concerning human brain evolution. We here provide a comprehensive overview of awake monkey fMRI studies mainly confined to the visual system. We review the latest insights about the topographic organization of monkey visual cortex and discuss the spatial relationships between retinotopy and category- and feature-selective clusters. We briefly discuss the functional layout of parietal and frontal cortex and continue with a summary of some fascinating functional and effective connectivity studies. Finally, we review recent comparative fMRI experiments and speculate about the future of nonhuman primate imaging. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. MRI in occipital lobe infarcts: classification by involvement of the striate cortex

    Energy Technology Data Exchange (ETDEWEB)

    Kitajima, M. [Department of Radiology, Kumamoto University School of Medicine, Kumamoto (Japan)]|[Department of Radiology, Kumamoto Rousai Hospital, Kumamoto (Japan); Korogi, Y.; Takahashi, M. [Department of Radiology, Kumamoto University School of Medicine, Kumamoto (Japan); Kido, T.; Ikeda, O.; Morishita, S. [Department of Radiology, Kumamoto Rousai Hospital, Kumamoto (Japan)

    1998-11-01

    We reviewed the MRI studies of 25 patients with occipital lobe infarcts to clarify the distribution of infarcts in the posterior cerebral arterial territory, focussing on their relationship to the striate cortex. Visual field defects and MRI findings were also correlated in 16 patients. On coronal and/or sagittal images, the distribution of the infarct and its relationship to the striate cortex were classified. Involvement of the cortex of both upper and lower lips of the calcarine fissure was observed in 10 patients, and involvement of the lower lip alone in 15. The upper cortical lesions were always accompanied by lower cortical lesions. The visual field defects were complete hemianopia in nine patients, superior quadrantanopia in six and hemianopia with a preserved temporal crescent in one. All patients with superior quadrantanopia had involvement of the lower cortex alone; there were no cases of inferior quadrantanopia. The characteristic vascular anatomy, and poor development of the collateral circulation in the lower cortical area, may explain the vulnerability of this area to infarcts. (orig.) With 6 figs., 21 refs.

  15. Inactivation of the infragranular striate cortex broadens orientation tuning of supragranular visual neurons in the cat.

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    Allison, J D; Bonds, A B

    1994-01-01

    Intracortical inhibition is believed to enhance the orientation tuning of striate cortical neurons, but the origin of this inhibition is unclear. To examine the possible influence of ascending inhibitory projections from the infragranular layers of striate cortex on the orientation selectivity of neurons in the supragranular layers, we measured the spatiotemporal response properties of 32 supragranular neurons in the cat before, during, and after neural activity in the infragranular layers beneath the recorded cells was inactivated by iontophoretic administration of GABA. During GABA iontophoresis, the orientation tuning bandwidth of 15 (46.9%) supragranular neurons broadened as a result of increases in response amplitude to stimuli oriented about +/- 20 degrees away from the preferred stimulus angle. The mean (+/- SD) baseline orientation tuning bandwidth (half width at half height) of these neurons was 13.08 +/- 2.3 degrees. Their mean tuning bandwidth during inactivation of the infragranular layers increased to 19.59 +/- 2.54 degrees, an increase of 49.7%. The mean percentage increase in orientation tuning bandwidth of the individual neurons was 47.4%. Four neurons exhibited symmetrical changes in their orientation tuning functions, while 11 neurons displayed asymmetrical changes. The change in form of the orientation tuning functions appeared to depend on the relative vertical alignment of the recorded neuron and the infragranular region of inactivation. Neurons located in close vertical register with the inactivated infragranular tissue exhibited symmetric changes in their orientation tuning functions. The neurons exhibiting asymmetric changes in their orientation tuning functions were located just outside the vertical register. Eight of these 11 neurons also demonstrated a mean shift of 6.67 +/- 5.77 degrees in their preferred stimulus orientation. The magnitude of change in the orientation tuning functions increased as the delivery of GABA was prolonged

  16. A functional magnetic resonance imaging investigation of visual hallucinations in the human striate cortex.

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    Abid, Hina; Ahmad, Fayyaz; Lee, Soo Y; Park, Hyun W; Im, Dongmi; Ahmad, Iftikhar; Chaudhary, Safee U

    2016-11-29

    Human beings frequently experience fear, phobia, migraine and hallucinations, however, the cerebral mechanisms underpinning these conditions remain poorly understood. Towards this goal, in this work, we aim to correlate the human ocular perceptions with visual hallucinations, and map them to their cerebral origins. An fMRI study was performed to examine the visual cortical areas including the striate, parastriate and peristriate cortex in the occipital lobe of the human brain. 24 healthy subjects were enrolled and four visual patterns including hallucination circle (HCC), hallucination fan (HCF), retinotopy circle (RTC) and retinotopy cross (RTX) were used towards registering their impact in the aforementioned visual related areas. One-way analysis of variance was used to evaluate the significance of difference between induced activations. Multinomial regression and and K-means were used to cluster activation patterns in visual areas of the brain. Significant activations were observed in the visual cortex as a result of stimulus presentation. The responses induced by visual stimuli were resolved to Brodmann areas 17, 18 and 19. Activation data clustered into independent and mutually exclusive clusters with HCC registering higher activations as compared to HCF, RTC and RTX. We conclude that small circular objects, in rotation, tend to leave greater hallucinating impressions in the visual region. The similarity between observed activation patterns and those reported in conditions such as epilepsy and visual hallucinations can help elucidate the cortical mechanisms underlying these conditions. Trial Registration 1121_GWJUNG.

  17. Figure-ground segregation at contours: a neural mechanism in the visual cortex of the alert monkey.

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    Baumann, R; van der Zwan, R; Peterhans, E

    1997-06-01

    An important task of vision is the segregation of figure and ground in situations of spatial occlusion. Psychophysical evidence suggests that the depth order at contours is defined early in visual processing. We have analysed this process in the visual cortex of the alert monkey. The animals were trained on a visual fixation task which reinforced foveal viewing. During periods of active visual fixation, we recorded the responses of single neurons in striate and prestriate cortex (areas V1, V2, and V3/V3A). The stimuli mimicked situations of spatial occlusion, usually a uniform light (or dark) rectangle overlaying a grating texture of opposite contrast. The direction of figure and ground at the borders of these rectangles was defined by the direction of the terminating grating lines (occlusion cues). Neuronal responses were analysed with respect to figure-ground direction and contrast polarity at such contours. Striate neurons often failed to respond to such stimuli, or were selective for contrast polarity; others were non-selective. Some neurons preferred a certain combination of figure-ground direction and contrast polarity. These neurons were rare both in striate and prestriate cortex. The majority of neurons signalled figure-ground direction independent of contrast polarity. These neurons were only found in prestriate cortex. We explain these responses in terms of a model which also explains neuronal signals of illusory contours. These results suggest that occlusion cues are used at an early level of processing to segregate figure and ground at contours.

  18. Laminar Differences in Associative Memory Signals in Monkey Perirhinal Cortex.

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    Vogels, Rufin

    2016-10-19

    New research published in Neuron describes assignment of cortical layer to single neurons recorded in awake monkeys. Applying the procedure to perirhinal cortex, Koyano et al. (2016) found marked and unsuspected differences among layers in the coding of associative memory signals. Copyright © 2016. Published by Elsevier Inc.

  19. Background and stimulus-induced patterns of high metabolic activity in the visual cortex (area 17) of the squirrel and macaque monkey

    International Nuclear Information System (INIS)

    Humphrey, A.L.; Hendrickson, A.E.

    1983-01-01

    We have used 2-deoxy-D-[ 14 C]glucose (2-DG) autoradiography and cytochrome oxidase histochemistry to examine background and stimulus-induced patterns of metabolic activity in monkey striate cortex. In squirrel monkeys (Saimiri sciureus) that binocularly or monocularly viewed diffuse white light or binocularly viewed bars of many orientations and spatial frequencies, 2-DG consumption was not uniform across the cortex but consisted of regularly spaced radial zones of high uptake. The zones extended through all laminae except IVc beta and, when viewed tangentially, formed separate patches 500 microns apart. The cytochrome oxidase stain in these animals also revealed patches of high metabolism which coincided with the 2-DG patches. Squirrel monkeys binocularly viewing vertical stripes showed parallel bands of increased 2-DG uptake in the cortex, while the cytochrome label in these animals remained patchy. When monkeys were kept in the dark during 2-DG exposure, 2-DG-labeled patches were not seen but cytochrome oxidase-positive patches remained. In macaque (Macaca nemestrina) monkeys, binocular stimulation with many orientations and spatial frequencies produced radial zones of high 2-DG uptake in layers I to IVa and VI. When viewed tangentially, these zones formed a dots-in-rows pattern with a spacing of 350 X 500 microns; cytochrome oxidase staining produced an identical pattern. Macaca differed from Saimiri in that monocular stimulation labeled alternate rows. These results indicate that there are radial zones of high background metabolism across squirrel and macaque monkey striate cortex. In Saimiri these zones do not appear to be related to an eye dominance system, while in Macaca they do. The presence of these zones of high metabolism may complicate the interpretation of 2-DG autoradiographs that result from specific visual stimuli

  20. Temporal-frequency tuning of cross-orientation suppression in the cat striate cortex.

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    Allison, J D; Smith, K R; Bonds, A B

    2001-01-01

    A sinusoidal mask grating oriented orthogonally to and superimposed onto an optimally oriented base grating reduces a cortical neuron's response amplitude. The spatial selectivity of cross-orientation suppression (XOR) has been described, so for this paper we investigated the temporal properties of XOR. We recorded from single striate cortical neurons (n = 72) in anesthetized and paralyzed cats. After quantifying the spatial and temporal characteristics of each cell's excitatory response to a base grating, we measured the temporal-frequency tuning of XOR by systematically varying the temporal frequency of a mask grating placed at a null orientation outside of the cell's excitatory orientation domain. The average preferred temporal frequency of the excitatory response of the neurons in our sample was 3.8 (+/- 1.5 S.D.) Hz. The average cutoff frequency for the sample was 16.3 (+/- 1.7) Hz. The average preferred temporal frequency (7.0 +/- 2.6 Hz) and cutoff frequency (20.4 +/- 6.9 Hz) of the XOR were significantly higher. The differences averaged 1.1 (+/- 0.6) octaves for the peaks and 0.3 (+/- 0.4) octaves for the cutoffs. The XOR mechanism's preference for high temporal frequencies suggests a possible extrastriate origin for the effect and could help explain the low-pass temporal-frequency response profile displayed by most striate cortical neurons.

  1. Effect of retinal impulse blockage on cytochrome oxidase-poor interpuffs in the macaque striate cortex: quantitative EM analysis of neurons.

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    Wong-Riley, M T; Trusk, T C; Kaboord, W; Huang, Z

    1994-09-01

    One of the hallmarks of the primate striate cortex is the presence of cytochrome oxidase-rich puffs in its supragranular layers. Neurons in puffs have been classified as type A, B, and C in ascending order of cytochrome oxidase content, with type C cells being the most vulnerable to retinal impulse blockade. The present study aimed at analysing cytochrome oxidase-poor interpuffs with reference to their metabolic cell types and the effect of intraretinal tetrodotoxin treatment. The same three metabolic types were found in interpuffs, except that type B and C neurons were smaller and less cytochrome oxidase-reactive in interpuffs than in puffs. Type A neurons had small perikarya, low levels of cytochrome oxidase, and received exclusively symmetric axosomatic synapses. The largest neurons were pyramidal, type B cells with moderate cytochrome oxidase activity and were also contacted exclusively by symmetric axosomatic synapses. Type C cells medium-sized with a rich supply of large, darkly reactive mitochondria and possessed all the characteristics of GABAergic neurons. They were the only cell type that received both symmetric and asymmetric axosomatic synapses. Two weeks of monocular tetrodotoxin blockade in adult monkeys caused all three major cell types in deprived interpuffs to suffer a significant downward shift in the size and cytochrome oxidase reactivity of their mitochondria, but the effects were more severe in type B and C neurons. In nondeprived interpuffs, all three cell types gained both in size and absolute number of mitochondria, and type A cells also had an elevated level of cytochrome oxidase, indicating that they might be functioning at a competitive advantage over cells in deprived columns. However, type B and C neurons showed a net loss of darkly reactive mitochondria, indicating that these cells became less active. Thus, mature interpuff neurons remained vulnerable to retinal impulse blockade and the metabolic capacity of these cells remains tightly

  2. Temporal dynamics of contrast gain in single cells of the cat striate cortex.

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    Bonds, A B

    1991-03-01

    The response amplitude of cat striate cortical cells is usually reduced after exposure to high-contrast stimuli. The temporal characteristics and contrast sensitivity of this phenomenon were explored by stimulating cortical cells with drifting gratings in which contrast sequentially incremented and decremented in stepwise fashion over time. All responses showed a clear hysteresis, in which contrast gain dropped on average 0.36 log unit and then returned to baseline values within 60 s. Noticeable gain adjustments were seen in as little as 3 s and with peak contrasts as low as 3%. Contrast adaptation was absent in responses from LGN cells. Adaptation was found to depend on temporal frequency of stimulation, with greater and more rapid adaptation at higher temporal frequencies. Two different tests showed that the mechanism controlling response reduction was influenced primarily by stimulus contrast rather than response amplitude. These results support the existence of a rapid and sensitive cortically based system that normalizes the output of cortical cells as a function of local mean contrast. Control of the adaptation appears to arise at least in part across a population of cells, which is consistent with the idea that the gain control serves to limit the information converging from many cells onto subsequent processing areas.

  3. Role of inhibition in the specification of orientation selectivity of cells in the cat striate cortex.

    Science.gov (United States)

    Bonds, A B

    1989-01-01

    Mechanisms supporting orientation selectivity of cat striate cortical cells were studied by stimulation with two superimposed sine-wave gratings of different orientations. One grating (base) generated a discharge of known amplitude which could be modified by the second grating (mask). Masks presented at nonoptimal orientations usually reduced the base-generated response, but the degree of reduction varied widely between cells. Cells with narrow orientation tuning tended to be more susceptible to mask presence than broadly tuned cells; similarly, simple cells generally showed more response reduction than did complex cells. The base and mask stimuli were drifted at different temporal frequencies which, in simple cells, permitted the identification of individual response components from each stimulus. This revealed that the reduction of the base response by the mask usually did not vary regularly with mask orientation, although response facilitation from the mask was orientation selective. In some sharply tuned simple cells, response reduction had clear local maxima near the limits of the cell's orientation-tuning function. Response reduction resulted from a nearly pure rightward shift of the response versus log contrast function. The lowest mask contrast yielding reduction was within 0.1-0.3 log unit of the lowest contrast effective for excitation. The temporal-frequency bandpass of the response-reduction mechanism resembled that of most cortical cells. The spatial-frequency bandpass was much broader than is typical for single cortical cells, spanning essentially the entire visual range of the cat. These findings are compatible with a model in which weak intrinsic orientation-selective excitation is enhanced in two stages: (1) control of threshold by nonorientation-selective inhibition that is continuously dependent on stimulus contrast; and (2) in the more narrowly tuned cells, orientation-selective inhibition that has local maxima serving to increase the slope of

  4. Intersection of reward and memory in monkey rhinal cortex.

    Science.gov (United States)

    Clark, Andrew M; Bouret, Sebastien; Young, Adrienne M; Richmond, Barry J

    2012-05-16

    In humans and other animals, the vigor with which a reward is pursued depends on its desirability, that is, on the reward's predicted value. Predicted value is generally context-dependent, varying according to the value of rewards obtained in the recent and distant past. Signals related to reward prediction and valuation are believed to be encoded in a circuit centered around midbrain dopamine neurons and their targets in the prefrontal cortex and basal ganglia. Notably absent from this hypothesized reward pathway are dopaminergic targets in the medial temporal lobe. Here we show that a key part of the medial temporal lobe memory system previously reported to be important for sensory mnemonic and perceptual processing, the rhinal cortex (Rh), is required for using memories of previous reward values to predict the value of forthcoming rewards. We tested monkeys with bilateral Rh lesions on a task in which reward size varied across blocks of uncued trials. In this experiment, the only cues for predicting current reward value are the sizes of rewards delivered in previous blocks. Unexpectedly, monkeys with Rh ablations, but not intact controls, were insensitive to differences in predicted reward, responding as if they expected all rewards to be of equal magnitude. Thus, it appears that Rh is critical for using memory of previous rewards to predict the value of forthcoming rewards. These results are in agreement with accumulating evidence that Rh is critical for establishing the relationships between temporally interleaved events, which is a key element of episodic memory.

  5. Neural Representations of Natural and Scrambled Movies Progressively Change from Rat Striate to Temporal Cortex

    Science.gov (United States)

    Vinken, Kasper; Van den Bergh, Gert; Vermaercke, Ben; Op de Beeck, Hans P.

    2016-01-01

    In recent years, the rodent has come forward as a candidate model for investigating higher level visual abilities such as object vision. This view has been backed up substantially by evidence from behavioral studies that show rats can be trained to express visual object recognition and categorization capabilities. However, almost no studies have investigated the functional properties of rodent extrastriate visual cortex using stimuli that target object vision, leaving a gap compared with the primate literature. Therefore, we recorded single-neuron responses along a proposed ventral pathway in rat visual cortex to investigate hallmarks of primate neural object representations such as preference for intact versus scrambled stimuli and category-selectivity. We presented natural movies containing a rat or no rat as well as their phase-scrambled versions. Population analyses showed increased dissociation in representations of natural versus scrambled stimuli along the targeted stream, but without a clear preference for natural stimuli. Along the measured cortical hierarchy the neural response seemed to be driven increasingly by features that are not V1-like and destroyed by phase-scrambling. However, there was no evidence for category selectivity for the rat versus nonrat distinction. Together, these findings provide insights about differences and commonalities between rodent and primate visual cortex. PMID:27146315

  6. Posttraining transcranial magnetic stimulation of striate cortex disrupts consolidation early in visual skill learning.

    Science.gov (United States)

    De Weerd, Peter; Reithler, Joel; van de Ven, Vincent; Been, Marin; Jacobs, Christianne; Sack, Alexander T

    2012-02-08

    Practice-induced improvements in skilled performance reflect "offline " consolidation processes extending beyond daily training sessions. According to visual learning theories, an early, fast learning phase driven by high-level areas is followed by a late, asymptotic learning phase driven by low-level, retinotopic areas when higher resolution is required. Thus, low-level areas would not contribute to learning and offline consolidation until late learning. Recent studies have challenged this notion, demonstrating modified responses to trained stimuli in primary visual cortex (V1) and offline activity after very limited training. However, the behavioral relevance of modified V1 activity for offline consolidation of visual skill memory in V1 after early training sessions remains unclear. Here, we used neuronavigated transcranial magnetic stimulation (TMS) directed to a trained retinotopic V1 location to test for behaviorally relevant consolidation in human low-level visual cortex. Applying TMS to the trained V1 location within 45 min of the first or second training session strongly interfered with learning, as measured by impaired performance the next day. The interference was conditional on task context and occurred only when training in the location targeted by TMS was followed by training in a second location before TMS. In this condition, high-level areas may become coupled to the second location and uncoupled from the previously trained low-level representation, thereby rendering consolidation vulnerable to interference. Our data show that, during the earliest phases of skill learning in the lowest-level visual areas, a behaviorally relevant form of consolidation exists of which the robustness is controlled by high-level, contextual factors.

  7. Stimulus rate dependence of regional cerebral blood flow in human striate cortex, demonstrated by positron emission tomography

    International Nuclear Information System (INIS)

    Fox, P.T.; Raichle, M.E.

    1984-01-01

    The purpose of this investigation was to determine the relationship between the repetition rate of a simple sensory stimulus and regional cerebral blood flow (rCBF) in the human brain. Positron emission tomography (PET), using intravenously administered H 2 ( 15 )O as the diffusible blood-flow tracer, was employed for all CBF measurements. The use of H 2 ( 15 )O with PET allowed eight CBF measurements to be made in rapid sequence under multiple stimulation conditions without removing the subject from the tomograph. Nine normal volunteers each underwent a series of eight H2( 15 )O PET measurements of CBF. Initial and final scans were made during visual deprivation. The six intervening scans were made during visual activation with patterned-flash stimuli given in random order at 1.0-, 3.9-, 7.8-, 15.5-, 33.1-, and 61-Hz repetition rates. The region of greatest rCBF increase was determined. Within this region the rCBF was determined for every test condition and then expressed as the percentage change from the value of the initial unstimulated scan (rCBF% delta). In every subject, striate cortex rCBF% delta varied systematically with stimulus rate. Between 0 and 7.8 Hz, rCBF% delta was a linear function of stimulus repetition rate. The rCBF response peaked at 7.8 Hz and then declined. The rCBF% delta during visual stimulation was significantly greater than that during visual deprivation for every stimulus rate except 1.0 Hz. The anatomical localization of the region of peak rCBF response was determined for every subject to be the mesial occipital lobes along the calcarine fissure, primary visual cortex. Stimulus rate is a significant determinant of rCBF response in the visual cortex. Investigators of brain responses to selective activation procedures should be aware of the potential effects of stimulus rate on rCBF and other measurements of cerebral metabolism

  8. Methylmercury intoxication and histochemical demonstration of NADPH-diaphorase activity in the striate cortex of adult cats

    Directory of Open Access Journals (Sweden)

    R.B. Oliveira

    1998-09-01

    Full Text Available The effects of methylmercury (MeHg on histochemical demonstration of the NADPH-diaphorase (NADPH-d activity in the striate cortex were studied in 4 adult cats. Two animals were used as control. The contaminated animals received 50 ml milk containing 0.42 µg MeHg and 100 g fish containing 0.03 µg MeHg daily for 2 months. The level of MeHg in area 17 of intoxicated animals was 3.2 µg/g wet weight brain tissue. Two cats were perfused 24 h after the last dose (group 1 and the other animals were perfused 6 months later (group 2. After microtomy, sections were processed for NADPHd histochemistry procedures using the malic enzyme method. Dendritic branch counts were performed from camera lucida drawings for control and intoxicated animals (N = 80. Average, standard deviation and Student t-test were calculated for each data group. The concentrations of mercury (Hg in milk, fish and brain tissue were measured by acid digestion of samples, followed by reduction of total Hg in the digested sample to metallic Hg using stannous chloride followed by atomic fluorescence analysis. Only group 2 revealed a reduction of the neuropil enzyme activity and morphometric analysis showed a reduction in dendritic field area and in the number of distal dendrite branches of the NADPHd neurons in the white matter (P<0.05. These results suggest that NADPHd neurons in the white matter are more vulnerable to the long-term effects of MeHg than NADPHd neurons in the gray matter.

  9. Asymmetric Dichoptic Masking in Visual Cortex of Amblyopic Macaque Monkeys.

    Science.gov (United States)

    Shooner, Christopher; Hallum, Luke E; Kumbhani, Romesh D; García-Marín, Virginia; Kelly, Jenna G; Majaj, Najib J; Movshon, J Anthony; Kiorpes, Lynne

    2017-09-06

    In amblyopia, abnormal visual experience leads to an extreme form of eye dominance, in which vision through the nondominant eye is degraded. A key aspect of this disorder is perceptual suppression: the image seen by the stronger eye often dominates during binocular viewing, blocking the image of the weaker eye from reaching awareness. Interocular suppression is the focus of ongoing work aimed at understanding and treating amblyopia, yet its physiological basis remains unknown. We measured binocular interactions in visual cortex of anesthetized amblyopic monkeys (female Macaca nemestrina ), using 96-channel "Utah" arrays to record from populations of neurons in V1 and V2. In an experiment reported recently (Hallum et al., 2017), we found that reduced excitatory input from the amblyopic eye (AE) revealed a form of balanced binocular suppression that is unaltered in amblyopia. Here, we report on the modulation of the gain of excitatory signals from the AE by signals from its dominant fellow eye (FE). Using a dichoptic masking technique, we found that AE responses to grating stimuli were attenuated by the presentation of a noise mask to the FE, as in a normal control animal. Responses to FE stimuli, by contrast, could not be masked from the AE. We conclude that a weakened ability of the amblyopic eye to modulate cortical response gain creates an imbalance of suppression that favors the dominant eye. SIGNIFICANCE STATEMENT In amblyopia, vision in one eye is impaired as a result of abnormal early visual experience. Behavioral observations in humans with amblyopia suggest that much of their visual loss is due to active suppression of their amblyopic eye. Here we describe experiments in which we studied binocular interactions in macaques with experimentally induced amblyopia. In normal monkeys, the gain of neuronal response to stimulation of one eye is modulated by contrast in the other eye, but in monkeys with amblyopia the balance of gain modulation is altered so that

  10. Auditory Association Cortex Lesions Impair Auditory Short-Term Memory in Monkeys

    Science.gov (United States)

    Colombo, Michael; D'Amato, Michael R.; Rodman, Hillary R.; Gross, Charles G.

    1990-01-01

    Monkeys that were trained to perform auditory and visual short-term memory tasks (delayed matching-to-sample) received lesions of the auditory association cortex in the superior temporal gyrus. Although visual memory was completely unaffected by the lesions, auditory memory was severely impaired. Despite this impairment, all monkeys could discriminate sounds closer in frequency than those used in the auditory memory task. This result suggests that the superior temporal cortex plays a role in auditory processing and retention similar to the role the inferior temporal cortex plays in visual processing and retention.

  11. Effects of cholinergic deafferentation of the rhinal cortex on visual recognition memory in monkeys.

    Science.gov (United States)

    Turchi, Janita; Saunders, Richard C; Mishkin, Mortimer

    2005-02-08

    Excitotoxic lesion studies have confirmed that the rhinal cortex is essential for visual recognition ability in monkeys. To evaluate the mnemonic role of cholinergic inputs to this cortical region, we compared the visual recognition performance of monkeys given rhinal cortex infusions of a selective cholinergic immunotoxin, ME20.4-SAP, with the performance of monkeys given control infusions into this same tissue. The immunotoxin, which leads to selective cholinergic deafferentation of the infused cortex, yielded recognition deficits of the same magnitude as those produced by excitotoxic lesions of this region, providing the most direct demonstration to date that cholinergic activation of the rhinal cortex is essential for storing the representations of new visual stimuli and thereby enabling their later recognition.

  12. Metabolic changes in the visual cortex of binocular blindness macaque monkeys: a proton magnetic resonance spectroscopy study.

    Directory of Open Access Journals (Sweden)

    Lingjie Wu

    Full Text Available PURPOSE: To evaluate proton magnetic resonance spectroscopy ((1H-MRS in a study of cross-modal plasticity in the visual cortex of binocular blindness macaque monkeys. MATERIALS AND METHODS: Four healthy neonatal macaque monkeys were randomly divided into 2 groups, with 2 in each group. Optic nerve transection was performed in both monkeys in the experimental group (group B to obtain binocular blindness. Two healthy macaque monkeys served as a control group (group A. After sixteen months post-procedure, (1H-MRS was performed in the visual cortex of all monkeys. We compared the peak areas of NAA, Cr, Cho, Glx and Ins and the ratios of NAA/Cr, Cho/Cr, Glx/Cr and Ins/Cr of each monkey in group B with group A. RESULTS: The peak area of NAA and the NAA/Cr ratio in the visual cortex of monkey 4 in group B were found to be dramatically decreased, the peak area of NAA slightly decreased and the NAA/Cr ratio clearly decreased in visual cortex of monkey 3 in group B than those in group A. The peak area of Ins and the Ins/Cr ratio in the visual cortex of monkey 4 in group B slightly increased. The peak area of Cho and the Cho/Cr ratio in the visual cortex of all monkeys in group B dramatically increased compared with group A. The peak area of Glx in the visual cortex of all monkeys in group B slightly increased compared with group A. CONCLUSIONS: (1H-MRS could detect biochemical and metabolic changes in the visual cortex and therefore this technique can be used to provide valuable information for investigating the mechanisms of cross-modal plasticity of binocular blindness in a macaque monkey model.

  13. Implicit and Explicit Learning Mechanisms Meet in Monkey Prefrontal Cortex.

    Science.gov (United States)

    Chafee, Matthew V; Crowe, David A

    2017-10-11

    In this issue, Loonis et al. (2017) provide the first description of unique synchrony patterns differentiating implicit and explicit forms of learning in monkey prefrontal networks. Their results have broad implications for how prefrontal networks integrate the two learning mechanisms to control behavior. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. A neural substrate for object permanence in monkey inferotemporal cortex

    OpenAIRE

    Puneeth, NC; Arun, SP

    2016-01-01

    We take it for granted that objects continue to exist after being occluded. This knowledge ? known as object permanence ? is present even in childhood, but its neural basis is not fully understood. Here, we show that monkey inferior temporal (IT) neurons carry potential signals of object permanence even in animals that received no explicit behavioral training. We compared two conditions with identical visual stimulation: the same object emerged from behind an occluder as expected following it...

  15. Mapping visual cortex in monkeys and humans using surface-based atlases

    Science.gov (United States)

    Van Essen, D. C.; Lewis, J. W.; Drury, H. A.; Hadjikhani, N.; Tootell, R. B.; Bakircioglu, M.; Miller, M. I.

    2001-01-01

    We have used surface-based atlases of the cerebral cortex to analyze the functional organization of visual cortex in humans and macaque monkeys. The macaque atlas contains multiple partitioning schemes for visual cortex, including a probabilistic atlas of visual areas derived from a recent architectonic study, plus summary schemes that reflect a combination of physiological and anatomical evidence. The human atlas includes a probabilistic map of eight topographically organized visual areas recently mapped using functional MRI. To facilitate comparisons between species, we used surface-based warping to bring functional and geographic landmarks on the macaque map into register with corresponding landmarks on the human map. The results suggest that extrastriate visual cortex outside the known topographically organized areas is dramatically expanded in human compared to macaque cortex, particularly in the parietal lobe.

  16. A neural substrate for object permanence in monkey inferotemporal cortex.

    Science.gov (United States)

    Puneeth, N C; Arun, S P

    2016-08-03

    We take it for granted that objects continue to exist after being occluded. This knowledge - known as object permanence - is present even in childhood, but its neural basis is not fully understood. Here, we show that monkey inferior temporal (IT) neurons carry potential signals of object permanence even in animals that received no explicit behavioral training. We compared two conditions with identical visual stimulation: the same object emerged from behind an occluder as expected following its occlusion, or unexpectedly after occlusion of a different object. Some neurons produced a larger (surprise) signal when the object emerged unexpectedly, whereas other neurons produced a larger (match) signal when the object reappeared as expected. Neurons carrying match signals also reinstated selective delay period activity just before the object emerged. Thus, signals related to object permanence are present in IT neurons and may arise through an interplay of memory and match computations.

  17. The origins of thalamic inputs to grasp zones in frontal cortex of macaque monkeys

    OpenAIRE

    Gharbawie, Omar A.; Stepniewska, Iwona; Kaas, Jon H.

    2015-01-01

    The hand representation in primary motor cortex (M1) is instrumental to manual dexterity in primates. In Old World monkeys, rostral and caudal aspects of the hand representation are located in the precentral gyrus and the anterior bank of the central sulcus, respectively. We previously reported the organization of the cortico-cortical connections of the grasp zone in rostral M1. Here we describe the organization of thalamocortical connections that were labeled from the same tracer injections....

  18. Synaptogenesis in visual cortex of normal and preterm monkeys: evidence for intrinsic regulation of synaptic overproduction.

    OpenAIRE

    Bourgeois, J P; Jastreboff, P J; Rakic, P

    1989-01-01

    We used quantitative electron microscopy to determine the effect of precocious visual experience on the time course, magnitude, and pattern of perinatal synaptic overproduction in the primary visual cortex of the rhesus monkey. Fetuses were delivered by caesarean section 3 weeks before term, exposed to normal light intensity and day/night cycles, and killed within the first postnatal month, together with age-matched controls that were delivered at term. We found that premature visual stimulat...

  19. Cyto-, myelo- and chemoarchitecture of the prefrontal cortex of the Cebus monkey

    Science.gov (United States)

    2011-01-01

    Background According to several lines of evidence, the great expansion observed in the primate prefrontal cortex (PfC) was accompanied by the emergence of new cortical areas during phylogenetic development. As a consequence, the structural heterogeneity noted in this region of the primate frontal lobe has been associated with diverse behavioral and cognitive functions described in human and non-human primates. A substantial part of this evidence was obtained using Old World monkeys as experimental model; while the PfC of New World monkeys has been poorly studied. In this study, the architecture of the PfC in five capuchin monkeys (Cebus apella) was analyzed based on four different architectonic tools, Nissl and myelin staining, histochemistry using the lectin Wisteria floribunda agglutinin and immunohistochemistry using SMI-32 antibody. Results Twenty-two architectonic areas in the Cebus PfC were distinguished: areas 8v, 8d, 9d, 12l, 45, 46v, 46d, 46vr and 46dr in the lateral PfC; areas 11l, 11m, 12o, 13l, 13m, 13i, 14r and 14c in the orbitofrontal cortex, with areas 14r and 14c occupying the ventromedial corner; areas 32r, 32c, 25 and 9m in the medial PfC, and area 10 in the frontal pole. This number is significantly higher than the four cytoarchitectonic areas previously recognized in the same species. However, the number and distribution of these areas in Cebus were to a large extent similar to those described in Old World monkeys PfC in more recent studies. Conclusions The present parcellation of the Cebus PfC considerably modifies the scheme initially proposed for this species but is in line with previous studies on Old World monkeys. Thus, it was observed that the remarkable anatomical similarity between the brains of genera Macaca and Cebus may extend to architectonic aspects. Since monkeys of both genera evolved independently over a long period of time facing different environmental pressures, the similarities in the architectonic maps of PfC in both genera

  20. Motor role of parietal cortex in a monkey model of hemispatial neglect.

    Science.gov (United States)

    Kubanek, Jan; Li, Jingfeng M; Snyder, Lawrence H

    2015-04-21

    Parietal cortex is central to spatial cognition. Lesions of parietal cortex often lead to hemispatial neglect, an impairment of choices of targets in space. It has been unclear whether parietal cortex implements target choice at the general cognitive level, or whether parietal cortex subserves the choice of targets of particular actions. To address this question, monkeys engaged in choice tasks in two distinct action contexts--eye movements and arm movements. We placed focused reversible lesions into specific parietal circuits using the GABAA receptor agonist muscimol and validated the lesion placement using MRI. We found that lesions on the lateral bank of the intraparietal sulcus [lateral intraparietal area (LIP)] specifically biased choices made using eye movements, whereas lesions on the medial bank of the intraparietal sulcus [parietal reach region (PRR)] specifically biased choices made using arm movements. This double dissociation suggests that target choice is implemented in dedicated parietal circuits in the context of specific actions. This finding emphasizes a motor role of parietal cortex in spatial choice making and contributes to our understanding of hemispatial neglect.

  1. Effects on executive function following damage to the prefrontal cortex in the rhesus monkey (Macaca mulatta).

    Science.gov (United States)

    Moore, Tara L; Schettler, Stephen P; Killiany, Ronald J; Rosene, Douglas L; Moss, Mark B

    2009-04-01

    Executive function is a term used to describe the cognitive processes subserved by the prefrontal cortex (PFC). An extensive body of work has characterized the effects of damage to the PFC in nonhuman primates, but it has focused primarily on the capacity of recognition and working memory. One limitation in studies of the functional parcellation of the PFC has been the absence of tests that assess executive function or its functional components. The current study used an adaptation of the Wisconsin Card Sorting Test, a classic test of frontal lobe and executive function in humans, to assess the effects of bilateral lesions in the dorsolateral PFC on executive function in the rhesus monkey (Macaca mulatta). The authors used the category set-shifting task, which requires the monkey to establish a pattern of responding to a specific category (color or shape) based on reward contingency, maintain that pattern of responding, and then shift to responding to a different category when the reward contingency changes. Rhesus monkeys with lesions of the dorsolateral PFC were impaired in abstraction, establishing a response pattern to a specific category and maintaining and shifting that response pattern on the category set-shifting task. (c) 2009 APA, all rights reserved.

  2. Neuronal Correlates of Auditory Streaming in Monkey Auditory Cortex for Tone Sequences without Spectral Differences

    Directory of Open Access Journals (Sweden)

    Stanislava Knyazeva

    2018-01-01

    Full Text Available This study finds a neuronal correlate of auditory perceptual streaming in the primary auditory cortex for sequences of tone complexes that have the same amplitude spectrum but a different phase spectrum. Our finding is based on microelectrode recordings of multiunit activity from 270 cortical sites in three awake macaque monkeys. The monkeys were presented with repeated sequences of a tone triplet that consisted of an A tone, a B tone, another A tone and then a pause. The A and B tones were composed of unresolved harmonics formed by adding the harmonics in cosine phase, in alternating phase, or in random phase. A previous psychophysical study on humans revealed that when the A and B tones are similar, humans integrate them into a single auditory stream; when the A and B tones are dissimilar, humans segregate them into separate auditory streams. We found that the similarity of neuronal rate responses to the triplets was highest when all A and B tones had cosine phase. Similarity was intermediate when the A tones had cosine phase and the B tones had alternating phase. Similarity was lowest when the A tones had cosine phase and the B tones had random phase. The present study corroborates and extends previous reports, showing similar correspondences between neuronal activity in the primary auditory cortex and auditory streaming of sound sequences. It also is consistent with Fishman’s population separation model of auditory streaming.

  3. Neuronal Correlates of Auditory Streaming in Monkey Auditory Cortex for Tone Sequences without Spectral Differences.

    Science.gov (United States)

    Knyazeva, Stanislava; Selezneva, Elena; Gorkin, Alexander; Aggelopoulos, Nikolaos C; Brosch, Michael

    2018-01-01

    This study finds a neuronal correlate of auditory perceptual streaming in the primary auditory cortex for sequences of tone complexes that have the same amplitude spectrum but a different phase spectrum. Our finding is based on microelectrode recordings of multiunit activity from 270 cortical sites in three awake macaque monkeys. The monkeys were presented with repeated sequences of a tone triplet that consisted of an A tone, a B tone, another A tone and then a pause. The A and B tones were composed of unresolved harmonics formed by adding the harmonics in cosine phase, in alternating phase, or in random phase. A previous psychophysical study on humans revealed that when the A and B tones are similar, humans integrate them into a single auditory stream; when the A and B tones are dissimilar, humans segregate them into separate auditory streams. We found that the similarity of neuronal rate responses to the triplets was highest when all A and B tones had cosine phase. Similarity was intermediate when the A tones had cosine phase and the B tones had alternating phase. Similarity was lowest when the A tones had cosine phase and the B tones had random phase. The present study corroborates and extends previous reports, showing similar correspondences between neuronal activity in the primary auditory cortex and auditory streaming of sound sequences. It also is consistent with Fishman's population separation model of auditory streaming.

  4. Association fiber pathways to the frontal cortex from the superior temporal region in the rhesus monkey

    International Nuclear Information System (INIS)

    Petrides, M.; Pandya, D.N.

    1988-01-01

    The projections to the frontal cortex that originate from the various areas of the superior temporal region of the rhesus monkey were investigated with the autoradiographic technique. The results demonstrated that the rostral part of the superior temporal gyrus (areas Pro, Ts1, and Ts2) projects to the proisocortical areas of the orbital and medial frontal cortex, as well as to the nearby orbital areas 13, 12, and 11, and to medial areas 9, 10, and 14. These fibers travel to the frontal lobe as part of the uncinate fascicle. The middle part of the superior temporal gyrus (areas Ts3 and paAlt) projects predominantly to the lateral frontal cortex (areas 12, upper 46, and 9) and to the dorsal aspect of the medial frontal lobe (areas 9 and 10). Only a small number of these fibers terminated within the orbitofrontal cortex. The temporofrontal fibers originating from the middle part of the superior temporal gyrus occupy the lower portion of the extreme capsule and lie just dorsal to the fibers of the uncinate fascicle. The posterior part of the superior temporal gyrus projects to the lateral frontal cortex (area 46, dorsal area 8, and the rostralmost part of dorsal area 6). Some of the fibers from the posterior superior temporal gyrus run initially through the extreme capsule and then cross the claustrum as they ascend to enter the external capsule before continuing their course to the frontal lobe. A larger group of fibers curves round the caudalmost Sylvian fissure and travels to the frontal cortex occupying a position just above and medial to the upper branch of the circular sulcus. This latter pathway constitutes a part of the classically described arcuate fasciculus

  5. Association fiber pathways to the frontal cortex from the superior temporal region in the rhesus monkey.

    Science.gov (United States)

    Petrides, M; Pandya, D N

    1988-07-01

    The projections to the frontal cortex that originate from the various areas of the superior temporal region of the rhesus monkey were investigated with the autoradiographic technique. The results demonstrated that the rostral part of the superior temporal gyrus (areas Pro, Ts1, and Ts2) projects to the proisocortical areas of the orbital and medial frontal cortex, as well as to the nearby orbital areas 13, 12, and 11, and to medial areas 9, 10, and 14. These fibers travel to the frontal lobe as part of the uncinate fascicle. The middle part of the superior temporal gyrus (areas Ts3 and paAlt) projects predominantly to the lateral frontal cortex (areas 12, upper 46, and 9) and to the dorsal aspect of the medial frontal lobe (areas 9 and 10). Only a small number of these fibers terminated within the orbitofrontal cortex. The temporofrontal fibers originating from the middle part of the superior temporal gyrus occupy the lower portion of the extreme capsule and lie just dorsal to the fibers of the uncinate fascicle. The posterior part of the superior temporal gyrus projects to the lateral frontal cortex (area 46, dorsal area 8, and the rostralmost part of dorsal area 6). Some of the fibers from the posterior superior temporal gyrus run initially through the extreme capsule and then cross the claustrum as they ascend to enter the external capsule before continuing their course to the frontal lobe. A larger group of fibers curves round the caudalmost Sylvian fissure and travels to the frontal cortex occupying a position just above and medial to the upper branch of the circular sulcus. This latter pathway constitutes a part of the classically described arcuate fasciculus.

  6. Association fiber pathways to the frontal cortex from the superior temporal region in the rhesus monkey

    Energy Technology Data Exchange (ETDEWEB)

    Petrides, M.; Pandya, D.N.

    1988-07-01

    The projections to the frontal cortex that originate from the various areas of the superior temporal region of the rhesus monkey were investigated with the autoradiographic technique. The results demonstrated that the rostral part of the superior temporal gyrus (areas Pro, Ts1, and Ts2) projects to the proisocortical areas of the orbital and medial frontal cortex, as well as to the nearby orbital areas 13, 12, and 11, and to medial areas 9, 10, and 14. These fibers travel to the frontal lobe as part of the uncinate fascicle. The middle part of the superior temporal gyrus (areas Ts3 and paAlt) projects predominantly to the lateral frontal cortex (areas 12, upper 46, and 9) and to the dorsal aspect of the medial frontal lobe (areas 9 and 10). Only a small number of these fibers terminated within the orbitofrontal cortex. The temporofrontal fibers originating from the middle part of the superior temporal gyrus occupy the lower portion of the extreme capsule and lie just dorsal to the fibers of the uncinate fascicle. The posterior part of the superior temporal gyrus projects to the lateral frontal cortex (area 46, dorsal area 8, and the rostralmost part of dorsal area 6). Some of the fibers from the posterior superior temporal gyrus run initially through the extreme capsule and then cross the claustrum as they ascend to enter the external capsule before continuing their course to the frontal lobe. A larger group of fibers curves round the caudalmost Sylvian fissure and travels to the frontal cortex occupying a position just above and medial to the upper branch of the circular sulcus. This latter pathway constitutes a part of the classically described arcuate fasciculus.

  7. Connections of the medial posterior parietal cortex (area 7m) in the monkey.

    Science.gov (United States)

    Leichnetz, G R

    2001-06-01

    The afferent and efferent cortical and subcortical connections of the medial posterior parietal cortex (area 7m) were studied in cebus (Cebus apella) and macaque (Macaca fascicularis) monkeys using the retrograde and anterograde capabilities of the horseradish peroxidase (HRP) technique. The principal intraparietal corticocortical connections of area 7m in both cebus and macaque cases were with the ipsilateral medial bank of the intraparietal sulcus (MIP) and adjacent superior parietal lobule (area 5), inferior parietal lobule (area 7a), lateral bank of the IPS (area 7ip), caudal parietal operculum (PGop), dorsal bank of the caudal superior temporal sulcus (visual area MST), and medial prestriate cortex (including visual area PO and caudal medial lobule). Its principal frontal corticocortical connections were with the prefrontal cortex in the shoulder above the principal sulcus and the cortex in the shoulder above the superior ramus of the arcuate sulcus (SAS), the area purported to contain the smooth eye movement-related frontal eye field (FEFsem) in the cebus monkey by other investigators. There were moderate connections with the cortex in the rostral bank of the arcuate sulcus (purported to contain the saccade-related frontal eye field; FEFsac), supplementary eye field (SEF), and rostral dorsal premotor area (PMDr). Area 7m also had major connections with the cingulate cortex (area 23), particularly the ventral bank of the cingulate sulcus. The principal subcortical connections of area 7m were with the dorsal portion of the ventrolateral thalamic (VLc) nucleus, lateral posterior thalamic nucleus, lateral pulvinar, caudal mediodorsal thalamic nucleus and medial pulvinar, central lateral, central superior lateral, and central inferior intralaminar thalamic nuclei, dorsolateral caudate nucleus and putamen, middle region of the claustrum, nucleus of the diagonal band, zona incerta, pregeniculate nucleus, anterior and posterior pretectal nuclei, intermediate layer of

  8. Alpha and gamma oscillations characterize feedback and feedforward processing in monkey visual cortex.

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    van Kerkoerle, Timo; Self, Matthew W; Dagnino, Bruno; Gariel-Mathis, Marie-Alice; Poort, Jasper; van der Togt, Chris; Roelfsema, Pieter R

    2014-10-07

    Cognitive functions rely on the coordinated activity of neurons in many brain regions, but the interactions between cortical areas are not yet well understood. Here we investigated whether low-frequency (α) and high-frequency (γ) oscillations characterize different directions of information flow in monkey visual cortex. We recorded from all layers of the primary visual cortex (V1) and found that γ-waves are initiated in input layer 4 and propagate to the deep and superficial layers of cortex, whereas α-waves propagate in the opposite direction. Simultaneous recordings from V1 and downstream area V4 confirmed that γ- and α-waves propagate in the feedforward and feedback direction, respectively. Microstimulation in V1 elicited γ-oscillations in V4, whereas microstimulation in V4 elicited α-oscillations in V1, thus providing causal evidence for the opposite propagation of these rhythms. Furthermore, blocking NMDA receptors, thought to be involved in feedback processing, suppressed α while boosting γ. These results provide new insights into the relation between brain rhythms and cognition.

  9. Distinct neural patterns enable grasp types decoding in monkey dorsal premotor cortex

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    Hao, Yaoyao; Zhang, Qiaosheng; Controzzi, Marco; Cipriani, Christian; Li, Yue; Li, Juncheng; Zhang, Shaomin; Wang, Yiwen; Chen, Weidong; Chiara Carrozza, Maria; Zheng, Xiaoxiang

    2014-12-01

    Objective. Recent studies have shown that dorsal premotor cortex (PMd), a cortical area in the dorsomedial grasp pathway, is involved in grasp movements. However, the neural ensemble firing property of PMd during grasp movements and the extent to which it can be used for grasp decoding are still unclear. Approach. To address these issues, we used multielectrode arrays to record both spike and local field potential (LFP) signals in PMd in macaque monkeys performing reaching and grasping of one of four differently shaped objects. Main results. Single and population neuronal activity showed distinct patterns during execution of different grip types. Cluster analysis of neural ensemble signals indicated that the grasp related patterns emerged soon (200-300 ms) after the go cue signal, and faded away during the hold period. The timing and duration of the patterns varied depending on the behaviors of individual monkey. Application of support vector machine model to stable activity patterns revealed classification accuracies of 94% and 89% for each of the two monkeys, indicating a robust, decodable grasp pattern encoded in the PMd. Grasp decoding using LFPs, especially the high-frequency bands, also produced high decoding accuracies. Significance. This study is the first to specify the neuronal population encoding of grasp during the time course of grasp. We demonstrate high grasp decoding performance in PMd. These findings, combined with previous evidence for reach related modulation studies, suggest that PMd may play an important role in generation and maintenance of grasp action and may be a suitable locus for brain-machine interface applications.

  10. Neural correlates of associative face memory in the anterior inferior temporal cortex of monkeys.

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    Eifuku, Satoshi; Nakata, Ryuzaburo; Sugimori, Michiya; Ono, Taketoshi; Tamura, Ryoi

    2010-11-10

    To investigate the neural basis of the associative aspects of facial identification, we recorded neuronal activity from the ventral, anterior inferior temporal cortex (AITv) of macaque monkeys during the performance of an asymmetrical paired-association (APA) task that required associative pairing between an abstract pattern and five different facial views of a single person. In the APA task, after one element of a pair (either an abstract pattern or a face) was presented as a sample cue, the reward-seeking monkey correctly identified the other element of the pair among various repeatedly presented test stimuli (faces or patterns) that were temporally separated by interstimulus delays. The results revealed that a substantial number of AITv neurons responded both to faces and abstract patterns, and the majority of these neurons responded selectively to a particular associative pair. It was demonstrated that in addition to the view-invariant identity of faces used in the APA task, the population of AITv neurons was also able to represent the associative pairing between faces and abstract patterns, which was acquired by training in the APA task. It also appeared that the effect of associative pairing was not so strong that the abstract pattern could be treated in a manner similar to a series of faces belonging to a unique identity. Together, these findings indicate that the AITv plays a crucial role in both facial identification and semantic associations with facial identities.

  11. Seven years of recording from monkey cortex with a chronically implanted multiple microelectrode

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    Jürgen Krüger

    2010-05-01

    Full Text Available A brush of 64 microwires was chronically implanted in the ventral premotor cortex of a macaque monkey. Contrary to common approaches, the wires were inserted from the white matter side. This approach, by avoiding mechanical pressure on the dura and pia mater during penetration, disturbed only minimally the cortical recording site. With this approach isolated potentials and multiunit activity were recorded for more than seven years in about one third of electrodes. The indirect insertion method also provided an excellent stability within each recording session, and in some cases even allowed recording from the same neurons for several years. Histological examination of the implanted brain region shows only a very marginal damage the recording area. Advantages and problems related to long-term recording are discussed.

  12. Comparison of functional recovery of manual dexterity after unilateral spinal cord lesion or motor cortex lesion in adult macaque monkeys

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    Florence eHoogewoud

    2013-07-01

    Full Text Available In relation to mechanisms involved in functional recovery of manual dexterity from cervical cord injury or from motor cortical injury, our goal was to determine whether the movements that characterize post-lesion functional recovery are comparable to original movement patterns or do monkeys adopt distinct strategies to compensate the deficits depending on the type of lesion? To this aim, data derived from earlier studies, using a skilled finger task (the modified Brinkman board from which pellets are retrieved from vertical or horizontal slots, in spinal cord and motor cortex injured monkeys were analyzed and compared. Twelve adult macaque monkeys were subjected to a hemi-section of the cervical cord (n=6 or to a unilateral excitotoxic lesion of the hand representation in the primary motor cortex (n=6. In addition, in each subgroup, one half of monkeys (n=3 were treated for 30 days with a function blocking antibody against the neurite growth inhibitory protein Nogo-A, while the other half (n=3 represented control animals. The motor deficits, and the extent and time course of functional recovery were assessed.For some of the parameters investigated (wrist angle for horizontal slots and movement types distribution for vertical slots after cervical injury; movement types distribution for horizontal slots after motor cortex lesion, post-lesion restoration of the original movement patterns (true recovery led to a quantitatively better functional recovery. In the motor cortex lesion groups, pharmacological reversible inactivation experiments showed that the peri-lesion territory of the primary motor cortex or re-arranged, spared domain of the lesion zone, played a major role in the functional recovery, together with the ipsilesional intact premotor cortex.

  13. An electrocorticographic electrode array for simultaneous recording from medial, lateral, and intrasulcal surface of the cortex in macaque monkeys.

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    Fukushima, Makoto; Saunders, Richard C; Mullarkey, Matthew; Doyle, Alexandra M; Mishkin, Mortimer; Fujii, Naotaka

    2014-08-15

    Electrocorticography (ECoG) permits recording electrical field potentials with high spatiotemporal resolution over a large part of the cerebral cortex. Application of chronically implanted ECoG arrays in animal models provides an opportunity to investigate global spatiotemporal neural patterns and functional connectivity systematically under various experimental conditions. Although ECoG is conventionally used to cover the gyral cortical surface, recent studies have shown the feasibility of intrasulcal ECoG recordings in macaque monkeys. Here we developed a new ECoG array to record neural activity simultaneously from much of the medial and lateral cortical surface of a single hemisphere, together with the supratemporal plane (STP) of the lateral sulcus in macaque monkeys. The ECoG array consisted of 256 electrodes for bipolar recording at 128 sites. We successfully implanted the ECoG array in the left hemisphere of three rhesus monkeys. The electrodes in the auditory and visual cortex detected robust event related potentials to auditory and visual stimuli, respectively. Bipolar recording from adjacent electrode pairs effectively eliminated chewing artifacts evident in monopolar recording, demonstrating the advantage of using the ECoG array under conditions that generate significant movement artifacts. Compared with bipolar ECoG arrays previously developed for macaque monkeys, this array significantly expands the number of cortical target areas in gyral and intralsulcal cortex. This new ECoG array provides an opportunity to investigate global network interactions among gyral and intrasulcal cortical areas. Published by Elsevier B.V.

  14. Synaptogenesis in visual cortex of normal and preterm monkeys: evidence for intrinsic regulation of synaptic overproduction.

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    Bourgeois, J P; Jastreboff, P J; Rakic, P

    1989-01-01

    We used quantitative electron microscopy to determine the effect of precocious visual experience on the time course, magnitude, and pattern of perinatal synaptic overproduction in the primary visual cortex of the rhesus monkey. Fetuses were delivered by caesarean section 3 weeks before term, exposed to normal light intensity and day/night cycles, and killed within the first postnatal month, together with age-matched controls that were delivered at term. We found that premature visual stimulation does not affect the rate of synaptic accretion and overproduction. Both of these processes proceed in relation to the time of conception rather than to the time of delivery. In contrast, the size, type, and laminar distribution of synapses were significantly different between preterm and control infants. The changes and differences in these parameters correlate with the duration of visual stimulation and become less pronounced with age. If visual experience in infancy influences the maturation of the visual cortex, it must do so predominantly by strengthening, modifying, and/or eliminating synapses that have already been formed, rather than by regulating the rate of synapse production. Images PMID:2726773

  15. Altered Balance of Receptive Field Excitation and Suppression in Visual Cortex of Amblyopic Macaque Monkeys.

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    Hallum, Luke E; Shooner, Christopher; Kumbhani, Romesh D; Kelly, Jenna G; García-Marín, Virginia; Majaj, Najib J; Movshon, J Anthony; Kiorpes, Lynne

    2017-08-23

    In amblyopia, a visual disorder caused by abnormal visual experience during development, the amblyopic eye (AE) loses visual sensitivity whereas the fellow eye (FE) is largely unaffected. Binocular vision in amblyopes is often disrupted by interocular suppression. We used 96-electrode arrays to record neurons and neuronal groups in areas V1 and V2 of six female macaque monkeys ( Macaca nemestrina ) made amblyopic by artificial strabismus or anisometropia in early life, as well as two visually normal female controls. To measure suppressive binocular interactions directly, we recorded neuronal responses to dichoptic stimulation. We stimulated both eyes simultaneously with large sinusoidal gratings, controlling their contrast independently with raised-cosine modulators of different orientations and spatial frequencies. We modeled each eye's receptive field at each cortical site using a difference of Gaussian envelopes and derived estimates of the strength of central excitation and surround suppression. We used these estimates to calculate ocular dominance separately for excitation and suppression. Excitatory drive from the FE dominated amblyopic visual cortex, especially in more severe amblyopes, but suppression from both the FE and AEs was prevalent in all animals. This imbalance created strong interocular suppression in deep amblyopes: increasing contrast in the AE decreased responses at binocular cortical sites. These response patterns reveal mechanisms that likely contribute to the interocular suppression that disrupts vision in amblyopes. SIGNIFICANCE STATEMENT Amblyopia is a developmental visual disorder that alters both monocular vision and binocular interaction. Using microelectrode arrays, we examined binocular interaction in primary visual cortex and V2 of six amblyopic macaque monkeys ( Macaca nemestrina ) and two visually normal controls. By stimulating the eyes dichoptically, we showed that, in amblyopic cortex, the binocular combination of signals is

  16. Amygdala lesions disrupt modulation of functional MRI activity evoked by facial expression in the monkey inferior temporal cortex

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    Hadj-Bouziane, Fadila; Liu, Ning; Bell, Andrew H.; Gothard, Katalin M.; Luh, Wen-Ming; Tootell, Roger B. H.; Murray, Elisabeth A.; Ungerleider, Leslie G.

    2012-01-01

    We previously showed that facial expressions modulate functional MRI activity in the face-processing regions of the macaque monkey’s amygdala and inferior temporal (IT) cortex. Specifically, we showed that faces expressing emotion yield greater activation than neutral faces; we term this difference the “valence effect.” We hypothesized that amygdala lesions would disrupt the valence effect by eliminating the modulatory feedback from the amygdala to the IT cortex. We compared the valence effects within the IT cortex in monkeys with excitotoxic amygdala lesions (n = 3) with those in intact control animals (n = 3) using contrast agent-based functional MRI at 3 T. Images of four distinct monkey facial expressions—neutral, aggressive (open mouth threat), fearful (fear grin), and appeasing (lip smack)—were presented to the subjects in a blocked design. Our results showed that in monkeys with amygdala lesions the valence effects were strongly disrupted within the IT cortex, whereas face responsivity (neutral faces > scrambled faces) and face selectivity (neutral faces > non-face objects) were unaffected. Furthermore, sparing of the anterior amygdala led to intact valence effects in the anterior IT cortex (which included the anterior face-selective regions), whereas sparing of the posterior amygdala led to intact valence effects in the posterior IT cortex (which included the posterior face-selective regions). Overall, our data demonstrate that the feedback projections from the amygdala to the IT cortex mediate the valence effect found there. Moreover, these modulatory effects are consistent with an anterior-to-posterior gradient of projections, as suggested by classical tracer studies. PMID:23184972

  17. Differential encoding of factors influencing predicted reward value in monkey rostral anterior cingulate cortex.

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    Toda, Koji; Sugase-Miyamoto, Yasuko; Mizuhiki, Takashi; Inaba, Kiyonori; Richmond, Barry J; Shidara, Munetaka

    2012-01-01

    The value of a predicted reward can be estimated based on the conjunction of both the intrinsic reward value and the length of time to obtain it. The question we addressed is how the two aspects, reward size and proximity to reward, influence the responses of neurons in rostral anterior cingulate cortex (rACC), a brain region thought to play an important role in reward processing. We recorded from single neurons while two monkeys performed a multi-trial reward schedule task. The monkeys performed 1-4 sequential color discrimination trials to obtain a reward of 1-3 liquid drops. There were two task conditions, a valid cue condition, where the number of trials and reward amount were associated with visual cues, and a random cue condition, where the cue was picked from the cue set at random. In the valid cue condition, the neuronal firing is strongly modulated by the predicted reward proximity during the trials. Information about the predicted reward amount is almost absent at those times. In substantial subpopulations, the neuronal responses decreased or increased gradually through schedule progress to the predicted outcome. These two gradually modulating signals could be used to calculate the effect of time on the perception of reward value. In the random cue condition, little information about the reward proximity or reward amount is encoded during the course of the trial before reward delivery, but when the reward is actually delivered the responses reflect both the reward proximity and reward amount. Our results suggest that the rACC neurons encode information about reward proximity and amount in a manner that is dependent on utility of reward information. The manner in which the information is represented could be used in the moment-to-moment calculation of the effect of time and amount on predicted outcome value.

  18. Neural representation of hand kinematics during prehension in posterior parietal cortex of the macaque monkey.

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    Chen, Jessie; Reitzen, Shari D; Kohlenstein, Jane B; Gardner, Esther P

    2009-12-01

    Studies of hand manipulation neurons in posterior parietal cortex of monkeys suggest that their spike trains represent objects by the hand postures needed for grasping or by the underlying patterns of muscle activation. To analyze the role of hand kinematics and object properties in a trained prehension task, we correlated the firing rates of neurons in anterior area 5 with hand behaviors as monkeys grasped and lifted knobs of different shapes and locations in the workspace. Trials were divided into four classes depending on the approach trajectory: forward, lateral, and local approaches, and regrasps. The task factors controlled by the animal-how and when he used the hand-appeared to play the principal roles in modulating firing rates of area 5 neurons. In all, 77% of neurons studied (58/75) showed significant effects of approach style on firing rates; 80% of the population responded at higher rates and for longer durations on forward or lateral approaches that included reaching, wrist rotation, and hand preshaping prior to contact, but only 13% distinguished the direction of reach. The higher firing rates in reach trials reflected not only the arm movements needed to direct the hand to the target before contact, but persisted through the contact, grasp, and lift stages. Moreover, the approach style exerted a stronger effect on firing rates than object features, such as shape and location, which were distinguished by half of the population. Forty-three percent of the neurons signaled both the object properties and the hand actions used to acquire them. However, the spread in firing rates evoked by each knob on reach and no-reach trials was greater than distinctions between different objects grasped with the same approach style. Our data provide clear evidence for synergies between reaching and grasping that may facilitate smooth, coordinated actions of the arm and hand.

  19. Effect of silhouetting and inversion on view invariance in the monkey inferotemporal cortex.

    Science.gov (United States)

    Ratan Murty, N Apurva; Arun, S P

    2017-07-01

    We effortlessly recognize objects across changes in viewpoint, but we know relatively little about the features that underlie viewpoint invariance in the brain. Here, we set out to characterize how viewpoint invariance in monkey inferior temporal (IT) neurons is influenced by two image manipulations-silhouetting and inversion. Reducing an object into its silhouette removes internal detail, so this would reveal how much viewpoint invariance depends on the external contours. Inverting an object retains but rearranges features, so this would reveal how much viewpoint invariance depends on the arrangement and orientation of features. Our main findings are 1 ) view invariance is weakened by silhouetting but not by inversion; 2 ) view invariance was stronger in neurons that generalized across silhouetting and inversion; 3 ) neuronal responses to natural objects matched early with that of silhouettes and only later to that of inverted objects, indicative of coarse-to-fine processing; and 4 ) the impact of silhouetting and inversion depended on object structure. Taken together, our results elucidate the underlying features and dynamics of view-invariant object representations in the brain. NEW & NOTEWORTHY We easily recognize objects across changes in viewpoint, but the underlying features are unknown. Here, we show that view invariance in the monkey inferotemporal cortex is driven mainly by external object contours and is not specialized for object orientation. We also find that the responses to natural objects match with that of their silhouettes early in the response, and with inverted versions later in the response-indicative of a coarse-to-fine processing sequence in the brain. Copyright © 2017 the American Physiological Society.

  20. Vertical organization of gamma-aminobutyric acid-accumulating intrinsic neuronal systems in monkey cerebral cortex

    International Nuclear Information System (INIS)

    DeFelipe, J.; Jones, E.G.

    1985-01-01

    Light and electron microscopic methods were used to examine the neurons in the monkey cerebral cortex labeled autoradiographically following the uptake and transport of [ 3 H]-gamma-aminobutyric acid (GABA). Nonpyramidal cell somata in the sensory-motor areas and primary visual area (area 17) were labeled close to the injection site and at distances of 1 to 1.5 mm beyond the injection site, indicating labeling by retrograde axoplasmic transport. This labeling occurred preferentially in the vertical dimension of the cortex. Prior injections of colchicine, an inhibitor of axoplasmic transport, abolished all labeling of somata except those within the injection site. In each area, injections of superficial layers (I to III) produced labeling of clusters of cell somata in layer V, and injections of the deep layers (V and VI) produced labeling of clusters of cell somata in layers II and III. In area 17, injections of the superficial layers produced dense retrograde cell labeling in three bands: in layers IVC, VA, and VI. Vertically oriented chains of silver grains linked the injection sites with the resulting labeled cell clusters. In all areas, the labeling of cells in the horizontal dimension was insignificant. Electron microscopic examination of labeled neurons confirms that the neurons labeled at a distance from an injection site are nonpyramidal neurons, many with somata so small that they would be mistaken for neuroglial cells light microscopically. They receive few axosomatic synapses, most of which have symmetric membrane thickenings. The vertical chains of silver grains overlie neuronal processes identifiable as both dendrites and myelinated axons, but unmyelinated axons may also be included. The clusters of [ 3 H]GABA-labeled cells are joined to one another and to adjacent unlabeled cells by junctional complexes, including puncta adherentia and multi-lamellar cisternal complexes

  1. Attention modulates the responses of simple cells in monkey primary visual cortex.

    Science.gov (United States)

    McAdams, Carrie J; Reid, R Clay

    2005-11-23

    Spatial attention has long been postulated to act as a spotlight that increases the salience of visual stimuli at the attended location. We examined the effects of attention on the receptive fields of simple cells in primary visual cortex (V1) by training macaque monkeys to perform a task with two modes. In the attended mode, the stimuli relevant to the animal's task overlay the receptive field of the neuron being recorded. In the unattended mode, the animal was cued to attend to stimuli outside the receptive field of that neuron. The relevant stimulus, a colored pixel, was briefly presented within a white-noise stimulus, a flickering grid of black and white pixels. The receptive fields of the neurons were mapped by correlating spikes with the white-noise stimulus in both attended and unattended modes. We found that attention could cause significant modulation of the visually evoked response despite an absence of significant effects on the overall firing rates. On further examination of the relationship between the strength of the visual stimulation and the firing rate, we found that attention appears to cause multiplicative scaling of the visually evoked responses of simple cells, demonstrating that attention reaches back to the initial stages of visual cortical processing.

  2. Prediction suppression in monkey inferotemporal cortex depends on the conditional probability between images.

    Science.gov (United States)

    Ramachandran, Suchitra; Meyer, Travis; Olson, Carl R

    2016-01-01

    When monkeys view two images in fixed sequence repeatedly over days and weeks, neurons in area TE of the inferotemporal cortex come to exhibit prediction suppression. The trailing image elicits only a weak response when presented following the leading image that preceded it during training. Induction of prediction suppression might depend either on the contiguity of the images, as determined by their co-occurrence and captured in the measure of joint probability P(A,B), or on their contingency, as determined by their correlation and as captured in the measures of conditional probability P(A|B) and P(B|A). To distinguish between these possibilities, we measured prediction suppression after imposing training regimens that held P(A,B) constant but varied P(A|B) and P(B|A). We found that reducing either P(A|B) or P(B|A) during training attenuated prediction suppression as measured during subsequent testing. We conclude that prediction suppression depends on contingency, as embodied in the predictive relations between the images, and not just on contiguity, as embodied in their co-occurrence. Copyright © 2016 the American Physiological Society.

  3. Avalanche analysis from multi-electrode ensemble recordings in cat, monkey and human cerebral cortex during wakefulness and sleep.

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    Nima eDehghani

    2012-08-01

    Full Text Available Self-organized critical states are found in many natural systems, from earthquakes to forest fires, they have also been observed in neural systems, particularly, in neuronal cultures. However, the presence of critical states in the awake brain remains controversial. Here, we compared avalanche analyses performed on different in vivo preparations during wakefulness, slow-wave sleep and REM sleep, using high-density electrode arrays in cat motor cortex (96 electrodes, monkey motor cortex and premotor cortex and human temporal cortex (96 electrodes in epileptic patients. In neuronal avalanches defined from units (up to 160 single units, the size of avalanches never clearly scaled as power-law, but rather scaled exponentially or displayed intermediate scaling. We also analyzed the dynamics of local field potentials (LFPs and in particular LFP negative peaks (nLFPs among the different electrodes (up to 96 sites in temporal cortex or up to 128 sites in adjacent motor and pre-motor cortices. In this case, the avalanches defined from nLFPs displayed power-law scaling in double logarithmic representations, as reported previously in monkey. However, avalanche defined as positive LFP (pLFP peaks, which are less directly related to neuronal firing, also displayed apparent power-law scaling. Closer examination of this scaling using the more reliable cumulative distribution function (CDF and other rigorous statistical measures, did not confirm power-law scaling. The same pattern was seen for cats, monkey and human, as well as for different brain states of wakefulness and sleep. We also tested other alternative distributions. Multiple exponential fitting yielded optimal fits of the avalanche dynamics with bi-exponential distributions. Collectively, these results show no clear evidence for power-law scaling or self-organized critical states in the awake and sleeping brain of mammals, from cat to man.

  4. Phenol emulsion-enhanced DNA-driven subtractive cDNA cloning: isolation of low-abundance monkey cortex-specific mRNAs

    International Nuclear Information System (INIS)

    Travis, G.H.; Sutcliffe, J.G.

    1988-01-01

    To isolate cDNA clones of low-abundance mRNAs expressed in monkey cerebral cortex but absent from cerebellum, the authors developed an improved subtractive cDNA cloning procedure that requires only modest quantities of mRNA. Plasmid DNA from a monkey cerebellum cDNA library was hybridized in large excess to radiolabeled monkey cortex cDNA in a phenol emulsion-enhanced reaction. The unhybridized cortex cDNA was isolated by chromatography on hydroxyapatite and used to probe colonies from a monkey cortex cDNA library. Of 60,000 colonies screened, 163 clones were isolated and confirmed by colony hybridization or RNA blotting to represent mRNAs, ranging from 0.001% to 0.1% abundance, specific to or highly enriched in cerebral cortex relative to cerebellum. Clones of one medium-abundance mRNA were recovered almost quantitatively. Two of the lower-abundance mRNAs were expressed at levels reduced by a factor of 10 in Alzheimer disease relative to normal human cortex. One of these was identified as the monkey preprosomatostatin I mRNA

  5. Intrinsic connections and architectonics of posterior parietal cortex in the rhesus monkey

    International Nuclear Information System (INIS)

    Pandya, D.N.; Seltzer, B.

    1982-01-01

    By means of autoradiographic and ablation-degeneration techniques, the intrinsic cortical connections of the posterior parietal cortex in the rhesus monkey were traced and correlated with a reappraisal of cerebral architectonics. Two major rostral-to-caudal connectional sequences exist. One begins in the dorsal postcentral gyrus (area 2) and proceeds, through architectonic divisions of the superior parietal lobule (areas PE and PEc), to a cortical region on the medial surface of the parietal lobe (area PGm). This area has architectonic features similar to those of the caudal inferior parietal lobule (area PG). The second sequence begins in the ventral post/central gyrus (area 2) and passes through the rostral inferior parietal lobule (areas PG and PFG) to reach the caudal inferior parietal lobule (area PG). Both the superior parietal lobule and the rostral inferior parietal lobule also send projections to various other zones located in the parietal opercular region, the intraparietal sulcus, and the caudalmost portion of the cingulate sulcus. Areas PGm and PG, on the other hand, project to each other, to the cingulate region, to the caudalmost portion of the superior temporal gyrus, and to the upper bank of the superior temporal sulcus. Finally, a reciprocal sequence of connections, directed from caudal to rostral, links together many of the above-mentioned parietal zones. With regard to the laminar pattern of termination, the rostral-to-caudal connections are primarily distributed in the form of cortical ''columns'' while the caudal-to-rostral connections are found mainly over the first cortical cell layer

  6. Primary motor cortex of the parkinsonian monkey: altered encoding of active movement

    Science.gov (United States)

    Pasquereau, Benjamin; DeLong, Mahlon R.

    2016-01-01

    Abnormalities in the movement-related activation of the primary motor cortex (M1) are thought to be a major contributor to the motor signs of Parkinson’s disease. The existing evidence, however, variably indicates that M1 is under-activated with movement, overactivated (due to a loss of functional specificity) or activated with abnormal timing. In addition, few models consider the possibility that distinct cortical neuron subtypes may be affected differently. Those gaps in knowledge were addressed by studying the extracellular activity of antidromically-identified lamina 5b pyramidal-tract type neurons (n = 153) and intratelencephalic-type corticostriatal neurons (n = 126) in the M1 of two monkeys as they performed a step-tracking arm movement task. We compared movement-related discharge before and after the induction of parkinsonism by administration of MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) and quantified the spike rate encoding of specific kinematic parameters of movement using a generalized linear model. The fraction of M1 neurons with movement-related activity declined following MPTP but only marginally. The strength of neuronal encoding of parameters of movement was reduced markedly (mean 29% reduction in the coefficients from the generalized linear model). This relative decoupling of M1 activity from kinematics was attributable to reductions in the coefficients that estimated the spike rate encoding of movement direction (−22%), speed (−40%), acceleration (−49%) and hand position (−33%). After controlling for MPTP-induced changes in motor performance, M1 activity related to movement itself was reduced markedly (mean 36% hypoactivation). This reduced activation was strong in pyramidal tract-type neurons (−50%) but essentially absent in corticostriatal neurons. The timing of M1 activation was also abnormal, with earlier onset times, prolonged response durations, and a 43% reduction in the prevalence of movement-related changes

  7. Activity-dependent regulation of MHC class I expression in the developing primary visual cortex of the common marmoset monkey

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    Schlumbohm Christina

    2011-01-01

    Full Text Available Abstract Background Several recent studies have highlighted the important role of immunity-related molecules in synaptic plasticity processes in the developing and adult mammalian brains. It has been suggested that neuronal MHCI (major histocompatibility complex class I genes play a role in the refinement and pruning of synapses in the developing visual system. As a fast evolutionary rate may generate distinct properties of molecules in different mammalian species, we studied the expression of MHCI molecules in a nonhuman primate, the common marmoset monkey (Callithrix jacchus. Methods and results Analysis of expression levels of MHCI molecules in the developing visual cortex of the common marmoset monkeys revealed a distinct spatio-temporal pattern. High levels of expression were detected very early in postnatal development, at a stage when synaptogenesis takes place and ocular dominance columns are formed. To determine whether the expression of MHCI molecules is regulated by retinal activity, animals were subjected to monocular enucleation. Levels of MHCI heavy chain subunit transcripts in the visual cortex were found to be elevated in response to monocular enucleation. Furthermore, MHCI heavy chain immunoreactivity revealed a banded pattern in layer IV of the visual cortex in enucleated animals, which was not observed in control animals. This pattern of immunoreactivity indicated that higher expression levels were associated with retinal activity coming from the intact eye. Conclusions These data demonstrate that, in the nonhuman primate brain, expression of MHCI molecules is regulated by neuronal activity. Moreover, this study extends previous findings by suggesting a role for neuronal MHCI molecules during synaptogenesis in the visual cortex.

  8. Experience-induced plasticity of cutaneous maps in the primary somatosensory cortex of adult monkeys and rats.

    Science.gov (United States)

    Xerri, C; Coq, J O; Merzenich, M M; Jenkins, W M

    1996-01-01

    In a first study, the representations of skin surfaces of the hand in the primary somatosensory cortex, area 3b, were reconstructed in owl monkeys and squirrel monkeys trained to pick up food pellets from small, shallow wells, a task which required skilled use of the digits. Training sessions included limited manual exercise over a total period of a few hours of practice. From an early clumsy performance in which many retrieval attempts were required for each successful pellet retrieval, the monkeys exhibited a gradual improvement. Typically, the animals used various combinations of digits before developing a successful retrieval strategy. As the behavior came to be stereotyped, monkeys consistently engaged surfaces of the distal phalanges of one or two digits in the palpation and capture of food pellets from the smallest wells. Microelectrode mapping of the hand surfaces revealed that the glabrous skin of the fingertips predominantly involved in the dexterity task was represented over topographically expanded cortical sectors. Furthermore, cutaneous receptive fields which covered the most frequently stimulated digital tip surfaces were less than half as large as were those representing the corresponding surfaces of control digits. In a second series of experiments, Long-Evans rats were assigned to environments promoting differential tactile experience (standard, enriched, and impoverished) for 80 to 115 days from the time of weaning. A fourth group of young adult rat experienced a severe restriction of forepaw exploratory movement for either 7 or 15 days. Cortical maps derived in the primary somatosensory cortex showed that environmental enrichment induced a substantial enlargement of the cutaneous forepaw representation, and improved its spatial resolution (smaller glabrous receptive fields). In contrast, tactile impoverishment resulted in a degradation of the forepaw representation that was characterized by larger cutaneous receptive fields and the emergence of

  9. Exploring the extent and function of higher-order auditory cortex in rhesus monkeys.

    Science.gov (United States)

    Poremba, Amy; Mishkin, Mortimer

    2007-07-01

    Just as cortical visual processing continues far beyond the boundaries of early visual areas, so too does cortical auditory processing continue far beyond the limits of early auditory areas. In passively listening rhesus monkeys examined with metabolic mapping techniques, cortical areas reactive to auditory stimulation were found to include the entire length of the superior temporal gyrus (STG) as well as several other regions within the temporal, parietal, and frontal lobes. Comparison of these widespread activations with those from an analogous study in vision supports the notion that audition, like vision, is served by several cortical processing streams, each specialized for analyzing a different aspect of sensory input, such as stimulus quality, location, or motion. Exploration with different classes of acoustic stimuli demonstrated that most portions of STG show greater activation on the right than on the left regardless of stimulus class. However, there is a striking shift to left-hemisphere "dominance" during passive listening to species-specific vocalizations, though this reverse asymmetry is observed only in the region of temporal pole. The mechanism for this left temporal pole "dominance" appears to be suppression of the right temporal pole by the left hemisphere, as demonstrated by a comparison of the results in normal monkeys with those in split-brain monkeys.

  10. Audio-vocal interaction in single neurons of the monkey ventrolateral prefrontal cortex.

    Science.gov (United States)

    Hage, Steffen R; Nieder, Andreas

    2015-05-06

    Complex audio-vocal integration systems depend on a strong interconnection between the auditory and the vocal motor system. To gain cognitive control over audio-vocal interaction during vocal motor control, the PFC needs to be involved. Neurons in the ventrolateral PFC (VLPFC) have been shown to separately encode the sensory perceptions and motor production of vocalizations. It is unknown, however, whether single neurons in the PFC reflect audio-vocal interactions. We therefore recorded single-unit activity in the VLPFC of rhesus monkeys (Macaca mulatta) while they produced vocalizations on command or passively listened to monkey calls. We found that 12% of randomly selected neurons in VLPFC modulated their discharge rate in response to acoustic stimulation with species-specific calls. Almost three-fourths of these auditory neurons showed an additional modulation of their discharge rates either before and/or during the monkeys' motor production of vocalization. Based on these audio-vocal interactions, the VLPFC might be well positioned to combine higher order auditory processing with cognitive control of the vocal motor output. Such audio-vocal integration processes in the VLPFC might constitute a precursor for the evolution of complex learned audio-vocal integration systems, ultimately giving rise to human speech. Copyright © 2015 the authors 0270-6474/15/357030-11$15.00/0.

  11. Double-bouquet cells in the monkey and human cerebral cortex with special reference to areas 17 and 18.

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    DeFelipe, Javier; Ballesteros-Yáñez, Inmaculada; Inda, Maria Carmen; Muñoz, Alberto

    2006-01-01

    The detailed microanatomical study of the human cerebral cortex began in 1899 with the experiments of Santiago Ramón y Cajal, who applied the Golgi method to define the structure of the visual, motor, auditory and olfactory cortex. In the first article of this series, he described a special type of interneuron in the visual cortex capable of exerting its influence in the vertical dimension. These neurons are now more commonly referred to as double-bouquet cells (DBCs). The DBCs are readily distinguished owing to their characteristic axons that give rise to tightly interwoven bundles of long, vertically oriented axonal collaterals resembling a horsetail (DBC horsetail). Nevertheless, the most striking characteristic of these neurons is that they are so numerous and regularly distributed that the DBC horsetails form a microcolumnar structure. In addition, DBCs establish hundreds of inhibitory synapses within a very narrow column of cortical tissue. These features have generated considerable interest in DBCs over recent years, principally among those researchers interested in the analysis of cortical circuits. In the present chapter, we shall discuss the morphology, synaptic connections and neurochemical features of DBCs that have been defined through the study of these cells in different cortical areas and species. We will mainly consider the immunocytochemical studies of DBCs that have been carried out in the visual cortex (areas 17 and 18) of human and macaque monkey. We will see that there are important differences in the morphology, number and distribution of DBC horsetails between areas 17 and 18 in the primate. This suggests important differences in the microcolumnar organization between these areas, the functional significance of which awaits detailed correlative physiological and microanatomical studies.

  12. The effect of learning on the function of monkey extrastriate visual cortex.

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    Gregor Rainer

    2004-02-01

    Full Text Available One of the most remarkable capabilities of the adult brain is its ability to learn and continuously adapt to an ever-changing environment. While many studies have documented how learning improves the perception and identification of visual stimuli, relatively little is known about how it modifies the underlying neural mechanisms. We trained monkeys to identify natural images that were degraded by interpolation with visual noise. We found that learning led to an improvement in monkeys' ability to identify these indeterminate visual stimuli. We link this behavioral improvement to a learning-dependent increase in the amount of information communicated by V4 neurons. This increase was mediated by a specific enhancement in neural activity. Our results reveal a mechanism by which learning increases the amount of information that V4 neurons are able to extract from the visual environment. This suggests that V4 plays a key role in resolving indeterminate visual inputs by coordinated interaction between bottom-up and top-down processing streams.

  13. Reversal of interlaminar signal between sensory and memory processing in monkey temporal cortex.

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    Takeuchi, Daigo; Hirabayashi, Toshiyuki; Tamura, Keita; Miyashita, Yasushi

    2011-03-18

    The primate temporal cortex implements visual long-term memory. However, how its interlaminar circuitry executes cognitive computations is poorly understood. Using linear-array multicontact electrodes, we simultaneously recorded unit activities across cortical layers in the perirhinal cortex of macaques performing a pair-association memory task. Cortical layers were estimated on the basis of current source density profiles with histological verifications, and the interlaminar signal flow was determined with cross-correlation analysis between spike trains. During the cue period, canonical "feed-forward" signals flowed from granular to supragranular layers and from supragranular to infragranular layers. During the delay period, however, the signal flow reversed to the "feed-back" direction: from infragranular to supragranular layers. This reversal of signal flow highlights how the temporal cortex differentially recruits its laminar circuits for sensory and mnemonic processing.

  14. The Cortical Connectivity of the Prefrontal Cortex in the Monkey Brain

    Science.gov (United States)

    Yeterian, Edward H.; Pandya, Deepak N.; Tomaiuolo, Francesco; Petrides, Michael

    2011-01-01

    One dimension of understanding the functions of the prefrontal cortex is knowledge of cortical connectivity. We have surveyed three aspects of prefrontal cortical connections: local projections (within the frontal lobe), the termination patterns of long association (post-Rolandic) projections, and the trajectories of major fiber pathways. The local connections appear to be organized in relation to dorsal (hippocampal origin) and ventral (paleocortical origin) architectonic trends. According to the proposal of a dual origin of the cerebral cortex, cortical areas can be traced as originating from archicortex (hippocampus) on the one hand, and paleocortex, on the other hand, in a stepwise manner (e.g., Sanides, 1969; Pandya and Yeterian, 1985). Prefrontal areas within each trend are connected with less architectonically differentiated areas, and, on the other hand, with more differentiated areas. Such organization may allow for the systematic exchange of information within each architectonic trend. The long connections of the prefrontal cortex with post-Rolandic regions seem to be organized preferentially in relation to dorsal and ventral prefrontal architectonic trends. Prefrontal areas are connected with post-Rolandic auditory, visual and somatosensory association areas, and with multimodal and paralimbic regions. This long connectivity likely works in conjunction with local connections to serve prefrontal cortical functions. The afferent and efferent connections of the prefrontal cortex with post-Rolandic regions are conveyed by specific long association pathways. These pathways as well appear to be organized in relation to dorsal and ventral prefrontal architectonic trends. Finally, although prefrontal areas have preferential connections in relation to dual architectonic trends, it is clear that there are interconnections between and among areas in each trend, which may provide a substrate for the overall integrative function of the prefrontal cortex. Prefrontal

  15. Thalamic connections of the core auditory cortex and rostral supratemporal plane in the macaque monkey.

    Science.gov (United States)

    Scott, Brian H; Saleem, Kadharbatcha S; Kikuchi, Yukiko; Fukushima, Makoto; Mishkin, Mortimer; Saunders, Richard C

    2017-11-01

    In the primate auditory cortex, information flows serially in the mediolateral dimension from core, to belt, to parabelt. In the caudorostral dimension, stepwise serial projections convey information through the primary, rostral, and rostrotemporal (AI, R, and RT) core areas on the supratemporal plane, continuing to the rostrotemporal polar area (RTp) and adjacent auditory-related areas of the rostral superior temporal gyrus (STGr) and temporal pole. In addition to this cascade of corticocortical connections, the auditory cortex receives parallel thalamocortical projections from the medial geniculate nucleus (MGN). Previous studies have examined the projections from MGN to auditory cortex, but most have focused on the caudal core areas AI and R. In this study, we investigated the full extent of connections between MGN and AI, R, RT, RTp, and STGr using retrograde and anterograde anatomical tracers. Both AI and R received nearly 90% of their thalamic inputs from the ventral subdivision of the MGN (MGv; the primary/lemniscal auditory pathway). By contrast, RT received only ∼45% from MGv, and an equal share from the dorsal subdivision (MGd). Area RTp received ∼25% of its inputs from MGv, but received additional inputs from multisensory areas outside the MGN (30% in RTp vs. 1-5% in core areas). The MGN input to RTp distinguished this rostral extension of auditory cortex from the adjacent auditory-related cortex of the STGr, which received 80% of its thalamic input from multisensory nuclei (primarily medial pulvinar). Anterograde tracers identified complementary descending connections by which highly processed auditory information may modulate thalamocortical inputs. © 2017 Wiley Periodicals, Inc.

  16. Expressions of multiple neuronal dynamics during sensorimotor learning in the motor cortex of behaving monkeys.

    Directory of Open Access Journals (Sweden)

    Yael Mandelblat-Cerf

    Full Text Available Previous studies support the notion that sensorimotor learning involves multiple processes. We investigated the neuronal basis of these processes by recording single-unit activity in motor cortex of non-human primates (Macaca fascicularis, during adaptation to force-field perturbations. Perturbed trials (reaching to one direction were practiced along with unperturbed trials (to other directions. The number of perturbed trials relative to the unperturbed ones was either low or high, in two separate practice schedules. Unsurprisingly, practice under high-rate resulted in faster learning with more pronounced generalization, as compared to the low-rate practice. However, generalization and retention of behavioral and neuronal effects following practice in high-rate were less stable; namely, the faster learning was forgotten faster. We examined two subgroups of cells and showed that, during learning, the changes in firing-rate in one subgroup depended on the number of practiced trials, but not on time. In contrast, changes in the second subgroup depended on time and practice; the changes in firing-rate, following the same number of perturbed trials, were larger under high-rate than low-rate learning. After learning, the neuronal changes gradually decayed. In the first subgroup, the decay pace did not depend on the practice rate, whereas in the second subgroup, the decay pace was greater following high-rate practice. This group shows neuronal representation that mirrors the behavioral performance, evolving faster but also decaying faster at learning under high-rate, as compared to low-rate. The results suggest that the stability of a new learned skill and its neuronal representation are affected by the acquisition schedule.

  17. Co-localization of glycine and gaba immunoreactivity in interneurons in Macaca monkey cerebellar cortex.

    Science.gov (United States)

    Crook, J; Hendrickson, A; Robinson, F R

    2006-09-15

    of 120 cells/linear mm. Their morphology indicates that they include Golgi and Lugaro cell types with the majority containing both glycine and GABA or glutamic acid decarboxylase. These data are consistent with the proposal that, as in the rat cerebellum, these granular cell layer interneurons corelease glycine and GABA in the primate cerebellum. The patterns of labeling for glycine and GABA within Golgi and Lugaro cells also indicate that there are biochemical sub-types which are morphologically similar. Further, we find that glycine, GABA and glutamic acid decarboxylase identified candelabrum cells adjacent to the Purkinje cells which is the first time that this interneuron has been reported in primate cerebellar cortex. We propose that candelabrum cells, like the majority of Golgi and Lugaro cells, release both glycine and GABA.

  18. [Neuronal activity of monkey dorso-lateral premotor cortex during tasks of figure recognition guided motor sequence vs memorized spatial motor sequence].

    Science.gov (United States)

    Chen, Y C; Huang, F D; Chen, N H; Shou, J Y; Wu, L

    1998-04-01

    In the last 2-3 decades the role of the premotor cortex (PM) of monkey in memorized spatial sequential (MSS) movements has been amply investigated. However, it is as yet not known whether PM participates in the movement sequence behaviour guided by recognition of visual figures (i.e. the figure-recognition sequence, FRS). In the present work three monkeys were trained to perform both FRS and MSS tasks. Postmortem examination showed that 202 cells were in the dorso-lateral premotor cortex. Among 111 cells recorded during the two tasks, more than 50% changed their activity during the cue periods in either task. During the response period, the ratios of cells with changes of firing rate in both FRS and MSS were high and roughly equal to each other, while during the image period, the proportion in the FRS (83.7%) was significantly higher than that in the MSS (66.7%). Comparison of neuronal activities during same motor sequence of two different tasks showed that during the image periods PM neuronal activities were more closely related to the FRS task, while during the cue periods no difference could be found. Analysis of cell responses showed that the neurons with longer latency were much more in MSS than in FRS in either cue or image period. The present results indicate that the premotor cortex participates in FRS motor sequence as well as in MSS and suggest that the dorso-lateral PM represents another subarea in function shared by both FRS and MSS tasks. However, in view of the differences of PM neuronal responses in cue or image periods of FRS and MSS tasks, it seems likely that neural networks involved in FRS and MSS tasks are different.

  19. Comprehensive analysis of area-specific and time-dependent changes in gene expression in the motor cortex of macaque monkeys during recovery from spinal cord injury.

    Science.gov (United States)

    Higo, Noriyuki; Sato, Akira; Yamamoto, Tatsuya; Oishi, Takao; Nishimura, Yukio; Murata, Yumi; Onoe, Hirotaka; Isa, Tadashi; Kojima, Toshio

    2018-05-01

    The present study aimed to assess the molecular bases of cortical compensatory mechanisms following spinal cord injury in primates. To accomplish this, comprehensive changes in gene expression were investigated in the bilateral primary motor cortex (M1), dorsal premotor cortex (PMd), and ventral premotor cortex (PMv) after a unilateral lesion of the lateral corticospinal tract (l-CST). At 2 weeks after the lesion, a large number of genes exhibited altered expression levels in the contralesional M1, which is directly linked to the lesioned l-CST. Gene ontology and network analyses indicated that these changes in gene expression are involved in the atrophy and plasticity changes observed in neurons. Orchestrated gene expression changes were present when behavioral recovery was attained 3 months after the lesion, particularly among the bilateral premotor areas, and a large number of these genes are involved in plasticity. Moreover, several genes abundantly expressed in M1 of intact monkeys were upregulated in both the PMd and PMv after the l-CST lesion. These area-specific and time-dependent changes in gene expression may underlie the molecular mechanisms of functional recovery following a lesion of the l-CST. © 2018 Wiley Periodicals, Inc.

  20. A Pressure Injection System for Investigating the Neuropharmacology of Information Processing in Awake Behaving Macaque Monkey Cortex.

    Science.gov (United States)

    Veith, Vera K; Quigley, Cliodhna; Treue, Stefan

    2016-03-14

    The top-down modulation of feed-forward cortical information processing is functionally important for many cognitive processes, including the modulation of sensory information processing by attention. However, little is known about which neurotransmitter systems are involved in such modulations. A practical way to address this question is to combine single-cell recording with local and temporary neuropharmacological manipulation in a suitable animal model. Here we demonstrate a technique combining acute single-cell recordings with the injection of neuropharmacological agents in the direct vicinity of the recording electrode. The video shows the preparation of the pressure injection/recording system, including preparation of the substance to be injected. We show a rhesus monkey performing a visual attention task and the procedure of single-unit recording with block-wise pharmacological manipulations.

  1. Neural mechanisms of memory retrieval: role of the prefrontal cortex.

    Science.gov (United States)

    Hasegawa, I

    2000-01-01

    In the primate brain, long-term memory is stored in the neocortical association area which is also engaged in sensory perception. The coded representation of memory is retrieved via interactions of hierarchically different cortical areas along bottom-up and top-down anatomical connections. The functional significance of the fronto-cortical top-down neuronal projections has been relevantly assessed in a new experimental paradigm using posterior-split-brain monkeys. When the splenium of the corpus callosum and the anterior commissure were selectively split, the bottom-up visual signal originating from the unilateral striate cortex could not reach the contralateral visual cortical areas. In this preparation, long-term memory acquired through visual stimulus-stimulus association learning was prevented from transferring across hemispheres. Nonetheless, following the presentation of a visual cue to one hemisphere, the prefrontal cortex could instruct the contralateral hemisphere to retrieve the correct stimulus specified by the cue. These results support the hypothesis that the prefrontal cortex can regulate memory recall in the absence of bottom-up sensory input. In humans, functional neuroimaging studies have revealed activation of a distributed neural network, including the prefrontal cortex, during memory retrieval tasks. Thus, the prefrontal cortex is consistently involved in retrieval of long-term memory in primates.

  2. P1-5: Effect of Luminance Contrast on the Color Selective Responses in the Inferior Temporal Cortex Neurons of the Macaque Monkey

    Directory of Open Access Journals (Sweden)

    Tomoyuki Namima

    2012-10-01

    Full Text Available Although the relationship between color signal and luminance signal is an important problem in visual perception, relatively little is known about how the luminance contrast affects the responses of color selective neurons in the visual cortex. In this study, we examined this problem in the inferior temporal (IT of the awake monkey performing a visual fixation task. Single neuron activities were recorded from the anterior and posterior color selective regions in IT cortex (AITC and PITC identified in previous studies where color selective neurons are accumulated. Color stimuli consisted of 28 stimuli that evenly distribute across the gamut of the CRT display defined on the CIE- xychromaticity diagram at two different luminance levels (5 cd/m 2or 20 cd/m 2 and 2 stimuli at white points. The background was maintained at 10 cd/m 2gray. We found that the effect of luminance contrast on the color selectivity was markedly different between AITC and PITC. When we examined the correlation between the responses to the bright stimuli and those to the dark stimuli with the same chromaticity coordinates, most AITC neurons exhibited high correlation whereas many PITC neurons showed no correlation or only weak correlation. In PITC, the effect was specifically large for neutral colors (white, gray, black and for colors with low saturation. These results indicate that the effect of luminance contrast on the color selective responses differs across different areas and suggest that the separation between color signal and luminance signal involves a higher stage of the cortical color processing.

  3. Topography of Striate-Extrastriate Connections in Neonatally Enucleated Rats

    Directory of Open Access Journals (Sweden)

    Robyn J. Laing

    2013-01-01

    Full Text Available It is known that retinal input is necessary for the normal development of striate cortex and its corticocortical connections, but there is little information on the role that retinal input plays in the development of retinotopically organized connections between V1 and surrounding visual areas. In nearly all lateral extrastriate areas, the anatomical and physiological representation of the nasotemporal axis of the visual field mirrors the representation of this axis in V1. To determine whether the mediolateral topography of striate-extrastriate projections is preserved in neonatally enucleated rats, we analyzed the patterns of projections resulting from tracer injections placed at different sites along the mediolateral axis of V1. We found that the correlation between the distance from injection sites to the lateral border of V1 and the distance of the labeling patterns in area 18a was strong in controls and much weaker in enucleates. Data from pairs of injections in the same animal revealed that the separation of area 18a projection fields for a given separation of injection sites was more variable in enucleated than in control rats. Our analysis of single and double tracer injections suggests that neonatal bilateral enucleation weakens, but not completely abolishes, the mediolateral topography in area 18a.

  4. Striated Muscle Function, Regeneration, and Repair

    Science.gov (United States)

    Shadrin, I.Y.; Khodabukus, A.; Bursac, N.

    2016-01-01

    As the only striated muscle tissues in the body, skeletal and cardiac muscle share numerous structural and functional characteristics, while exhibiting vastly different size and regenerative potential. Healthy skeletal muscle harbors a robust regenerative response that becomes inadequate after large muscle loss or in degenerative pathologies and aging. In contrast, the mammalian heart loses its regenerative capacity shortly after birth, leaving it susceptible to permanent damage by acute injury or chronic disease. In this review, we compare and contrast the physiology and regenerative potential of native skeletal and cardiac muscles, mechanisms underlying striated muscle dysfunction, and bioengineering strategies to treat muscle disorders. We focus on different sources for cellular therapy, biomaterials to augment the endogenous regenerative response, and progress in engineering and application of mature striated muscle tissues in vitro and in vivo. Finally, we discuss the challenges and perspectives in translating muscle bioengineering strategies to clinical practice. PMID:27271751

  5. Differential effects of m1 and m2 receptor antagonists in perirhinal cortex on visual recognition memory in monkeys.

    Science.gov (United States)

    Wu, Wei; Saunders, Richard C; Mishkin, Mortimer; Turchi, Janita

    2012-07-01

    Microinfusions of the nonselective muscarinic antagonist scopolamine into perirhinal cortex impairs performance on visual recognition tasks, indicating that muscarinic receptors in this region play a pivotal role in recognition memory. To assess the mnemonic effects of selective blockade in perirhinal cortex of muscarinic receptor subtypes, we locally infused either the m1-selective antagonist pirenzepine or the m2-selective antagonist methoctramine in animals performing one-trial visual recognition, and compared these scores with those following infusions of equivalent volumes of saline. Compared to these control infusions, injections of pirenzepine, but not of methoctramine, significantly impaired recognition accuracy. Further, similar doses of scopolamine and pirenzepine yielded similar deficits, suggesting that the deficits obtained earlier with scopolamine were due mainly, if not exclusively, to blockade of m1 receptors. The present findings indicate that m1 and m2 receptors have functionally dissociable roles, and that the formation of new visual memories is critically dependent on the cholinergic activation of m1 receptors located on perirhinal cells. Published by Elsevier Inc.

  6. Strength of figure-ground activity in monkey primary visual cortex predicts saccadic reaction time in a delayed detection task.

    Science.gov (United States)

    Supèr, Hans; Lamme, Victor A F

    2007-06-01

    When and where are decisions made? In the visual system a saccade, which is a fast shift of gaze toward a target in the visual scene, is the behavioral outcome of a decision. Current neurophysiological data and reaction time models show that saccadic reaction times are determined by a build-up of activity in motor-related structures, such as the frontal eye fields. These structures depend on the sensory evidence of the stimulus. Here we use a delayed figure-ground detection task to show that late modulated activity in the visual cortex (V1) predicts saccadic reaction time. This predictive activity is part of the process of figure-ground segregation and is specific for the saccade target location. These observations indicate that sensory signals are directly involved in the decision of when and where to look.

  7. Correlated inter-regional variations in low frequency local field potentials and resting state BOLD signals within S1 cortex of monkeys.

    Science.gov (United States)

    Wilson, George H; Yang, Pai-Feng; Gore, John C; Chen, Li Min

    2016-08-01

    The hypothesis that specific frequency components of the spontaneous local field potentials (LFPs) underlie low frequency fluctuations of resting state fMRI (rsfMRI) signals was tested. The previous analyses of rsfMRI signals revealed differential inter-regional correlations among areas 3a, 3b, and 1 of primary somatosensory cortex (S1) in anesthetized monkeys (Wang et al. [2013]: Neuron 78:1116-1126). Here LFP band(s) which correlated between S1 regions, and how these inter-regional correlation differences covaried with rsfMRI signals were examined. LFP signals were filtered into seven bands (delta, theta, alpha, beta, gamma low, gamma high, and gamma very high), and then a Hilbert transformation was applied to obtain measures of instantaneous amplitudes and temporal lags between regions of interest (ROI) digit-digit pairs (areas 3b-area 1, area 3a-area 1, area 3a-area 3b) and digit-face pairs (area 3b-face, area 1-face, and area 3a-face). It was found that variations in the inter-regional correlation strengths between digit-digit and digit-face pairs in the delta (1-4 Hz), alpha (9-14 Hz), beta (15-30 Hz), and gamma (31-50 Hz) bands parallel those of rsfMRI signals to varying degrees. Temporal lags between digit-digit area pairs varied across LFP bands, with area 3a mostly leading areas 1/2 and 3b. In summary, the data demonstrates that the low and middle frequency range (1-50 Hz) of spontaneous LFP signals similarly covary with the low frequency fluctuations of rsfMRI signals within local circuits of S1, supporting a neuronal electrophysiological basis of rsfMRI signals. Inter-areal LFP temporal lag differences provided novel insights into the directionality of information flow among S1 areas at rest. Hum Brain Mapp 37:2755-2766, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  8. Early monocular defocus disrupts the normal development of receptive-field structure in V2 neurons of macaque monkeys.

    Science.gov (United States)

    Tao, Xiaofeng; Zhang, Bin; Shen, Guofu; Wensveen, Janice; Smith, Earl L; Nishimoto, Shinji; Ohzawa, Izumi; Chino, Yuzo M

    2014-10-08

    Experiencing different quality images in the two eyes soon after birth can cause amblyopia, a developmental vision disorder. Amblyopic humans show the reduced capacity for judging the relative position of a visual target in reference to nearby stimulus elements (position uncertainty) and often experience visual image distortion. Although abnormal pooling of local stimulus information by neurons beyond striate cortex (V1) is often suggested as a neural basis of these deficits, extrastriate neurons in the amblyopic brain have rarely been studied using microelectrode recording methods. The receptive field (RF) of neurons in visual area V2 in normal monkeys is made up of multiple subfields that are thought to reflect V1 inputs and are capable of encoding the spatial relationship between local stimulus features. We created primate models of anisometropic amblyopia and analyzed the RF subfield maps for multiple nearby V2 neurons of anesthetized monkeys by using dynamic two-dimensional noise stimuli and reverse correlation methods. Unlike in normal monkeys, the subfield maps of V2 neurons in amblyopic monkeys were severely disorganized: subfield maps showed higher heterogeneity within each neuron as well as across nearby neurons. Amblyopic V2 neurons exhibited robust binocular suppression and the strength of the suppression was positively correlated with the degree of hereogeneity and the severity of amblyopia in individual monkeys. Our results suggest that the disorganized subfield maps and robust binocular suppression of amblyopic V2 neurons are likely to adversely affect the higher stages of cortical processing resulting in position uncertainty and image distortion. Copyright © 2014 the authors 0270-6474/14/3413840-15$15.00/0.

  9. Dynamic Regulation of Sarcomeric Actin Filaments in Striated Muscle

    OpenAIRE

    Ono, Shoichiro

    2010-01-01

    In striated muscle, the actin cytoskeleton is differentiated into myofibrils. Actin and myosin filaments are organized in sarcomeres and specialized for producing contractile forces. Regular arrangement of actin filaments with uniform length and polarity is critical for the contractile function. However, the mechanisms of assembly and maintenance of sarcomeric actin filaments in striated muscle are not completely understood. Live imaging of actin in striated muscle has revealed that actin sub...

  10. Playing the electric light orchestra--how electrical stimulation of visual cortex elucidates the neural basis of perception.

    Science.gov (United States)

    Cicmil, Nela; Krug, Kristine

    2015-09-19

    Vision research has the potential to reveal fundamental mechanisms underlying sensory experience. Causal experimental approaches, such as electrical microstimulation, provide a unique opportunity to test the direct contributions of visual cortical neurons to perception and behaviour. But in spite of their importance, causal methods constitute a minority of the experiments used to investigate the visual cortex to date. We reconsider the function and organization of visual cortex according to results obtained from stimulation techniques, with a special emphasis on electrical stimulation of small groups of cells in awake subjects who can report their visual experience. We compare findings from humans and monkeys, striate and extrastriate cortex, and superficial versus deep cortical layers, and identify a number of revealing gaps in the 'causal map' of visual cortex. Integrating results from different methods and species, we provide a critical overview of the ways in which causal approaches have been used to further our understanding of circuitry, plasticity and information integration in visual cortex. Electrical stimulation not only elucidates the contributions of different visual areas to perception, but also contributes to our understanding of neuronal mechanisms underlying memory, attention and decision-making.

  11. Playing the electric light orchestra—how electrical stimulation of visual cortex elucidates the neural basis of perception

    Science.gov (United States)

    Cicmil, Nela; Krug, Kristine

    2015-01-01

    Vision research has the potential to reveal fundamental mechanisms underlying sensory experience. Causal experimental approaches, such as electrical microstimulation, provide a unique opportunity to test the direct contributions of visual cortical neurons to perception and behaviour. But in spite of their importance, causal methods constitute a minority of the experiments used to investigate the visual cortex to date. We reconsider the function and organization of visual cortex according to results obtained from stimulation techniques, with a special emphasis on electrical stimulation of small groups of cells in awake subjects who can report their visual experience. We compare findings from humans and monkeys, striate and extrastriate cortex, and superficial versus deep cortical layers, and identify a number of revealing gaps in the ‘causal map′ of visual cortex. Integrating results from different methods and species, we provide a critical overview of the ways in which causal approaches have been used to further our understanding of circuitry, plasticity and information integration in visual cortex. Electrical stimulation not only elucidates the contributions of different visual areas to perception, but also contributes to our understanding of neuronal mechanisms underlying memory, attention and decision-making. PMID:26240421

  12. Systems Biology Approaches to Discerning Striated Muscle Pathologies

    OpenAIRE

    Mukund, Kavitha

    2016-01-01

    The human muscular system represents nearly 75% of the body mass and encompasses two major muscle forms- striated and smooth. Striated muscle, composed broadly of myofibers, accompanying membrane systems, cytoskeletal networks together with the metabolic and regulatory machinery, have revealed complexities in composition, structure and function. A disruption to any component within this complex system of interactions lead to disorders of the muscle, typically characterized by muscle fiber los...

  13. Poorly Understood Aspects of Striated Muscle Contraction

    Directory of Open Access Journals (Sweden)

    Alf Månsson

    2015-01-01

    Full Text Available Muscle contraction results from cyclic interactions between the contractile proteins myosin and actin, driven by the turnover of adenosine triphosphate (ATP. Despite intense studies, several molecular events in the contraction process are poorly understood, including the relationship between force-generation and phosphate-release in the ATP-turnover. Different aspects of the force-generating transition are reflected in the changes in tension development by muscle cells, myofibrils and single molecules upon changes in temperature, altered phosphate concentration, or length perturbations. It has been notoriously difficult to explain all these events within a given theoretical framework and to unequivocally correlate observed events with the atomic structures of the myosin motor. Other incompletely understood issues include the role of the two heads of myosin II and structural changes in the actin filaments as well as the importance of the three-dimensional order. We here review these issues in relation to controversies regarding basic physiological properties of striated muscle. We also briefly consider actomyosin mutation effects in cardiac and skeletal muscle function and the possibility to treat these defects by drugs.

  14. Morphology and kainate-receptor immunoreactivity of identified neurons within the entorhinal cortex projecting to superior temporal sulcus in the cynomolgus monkey

    Science.gov (United States)

    Good, P. F.; Morrison, J. H.; Bloom, F. E. (Principal Investigator)

    1995-01-01

    Projections of the entorhinal cortex to the hippocampus are well known from the classical studies of Cajal (Ramon y Cajal, 1904) and Lorente de No (1933). Projections from the entorhinal cortex to neocortical areas are less well understood. Such connectivity is likely to underlie the consolidation of long-term declarative memory in neocortical sites. In the present study, a projection arising in layer V of the entorhinal cortex and terminating in a polymodal association area of the superior temporal gyrus has been identified with the use of retrograde tracing. The dendritic arbors of neurons giving rise to this projection were further investigated by cell filling and confocal microscopy with computer reconstruction. This analysis demonstrated that the dendritic arbor of identified projection neurons was largely confined to layer V, with the exception of a solitary, simple apical dendrite occasionally ascending to superficial laminae but often confined to the lamina dissecans (layer IV). Finally, immunoreactivity for glutamate-receptor subunit proteins GluR 5/6/7 of the dendritic arbor of identified entorhinal projection neurons was examined. The solitary apical dendrite of identified entorhinal projection neurons was prominently immunolabeled for GluR 5/6/7, as was the dendritic arbor of basilar dendrites of these neurons. The restriction of the large bulk of the dendritic arbor of identified entorhinal projection neurons to layer V implies that these neurons are likely to be heavily influenced by hippocampal output arriving in the deep layers of the entorhinal cortex. Immunoreactivity for GluR 5/6/7 throughout the dendritic arbor of such neurons indicates that this class of glutamate receptor is in a position to play a prominent role in mediating excitatory neurotransmission within hippocampal-entorhinal circuits.

  15. Neurohypophyseal hormones: novel actors of striated muscle development and homeostasis

    Directory of Open Access Journals (Sweden)

    Alessandra Costa

    2014-09-01

    Full Text Available Since the 1980's, novel functional roles of the neurohypophyseal hormones vasopressin and oxytocin have emerged. Several studies have investigated the effects of these two neurohormones on striated muscle tissues, both in vitro and in vivo. The effects of vasopressin on skeletal myogenic cells, developing muscle and muscle homeostasis have been documented. Oxytocin appears to have a greater influence on cardiomyocite differentiation and heart homeostasis. This review summarizes the studies on these novel roles of the two neurohypophyseal hormones, and open the possibility of new therapeutic approaches for diseases affecting striated muscle.

  16. Monkey Business

    Science.gov (United States)

    Blackwood, Christine Horvatis

    2012-01-01

    A ballerina, a gladiator, a camper, a baseball player, a surfer, and a shopper; these are just a few of the amazing monkeys that the author's seventh graders created from papier-mache. This project provided an opportunity for students to express themselves through the creation of sculptural characters based on their own interests, hobbies, and…

  17. Fiber types in the striated urethral and anal sphincters

    DEFF Research Database (Denmark)

    Schrøder, H D; Reske-Nielsen, E

    1983-01-01

    Seven normal human striated urethral and anal sphincters obtained by autopsy were examined using histochemical techniques. In both the urethral sphincter and the subcutaneous (s.c.) and superficial part of the anal sphincter a characteristic pattern with two populations of muscle fibers, abundant...

  18. The striated MR nephrogram, not a reflection of pathology

    Energy Technology Data Exchange (ETDEWEB)

    Trout, Andrew T.; Care, Marguerite M.; Towbin, Alexander J. [Cincinnati Children' s Hospital Medical Center, Department of Radiology - MLC 5031, Cincinnati, OH (United States); Zhang, Bin [Cincinnati Children' s Hospital Medical Center, Division of Biostatistics and Epidemiology, Cincinnati, OH (United States)

    2015-10-15

    We have intermittently observed low signal striations in the kidneys on delayed post-contrast MR exams of the spine. While we suspected these striations were due to concentrated gadolinium, the clinical importance of this finding was uncertain. To describe the striated MR nephrogram (low signal striations in the kidney) and assess its clinical relevance. Retrospective review of delayed post-contrast MRIs of the spine (mean: 45 min after contrast administration). The presence of the striated MR nephrogram was correlated with imaging parameters (field strength, time since contrast), and findings (gadolinium in the bladder, inferior vena cava and aorta diameters) and with clinical factors (history of renal disease, laboratory values). Seven hundred seventy-three exams performed on 229 patients, 8.3 ± 5.3 years of age, were reviewed. The striated MR nephrogram was observed in 102/773 examinations (13.2%) and was present on at least one study in 54/229 patients (23.6%). The presence of striations was associated with the specific magnet on which the exam was performed (P < 0.01) but not with magnet field strength. Serum creatinine was minimally lower in patients with striations (0.43 ± 0.12 vs. 0.49 ± 0.18 mg/dL, P = 0.002), but no other clinical or historical data, including time from contrast administration (P = 0.54), fluid status (P = 0.17) and clinical history of renal disease (P = 0.14), were predictive of the presence of striations. The striated MR nephrogram was observed in 13% of delayed post-contrast MR exams of the spine. Precipitating factors are unclear, but the striated nephrogram does not appear to be a marker of clinically apparent renal dysfunction. (orig.)

  19. Autoradiographic analysis of protein regeneration in striated skeleton muscle

    International Nuclear Information System (INIS)

    Dadoune, J.P.

    1977-01-01

    An autoradiographic study was conducted of protein regeneration in striated muscles aimed at clarifying the contradictions in the literature: while some authors hold that the regeneration rate is identical for all types of myofibril proteins and the myofibril is thus regenerated as a whole, others claim that the regeneration rate differs depending on the type of the myofibril protein. Tritium-labelled leucine incorporation experiments showed the existence of at least 2 pools of newly formed proteins in striated muscles in both adult and young animals. One pool is regenerated in 1 to 2 weeks, the other roughly in a month. The regeneration of proteins is initially more significant in red fibres; thus the rate of myofibril protein regeneration is not uniform. In adult animals regeneration seems to be slower in filaments than in the sarcoplasm and in the mitochondria. (A.K.)

  20. Audiovisual Association Learning in the Absence of Primary Visual Cortex

    OpenAIRE

    Seirafi, Mehrdad; De Weerd, Peter; Pegna, Alan J.; de Gelder, Beatrice

    2016-01-01

    Learning audiovisual associations is mediated by the primary cortical areas; however, recent animal studies suggest that such learning can take place even in the absence of the primary visual cortex. Other studies have demonstrated the involvement of extra-geniculate pathways and especially the superior colliculus (SC) in audiovisual association learning. Here, we investigated such learning in a rare human patient with complete loss of the bilateral striate cortex. We carried out an implicit ...

  1. Serial functional imaging poststroke reveals visual cortex reorganization.

    Science.gov (United States)

    Brodtmann, Amy; Puce, Aina; Darby, David; Donnan, Geoffrey

    2009-02-01

    Visual cortical reorganization following injury remains poorly understood. The authors performed serial functional magnetic resonance imaging (fMRI) on patients with visual cortex infarction to evaluate early and late striate, ventral, and dorsal extrastriate cortical activation. Patients were studied with fMRI within 10 days and at 6 months. The authors used a high-level visual activation task designed to activate the ventral extrastriate cortex. These data were compared to those of age-appropriate healthy control participants. The results from 24 healthy control individuals (mean age 65.7 +/- SE 3.6 years, range 32-89) were compared to those from 5 stroke patients (mean age 73.8 +/- SE 7 years, range 49-86). Patients had infarcts involving the striate and ventral extrastriate cortex. Patient activation patterns were markedly different to controls. Bilateral striate and ventral extrastriate activation was reduced at both sessions, but dorsal extrastriate activated voxel counts remained comparable to controls. Conversely, mean percent magnetic resonance signal change increased in dorsal sites. These data provide strong evidence of bilateral poststroke functional depression of striate and ventral extrastriate cortices. Possible utilization or surrogacy of the dorsal visual system was demonstrated following stroke. This activity could provide a target for novel visual rehabilitation therapies.

  2. Expression of various sarcomeric tropomyosin isoforms in equine striated muscles

    Directory of Open Access Journals (Sweden)

    Syamalima Dube

    2017-06-01

    Full Text Available In order to better understand the training and athletic activity of horses, we must have complete understanding of the isoform diversity of various myofibrillar protein genes like tropomyosin. Tropomyosin (TPM, a coiled-coil dimeric protein, is a component of thin filament in striated muscles. In mammals, four TPM genes (TPM1, TPM2, TPM3, and TPM4 generate a multitude of TPM isoforms via alternate splicing and/or using different promoters. Unfortunately, our knowledge of TPM isoform diversity in the horse is very limited. Hence, we undertook a comprehensive exploratory study of various TPM isoforms from horse heart and skeletal muscle. We have cloned and sequenced two sarcomeric isoforms of the TPM1 gene called TPM1α and TPM1κ, one sarcomeric isoform of the TPM2 and one of the TPM3 gene, TPM2α and TPM3α respectively. By qRT-PCR using both relative expression and copy number, we have shown that TPM1α expression compared to TPM1κ is very high in heart. On the other hand, the expression of TPM1α is higher in skeletal muscle compared to heart. Further, the expression of TPM2α and TPM3α are higher in skeletal muscle compared to heart. Using western blot analyses with CH1 monoclonal antibody we have shown the high expression levels of sarcomeric TPM proteins in cardiac and skeletal muscle. Due to the paucity of isoform specific antibodies we cannot specifically detect the expression of TPM1κ in horse striated muscle. To the best of our knowledge this is the very first report on the characterization of sarcmeric TPMs in horse striated muscle.

  3. Allergic Interstitial Nephritis Manifesting as a Striated Nephrogram

    Directory of Open Access Journals (Sweden)

    Irfan Moinuddin

    2015-01-01

    Full Text Available Allergic interstitial nephritis (AIN is an underdiagnosed cause of acute kidney injury (AKI. Guidelines suggest that AIN should be suspected in a patient who presents with an elevated serum creatinine and a urinalysis that shows white cells, white cell casts, or eosinophiluria. Drug-induced AIN is suspected if AKI is temporally related to the initiation of a new drug. However, patients with bland sediment and normal urinalysis can also have AIN. Currently, a definitive diagnosis of AIN is made by renal biopsy which is invasive and fraught with risks such as bleeding, infection, and hematoma. Additionally, it is frequently unclear when a kidney biopsy should be undertaken. We describe a biopsy proven case of allergic interstitial nephritis which manifested on contrast enhanced Magnetic Resonance Imaging (MRI as a striated nephrogram. Newer and more stable macrocyclic gadolinium contrast agents have a well-demonstrated safety profile. Additionally, in the presentation of AKI, gadolinium contrast agents are safe to administer in patients who demonstrate good urine output and a downtrending creatinine. We propose that the differential for a striated nephrogram may include AIN. In cases in which the suspicion for AIN is high, this diagnostic consideration may be further characterized by contrast enhanced MRI.

  4. Contracture of Slow Striated Muscle during Calcium Deprivation

    Science.gov (United States)

    Irwin, Richard L.; Hein, Manfred M.

    1963-01-01

    When deprived of calcium the slow striated muscle fibers of the frog develop reversible contractures in either hypertonic or isotonic solutions. While calcium deprivation continues because of a flowing calcium-free solution the muscles relax slowly and completely. Restoration of calcium during contracture relaxes the muscle promptly to initial tension. When relaxed during calcium lack the return of calcium does not change tension and the muscle stays relaxed. When contractures are induced by solutions containing small amounts of calcium relaxation does not occur or requires several hours. The rate of tension development depends upon the rate at which calcium moves outward since the contractures develop slower in low concentrations of calcium and are absent or greatly slowed in a stagnant calcium-free solution. Withdrawal of calcium prevents the contractile responses to ACh, KCl, or electrical stimulation through the nerve. Muscles return to their original excitability after calcium is restored. Origin of the contractures is unrelated to nerve activity since they are maximal during transmission failure from calcium lack, occur in denervated muscles, and are not blocked by high concentrations of d-tubocurarine, procaine, or atropine. The experiments also indicate that the contractures do not originate from repetitive activity of muscle membranes. The findings are most simply explained by relating the outward movement of calcium as a link for initiating contraction in slow type striated muscle. PMID:14065284

  5. Influence of end-joint methods on magnetization loss in striated helical conductors

    International Nuclear Information System (INIS)

    Kim, Woo Seok; Kim, Yung Il; Choi, Kyeong Dal; Lee, Ji Kwang

    2013-01-01

    To reduce the magnetization loss of a coated conductor, the striation and the transposition have to be accomplished for magnetic decoupling. The loss reduction effect in incomplete as well as complete striated YBCO CCs was reported in previous research. At the case of the incomplete striated sample, the end region of the sample is non-striated. So, it is not jointed with each other. In power applications, the joint is needed because current leads must be connected with HTS coils. In this research, the influence of end-joint methods with copper and superconducting joint on magnetization loss in striated YBCO CC and spiral winding samples are presented and compared with non-striated measured result.

  6. Distribution of [1-14C]acrylonitrile in rat and monkey

    International Nuclear Information System (INIS)

    Sandberg, E.Ch.; Slanina, P.

    1980-01-01

    The distribution of [1- 14 C]acrylonitrile (ACN) in rat and monkey has been studied by whole-body autoradiography, after being administered orally and intravenously to rats and orally to monkeys. Uptake of radioactivity was seen in the blood, liver, kidney, lung, adrenal cortex and stomach mucosa. (Auth.)

  7. Study of the striated nature of a glow discharge

    International Nuclear Information System (INIS)

    Hernandez A, M.

    1995-01-01

    In an investigation in progress here, plasma diagnostics and detection of standing and moving striations is being made in a discharge in Argon at pressures of 2 x 10 -1 to 9 x 10 -1 mb and currents of 2 to 9 m-amp inside an discharge tube. Measurement of the temperature of the electrons, the concentration of electrons and the plasma potential are obtained in different places of the discharge by the double probe method, together with the computation system reported in [1]. In similar way an experimental work of the striated column in a discharge plasma to find the regimen of appearance of the standing and moving striations show some properties of moving striations (frequency and velocity) and standing striations. Two different oscilations are observed in motion in contrary directions along the discharge tube with a photomultiplier. (Author)

  8. Protein expression of MEF2C during the critical period for visual development in vervet monkeys

    OpenAIRE

    Bernad, Daniel M; Lachance, Pascal E; Chaudhuri, Avijit

    2008-01-01

    During the early development of the visual cortex, there is a critical period when neuronal connections are highly sensitive to changes in visual input. Deprivation of visual stimuli during the critical period elicits robust anatomical and physiological rearrangements in the monkey visual cortex and serves as an excellent model for activity-dependent neuroplasticity. DNA microarray experiments were previously performed in our lab to analyze gene expression patterns in area V1 of vervet monkey...

  9. Burst firing and modulation of functional connectivity in cat striate cortex.

    Science.gov (United States)

    Snider, R K; Kabara, J F; Roig, B R; Bonds, A B

    1998-08-01

    We studied the influences of the temporal firing patterns of presynaptic cat visual cortical cells on spike generation by postsynaptic cells. Multiunit recordings were dissected into the activity of individual neurons within the recorded group. Cross-correlation analysis was then used to identify directly coupled neuron pairs. The 22 multiunit groups recorded typically showed activity from two to six neurons, each containing between 1 and 15 neuron pairs. From a total of 241 neuron pairs, 91 (38%) had a shifted cross-correlation peak, which indicated a possible direct connection. Only two multiunit groups contained no shifted peaks. Burst activity, defined by groups of two or more spikes with intervals of

  10. Genome Editing of Monkey.

    Science.gov (United States)

    Liu, Zhen; Cai, Yijun; Sun, Qiang

    2017-01-01

    Gene-modified monkey models would be particularly valuable in biomedical and neuroscience research. Virus-based transgenic and programmable nucleases-based site-specific gene editing methods (TALEN, CRISPR-cas9) enable the generation of gene-modified monkeys with gain or loss of function of specific genes. Here, we describe the generation of transgenic and knock-out (KO) monkeys with high efficiency by lentivirus and programmable nucleases.

  11. The homeobox gene Msx in development and transdifferentiation of jellyfish striated muscle.

    Science.gov (United States)

    Galle, Sabina; Yanze, Nathalie; Seipel, Katja

    2005-01-01

    Bilaterian Msx homeobox genes are generally expressed in areas of cell proliferation and in association with multipotent progenitor cells. Likewise, jellyfish Msx is expressed in progenitor cells of the developing entocodon, a cell layer giving rise to the striated and smooth muscles of the medusa. However, in contrast to the bilaterian homologs, Msx gene expression is maintained at high levels in the differentiated striated muscle of the medusa in vivo and in vitro. This tissue exhibits reprogramming competence. Upon induction, the Msx gene is immediately switched off in the isolated striated muscle undergoing transdifferentiation, to be upregulated again in the emerging smooth muscle cells which, in a stem cell like manner, undergo quantal cell divisions producing two cell types, a proliferating smooth muscle cell and a differentiating nerve cell. This study indicates that the Msx protein may be a key component of the reprogramming machinery responsible for the extraordinary transdifferentation and regeneration potential of striated muscle in the hydrozoan jellyfish.

  12. Ultrastructure of striated muscle fibers in the middle third of the human esophagus

    OpenAIRE

    Faussone-Pellegrini, M.S; Cortesini, C.

    1986-01-01

    Striated muscle fibers and .their spatial relationship to smooth muscle cells have been studied in the middle third of human esophagus. Biopsies were obtained from 3 patients during surgery. In both the circular and longitudinal layers, the muscle coat of this transition zone was composed of fascicles of uniform dimensioi~ (100-200 pm of diameter); some of these bundles were made up of striated muscle fibers, others were pure bundles of smooth muscle cells and ...

  13. Audiovisual Blindsight: Audiovisual learning in the absence of primary visual cortex

    OpenAIRE

    Mehrdad eSeirafi; Peter eDe Weerd; Alan J Pegna; Beatrice ede Gelder

    2016-01-01

    Learning audiovisual associations is mediated by the primary cortical areas; however, recent animal studies suggest that such learning can take place even in the absence of the primary visual cortex. Other studies have demonstrated the involvement of extra-geniculate pathways and especially the superior colliculus (SC) in audiovisual association learning. Here, we investigated such learning in a rare human patient with complete loss of the bilateral striate cortex. We carried out an implicit...

  14. In vivo functional and morphological characterization of bone and striated muscle microcirculation in NSG mice.

    Directory of Open Access Journals (Sweden)

    Haider Mussawy

    Full Text Available Organ-specific microcirculation plays a central role in tumor growth, tumor cell homing, tissue engineering, and wound healing. Mouse models are widely used to study these processes; however, these mouse strains often possess unique microhemodynamic parameters, making it difficult to directly compare experiments. The full functional characterization of bone and striated muscle microcirculatory parameters in non-obese diabetic-severe combined immunodeficiency/y-chain; NOD-Prkds IL2rg (NSG mice has not yet been reported. Here, we established either a dorsal skinfold chamber or femur window in NSG mice (n = 23, allowing direct analysis of microcirculatory parameters in vivo by intravital fluorescence microscopy at 7, 14, 21, and 28 days after chamber preparation. Organ-specific differences were observed. Bone had a significantly lower vessel density but a higher vessel diameter than striated muscle. Bone also showed higher effective vascular permeability than striated muscle. The centerline velocity values were similar in the femur window and dorsal skinfold chamber, with a higher volumetric blood flow in bone. Interestingly, bone and striated muscle showed similar tissue perfusion rates. Knowledge of physiological microhemodynamic values of bone and striated muscle in NSG mice makes it possible to analyze pathophysiological processes at these anatomic sites, such as tumor growth, tumor metastasis, and tumor microcirculation, as well as the response to therapeutic agents.

  15. Human primary visual cortex topography imaged via positron tomography

    International Nuclear Information System (INIS)

    Schwartz, E.L.; Christman, D.R.; Wolf, A.P.

    1984-01-01

    The visuotopic structure of primary visual cortex was studied in a group of 7 human volunteers using positron emission transaxial tomography (PETT) and 18 F-labeled 2-deoxy-2-fluoro-D-glucose ([ 18 F]DG). A computer animation was constructed with a spatial structure which was matched to estimates of human cortical magnification factor and to striate cortex stimulus preferences. A lateralized cortical 'checker-board' pattern of [ 18 F]DG was stimulated in primary visual cortex by having subjects view this computer animation following i.v. injection of [ 18 F]DG. The spatial structure of the stimulus was designed to produce an easily recognizable 'signature' in a series of 9 serial PETT scans obtained from each of a group of 7 volunteers. The predicted lateralized topographic 'signature' was observed in 6 of 7 subjects. Applications of this method for further PETT studies of human visual cortex are discussed. (Auth.)

  16. Monkey prefrontal neurons during Sternberg task performance: full contents of working memory or most recent item?

    Science.gov (United States)

    Konecky, R O; Smith, M A; Olson, C R

    2017-06-01

    To explore the brain mechanisms underlying multi-item working memory, we monitored the activity of neurons in the dorsolateral prefrontal cortex while macaque monkeys performed spatial and chromatic versions of a Sternberg working-memory task. Each trial required holding three sequentially presented samples in working memory so as to identify a subsequent probe matching one of them. The monkeys were able to recall all three samples at levels well above chance, exhibiting modest load and recency effects. Prefrontal neurons signaled the identity of each sample during the delay period immediately following its presentation. However, as each new sample was presented, the representation of antecedent samples became weak and shifted to an anomalous code. A linear classifier operating on the basis of population activity during the final delay period was able to perform at approximately the level of the monkeys on trials requiring recall of the third sample but showed a falloff in performance on trials requiring recall of the first or second sample much steeper than observed in the monkeys. We conclude that delay-period activity in the prefrontal cortex robustly represented only the most recent item. The monkeys apparently based performance of this classic working-memory task on some storage mechanism in addition to the prefrontal delay-period firing rate. Possibilities include delay-period activity in areas outside the prefrontal cortex and changes within the prefrontal cortex not manifest at the level of the firing rate. NEW & NOTEWORTHY It has long been thought that items held in working memory are encoded by delay-period activity in the dorsolateral prefrontal cortex. Here we describe evidence contrary to that view. In monkeys performing a serial multi-item working memory task, dorsolateral prefrontal neurons encode almost exclusively the identity of the sample presented most recently. Information about earlier samples must be encoded outside the prefrontal cortex or

  17. Quantitative histological studies on aging changes in cerebral cortex of rhesus monkey and albino rat with notes on effects of prolonged low-dose ionizing irradiation in the rat

    International Nuclear Information System (INIS)

    Brizzee, K.R.

    1973-01-01

    Brains of a series of eight young adult control (150 days) and eight middle-aged control (550 days) rats were fixed by a two-stage perfusion procedure employing Heidenhain's 'susa' solution. An equal number of rats were exposed to γ-irradiation at 6.5 R/day beginning on the 50th postnatal day and were sacrificed in the same manner and at the same age levels as the previous group. Paraffin sections were cut at 20 and 6 μ from cerebral cortical area 3 in the rat brains. Sections used for cell counts were stained with Harris' hematoxylin and eosin or iron hematoxylin, gallocyanin, acid fuchsin and ponceau de xylidene. Counts of neurons and glia were carried out at 20 equally spaced submolecular depth levels, and cell frequency profiles were plotted for each of the two cell types. The mean neuron and glial packing density for the total depth of the submolecular cortex of area 3 was not significantly different in young adult and middle-aged controls or in young adult irradiated (total dose 650 R) and control animals. However, statistical evaluation of data for relative depth levels 7 through 20 indicated that the packing density in this zone was significantly less (P<0.02) in middle-aged controls than in young adult animals. In middle-aged irradiated rats (total dose about 3250 R) neuron and glial packing densities for total depth of submolecular cortex were not significantly different than in control animals at the same age level. However, the values obtained for neuron packing density at relative depth levels 1 through 8 were significantly lower in middle-aged irradiated than in middle-aged control rats. The neuron packing density in middle-aged irradiated rats was significantly lower than in the young adult irradiated males. In electron micrographs, an increase in the amount of glycogen granules in astrocyte cell processes in cerebral cortex of irradiated middle-aged rats was noted, but there was no evidence of any other ultrastructural alterations

  18. Neurotoxic response of infant monkeys to methylmercury

    Energy Technology Data Exchange (ETDEWEB)

    Willes, R.F.; Truelove, J.F.; Nera, E.A.

    1978-02-01

    Four infant monkeys were dosed orally with 500 ..mu..g Hg/kg body wt./day (as methylmercury (MeHg) chloride dissolved sodium carbonate) beginning at 1 day of age. Neurological and behavioral signs of MeHg toxicity and blood Hg levels were monitored weekly. At first sign of MeHg intoxication, dosing with MeHg was terminated and the infants were monitored to assess reversal of the signs of MeHg toxicity. The first signs of MeHg toxicity, exhibited as a loss in dexterity and locomotor ability, were observed after 28 to 29 days of treatment; the blood Hg levels were 8.0 to 9.4 ..mu..g Hg/g blood. Dosing was terminated at 28 to 29 days of treatment but the signs of MeHg toxicity continued to develop. The infants became ataxic, blind, comatose and were necropsied at 35 to 43 days after initiating treatment with MgHg. The mercury concentrations in tissues analyzed after necropsy were highest in liver followed by occipital cortex and renal cortex. The mean blood/brain ratio was 0.21 +- 0.4. Histopathologic lesions were marked in the cerebrum with less severe lesions in the cerebellar nuclei. The Purkinje and granular cells of the cerebellar vermis appeared histologically normal. Lesions were not observed in the peripheral nervous system. The signs of MeHg intoxication, the tissue distribution of MeHg and histopathologic lesions observed in the infant monkeys were similar to those reported for adult monkeys.

  19. Neurotoxic response of infant monkeys to methylmercury.

    Science.gov (United States)

    Willes, R F; Truelove, J F; Nera, E A

    1978-02-01

    Four infant monkeys were dosed orally with 500 microgram Hg/kg body wt./day /as methylmercury (MeHg) chloride dissolved sodium carbonate) beginning at 1 day of age. Neurological and behavioral signs of MeHg toxicity and blood Hg levels were monitored weekly. At first sign of MeHg intoxication, dosing with MeHg was terminated and the infants were monitored to assess reversal of the signs of MeHg toxicity. The first signs of MeHg toxicity, exhibited as a loss in dexterity and locomotor ability, were observed after 28--29 days of treatment; the blood Hg levels were 8.0--9.4 microgram Hg/g blood. Dosing was terminated at 28--29 days of treatment but the signs of MeHg toxicity continued to develop. The infants became ataxic, blind, comatose and were necropsied at 35--43 days after initiating treatment with MgHg. The mercury concentrations in tissues analyzed after necropsy were highest in liver (55.8 +/- 3.2 microgram Hg/g) followed by occipital cortex (35.6 +/- 4.8 microgram Hg/g) renal cortex (32.8 +/- 1.6 microgram Hg/g). The frontal and temporal cortices had 27.0 +/- 3.4 and 29.6 +/- 4.9 microgram Hg/g respectively while the cerebellar Hg concentration averaged 13.0 +/- 1.5 microgram Hg/g. The mean blood/brain ratio was 0.21 +/- 0.4. Histopathologic lesions were marked in the cerebrum with less severe lesions in the cerebellar nuclei. The Purkinje and granular cells of the cerebellar vermis appeared histologically normal. Lesions were not observed in the peripheral nervous system. The signs of MeHg intoxication, the tissue distribution of MeHg and histopathologic lesions observed in the infant monkeys were similar to those reported for adult monkeys.

  20. Psychophysical chromatic mechanisms in macaque monkey.

    Science.gov (United States)

    Stoughton, Cleo M; Lafer-Sousa, Rosa; Gagin, Galina; Conway, Bevil R

    2012-10-24

    Chromatic mechanisms have been studied extensively with psychophysical techniques in humans, but the number and nature of the mechanisms are still controversial. Appeals to monkey neurophysiology are often used to sort out the competing claims and to test hypotheses arising from the experiments in humans, but psychophysical chromatic mechanisms have never been assessed in monkeys. Here we address this issue by measuring color-detection thresholds in monkeys before and after chromatic adaptation, employing a standard approach used to determine chromatic mechanisms in humans. We conducted separate experiments using adaptation configured as either flickering full-field colors or heterochromatic gratings. Full-field colors would favor activity within the visual system at or before the arrival of retinal signals to V1, before the spatial transformation of color signals by the cortex. Conversely, gratings would favor activity within the cortex where neurons are often sensitive to spatial chromatic structure. Detection thresholds were selectively elevated for the colors of full-field adaptation when it modulated along either of the two cardinal chromatic axes that define cone-opponent color space [L vs M or S vs (L + M)], providing evidence for two privileged cardinal chromatic mechanisms implemented early in the visual-processing hierarchy. Adaptation with gratings produced elevated thresholds for colors of the adaptation regardless of its chromatic makeup, suggesting a cortical representation comprised of multiple higher-order mechanisms each selective for a different direction in color space. The results suggest that color is represented by two cardinal channels early in the processing hierarchy and many chromatic channels in brain regions closer to perceptual readout.

  1. Esophageal striated muscle contractions in patients with Chagas' disease and idiopathic achalasia

    Directory of Open Access Journals (Sweden)

    R.O. Dantas

    2002-06-01

    Full Text Available Chagas' disease causes degeneration and reduction of the number of intrinsic neurons of the esophageal myenteric plexus, with consequent absent or partial lower esophageal sphincter relaxation and loss of peristalsis in the esophageal body. The impairment of esophageal motility is seen mainly in the distal smooth muscle region. There is no study about esophageal striated muscle contractions in the disease. In 81 patients with heartburn (44 with esophagitis taken as controls, 51 patients with Chagas' disease (21 with esophageal dilatation and 18 patients with idiopathic achalasia (11 with esophageal dilatation we studied the amplitude, duration and area under the curve of esophageal proximal contractions. Using the manometric method and a continuous perfusion system we measured the esophageal striated muscle contractions 2 to 3 cm below the upper esophageal sphincter after swallows of a 5-ml bolus of water. There was no significant difference in striated muscle contractions between patients with heartburn and esophagitis and patients with heartburn without esophagitis. There was also no significant difference between patients with heartburn younger or older than 50 years or between men and women or in esophageal striated muscle contractions between patients with heartburn and Chagas' disease. The esophageal proximal amplitude of contractions was lower in patients with idiopathic achalasia than in patients with heartburn. In patients with Chagas' disease there was no significant difference between patients with esophageal dilatation and patients with normal esophageal diameter. Esophageal striated muscle contractions in patients with Chagas' disease have the same amplitude and duration as seen in patients with heartburn. Patients with idiopathic achalasia have a lower amplitude of contraction than patients with heartburn.

  2. The effect of first visual stimulation incorporation of labelled leucine into cerebral cortex of binocularly deprived kittens

    International Nuclear Information System (INIS)

    Mitros, K.; Kossut, M.; Skangiel-Kramska, J.; Mueller, L.; Niemierko, S.; Zernicki, B.

    1978-01-01

    One-month old kittens, binocularly deprived with hoods from birth, were used. Before the experiments in which visual stimulation was applied the brainstem of kittens was transected at the pretrigeminal level. Cortical EEG activity and ocular behavior indicated that the isolated cerebrum of preparations was usually awake during experiment. Patterned visual stimulation was directed to one hemisphere, while the other was used as a control. Visual stimulation evoked in some cases (in 8 out of 17) an increase of incorporation of labelled leucine into the proteins of the striate cortex. Electrophoresis on polyacrylamide gel did not reveal any differences in the pattern of insoluble proteins between the stimulated and control visual cortex. It is suggested that first visual stimulation may enhance the protein metabolism of striate cortex in young kittens. Some unknown up to now physiological factors (motivation, attention) may be critical for these phenomena. (author)

  3. A case of polymicrogyria in macaque monkey: impact on anatomy and function of the motor system

    Directory of Open Access Journals (Sweden)

    Rouiller Eric M

    2009-12-01

    Full Text Available Abstract Background Polymicrogyria is a malformation of the cerebral cortex often resulting in epilepsy or mental retardation. It remains unclear whether this pathology affects the structure and function of the corticospinal (CS system. The anatomy and histology of the brain of one macaque monkey exhibiting a spontaneous polymicrogyria (PMG monkey were examined and compared to the brain of normal monkeys. The CS tract was labelled by injecting a neuronal tracer (BDA unilaterally in a region where low intensity electrical microstimulation elicited contralateral hand movements (presumably the primary motor cortex in the PMG monkey. Results The examination of the brain showed a large number of microgyri at macro- and microscopic levels, covering mainly the frontoparietal regions. The layered cortical organization was locally disrupted and the number of SMI-32 stained pyramidal neurons in the cortical layer III of the presumed motor cortex was reduced. We compared the distribution of labelled CS axons in the PMG monkey at spinal cervical level C5. The cumulated length of CS axon arbors in the spinal grey matter was not significantly different in the PMG monkey. In the red nucleus, numerous neurons presented large vesicles. We also assessed its motor performances by comparing its capacity to execute a complex reach and grasp behavioral task. The PMG monkey exhibited an increase of reaction time without any modification of other motor parameters, an observation in line with a normal CS tract organisation. Conclusion In spite of substantial cortical malformations in the frontal and parietal lobes, the PMG monkey exhibits surprisingly normal structure and function of the corticospinal system.

  4. Audiovisual Association Learning in the Absence of Primary Visual Cortex.

    Science.gov (United States)

    Seirafi, Mehrdad; De Weerd, Peter; Pegna, Alan J; de Gelder, Beatrice

    2015-01-01

    Learning audiovisual associations is mediated by the primary cortical areas; however, recent animal studies suggest that such learning can take place even in the absence of the primary visual cortex. Other studies have demonstrated the involvement of extra-geniculate pathways and especially the superior colliculus (SC) in audiovisual association learning. Here, we investigated such learning in a rare human patient with complete loss of the bilateral striate cortex. We carried out an implicit audiovisual association learning task with two different colors of red and purple (the latter color known to minimally activate the extra-genicular pathway). Interestingly, the patient learned the association between an auditory cue and a visual stimulus only when the unseen visual stimulus was red, but not when it was purple. The current study presents the first evidence showing the possibility of audiovisual association learning in humans with lesioned striate cortex. Furthermore, in line with animal studies, it supports an important role for the SC in audiovisual associative learning.

  5. Neural correlates of memory retrieval in the prefrontal cortex.

    Science.gov (United States)

    Nácher, Verónica; Ojeda, Sabiela; Cadarso-Suárez, Carmen; Roca-Pardiñas, Javier; Acuña, Carlos

    2006-08-01

    Working memory includes short-term representations of information that were recently experienced or retrieved from long-term representations of sensory stimuli. Evidence is presented here that working memory activates the same dorsolateral prefrontal cortex neurons that: (a) maintained recently perceived visual stimuli; and (b) retrieved visual stimuli from long-term memory (LTM). Single neuron activity was recorded in the dorsolateral prefrontal cortex while trained monkeys discriminated between two orientated lines shown sequentially, separated by a fixed interstimulus interval. This visual task required the monkey to compare the orientation of the second line with the memory trace of the first and to decide the relative orientation of the second. When the behavioural task required the monkey to maintain in working memory a first stimulus that continually changed from trial to trial, the discharge in these cells was related to the parameters--the orientation--of the memorized item. Then, what the monkey had to recall from memory was manipulated by switching to another task in which the first stimulus was not shown, and had to be retrieved from LTM. The discharge rates of the same neurons also varied depending on the parameters of the memorized stimuli, and their response was progressively delayed as the monkey performed the task. These results suggest that working memory activates dorsolateral prefrontal cortex neurons that maintain parametrical visual information in short-term and LTM, and that the contents of working memory cannot be limited to what has recently happened in the sensory environment.

  6. Interstitial cells of Cajal in the striated musculature of the mouse esophagus

    DEFF Research Database (Denmark)

    Rumessen, J J; de Kerchove d'Exaerde, A; Mignon, S

    2001-01-01

    . Sections and whole-mounts were studied by immunohistochemistry. KitW-lacZ transgenic mice, which carry the lacZ reporter gene inserted in place of the first exon of the Kit gene, were processed for Xgal histochemistry, for quantitative analysis and for ultrastructural studies. Spindle-shaped ICC were...... scarce in both muscle layers of the thoracic esophagus, while their number increased steeply toward the cardia in the striated portion of the intraabdominal esophagus. They did not form networks and had no relationship with intrinsic myenteric ganglia and motor end-plates. They were often close to nerve...... between striated muscle cells in the mouse esophagus. They are close to nerves with defined neurochemical coding and could possibly represent specialized esophageal spindle proprioceptors....

  7. Histological study of human sublingual gland with special emphasis on intercalated and striated ducts

    International Nuclear Information System (INIS)

    Rana, R.; Minhas, L.A.; Mubarik, A.

    2012-01-01

    Objective: To study the histomorphological characteristics of human sublingual gland, specially of intercalated and striated ducts. Study design: Descriptive study Place and duration of study: Army Medical College from Jan 2002 to Dec 2002 Materials and methods: Fifteen sublingual glands (right and left) from postmortem cases were obtained from District Headquarter Hospital Rawalpindi, within twelve hours of death. Five micrometer thick sections were made and stained with Haematoxylin and Eosin (H and E). Morphology of intercalated and striated ducts was studied and their number was counted. Results: The mean number of intercalated ducts in the right gland 'a'and 'b' parts, and in the left gland 'a' and 'b' parts was 1.45+-0.14, 1.39+-.009, 1.31+-0.11 and 1.18+-0.10 respectively. The mean diameter of intercalated ducts in the same parts was 19.76+-0.44 micro m, 20.6+-0.53 micro m, 20.34+-0.49 micro m and 19.84+-0.98 micro m respectively. The mean number of striated ducts in the right gland ''a'' and ''b'' parts, and in the left gland ''a'' and ''b'' parts was 0.55+-.008, 0.57+-.008, 0.80+-0.14 and 0.80+-0.14 while mean diameter of striated ducts in the right gland ''a'' and ''b'' parts, and in the left gland ''a'' and ''b'' parts was 49.90+-4.70 micro m, 53.23+-2.50 micro m, 61.68+-3.93 micro m and 57.73+-2.85 micro m respectively. Conclusion: The difference between the mean number and diameter of the ducts of right and left glands was statistically insignificant. (author)

  8. Morphology of lesions in striated muscle fibres from the beige mouse

    DEFF Research Database (Denmark)

    Kirkeby, S

    1982-01-01

    Lesions in striated muscle fibres from the beige mouse are described at both the light- and electronmicroscopical levels. The muscles have two types of lesions, one is well defined cores in the fibres and the other is diffusely enlarged intermyofibrillar spaces (IMS). The cores can be filled...... with membrane-like structures or a fluffy unstructured material. In the areas with enlarged IMS comparatively few organelles are present and the muscle fibres seem to be fragmented....

  9. Sporadic Premature Aging in a Japanese Monkey: A Primate Model for Progeria

    Science.gov (United States)

    Oishi, Takao; Imai, Hiroo; Go, Yasuhiro; Imamura, Masanori; Hirai, Hirohisa; Takada, Masahiko

    2014-01-01

    In our institute, we have recently found a child Japanese monkey who is characterized by deep wrinkles of the skin and cataract of bilateral eyes. Numbers of analyses were performed to identify symptoms representing different aspects of aging. In this monkey, the cell cycle of fibroblasts at early passage was significantly extended as compared to a normal control. Moreover, both the appearance of senescent cells and the deficiency in DNA repair were observed. Also, pathological examination showed that this monkey has poikiloderma with superficial telangiectasia, and biochemical assay confirmed that levels of HbA1c and urinary hyaluronan were higher than those of other (child, adult, and aged) monkey groups. Of particular interest was that our MRI analysis revealed expansion of the cerebral sulci and lateral ventricles probably due to shrinkage of the cerebral cortex and the hippocampus. In addition, the conduction velocity of a peripheral sensory but not motor nerve was lower than in adult and child monkeys, and as low as in aged monkeys. However, we could not detect any individual-unique mutations of known genes responsible for major progeroid syndromes. The present results indicate that the monkey suffers from a kind of progeria that is not necessarily typical to human progeroid syndromes. PMID:25365557

  10. The Crossed Projection to the Striatum in Two Species of Monkey and in Humans: Behavioral and Evolutionary Significance

    DEFF Research Database (Denmark)

    Innocenti, Giorgio M.; Dyrby, Tim Bjørn; Andersen, Kasper Winther

    2017-01-01

    The corpus callosum establishes the anatomical continuity between the 2 hemispheres and coordinates their activity. Using histological tracing, single axon reconstructions, and diffusion tractography, we describe a callosal projection to n caudatus and putamen in monkeys and humans. In both species......, the origin of this projection is more restricted than that of the ipsilateral projection. In monkeys, it consists of thin axons (0.4–0.6 µm), appropriate for spatial and temporal dispersion of subliminal inputs. For prefrontal cortex, contralateral minus ipsilateral delays to striatum calculated from axon...... diameters and conduction distance are monkey and, by extrapolation,

  11. Comparison of Object Recognition Behavior in Human and Monkey

    Science.gov (United States)

    Rajalingham, Rishi; Schmidt, Kailyn

    2015-01-01

    Although the rhesus monkey is used widely as an animal model of human visual processing, it is not known whether invariant visual object recognition behavior is quantitatively comparable across monkeys and humans. To address this question, we systematically compared the core object recognition behavior of two monkeys with that of human subjects. To test true object recognition behavior (rather than image matching), we generated several thousand naturalistic synthetic images of 24 basic-level objects with high variation in viewing parameters and image background. Monkeys were trained to perform binary object recognition tasks on a match-to-sample paradigm. Data from 605 human subjects performing the same tasks on Mechanical Turk were aggregated to characterize “pooled human” object recognition behavior, as well as 33 separate Mechanical Turk subjects to characterize individual human subject behavior. Our results show that monkeys learn each new object in a few days, after which they not only match mean human performance but show a pattern of object confusion that is highly correlated with pooled human confusion patterns and is statistically indistinguishable from individual human subjects. Importantly, this shared human and monkey pattern of 3D object confusion is not shared with low-level visual representations (pixels, V1+; models of the retina and primary visual cortex) but is shared with a state-of-the-art computer vision feature representation. Together, these results are consistent with the hypothesis that rhesus monkeys and humans share a common neural shape representation that directly supports object perception. SIGNIFICANCE STATEMENT To date, several mammalian species have shown promise as animal models for studying the neural mechanisms underlying high-level visual processing in humans. In light of this diversity, making tight comparisons between nonhuman and human primates is particularly critical in determining the best use of nonhuman primates to

  12. Dynamic differentiation of GABAA-sensitive influences on orientation selectivity of complex cells in the cat striate cortex.

    Science.gov (United States)

    Pfleger, B; Bonds, A B

    1995-01-01

    The influence of GABAA receptors on orientation selectivity of cat complex cells was tested by iontophoresis of the GABAA receptor blockers bicuculline and N-methyl-bicuculline while stimulating with drifting sinusoidal gratings. Reduction of orientation tuning was markedly less than reported in previous studies that used drifting bars as visual stimuli. Only 3/31 cells lost orientation selectivity, with an average increase in bandwidth of 33%, as opposed to half the cells losing selectivity and a bandwidth increase for the remainder of 47% as reported previously. Infusion of GABAA blockers revealed a prominent stimulus onset transient response, lasting about 120 ms, that showed a broadening of orientation selectivity comparable to that found using drifting bars under similar circumstances. We believe that drifting gratings emphasize a steady-state response component that retains, in the presence of GABAA blockers, significant orientation selectivity. Because the onset transient is initially unselective for orientation, we suggest that the steady-state, orientation-selective response component develops from an alternate inhibitory mechanism, possibly mediated by GABAB receptors.

  13. Decision salience signals in posterior cingulate cortex

    Directory of Open Access Journals (Sweden)

    Sarah eHeilbronner

    2011-04-01

    Full Text Available Despite its phylogenetic antiquity and clinical importance, the posterior cingulate cortex (CGp remains an enigmatic nexus of attention, memory, motivation, and decision making. Here we show that CGp neurons track decision salience—the degree to which an option differs from a standard—but not the subjective value of a decision. To do this, we recorded the spiking activity of CGp neurons in monkeys choosing between options varying in reward-related risk, delay to reward, and social outcomes, each of which varied in level of decision salience. Firing rates were higher when monkeys chose the risky option, consistent with their risk-seeking preferences, but were also higher when monkeys chose the delayed and social options, contradicting their preferences. Thus, across decision contexts, neuronal activity was uncorrelated with how much monkeys valued a given option, as inferred from choice. Instead, neuronal activity signaled the deviation of the chosen option from the standard, independently of how it differed. The observed decision salience signals suggest a role for CGp in the flexible allocation of neural resources to motivationally significant information, akin to the role of attention in selective processing of sensory inputs.

  14. Proton magnetic resonance spectroscopy ((1H-MRS reveals geniculocalcarine and striate area degeneration in primary glaucoma.

    Directory of Open Access Journals (Sweden)

    Yan Zhang

    Full Text Available BACKGROUND: Glaucoma is a collection of neurodegenerative diseases that affect both the retina and the central visual pathway. We investigated whether metabolites' concentrations changed in the geniculocalcarine (GCT and the striate area of occipital lobe by proton magnetic resonance spectroscopy ((1H-MRS, suggesting neurodegeneration of the central visual pathway in primary glaucoma. METHODOLOGY/PRINCIPAL FINDINGS: 20 patients with glaucoma in both eyes were paired with 20 healthy volunteers in same gender and an age difference less than 3 years. All the participants were examined by MR imaging including T1 Flair, T2 FSE and (1H-MRS. The T1 intensity and T2 intensity of their GCTs and striate areas were measured. The ratio of N-acetylaspartate (NAA/Creatine (Cr, Choline (Cho/Cr, glutamine and glutamate (Glx/Cr were derived by multi-voxels (1H-MRS in the GCT and the striate area of each brain hemisphere. The T1 intensity and T2 intensity had no difference between the groups. Significant decreases in NAA/Cr and Cho/Cr but no difference in Glx/Cr was found between the groups in both the GCT and the striate area. CONCLUSIONS/SIGNIFICANCE: Primary glaucoma affects metabolites' concentrations in the GCT and the striate area suggesting there is ongoing neurodegenerative process.

  15. What Do Monkey Calls Mean?

    Science.gov (United States)

    Schlenker, Philippe; Chemla, Emmanuel; Zuberbühler, Klaus

    2016-12-01

    A field of primate linguistics is gradually emerging. It combines general questions and tools from theoretical linguistics with rich data gathered in experimental primatology. Analyses of several monkey systems have uncovered very simple morphological and syntactic rules and have led to the development of a primate semantics that asks new questions about the division of semantic labor between the literal meaning of monkey calls, additional mechanisms of pragmatic enrichment, and the environmental context. We show that comparative studies across species may validate this program and may in some cases help in reconstructing the evolution of monkey communication over millions of years. Copyright © 2016. Published by Elsevier Ltd.

  16. Distinctive serum miRNA profile in mouse models of striated muscular pathologies.

    Directory of Open Access Journals (Sweden)

    Nicolas Vignier

    Full Text Available Biomarkers are critically important for disease diagnosis and monitoring. In particular, close monitoring of disease evolution is eminently required for the evaluation of therapeutic treatments. Classical monitoring methods in muscular dystrophies are largely based on histological and molecular analyses of muscle biopsies. Such biopsies are invasive and therefore difficult to obtain. The serum protein creatine kinase is a useful biomarker, which is however not specific for a given pathology and correlates poorly with the severity or course of the muscular pathology. The aim of the present study was the systematic evaluation of serum microRNAs (miRNAs as biomarkers in striated muscle pathologies. Mouse models for five striated muscle pathologies were investigated: Duchenne muscular dystrophy (DMD, limb-girdle muscular dystrophy type 2D (LGMD2D, limb-girdle muscular dystrophy type 2C (LGMD2C, Emery-Dreifuss muscular dystrophy (EDMD and hypertrophic cardiomyopathy (HCM. Two-step RT-qPCR methodology was elaborated, using two different RT-qPCR miRNA quantification technologies. We identified miRNA modulation in the serum of all the five mouse models. The most highly dysregulated serum miRNAs were found to be commonly upregulated in DMD, LGMD2D and LGMD2C mouse models, which all exhibit massive destruction of striated muscle tissues. Some of these miRNAs were down rather than upregulated in the EDMD mice, a model without massive myofiber destruction. The dysregulated miRNAs identified in the HCM model were different, with the exception of one dysregulated miRNA common to all pathologies. Importantly, a specific and distinctive circulating miRNA profile was identified for each studied pathological mouse model. The differential expression of a few dysregulated miRNAs in the DMD mice was further evaluated in DMD patients, providing new candidates of circulating miRNA biomarkers for DMD.

  17. Fast optical signal not detected in awake behaving monkeys.

    Science.gov (United States)

    Radhakrishnan, Harsha; Vanduffel, Wim; Deng, Hong Ping; Ekstrom, Leeland; Boas, David A; Franceschini, Maria Angela

    2009-04-01

    While the ability of near-infrared spectroscopy (NIRS) to measure cerebral hemodynamic evoked responses (slow optical signal) is well established, its ability to measure non-invasively the 'fast optical signal' is still controversial. Here, we aim to determine the feasibility of performing NIRS measurements of the 'fast optical signal' or Event-Related Optical Signals (EROS) under optimal experimental conditions in awake behaving macaque monkeys. These monkeys were implanted with a 'recording well' to expose the dura above the primary visual cortex (V1). A custom-made optical probe was inserted and fixed into the well. The close proximity of the probe to the brain maximized the sensitivity to changes in optical properties in the cortex. Motion artifacts were minimized by physical restraint of the head. Full-field contrast-reversing checkerboard stimuli were presented to monkeys trained to perform a visual fixation task. In separate sessions, two NIRS systems (CW4 and ISS FD oximeter), which previously showed the ability to measure the fast signal in human, were used. In some sessions EEG was acquired simultaneously with the optical signal. The increased sensitivity to cortical optical changes with our experimental setup was quantified with 3D Monte Carlo simulations on a segmented MRI monkey head. Averages of thousands of stimuli in the same animal, or grand averages across the two animals and across repeated sessions, did not lead to detection of the fast optical signal using either amplitude or phase of the optical signal. Hemodynamic responses and visual evoked potentials were instead always detected with single trials or averages of a few stimuli. Based on these negative results, despite the optimal experimental conditions, we doubt the usefulness of non-invasive fast optical signal measurements with NIRS.

  18. P1-24: Neural Representation of Gloss in the Macaque Inferior Temporal Cortex

    OpenAIRE

    Akiko Nishio; Naokazu Goda; Hidehiko Komatsu

    2012-01-01

    The variation of the appearance such as gloss provides one of the most important information for object recognition. However, little is known about the neural mechanisms related to the perception of gloss. We examined whether the neurons in the inferior temporal (IT) cortex of the monkeys are coding gloss of objects. We made visual stimuli which have various surface reflectance properties, and tested responses of IT neurons to these stimuli while a monkey was performing a visual fixation task...

  19. The Popeye Domain Containing Genes and Their Function in Striated Muscle

    Science.gov (United States)

    Schindler, Roland F. R.; Scotton, Chiara; French, Vanessa; Ferlini, Alessandra; Brand, Thomas

    2016-01-01

    The Popeye domain containing (POPDC) genes encode a novel class of cAMP effector proteins, which are abundantly expressed in heart and skeletal muscle. Here, we will review their role in striated muscle as deduced from work in cell and animal models and the recent analysis of patients carrying a missense mutation in POPDC1. Evidence suggests that POPDC proteins control membrane trafficking of interacting proteins. Furthermore, we will discuss the current catalogue of established protein-protein interactions. In recent years, the number of POPDC-interacting proteins has been rising and currently includes ion channels (TREK-1), sarcolemma-associated proteins serving functions in mechanical stability (dystrophin), compartmentalization (caveolin 3), scaffolding (ZO-1), trafficking (NDRG4, VAMP2/3) and repair (dysferlin) or acting as a guanine nucleotide exchange factor for Rho-family GTPases (GEFT). Recent evidence suggests that POPDC proteins might also control the cellular level of the nuclear proto-oncoprotein c-Myc. These data suggest that this family of cAMP-binding proteins probably serves multiple roles in striated muscle. PMID:27347491

  20. Orbital prefrontal cortex is required for object-in-place scene memory but not performance of a strategy implementation task.

    Science.gov (United States)

    Baxter, Mark G; Gaffan, David; Kyriazis, Diana A; Mitchell, Anna S

    2007-10-17

    The orbital prefrontal cortex is thought to be involved in behavioral flexibility in primates, and human neuroimaging studies have identified orbital prefrontal activation during episodic memory encoding. The goal of the present study was to ascertain whether deficits in strategy implementation and episodic memory that occur after ablation of the entire prefrontal cortex can be ascribed to damage to the orbital prefrontal cortex. Rhesus monkeys were preoperatively trained on two behavioral tasks, the performance of both of which is severely impaired by the disconnection of frontal cortex from inferotemporal cortex. In the strategy implementation task, monkeys were required to learn about two categories of objects, each associated with a different strategy that had to be performed to obtain food reward. The different strategies had to be applied flexibly to optimize the rate of reward delivery. In the scene memory task, monkeys learned 20 new object-in-place discrimination problems in each session. Monkeys were tested on both tasks before and after bilateral ablation of orbital prefrontal cortex. These lesions impaired new scene learning but had no effect on strategy implementation. This finding supports a role for the orbital prefrontal cortex in memory but places limits on the involvement of orbital prefrontal cortex in the representation and implementation of behavioral goals and strategies.

  1. Spatial Attention and Temporal Expectation Under Timed Uncertainty Predictably Modulate Neuronal Responses in Monkey V1

    Science.gov (United States)

    Sharma, Jitendra; Sugihara, Hiroki; Katz, Yarden; Schummers, James; Tenenbaum, Joshua; Sur, Mriganka

    2015-01-01

    The brain uses attention and expectation as flexible devices for optimizing behavioral responses associated with expected but unpredictably timed events. The neural bases of attention and expectation are thought to engage higher cognitive loci; however, their influence at the level of primary visual cortex (V1) remains unknown. Here, we asked whether single-neuron responses in monkey V1 were influenced by an attention task of unpredictable duration. Monkeys covertly attended to a spot that remained unchanged for a fixed period and then abruptly disappeared at variable times, prompting a lever release for reward. We show that monkeys responded progressively faster and performed better as the trial duration increased. Neural responses also followed monkey's task engagement—there was an early, but short duration, response facilitation, followed by a late but sustained increase during the time monkeys expected the attention spot to disappear. This late attentional modulation was significantly and negatively correlated with the reaction time and was well explained by a modified hazard function. Such bimodal, time-dependent changes were, however, absent in a task that did not require explicit attentional engagement. Thus, V1 neurons carry reliable signals of attention and temporal expectation that correlate with predictable influences on monkeys' behavioral responses. PMID:24836689

  2. Epidurography with metrizamide in Rhesus monkeys

    International Nuclear Information System (INIS)

    Kido, D.K.; Baker, R.A.; Saubermann, A.; Salem, J.; Schoene, W.C.; Fournier, P.

    1980-01-01

    Epidurography with metrizamide was performed on 9 Rhesus monkeys; physiologic saline was substituted for metrizamide in 3 control monkeys. Metrizamide successfully outlined the epidural space without causing any adverse clinical effects or direct tissue injury. (Auth.)

  3. A Balanced Comparison of Object Invariances in Monkey IT Neurons.

    Science.gov (United States)

    Ratan Murty, N Apurva; Arun, Sripati P

    2017-01-01

    Our ability to recognize objects across variations in size, position, or rotation is based on invariant object representations in higher visual cortex. However, we know little about how these invariances are related. Are some invariances harder than others? Do some invariances arise faster than others? These comparisons can be made only upon equating image changes across transformations. Here, we targeted invariant neural representations in the monkey inferotemporal (IT) cortex using object images with balanced changes in size, position, and rotation. Across the recorded population, IT neurons generalized across size and position both stronger and faster than to rotations in the image plane as well as in depth. We obtained a similar ordering of invariances in deep neural networks but not in low-level visual representations. Thus, invariant neural representations dynamically evolve in a temporal order reflective of their underlying computational complexity.

  4. Spontaneous Metacognition in Rhesus Monkeys.

    Science.gov (United States)

    Rosati, Alexandra G; Santos, Laurie R

    2016-09-01

    Metacognition is the ability to think about thinking. Although monitoring and controlling one's knowledge is a key feature of human cognition, its evolutionary origins are debated. In the current study, we examined whether rhesus monkeys (Macaca mulatta; N = 120) could make metacognitive inferences in a one-shot decision. Each monkey experienced one of four conditions, observing a human appearing to hide a food reward in an apparatus consisting of either one or two tubes. The monkeys tended to search the correct location when they observed this baiting event, but engaged in information seeking-by peering into a center location where they could check both potential hiding spots-if their view had been occluded and information seeking was possible. The monkeys only occasionally approached the center when information seeking was not possible. These results show that monkeys spontaneously use information about their own knowledge states to solve naturalistic foraging problems, and thus provide the first evidence that nonhumans exhibit information-seeking responses in situations with which they have no prior experience. © The Author(s) 2016.

  5. Vicarious Learning from Human Models in Monkeys

    OpenAIRE

    Falcone, Rossella; Brunamonti, Emiliano; Genovesio, Aldo

    2012-01-01

    We examined whether monkeys can learn by observing a human model, through vicarious learning. Two monkeys observed a human model demonstrating an object-reward association and consuming food found underneath an object. The monkeys observed human models as they solved more than 30 learning problems. For each problem, the human models made a choice between two objects, one of which concealed a piece of apple. In the test phase afterwards, the monkeys made a choice of their own. Learning was app...

  6. Cognitive performance of juvenile monkeys after chronic fluoxetine treatment.

    Science.gov (United States)

    Golub, Mari S; Hackett, Edward P; Hogrefe, Casey E; Leranth, Csaba; Elsworth, John D; Roth, Robert H

    2017-08-01

    Potential long term effects on brain development are a concern when drugs are used to treat depression and anxiety in childhood. In this study, male juvenile rhesus monkeys (three-four years of age) were dosed with fluoxetine or vehicle (N=16/group) for two years. Histomorphometric examination of cortical dendritic spines conducted after euthanasia at one year postdosing (N=8/group) suggested a trend toward greater dendritic spine synapse density in prefrontal cortex of the fluoxetine-treated monkeys. During dosing, subjects were trained for automated cognitive testing, and evaluated with a test of sustained attention. After dosing was discontinued, sustained attention, recognition memory and cognitive flexibility were evaluated. Sustained attention was affected by fluoxetine, both during and after dosing, as indexed by omission errors. Response accuracy was not affected by fluoxetine in post-dosing recognition memory and cognitive flexibility tests, but formerly fluoxetine-treated monkeys compared to vehicle controls had more missed trial initiations and choices during testing. Drug treatment also interacted with genetic and environmental variables: MAOA genotype (high- and low transcription rate polymorphisms) and testing location (upper or lower tier of cages). Altered development of top-down cortical regulation of effortful attention may be relevant to this pattern of cognitive test performance after juvenile fluoxetine treatment. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Get the Monkey off Your Back

    Science.gov (United States)

    Ciabattini, David; Custer, Timothy J.

    2008-01-01

    Monkeys are the problems that need solutions, the tasks that need to be accomplished, the decisions that need to be made, and the actions that need to be taken. According to a theory, people carry monkeys around on their backs until they can successfully shift their burden to someone else and the monkey leaps from one back to the next. Managers…

  8. Application of 31P-NMR spectroscopy to the study of striated muscle metabolism

    International Nuclear Information System (INIS)

    Meyer, R.A.; Kushmerick, M.J.; Brown, T.R.

    1982-01-01

    This review presents the principles and limitations of phosphorus nuclear magnetic resonance ( 31 P-NMR) spectroscopy as applied to the study of striated muscle metabolism. Application of the techniques discussed include noninvasive measurement of high-energy phosphate, intracellular pH, intracellular free Mg 2+ , and metabolite compartmentation. In perfused cat biceps (fast-twitch) muscles, but not in soleus (slow-twitch), NMR spectra indicate a substantially lower (1 mM) free inorganic phosphate level than when measured chemically (6 mM). In addition, saturation and inversion spin-transfer methods that enable direct measurement of the unidirectional fluxes through creatine kinase are described. In perfused cat biceps muscle, results suggest that this enzyme and its substrates are in simple chemical equilibrium

  9. Architecture of vagal motor units controlling striated muscle of esophagus: peripheral elements patterning peristalsis?

    Science.gov (United States)

    Powley, Terry L; Mittal, Ravinder K; Baronowsky, Elizabeth A; Hudson, Cherie N; Martin, Felecia N; McAdams, Jennifer L; Mason, Jacqueline K; Phillips, Robert J

    2013-12-01

    Little is known about the architecture of the vagal motor units that control esophageal striated muscle, in spite of the fact that these units are necessary, and responsible, for peristalsis. The present experiment was designed to characterize the motor neuron projection fields and terminal arbors forming esophageal motor units. Nucleus ambiguus compact formation neurons of the rat were labeled by bilateral intracranial injections of the anterograde tracer dextran biotin. After tracer transport, thoracic and abdominal esophagi were removed and prepared as whole mounts of muscle wall without mucosa or submucosa. Labeled terminal arbors of individual vagal motor neurons (n=78) in the esophageal wall were inventoried, digitized and analyzed morphometrically. The size of individual vagal motor units innervating striated muscle, throughout thoracic and abdominal esophagus, averaged 52 endplates per motor neuron, a value indicative of fine motor control. A majority (77%) of the motor terminal arbors also issued one or more collateral branches that contacted neurons, including nitric oxide synthase-positive neurons, of local myenteric ganglia. Individual motor neuron terminal arbors co-innervated, or supplied endplates in tandem to, both longitudinal and circular muscle fibers in roughly similar proportions (i.e., two endplates to longitudinal for every three endplates to circular fibers). Both the observation that vagal motor unit collaterals project to myenteric ganglia and the fact that individual motor units co-innervate longitudinal and circular muscle layers are consistent with the hypothesis that elements contributing to peristaltic programming inhere, or are "hardwired," in the peripheral architecture of esophageal motor units. © 2013.

  10. Effect of distribution of striated laser hardening tracks on dry sliding wear resistance of biomimetic surface

    Science.gov (United States)

    Su, Wei; Zhou, Ti; Zhang, Peng; Zhou, Hong; Li, Hui

    2018-01-01

    Some biological surfaces were proved to have excellent anti-wear performance. Being inspired, Nd:YAG pulsed laser was used to create striated biomimetic laser hardening tracks on medium carbon steel samples. Dry sliding wear tests biomimetic samples were performed to investigate specific influence of distribution of laser hardening tracks on sliding wear resistance of biomimetic samples. After comparing wear weight loss of biomimetic samples, quenched sample and untreated sample, it can be suggested that the sample covered with dense laser tracks (3.5 mm spacing) has lower wear weight loss than the one covered with sparse laser tracks (4.5 mm spacing); samples distributed with only dense laser tracks or sparse laser tracks (even distribution) were proved to have better wear resistance than samples distributed with both dense and sparse tracks (uneven distribution). Wear mechanisms indicate that laser track and exposed substrate of biomimetic sample can be regarded as hard zone and soft zone respectively. Inconsecutive striated hard regions, on the one hand, can disperse load into small branches, on the other hand, will hinder sliding abrasives during wear. Soft regions with small range are beneficial in consuming mechanical energy and storing lubricative oxides, however, soft zone with large width (>0.5 mm) will be harmful to abrasion resistance of biomimetic sample because damages and material loss are more obvious on surface of soft phase. As for the reason why samples with even distributed bionic laser tracks have better wear resistance, it can be explained by the fact that even distributed laser hardening tracks can inhibit severe worn of local regions, thus sliding process can be more stable and wear extent can be alleviated as well.

  11. A 4-channel 3 Tesla phased array receive coil for awake rhesus monkey fMRI and diffusion MRI experiments.

    Science.gov (United States)

    Khachaturian, Mark Haig

    2010-01-01

    Awake monkey fMRI and diffusion MRI combined with conventional neuroscience techniques has the potential to study the structural and functional neural network. The majority of monkey fMRI and diffusion MRI experiments are performed with single coils which suffer from severe EPI distortions which limit resolution. By constructing phased array coils for monkey MRI studies, gains in SNR and anatomical accuracy (i.e., reduction of EPI distortions) can be achieved using parallel imaging. The major challenges associated with constructing phased array coils for monkeys are the variation in head size and space constraints. Here, we apply phased array technology to a 4-channel phased array coil capable of improving the resolution and image quality of full brain awake monkey fMRI and diffusion MRI experiments. The phased array coil is that can adapt to different rhesus monkey head sizes (ages 4-8) and fits in the limited space provided by monkey stereotactic equipment and provides SNR gains in primary visual cortex and anatomical accuracy in conjunction with parallel imaging and improves resolution in fMRI experiments by a factor of 2 (1.25 mm to 1.0 mm isotropic) and diffusion MRI experiments by a factor of 4 (1.5 mm to 0.9 mm isotropic).

  12. Rhesus monkey neural stem cell transplantation promotes neural regeneration in rats with hippocampal lesions

    Directory of Open Access Journals (Sweden)

    Li-juan Ye

    2016-01-01

    Full Text Available Rhesus monkey neural stem cells are capable of differentiating into neurons and glial cells. Therefore, neural stem cell transplantation can be used to promote functional recovery of the nervous system. Rhesus monkey neural stem cells (1 × 105 cells/μL were injected into bilateral hippocampi of rats with hippocampal lesions. Confocal laser scanning microscopy demonstrated that green fluorescent protein-labeled transplanted cells survived and grew well. Transplanted cells were detected at the lesion site, but also in the nerve fiber-rich region of the cerebral cortex and corpus callosum. Some transplanted cells differentiated into neurons and glial cells clustering along the ventricular wall, and integrated into the recipient brain. Behavioral tests revealed that spatial learning and memory ability improved, indicating that rhesus monkey neural stem cells noticeably improve spatial learning and memory abilities in rats with hippocampal lesions.

  13. Vicarious learning from human models in monkeys.

    Science.gov (United States)

    Falcone, Rossella; Brunamonti, Emiliano; Genovesio, Aldo

    2012-01-01

    We examined whether monkeys can learn by observing a human model, through vicarious learning. Two monkeys observed a human model demonstrating an object-reward association and consuming food found underneath an object. The monkeys observed human models as they solved more than 30 learning problems. For each problem, the human models made a choice between two objects, one of which concealed a piece of apple. In the test phase afterwards, the monkeys made a choice of their own. Learning was apparent from the first trial of the test phase, confirming the ability of monkeys to learn by vicarious observation of human models.

  14. Vicarious learning from human models in monkeys.

    Directory of Open Access Journals (Sweden)

    Rossella Falcone

    Full Text Available We examined whether monkeys can learn by observing a human model, through vicarious learning. Two monkeys observed a human model demonstrating an object-reward association and consuming food found underneath an object. The monkeys observed human models as they solved more than 30 learning problems. For each problem, the human models made a choice between two objects, one of which concealed a piece of apple. In the test phase afterwards, the monkeys made a choice of their own. Learning was apparent from the first trial of the test phase, confirming the ability of monkeys to learn by vicarious observation of human models.

  15. Effects of anesthesia upon 18F-FDG uptake in rhesus monkey brains

    International Nuclear Information System (INIS)

    Itoh, Takashi; Wakahara, Shunichi; Nakano, Takayuki; Suzuki, Kazutoshi; Kobayashi, Kaoru; Inoue, Osamu

    2005-01-01

    The kinetics of 18 F-fluorodeoxyglucose ( 18 F-FDG) in the monkey brain were monitored, and comparisons were made between the conscious state and when under ketamine and pentobarbital anesthesia. Rhesus monkeys were intravenously injected with 18 F-FDG and followed by 60 min of PET scanning. In the conscious state, the 18 F-FDG concentration reached a plateau 5 min after intravenous injection. Under ketamine anesthesia, the 18 F-FDG concentration gradually increased with time in all monitored regions. At 60 min after injection, the concentration in the striatum was about 3.2 times greater than that in the conscious state, and about 4.5 times greater in the cerebral cortex. Under pentobarbital anesthesia, the 18 F-FDG concentration in the occipital cortex was slightly lower. These findings demonstrate that 18 F-FDG concentration in the monkey brain is significantly affected by anesthesia. The results also imply the existence of a short-term regulation mechanism for hexokinase activity in intact monkey brain. (author)

  16. Formal monkey linguistics : The debate

    NARCIS (Netherlands)

    Schlenker, Philippe; Chemla, Emmanuel; Schel, Anne M.|info:eu-repo/dai/nl/413333450; Fuller, James; Gautier, Jean Pierre; Kuhn, Jeremy; Veselinović, Dunja; Arnold, Kate; Cäsar, Cristiane; Keenan, Sumir; Lemasson, Alban; Ouattara, Karim; Ryder, Robin; Zuberbühler, Klaus

    2016-01-01

    We explain why general techniques from formal linguistics can and should be applied to the analysis of monkey communication - in the areas of syntax and especially semantics. An informed look at our recent proposals shows that such techniques needn't rely excessively on categories of human language:

  17. Learning a New Selection Rule in Visual and Frontal Cortex.

    Science.gov (United States)

    van der Togt, Chris; Stănişor, Liviu; Pooresmaeili, Arezoo; Albantakis, Larissa; Deco, Gustavo; Roelfsema, Pieter R

    2016-08-01

    How do you make a decision if you do not know the rules of the game? Models of sensory decision-making suggest that choices are slow if evidence is weak, but they may only apply if the subject knows the task rules. Here, we asked how the learning of a new rule influences neuronal activity in the visual (area V1) and frontal cortex (area FEF) of monkeys. We devised a new icon-selection task. On each day, the monkeys saw 2 new icons (small pictures) and learned which one was relevant. We rewarded eye movements to a saccade target connected to the relevant icon with a curve. Neurons in visual and frontal cortex coded the monkey's choice, because the representation of the selected curve was enhanced. Learning delayed the neuronal selection signals and we uncovered the cause of this delay in V1, where learning to select the relevant icon caused an early suppression of surrounding image elements. These results demonstrate that the learning of a new rule causes a transition from fast and random decisions to a more considerate strategy that takes additional time and they reveal the contribution of visual and frontal cortex to the learning process. © The Author 2016. Published by Oxford University Press.

  18. Neuronal Responses in Visual Area V2 (V2) of Macaque Monkeys with Strabismic Amblyopia

    OpenAIRE

    Bi, H.; Zhang, B.; Tao, X.; Harwerth, R. S.; Smith, E. L.; Chino, Y. M.

    2011-01-01

    Amblyopia, a developmental disorder of spatial vision, is thought to result from a cascade of cortical deficits over several processing stages beginning at the primary visual cortex (V1). However, beyond V1, little is known about how cortical development limits the visual performance of amblyopic primates. We quantitatively analyzed the monocular and binocular responses of V1 and V2 neurons in a group of strabismic monkeys exhibiting varying depths of amblyopia. Unlike in V1, the relative eff...

  19. A deficit in face-voice integration in developing vervet monkeys exposed to ethanol during gestation.

    Science.gov (United States)

    Zangenehpour, Shahin; Javadi, Pasha; Ervin, Frank R; Palmour, Roberta M; Ptito, Maurice

    2014-01-01

    Children with fetal alcohol spectrum disorders display behavioural and intellectual impairments that strongly implicate dysfunction within the frontal cortex. Deficits in social behaviour and cognition are amongst the most pervasive outcomes of prenatal ethanol exposure. Our naturalistic vervet monkey model of fetal alcohol exposure (FAE) provides an unparalleled opportunity to study the neurobehavioral outcomes of prenatal ethanol exposure in a controlled experimental setting. Recent work has revealed a significant reduction of the neuronal population in the frontal lobes of these monkeys. We used an intersensory matching procedure to investigate audiovisual perception of socially relevant stimuli in young FAE vervet monkeys. Here we show a domain-specific deficit in audiovisual integration of socially relevant stimuli. When FAE monkeys were shown a pair of side-by-side videos of a monkey concurrently presenting two different calls along with a single audio track matching the content of one of the calls, they were not able to match the correct video to the single audio track. This was manifest by their average looking time being equally spent towards both the matching and non-matching videos. However, a group of normally developing monkeys exhibited a significant preference for the non-matching video. This inability to integrate and thereby discriminate audiovisual stimuli was confined to the integration of faces and voices as revealed by the monkeys' ability to match a dynamic face to a complex tone or a black-and-white checkerboard to a pure tone, presumably based on duration and/or onset-offset synchrony. Together, these results suggest that prenatal ethanol exposure negatively affects a specific domain of audiovisual integration. This deficit is confined to the integration of information that is presented by the face and the voice and does not affect more elementary aspects of sensory integration.

  20. A deficit in face-voice integration in developing vervet monkeys exposed to ethanol during gestation.

    Directory of Open Access Journals (Sweden)

    Shahin Zangenehpour

    Full Text Available Children with fetal alcohol spectrum disorders display behavioural and intellectual impairments that strongly implicate dysfunction within the frontal cortex. Deficits in social behaviour and cognition are amongst the most pervasive outcomes of prenatal ethanol exposure. Our naturalistic vervet monkey model of fetal alcohol exposure (FAE provides an unparalleled opportunity to study the neurobehavioral outcomes of prenatal ethanol exposure in a controlled experimental setting. Recent work has revealed a significant reduction of the neuronal population in the frontal lobes of these monkeys. We used an intersensory matching procedure to investigate audiovisual perception of socially relevant stimuli in young FAE vervet monkeys. Here we show a domain-specific deficit in audiovisual integration of socially relevant stimuli. When FAE monkeys were shown a pair of side-by-side videos of a monkey concurrently presenting two different calls along with a single audio track matching the content of one of the calls, they were not able to match the correct video to the single audio track. This was manifest by their average looking time being equally spent towards both the matching and non-matching videos. However, a group of normally developing monkeys exhibited a significant preference for the non-matching video. This inability to integrate and thereby discriminate audiovisual stimuli was confined to the integration of faces and voices as revealed by the monkeys' ability to match a dynamic face to a complex tone or a black-and-white checkerboard to a pure tone, presumably based on duration and/or onset-offset synchrony. Together, these results suggest that prenatal ethanol exposure negatively affects a specific domain of audiovisual integration. This deficit is confined to the integration of information that is presented by the face and the voice and does not affect more elementary aspects of sensory integration.

  1. Distribution of an 125I-labelled chloroquine analogue in a pregnant macaca monkey

    International Nuclear Information System (INIS)

    Dencker, L.; Lindquist, N.G.; Ullberg, S.

    1975-01-01

    Whole body autoradiography of a pregnant monkey (Macaca irus) of late gestation was performed 72 h after an intravenous injection of the 125 I-labelled chloroquine analogue 4-(3-dimethylaminopropylamino)-7-iodoquinoline (DAPQ). The overall distribution pattern in the monkey was similar to that which was earlier observed in rodents. A few species differences, however, were found in the monkey as compared to the rodents: a high accumulation in the inner part of the adrenal cortex, a high level in the central nervous system, and generally a higher retention in the tissues. The accumulation in the cortex may be of significance for the cortisone-like effects of the 4-aminoquinolines in rheumatoid arthritis and allied conditions. The fact that no accumulation was found in the adrenal cortex of mice and rats indicates that these species may not be appropriate in studies on the mechanisms involved in the anti-inflammatory action of the 4-aminoquinolines. As was earlier observed in small rodents the melanin containing structures accumulated the drug. In both the mother and the fetus a high concentration was thus seen in the uveal tract of the eye, in the inner ear (in the stria vascularis of the cochlea and the planum semilunatum of the ampullae) and in the hair follicles. This accumulation can be related to reported disturbances-also transplacentally induced-in vision and hearing

  2. Cannabinoid CB1 Receptors Are Localized in Striated Muscle Mitochondria and Regulate Mitochondrial Respiration

    Directory of Open Access Journals (Sweden)

    Juan Mendizabal-Zubiaga

    2016-10-01

    Full Text Available The cannabinoid type 1 (CB1 receptor is widely distributed in the brain and peripheral organs where it regulates cellular functions and metabolism. In the brain, CB1 is mainly localized on presynaptic axon terminals but is also found on mitochondria (mtCB1, where it regulates cellular respiration and energy production. Likewise, CB1 is localized on muscle mitochondria, but very little is known about it. The aim of this study was to further investigate in detail the distribution and functional role of mtCB1 in three different striated muscles. Immunoelectron microscopy for CB1 was used in skeletal muscles (gastrocnemius and rectus abdominis and myocardium from wild-type and CB1-KO mice. Functional assessments were performed in mitochondria purified from the heart of the mice and the mitochondrial oxygen consumption upon application of different acute delta-9-tetrahidrocannabinol (Δ9-THC concentrations (100 nM or 200 nM was monitored. About 26% of the mitochondrial profiles in gastrocnemius, 22% in the rectus abdominis and 17% in the myocardium expressed CB1. Furthermore, the proportion of mtCB1 versus total CB1 immunoparticles was about 60% in the gastrocnemius, 55% in the rectus abdominis and 78% in the myocardium. Importantly, the CB1 immunolabeling pattern disappeared in muscles of CB1-KO mice. Functionally, acute 100 nM or 200 nM THC treatment specifically decreased mitochondria coupled respiration between 12% and 15% in wild-type isolated mitochondria of myocardial muscles but no significant difference was noticed between THC treated and vehicle in mitochondria isolated from CB1-KO heart. Furthermore, gene expression of key enzymes involved in pyruvate synthesis, tricarboxylic acid (TCA cycle and mitochondrial respiratory chain was evaluated in the striated muscle of CB1-WT and CB1-KO. CB1-KO showed an increase in the gene expression of Eno3, Pkm2, and Pdha1, suggesting an increased production of pyruvate. In contrast, no significant

  3. Constancy and variability in cortical structure. A study on synapses and dendritic spines in hedgehog and monkey.

    Science.gov (United States)

    Schüz, A; Demianenko, G P

    1995-01-01

    Synapses and dendritic spines were investigated in the parietal cortex of the hedgehog (Erinaceus europaeus) and the monkey (Macaca mulatta). There was no significant difference in the density of synapses between the two species (14 synapses/100 microns2 in the hedgehog, 15/100 microns2 in the monkey), neither in the size of the synaptic junctions, in the proportion of Type I and Type II synapses (8-10% were of Type II in the hedgehog, 10-14% in the monkey) nor in the proportion of perforated synapses (8% in the hedgehog, 5% in the monkey). The only striking difference at the electron microscopic level concerned the frequency of synapses in which the postsynaptic profile was deeply indented into the presynaptic terminal. Such synapses were 10 times more frequent in the monkey. Dendritic spines were investigated in Golgi-preparations. The density of spines along dendrites was similar in both species. The results are discussed with regard to connectivity in the cortex of small and large brains.

  4. Effects of striated laser tracks on thermal fatigue resistance of cast iron samples with biomimetic non-smooth surface

    International Nuclear Information System (INIS)

    Tong, Xin; Zhou, Hong; Liu, Min; Dai, Ming-jiang

    2011-01-01

    In order to enhance the thermal fatigue resistance of cast iron materials, the samples with biomimetic non-smooth surface were processed by Neodymium:Yttrium Aluminum Garnet (Nd:YAG) laser. With self-controlled thermal fatigue test method, the thermal fatigue resistance of smooth and non-smooth samples was investigated. The effects of striated laser tracks on thermal fatigue resistance were also studied. The results indicated that biomimetic non-smooth surface was benefit for improving thermal fatigue resistance of cast iron sample. The striated non-smooth units formed by laser tracks which were vertical with thermal cracks had the best propagation resistance. The mechanisms behind these influences were discussed, and some schematic drawings were introduced to describe them.

  5. Noisy Spiking in Visual Area V2 of Amblyopic Monkeys.

    Science.gov (United States)

    Wang, Ye; Zhang, Bin; Tao, Xiaofeng; Wensveen, Janice M; Smith, Earl L; Chino, Yuzo M

    2017-01-25

    Interocular decorrelation of input signals in developing visual cortex can cause impaired binocular vision and amblyopia. Although increased intrinsic noise is thought to be responsible for a range of perceptual deficits in amblyopic humans, the neural basis for the elevated perceptual noise in amblyopic primates is not known. Here, we tested the idea that perceptual noise is linked to the neuronal spiking noise (variability) resulting from developmental alterations in cortical circuitry. To assess spiking noise, we analyzed the contrast-dependent dynamics of spike counts and spiking irregularity by calculating the square of the coefficient of variation in interspike intervals (CV 2 ) and the trial-to-trial fluctuations in spiking, or mean matched Fano factor (m-FF) in visual area V2 of monkeys reared with chronic monocular defocus. In amblyopic neurons, the contrast versus response functions and the spike count dynamics exhibited significant deviations from comparable data for normal monkeys. The CV 2 was pronounced in amblyopic neurons for high-contrast stimuli and the m-FF was abnormally high in amblyopic neurons for low-contrast gratings. The spike count, CV 2 , and m-FF of spontaneous activity were also elevated in amblyopic neurons. These contrast-dependent spiking irregularities were correlated with the level of binocular suppression in these V2 neurons and with the severity of perceptual loss for individual monkeys. Our results suggest that the developmental alterations in normalization mechanisms resulting from early binocular suppression can explain much of these contrast-dependent spiking abnormalities in V2 neurons and the perceptual performance of our amblyopic monkeys. Amblyopia is a common developmental vision disorder in humans. Despite the extensive animal studies on how amblyopia emerges, we know surprisingly little about the neural basis of amblyopia in humans and nonhuman primates. Although the vision of amblyopic humans is often described as

  6. The neurophysiology of figure^ground segregation in primary visual cortex

    NARCIS (Netherlands)

    Lamme, V.A.F.

    1995-01-01

    Recorded neuronal activity in the monkey primary visual cortex while Ss were viewing full screen arrays of either oriented line segments or moving random dots. Almost every cell gave a significantly larger response for texture elements perceived as a figure (FI) than for background elements. Cell

  7. An Early Investigation Of The Striated Tail Of Comet Hale-Bopp (C/1995 O1)

    Science.gov (United States)

    Pittichová, J.; Sekanina, Z.; Birkle, K.; Boehnhardt, H.; Engels, D.; Keller, P.

    1997-07-01

    The Sekanina-Farrell particle fragmentation model for the striated tails of dust comets is successfully applied to two images of comet Hale-Bopp to study the motions of 12 striae in a time span of March 12 15, 1997. There is evidence for recurring outbursts with a periodicity of 11h21m, consistent with results based on analysis of dust jets. The ejecta in all the striae appear to have been released from one source on the nucleus between the end of January and the second half of February 1997, some 60 to 40 days before perihelion. The parent particles were subjected to a radiation pressure acceleration of βp ≃ 0.55 and their fragmentation lifetimes in 11 of the 12 striae were practically constant and equal to 13 15 days, when normalized to 1 AU from the Sun. Brief analysis of Watanabe et al.'s measurements of striae on their images from March 5 9, 1997 shows even shorter fragmentation lifetimes for the parent particles, mostly about 7 11 days at1 AU.

  8. Revealing t-tubules in striated muscle with new optical super-resolution microscopy techniques

    Directory of Open Access Journals (Sweden)

    Isuru D. Jayasinghe

    2014-12-01

    Full Text Available The t-tubular system plays a central role in the synchronisation of calcium signalling and excitation-contraction coupling in most striated muscle cells. Light microscopy has been used for imaging t-tubules for well over 100 years and together with electron microscopy (EM, has revealed the three-dimensional complexities of the t-system topology within cardiomyocytes and skeletal muscle fibres from a range of species. The emerging super-resolution single molecule localisation microscopy (SMLM techniques are offering a near 10-fold improvement over the resolution of conventional fluorescence light microscopy methods, with the ability to spectrally resolve nanometre scale distributions of multiple molecular targets. In conjunction with the next generation of electron microscopy, SMLM has allowed the visualisation and quantification of intricate t-tubule morphologies within large areas of muscle cells at an unprecedented level of detail. In this paper, we review recent advancements in the t-tubule structural biology with the utility of various microscopy techniques. We outline the technical considerations in adapting SMLM to study t-tubules and its potential to further our understanding of the molecular processes that underlie the sub-micron scale structural alterations observed in a range of muscle pathologies.

  9. Chaperones and the Proteasome System: Regulating the Construction and Demolition of Striated Muscle

    Directory of Open Access Journals (Sweden)

    Casey Carlisle

    2017-12-01

    Full Text Available Protein folding factors (chaperones are required for many diverse cellular functions. In striated muscle, chaperones are required for contractile protein function, as well as the larger scale assembly of the basic unit of muscle, the sarcomere. The sarcomere is complex and composed of hundreds of proteins and the number of proteins and processes recognized to be regulated by chaperones has increased dramatically over the past decade. Research in the past ten years has begun to discover and characterize the chaperones involved in the assembly of the sarcomere at a rapid rate. Because of the dynamic nature of muscle, wear and tear damage is inevitable. Several systems, including chaperones and the ubiquitin proteasome system (UPS, have evolved to regulate protein turnover. Much of our knowledge of muscle development focuses on the formation of the sarcomere but recent work has begun to elucidate the requirement and role of chaperones and the UPS in sarcomere maintenance and disease. This review will cover the roles of chaperones in sarcomere assembly, the importance of chaperone homeostasis and the cooperation of chaperones and the UPS in sarcomere integrity and disease.

  10. Steroid metabolism by monkey and human spermatozoa

    International Nuclear Information System (INIS)

    Rajalakshmi, M.; Sehgal, A.; Pruthi, J.S.; Anand-Kumar, T.C.

    1983-01-01

    Freshly ejaculated spermatozoa from monkey and human were washed and incubated with tritium labelled androgens or estradiol to study the pattern of spermatozoa steroid metabolism. When equal concentrations of steroid substrates were used for incubation, monkey and human spermatozoa showed very similar pattern of steroid conversion. Spermatozoa from both species converted testosterone mainly to androstenedione, but reverse conversion of androstenedione to testosterone was negligible. Estradiol-17 beta was converted mainly to estrone. The close similarity between the spermatozoa of monkey and men in their steroid metabolic pattern indicates that the rhesus monkey could be an useful animal model to study the effect of drugs on the metabolic pattern of human spermatozoa

  11. An Electron Microscopic Study of the Irradiation Effects on the Striated Duct Cells of the Submandibular Gland in Rats

    International Nuclear Information System (INIS)

    Lee, Kyu Chan; Lee, Sang Rae

    1990-01-01

    The purpose of this study was to investigate the effects of irradiation on the striated duct cells of the rat submandibular gland ductal tissues which control the characteristics of saliva. For this study, the experimental group was composed of 36 irradiated Sprague Dawley strain rats divided into 8 subgroups- 1 hour, 2 hours, 3 hours, 6 hours, 12 hours, 24 hours, 48 hours, 72 hours after irradiation. 4 non-irradiated rats were used as the control group. The experimental animals were singly irradiated with a dose of 18 Gy gamma ray to their head and neck region by the Co-6-teletherapy unit and sacrificed after each experimental duration. The specimens were examined with a light microscope with an H-E stain and with a transmission electron microscope. The results of this study were as follows. 1. In the light micrograph, a severe atrophic change occurred in the striated duct cells at 2 hours after irradiation and gradual recovery occurred from 6 hours after irradiation. 2. The nuclear chromosomes of the striated duct cells were changed granular at 2 hours after irradiation. Recovery was observed at 6 hours after irradiation. Nuclear bodies were also observed from 3 hours after irradiation. 3. The mitochondria of the striated duct cells had indistinct cristae at 2 hours after irradiation, and were degenerated or swollen at 3 hours after irradiation. They recovered, however, from 6 hours, with an increasing number at 48 hours a regular arrangement was observed at 72 hours after irradiation. 4. The microvilli showed atrophic changes at 2 hours after irradiation and were almost lost at 3 hours after irradiation. They were observed again from 48 hours after irradiation. 5. The rough endoplasmic reticulum and golgi body were not apparent at 1 hours after irradiation and were dilated with degeneration 2 hours after, but intact rough endoplasmic reticulum were observed from 3 hours after irradiation and developed well at 24 hours after irradiation. By the result of this

  12. Comparative anatomy of the prosubiculum, subiculum, presubiculum, postsubiculum, and parasubiculum in human, monkey, and rodent.

    Science.gov (United States)

    Ding, Song-Lin

    2013-12-15

    The subicular complex, including the prosubiculum (ProS), subiculum (Sub), presubiculum, postsubiculum (PoS), and parasubiculum (PaS), plays important roles in the medial temporal memory system and is heavily involved in many neurological diseases such as Alzheimer's disease and epilepsy. In the literature, the ProS (in primate) and PoS (in rodent) are inconstantly identified, making data comparison difficult across species. This review is an attempt to discuss equivalencies and extent of the five subicular components in human, monkey, and rodent based on available information on their cytoarchitecture, chemoarchitecture, molecular signature, and neural connectivity. All five subicular cortices exist in human, monkey, and rodent. In human and monkey, the ProS and Sub extend into the uncal region anteriorly, and the PoS and PaS reach the cingulate isthmus posteriorly. In rodent, most of the typical subicular cortices are located in the dorsal and caudal portions of the hippocampal formation, and the modified version of the ventral ProS and Sub corresponds to the modified description of the uncal ProS and Sub in monkey and human. An interesting triangular region in rodent located at the juncture of the PoS, PaS, retrosplenial cortex, and visual cortex appears to be the equivalent of the monkey area prostriata. Major connections of the five subicular cortices are also summarized based on unified criteria discussed in this review, with distinct connections revealed between the ProS and the Sub. Copyright © 2013 Wiley Periodicals, Inc.

  13. Thalamic, brainstem, and cerebellar glucose metabolism in the hemiplegic monkey

    Energy Technology Data Exchange (ETDEWEB)

    Shimoyama, I.; Dauth, G.W.; Gilman, S.; Frey, K.A.; Penney, J.B. Jr.

    1988-12-01

    Unilateral ablation of cerebral cortical areas 4 and 6 of Brodmann in the macaque monkey results in a contralateral hemiplegia that resolves partially with time. During the phase of dense hemiplegia, local cerebral metabolic rate for glucose (1CMRG1c) is decreased significantly in most of the thalamic nuclei ipsilateral to the ablation, and there are slight contralateral decreases. The lCMRGlc is reduced bilaterally in most of the brainstem nuclei and bilaterally in the deep cerebellar nuclei, but only in the contralateral cerebellar cortex. During the phase of partial motor recovery, lCMRGlc is incompletely restored in many of the thalamic nuclei ipsilateral to the ablation and completely restored in the contralateral nuclei. In the brainstem and deep cerebellar nuclei, poor to moderate recovery occurs bilaterally. Moderate recovery occurs in the contralateral cerebellar cortex. The findings demonstrate that a unilateral cerebral cortical lesion strongly affects lCMRGlc in the thalamus ipsilaterally and in the cerebellar cortex contralaterally, but in the brainstem bilaterally. Partial recovery of lCMRGlc accompanies the progressive motor recovery. The structures affected include those with direct, and also those with indirect, connections to the areas ablated.

  14. Insulin/IGF signaling-related gene expression in the brain of a sporadic Alzheimer's disease monkey model induced by intracerebroventricular injection of streptozotocin.

    Science.gov (United States)

    Lee, Youngjeon; Kim, Young-Hyun; Park, Sang-Je; Huh, Jae-Won; Kim, Sang-Hyun; Kim, Sun-Uk; Kim, Ji-Su; Jeong, Kang-Jin; Lee, Kyoung-Min; Hong, Yonggeun; Lee, Sang-Rae; Chang, Kyu-Tae

    2014-01-01

    We reported previously that the intracerebroventricular streptozotocin (icv-STZ)-treated cynomolgus monkey showed regionally specific glucose hypometabolism in FDG-PET imaging, similar to that observed in the early stages of sporadic Alzheimer's disease (sAD). However, further pathological analyses of this model at the molecular level are needed to validate it as a feasible model for sAD. Two cynomolgus monkeys were injected with 2 mg/kg STZ into the cerebellomedullary cistern at day 1, 7 and 14. Two control monkeys were given normal saline. At 5 months after injection, the expression levels of genes encoding 9 upstream molecules in insulin/insulin-like growth factor (IGF) signaling and markers for 4 cell-type populations in the frontal cortex, hippocampus, posterior cingulate, precuneus, and occipital cortex of control and icv-STZ treated cynomolgus monkeys were examined. Real-time quantitative PCR analyses demonstrated that the overall mRNA expression of insulin/IGF signaling-related genes was mainly impaired in the anterior part of the cerebrum, frontal cortex, and hippocampus, similar to the early stage of sAD. The changes were accompanied by the loss of oligodendrocytes and neurons. The posterior part of the cerebrum did not show degenerative alterations. The present study provides important fundamental information on the icv-STZ monkey model for sAD. These results may help guide future studies using this model for the investigation of pathological mechanisms and the development of drugs for sAD.

  15. Cup tool use by squirrel monkeys.

    Science.gov (United States)

    Buckmaster, Christine L; Hyde, Shellie A; Parker, Karen J; Lyons, David M

    2015-12-01

    Captive-born male and female squirrel monkeys spontaneously 'invented' a cup tool use technique to Contain (i.e., hold and control) food they reduced into fragments for consumption and to Contain water collected from a valve to drink. Food cup use was observed more frequently than water cup use. Observations indicate that 68% (n = 39/57) of monkeys in this population used a cup (a plastic slip cap) to Contain food, and a subset of these monkeys, 10% (n = 4/39), also used a cup to Contain water. Cup use was optional and did not replace, but supplemented, the hand/arm-to-mouth eating and direct valve drinking exhibited by all members of the population. Strategies monkeys used to bring food and cups together for food processing activity at preferred upper-level perching areas, in the arboreal-like environment in which they lived, provides evidence that monkeys may plan food processing activity with the cups. Specifically, prior to cup use monkeys obtained a cup first before food, or obtained food and a cup from the floor simultaneously, before transporting both items to upper-level perching areas. After food processing activity with cups monkeys rarely dropped the cups and more often placed the cups onto perching. Monkeys subsequently returned to use cups that they previously placed on perching after food processing activity. The latter behavior is consistent with the possibility that monkeys may keep cups at preferred perching sites for future food processing activity and merits experimental investigation. Reports of spontaneous tool use by squirrel monkeys are rare and this is the first report of population-level tool use. These findings offer insights into the cognitive abilities of squirrel monkeys and provide a new context for behavior studies with this genus and for comparative studies with other primates. © 2015 Wiley Periodicals, Inc.

  16. The nucleus pararaphales in the human, chimpanzee, and macaque monkey.

    Science.gov (United States)

    Baizer, Joan S; Weinstock, Nadav; Witelson, Sandra F; Sherwood, Chet C; Hof, Patrick R

    2013-03-01

    The human cerebral cortex and cerebellum are greatly expanded compared to those of other mammals, including the great apes. This expansion is reflected in differences in the size and organization of precerebellar brainstem structures, such as the inferior olive. In addition, there are cell groups unique to the human brainstem. One such group may be the nucleus pararaphales (PRa); however, there is disagreement among authors about the size and location of this nucleus in the human brainstem. The name "pararaphales" has also been used for neurons in the medulla shown to project to the flocculus in the macaque monkey. We have re-examined the existence and status of the PRa in eight humans, three chimpanzees, and four macaque monkeys using Nissl-stained sections as well as immunohistochemistry. In the human we found a cell group along the midline of the medulla in all cases; it had the form of interrupted cell columns and was variable among cases in rostrocaudal and dorsoventral extent. Cells and processes were highly immunoreactive for non-phosphorylated neurofilament protein (NPNFP); somata were immunoreactive to the synthetic enzyme for nitric oxide, nitric oxide synthase, and for calretinin. In macaque monkey, there was a much smaller oval cell group with NPNFP immunoreactivity. In the chimpanzee, we found a region of NPNFP-immunoreactive cells and fibers similar to what was observed in macaques. These results suggest that the "PRa" in the human may not be the same structure as the flocculus-projecting cell group described in the macaque. The PRa, like the arcuate nucleus, therefore may be unique to humans.

  17. Spider monkey, Muriqui and Woolly monkey relationships revisited.

    Science.gov (United States)

    de Lima, Margarida Maria Celeira; Sampaio, Iracilda; Vieira, Ricardo dos Santos; Schneider, Horacio

    2007-01-01

    The taxonomic relationships among the four genera of the Atelidae family, Alouatta (Howler), Ateles (Spider), Lagothrix (Woolly) and Brachyteles (Muriqui), have been the subject of great debate. In general, almost all authors agree with the assignment of Howler monkeys as the basal genus, either in its own tribe Alouattini or in the subfamily Alouattinae, but they disagree on the associations among the other members of the family. Muriquis have been grouped with Spider monkeys based on the fact that they share various behavioral and morphological characteristics. Cladistic analyses using morphological, biochemical, karyotype and behavioral characteristics depicted a phylogenetic tree that places Howler as the basal genus and the remaining genera in an unresolved politomy. More recent studies using molecular data have suggested that Muriqui and Woolly monkeys are sister groups. However, a recent study based on nuclear and mtDNA argued that politomy is what best represents the relationships among Spider, Woolly and Muriqui. To contribute to this debate we have added new data from two nuclear genes, Transferrin and von Willebrand Factor, and using an alignment of 17,997 bp we demonstrate that a total analysis strongly supports the Muriqui-Woolly clade. A gene-to-gene approach showed that four of the eight nuclear genes provide support for the Muriqui-Woolly clade, two strongly and two moderately, while none of the eight genes provide support for any alternative arrangement. The mitochondrial genes were not able to resolve the politomy. A possible reason for the difficulty in resolving atelid relationships may be the short period of time separating each cladogenetic event in the evolutionary process that shaped this family.

  18. Maps of space in human frontoparietal cortex.

    Science.gov (United States)

    Jerde, Trenton A; Curtis, Clayton E

    2013-12-01

    Prefrontal cortex (PFC) and posterior parietal cortex (PPC) are neural substrates for spatial cognition. We here review studies in which we tested the hypothesis that human frontoparietal cortex may function as a priority map. According to priority map theory, objects or locations in the visual world are represented by neural activity that is proportional to their attentional priority. Using functional magnetic resonance imaging (fMRI), we first identified topographic maps in PFC and PPC as candidate priority maps of space. We then measured fMRI activity in candidate priority maps during the delay periods of a covert attention task, a spatial working memory task, and a motor planning task to test whether the activity depended on the particular spatial cognition. Our hypothesis was that some, but not all, candidate priority maps in PFC and PPC would be agnostic with regard to what was being prioritized, in that their activity would reflect the location in space across tasks rather than a particular kind of spatial cognition (e.g., covert attention). To test whether patterns of delay period activity were interchangeable during the spatial cognitive tasks, we used multivariate classifiers. We found that decoders trained to predict the locations on one task (e.g., working memory) cross-predicted the locations on the other tasks (e.g., covert attention and motor planning) in superior precentral sulcus (sPCS) and in a region of intraparietal sulcus (IPS2), suggesting that these patterns of maintenance activity may be interchangeable across the tasks. Such properties make sPCS in frontal cortex and IPS2 in parietal cortex viable priority map candidates, and suggest that these areas may be the human homologs of the monkey frontal eye field (FEF) and lateral intraparietal area (LIP). Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. The Intriguing Dual Lattices of the Myosin Filaments in Vertebrate Striated Muscles: Evolution and Advantage

    Directory of Open Access Journals (Sweden)

    Pradeep K. Luther

    2014-12-01

    Full Text Available Myosin filaments in vertebrate striated muscle have a long roughly cylindrical backbone with cross-bridge projections on the surfaces of both halves except for a short central bare zone. In the middle of this central region the filaments are cross-linked by the M-band which holds them in a well-defined hexagonal lattice in the muscle A-band. During muscular contraction the M-band-defined rotation of the myosin filaments around their long axes influences the interactions that the cross-bridges can make with the neighbouring actin filaments. We can visualise this filament rotation by electron microscopy of thin cross-sections in the bare-region immediately adjacent to the M-band where the filament profiles are distinctly triangular. In the muscles of teleost fishes, the thick filament triangular profiles have a single orientation giving what we call the simple lattice. In other vertebrates, for example all the tetrapods, the thick filaments have one of two orientations where the triangles point in opposite directions (they are rotated by 60° or 180° according to set rules. Such a distribution cannot be developed in an ordered fashion across a large 2D lattice, but there are small domains of superlattice such that the next-nearest neighbouring thick filaments often have the same orientation. We believe that this difference in the lattice forms can lead to different contractile behaviours. Here we provide a historical review, and when appropriate cite recent work related to the emergence of the simple and superlattice forms by examining the muscles of several species ranging back to primitive vertebrates and we discuss the functional differences that the two lattice forms may have.

  20. The gaseous plasmonic response of a one-dimensional photonic crystal composed of striated plasma layers

    Science.gov (United States)

    Wang, B.; Righetti, F.; Cappelli, M. A.

    2018-03-01

    We present simulations of the response of a one-dimensional striated plasma slab to incident electromagnetic waves that span regions both above and below the plasma frequency, ωp. Photonic bandgap modes are present throughout these regions, and volume and surface plasmon modes facilitate the response below ωp, where the dielectric constant, ɛp frequency, there is a feature for transverse magnetic (TM) polarization that is associated with the emergence of new dispersion branches. Also for TM polarization, a very low frequency mode emerges outside of the light line. Both these features are plasmonic and are attributed to the excitation of symmetric and asymmetric surface plasmon polaritons (SPPs) at the plasma-dielectric interface of the multi-layer plasma slabs. The features seen in the bandgap maps near ωp reveal the possible presence of Fano resonances between the symmetric branch of the SPP and the Bragg resonance as a narrow stop band (anti-node) is superimposed on the otherwise broad transmission band seen for transverse-electric polarization. We provide renderings that allow the visualization of where the transmission bands are and compute the transmittance and reflectance to facilitate the design and interpretation of experiments. The transmission bands associated with photonic bandgap modes above the plasma frequency are rather broad. The plasmonic modes, i.e., those associated with ɛp ≤ 0, can be quite narrow and are tuned by varying the plasma density, affording an opportunity for the application of these structures as ultra-narrow tunable microwave transmission filters.

  1. Autoshaping in Japanese Monkeys (Macaca Fuscata)

    OpenAIRE

    Itakura, Shoji; Fushimi, Takao; Asano, Toshio; Shoji, Itakura; Takao, Fushimi; Toshio, Asano

    1992-01-01

    Three Japanese monkeys were exposed to autoshaping and omission procedures. The Japanese momkeys seemed to be more sensitive to response-reinforcer contingency than to stimulus-reinforcer contingency. These results were compared with pigeons and squirrel monkeys in the previous reports.

  2. On Loss Aversion in Capuchin Monkeys

    Science.gov (United States)

    Silberberg, Alan; Roma, Peter G.; Huntsberry, Mary E.; Warren-Boulton, Frederick R.; Sakagami, Takayuki; Ruggiero, Angela M.; Suomi, Stephen J.

    2008-01-01

    Chen, Lakshminarayanan, and Santos (2006) claim to show in three choice experiments that monkeys react rationally to price and wealth shocks, but, when faced with gambles, display hallmark, human-like biases that include loss aversion. We present three experiments with monkeys and humans consistent with a reinterpretation of their data that…

  3. Contributions of Lateral and Orbital Frontal Regions to Abstract Rule Acquisition and Reversal in Monkeys

    Science.gov (United States)

    La Camera, Giancarlo; Bouret, Sebastien; Richmond, Barry J.

    2018-01-01

    The ability to learn and follow abstract rules relies on intact prefrontal regions including the lateral prefrontal cortex (LPFC) and the orbitofrontal cortex (OFC). Here, we investigate the specific roles of these brain regions in learning rules that depend critically on the formation of abstract concepts as opposed to simpler input-output associations. To this aim, we tested monkeys with bilateral removals of either LPFC or OFC on a rapidly learned task requiring the formation of the abstract concept of same vs. different. While monkeys with OFC removals were significantly slower than controls at both acquiring and reversing the concept-based rule, monkeys with LPFC removals were not impaired in acquiring the task, but were significantly slower at rule reversal. Neither group was impaired in the acquisition or reversal of a delayed visual cue-outcome association task without a concept-based rule. These results suggest that OFC is essential for the implementation of a concept-based rule, whereas LPFC seems essential for its modification once established. PMID:29615854

  4. Selective bilateral amygdala lesions in rhesus monkeys fail to disrupt object reversal learning.

    Science.gov (United States)

    Izquierdo, Alicia; Murray, Elisabeth A

    2007-01-31

    Neuropsychological studies in nonhuman primates have led to the view that the amygdala plays an essential role in stimulus-reward association. The main evidence in support of this idea is that bilateral aspirative or radiofrequency lesions of the amygdala yield severe impairments on object reversal learning, a task that assesses the ability to shift choices of objects based on the presence or absence of food reward (i.e., reward contingency). The behavioral effects of different lesion techniques, however, can vary. The present study therefore evaluated the effects of selective, excitotoxic lesions of the amygdala in rhesus monkeys on object reversal learning. For comparison, we tested the same monkeys on a task known to be sensitive to amygdala damage, the reinforcer devaluation task. Contrary to previous results based on less selective lesion techniques, monkeys with complete excitotoxic amygdala lesions performed object reversal learning as quickly as controls. As predicted, however, the same operated monkeys were impaired in making object choices after devaluation of the associated food reinforcer. The results suggest two conclusions. First, the results demonstrate that the amygdala makes a selective contribution to stimulus-reward association; the amygdala is critical for guiding object choices after changes in reward value but not after changes in reward contingency. Second, the results implicate a critical contribution to object reversal learning of structures nearby the amygdala, perhaps the subjacent rhinal cortex.

  5. Single neurons in prefrontal cortex encode abstract rules.

    Science.gov (United States)

    Wallis, J D; Anderson, K C; Miller, E K

    2001-06-21

    The ability to abstract principles or rules from direct experience allows behaviour to extend beyond specific circumstances to general situations. For example, we learn the 'rules' for restaurant dining from specific experiences and can then apply them in new restaurants. The use of such rules is thought to depend on the prefrontal cortex (PFC) because its damage often results in difficulty in following rules. Here we explore its neural basis by recording from single neurons in the PFC of monkeys trained to use two abstract rules. They were required to indicate whether two successively presented pictures were the same or different depending on which rule was currently in effect. The monkeys performed this task with new pictures, thus showing that they had learned two general principles that could be applied to stimuli that they had not yet experienced. The most prevalent neuronal activity observed in the PFC reflected the coding of these abstract rules.

  6. Dorsal premotor cortex: neural correlates of reach target decisions based on a color-location matching rule and conflicting sensory evidence

    OpenAIRE

    Coallier, Émilie; Michelet, Thomas; Kalaska, John F.

    2015-01-01

    We recorded single-neuron activity in dorsal premotor (PMd) and primary motor cortex (M1) of two monkeys in a reach-target selection task. The monkeys chose between two color-coded potential targets by determining which target's color matched the predominant color of a multicolored checkerboard-like Decision Cue (DC). Different DCs contained differing numbers of colored squares matching each target. The DCs provided evidence about the correct target ranging from unambiguous (one color only) t...

  7. Increased hypoxia-inducible factor-1α in striated muscle of tumor-bearing mice.

    Science.gov (United States)

    Devine, Raymond D; Bicer, Sabahattin; Reiser, Peter J; Wold, Loren E

    2017-06-01

    that occur during cancer cachexia. NEW & NOTEWORTHY We used proteomics and metadata analysis software to identify contributors to metabolic changes in striated muscle during cancer cachexia. We found increased expression of hypoxia-inducible factor-1α in the heart and skeletal muscle, suggesting a potential target for the therapeutic treatment of cancer cachexia. Copyright © 2017 the American Physiological Society.

  8. Striated nephrogram as an incidental finding in MRI examination of children; Streifiges Nephrogramm als Zufallsbefund nach Kontrastmittelgabe bei Kindern in der MRT

    Energy Technology Data Exchange (ETDEWEB)

    Strocka, S.; Sorge, I.; Ritter, L.; Hirsch, F.W. [Leipzig Univ. (Germany). Dept. of Pediatric Radiology

    2016-01-15

    A highly striated contrast pattern of the kidneys occasionally appears in abdominal MRI examinations of children following the administration of gadolinium. As this phenomenon is well known but has not yet been explicitly described in literature, we investigated how frequently and in which clinical context this occurred. 855 abdominal MRI examinations with contrast media of 362 children between 2006 and 2014 were analysed retrospectively. A striated renal parenchyma was found in a total of nine children and eleven examinations (1.3 % of examinations) and did only occur at a field strength of 3 Tesla. Of these children, seven had previously had tumors and chemotherapy. In two children there was no evidence of a previously serious condition with medications or a kidney disease. All of them had a normal renal function. A noticeably striated nephrogram in the later phase of an MRI examination following administration of gadolinium may appear as an incidental finding in examinations at 3 Tesla without pathological relevance.

  9. 31P saturation transfer and phosphocreatine imaging in the monkey brain

    International Nuclear Information System (INIS)

    Mora, B.; Narasimhan, P.T.; Ross, B.D.; Allman, J.; Barker, P.B.

    1991-01-01

    31 P magnetic resonance imaging with chemical-shift discrimination by selective excitation has been employed to determine the phosphocreatine (PCr) distribution in the brains of three juvenile macaque monkeys. PCr images were also obtained while saturating the resonance of the γ-phosphate of ATP, which allowed the investigation of the chemical exchange between PCr and the γ-phosphate of ATP catalyzed by creatine kinase. Superposition of the PCr images over the proton image of the same monkey brain revealed topological variations in the distribution of PCr and creatine kinase activity. PCr images were also obtained with and without visual stimulation. In two out of four experiments, an apparently localized decrease in PCr concentration was noted in visual cortex upon visual stimulation. This result is interpreted in terms of a possible role for the local ADP concentration in stimulating the accompanying metabolic response

  10. Modeling vocalization with ECoG cortical activity recorded during vocal production in the macaque monkey.

    Science.gov (United States)

    Fukushima, Makoto; Saunders, Richard C; Fujii, Naotaka; Averbeck, Bruno B; Mishkin, Mortimer

    2014-01-01

    Vocal production is an example of controlled motor behavior with high temporal precision. Previous studies have decoded auditory evoked cortical activity while monkeys listened to vocalization sounds. On the other hand, there have been few attempts at decoding motor cortical activity during vocal production. Here we recorded cortical activity during vocal production in the macaque with a chronically implanted electrocorticographic (ECoG) electrode array. The array detected robust activity in motor cortex during vocal production. We used a nonlinear dynamical model of the vocal organ to reduce the dimensionality of `Coo' calls produced by the monkey. We then used linear regression to evaluate the information in motor cortical activity for this reduced representation of calls. This simple linear model accounted for circa 65% of the variance in the reduced sound representations, supporting the feasibility of using the dynamical model of the vocal organ for decoding motor cortical activity during vocal production.

  11. Nuclear weapon testing and the monkey business

    International Nuclear Information System (INIS)

    Murthy, M.S.S.

    1978-01-01

    Reasons for India's total ban on the export of rhesus monkeys to U.S. have been explained. The major reason is that some of the animals were used in nuclear weapon related radiation experiments. This was a clear violation of a stricture in the agreement about supply of monkeys. The stricture prohibited the use of animals for research concerning military operations, including nuclear weapon testing. It is pleaded that a strict enforcement of strictures rather than a total ban on the export of monkeys would be better in the interest of advancement of knowledge in human medicine and disease control. (M.G.B.)

  12. Contracture Coupling of Slow Striated Muscle in Non-Ionic Solutions and Replacement of Calcium, Sodium, and Potassium

    Science.gov (United States)

    Irwin, Richard L.; Hein, Manfred M.

    1964-01-01

    The development of contracture related to changes of ionic environment (ionic contracture coupling) has been studied in the slowly responding fibers of frog skeletal muscle. When deprived of external ions for 30 minutes by use of solutions of sucrose, mannitol, or glucose, the slow skeletal muscle fibers, but not the fast, develop pronounced and easily reversible contractures. Partial replacement of the non-ionic substance with calcium or sodium reduces the development of the contractures but replacement by potassium does not. The concentration of calcium necessary to prevent contracture induced by a non-ionic solution is greater than that needed to maintain relaxation in ionic solutions. To suppress the non-ionic-induced contractures to the same extent as does calcium requires several fold higher concentrations of sodium. Two types of ionic contracture coupling occur in slow type striated muscle fibers: (a) a calcium deprivation type which develops maximally at full physiological concentration of external sodium, shows a flow rate dependency for the calcium-depriving fluid, and is lessened when the sodium concentration is decreased by replacement with sucrose; (b) a sodium deprivation type which occurs maximally without external sodium, is lessened by increasing the sodium concentration, and has no flow rate dependency for ion deprivation. Both types of contracture are largely prevented by the presence of sufficient calcium. There thus seem to be calcium- and sodium-linked processes at work in the ionic contracture coupling of slow striated muscle. PMID:14127603

  13. VAPB/ALS8 MSP ligands regulate striated muscle energy metabolism critical for adult survival in caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Sung Min Han

    Full Text Available Mutations in VAPB/ALS8 are associated with amyotrophic lateral sclerosis (ALS and spinal muscular atrophy (SMA, two motor neuron diseases that often include alterations in energy metabolism. We have shown that C. elegans and Drosophila neurons secrete a cleavage product of VAPB, the N-terminal major sperm protein domain (vMSP. Secreted vMSPs signal through Roundabout and Lar-like receptors expressed on striated muscle. The muscle signaling pathway localizes mitochondria to myofilaments, alters their fission/fusion balance, and promotes energy production. Here, we show that neuronal loss of the C. elegans VAPB homolog triggers metabolic alterations that appear to compensate for muscle mitochondrial dysfunction. When vMSP levels drop, cytoskeletal or mitochondrial abnormalities in muscle induce elevated DAF-16, the Forkhead Box O (FoxO homolog, transcription factor activity. DAF-16 promotes muscle triacylglycerol accumulation, increases ATP levels in adults, and extends lifespan, despite reduced muscle mitochondria electron transport chain activity. Finally, Vapb knock-out mice exhibit abnormal muscular triacylglycerol levels and FoxO target gene transcriptional responses to fasting and refeeding. Our data indicate that impaired vMSP signaling to striated muscle alters FoxO activity, which affects energy metabolism. Abnormalities in energy metabolism of ALS patients may thus constitute a compensatory mechanism counterbalancing skeletal muscle mitochondrial dysfunction.

  14. Cytogenesis in the monkey retina

    International Nuclear Information System (INIS)

    La Vail, M.M.; Rapaport, D.H.; Rakic, P.

    1991-01-01

    Time of cell origin in the retina of the rhesus monkey (Macaca mulatta) was studied by plotting the number of heavily radiolabeled nuclei in autoradiograms prepared from 2- to 6-month-old animals, each of which was exposed to a pulse of 3H-thymidine (3H-TdR) on a single embryonic (E) or postnatal (P) day. Cell birth in the monkey retina begins just after E27, and approximately 96% of cells are generated by E120. The remaining cells are produced during the last (approximately 45) prenatal days and into the first several weeks after birth. Cell genesis begins near the fovea, and proceeds towards the periphery. Cell division largely ceases in the foveal and perifoveal regions by E56. Despite extensive overlap, a class-specific sequence of cell birth was observed. Ganglion and horizontal cells, which are born first, have largely congruent periods of cell genesis with the peak between E38 and E43, and termination around E70. The first labeled cones were apparent by E33, and their highest density was achieved between E43 and E56, tapering to low values at E70, although some cones are generated in the far periphery as late as E110. Amacrine cells are next in the cell birth sequence and begin genesis at E43, reach a peak production between E56 and E85, and cease by E110. Bipolar cell birth begins at the same time as amacrines, but appears to be separate from them temporally since their production reaches a peak between E56 and E102, and persists beyond the day of birth. Mueller cells and rod photoreceptors, which begin to be generated at E45, achieve a peak, and decrease in density at the same time as bipolar cells, but continue genesis at low density on the day of birth. Thus, bipolar, Mueller, and rod cells have a similar time of origin

  15. PET measurement of FK506 concentration in a monkey model of stroke

    International Nuclear Information System (INIS)

    Murakami, Yoshihiro; Takamatsu, Hiroyuki; Noda, Akihiro; Osoda, Kazuhiko; Nishimura, Shintaro

    2007-01-01

    Introduction: The immunosuppressive agent FK506 (tacrolimus) has neuroprotective properties in an experimental model of cerebral ischemia. To improve the accuracy of clinical studies in acute stroke, a clinical dose setting should be based on the brain concentration, but not on the blood concentration of agents in humans. We have already established a measurement method using PET for FK506 concentration in the normal monkey brain, which could be applicable for human study; however, under ischemic conditions, in this study, we aimed to examine the brain concentration of FK506 in a monkey model of stroke. Methods: Studies were performed on six male cynomolgus monkeys (Macaca fascicularis) and a middle cerebral artery (MCA) occlusion model was used. Regional cerebral blood flow (rCBF) was measured by an intravenous injection of [ 15 O]H 2 O 165 min after MCA occlusion. FK506 (0.1 mg/kg) containing [ 11 C]FK506 was intravenously injected into the monkeys 180 min after MCA occlusion, and dynamic PET images were acquired for 30 min after administration. FK506 concentrations in the brain were calculated in moles per liter (M) units using the specific activity of injected FK506. Results: MCA occlusion produced ischemia, confirmed by rCBF measurement before the administration of [ 11 C]FK506. Fifteen minutes after FK506 (0.1 mg/kg) administration, the concentrations in the contralateral and ipsilateral cortex were 22.4±6.4 and 19.7±4.0 ng/g, respectively. Conclusion: We successfully measured the brain concentration of FK506 in a monkey model of stroke. The difference between the contralateral and ipsilateral concentrations of FK506 was not significant. This characteristic that FK506 readily penetrates ischemic tissue as well as normal tissue might explain the neuroprotective effect of FK506 in the ischemic brain and is suitable for the treatment of stroke patients

  16. Long-term effects of neonatal medial temporal ablations on socioemotional behavior in monkeys

    Science.gov (United States)

    Málková, Ludise; Mishkin, Mortimer; Suomi, Stephen J.; Bachevalier, Jocelyne

    2010-01-01

    Socioemotional abnormalities, including low levels of social interaction and high levels of self-directed activity, were reported when rhesus monkeys with neonatal ablations of either the medial temporal lobe (AH) or the inferior temporal cortex (TE) were paired with unoperated peers at two and six months of age, though these abnormalities were more severe in the AH group (Bachevalier et al., 2001). As they reached adulthood (Experiment 1), the same monkeys were re-evaluated in the same dyads and their reactivity to novel toys, social status, and reactions to separation from age-matched peers were also assessed. Group TE now showed few if any of the abnormal behaviors observed when they were infants. By contrast, Group AH continued to display low levels of social interaction, high levels of self-directed activity and submissive behavior, and reduced responses to separation, although they reacted normally to novel toys. To determine whether this degree of socioemotional impairment was less severe than that produced by the same damage in adulthood, we assessed dyadic social interactions of monkeys raised until adulthood in laboratory conditions similar to those of the earlier groups and then given the AH ablation (Experiment 2). Two months postoperatively these adult-lesioned monkeys showed a small reduction in social interactions that became more pronounced six months postoperatively, yet remained less severe than that seen in the infant-lesioned monkeys. Also, except for an increase in food and water consumption throughout this 6-month period, they showed no other socioemotional effects. The finding that neonatal AH lesions produce more severe socioemotional disturbances than the same lesion in adulthood is the reverse of the effect commonly reported for other cognitive functions after cerebral damage. PMID:21133531

  17. Basic Math in Monkeys and College Students

    OpenAIRE

    Beran, Michael J

    2008-01-01

    Recent behavioral and neuroimaging studies with humans and monkeys provide compelling evidence of shared numerical capacities across species. Our understanding of the emergence of human mathematical competence is well-served by these kinds of comparative assessments.

  18. Neural correlates of auditory short-term memory in rostral superior temporal cortex.

    Science.gov (United States)

    Scott, Brian H; Mishkin, Mortimer; Yin, Pingbo

    2014-12-01

    Auditory short-term memory (STM) in the monkey is less robust than visual STM and may depend on a retained sensory trace, which is likely to reside in the higher-order cortical areas of the auditory ventral stream. We recorded from the rostral superior temporal cortex as monkeys performed serial auditory delayed match-to-sample (DMS). A subset of neurons exhibited modulations of their firing rate during the delay between sounds, during the sensory response, or during both. This distributed subpopulation carried a predominantly sensory signal modulated by the mnemonic context of the stimulus. Excitatory and suppressive effects on match responses were dissociable in their timing and in their resistance to sounds intervening between the sample and match. Like the monkeys' behavioral performance, these neuronal effects differ from those reported in the same species during visual DMS, suggesting different neural mechanisms for retaining dynamic sounds and static images in STM. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Language networks in anophthalmia: maintained hierarchy of processing in 'visual' cortex.

    Science.gov (United States)

    Watkins, Kate E; Cowey, Alan; Alexander, Iona; Filippini, Nicola; Kennedy, James M; Smith, Stephen M; Ragge, Nicola; Bridge, Holly

    2012-05-01

    Imaging studies in blind subjects have consistently shown that sensory and cognitive tasks evoke activity in the occipital cortex, which is normally visual. The precise areas involved and degree of activation are dependent upon the cause and age of onset of blindness. Here, we investigated the cortical language network at rest and during an auditory covert naming task in five bilaterally anophthalmic subjects, who have never received visual input. When listening to auditory definitions and covertly retrieving words, these subjects activated lateral occipital cortex bilaterally in addition to the language areas activated in sighted controls. This activity was significantly greater than that present in a control condition of listening to reversed speech. The lateral occipital cortex was also recruited into a left-lateralized resting-state network that usually comprises anterior and posterior language areas. Levels of activation to the auditory naming and reversed speech conditions did not differ in the calcarine (striate) cortex. This primary 'visual' cortex was not recruited to the left-lateralized resting-state network and showed high interhemispheric correlation of activity at rest, as is typically seen in unimodal cortical areas. In contrast, the interhemispheric correlation of resting activity in extrastriate areas was reduced in anophthalmia to the level of cortical areas that are heteromodal, such as the inferior frontal gyrus. Previous imaging studies in the congenitally blind show that primary visual cortex is activated in higher-order tasks, such as language and memory to a greater extent than during more basic sensory processing, resulting in a reversal of the normal hierarchy of functional organization across 'visual' areas. Our data do not support such a pattern of organization in anophthalmia. Instead, the patterns of activity during task and the functional connectivity at rest are consistent with the known hierarchy of processing in these areas

  20. Cognitive Control Signals in Posterior Cingulate Cortex

    Directory of Open Access Journals (Sweden)

    Benjamin eHayden

    2010-12-01

    Full Text Available Efficiently shifting between tasks is a central function of cognitive control. The role of the default network—a constellation of areas with high baseline activity that declines during task performance—in cognitive control remains poorly understood. We hypothesized that task switching demands cognitive control to shift the balance of processing towards the external world, and therefore predicted that switching between the two tasks would require suppression of activity of neurons within the CGp. To test this idea, we recorded the activity of single neurons in posterior cingulate cortex (CGp, a central node in the default network, in monkeys performing two interleaved tasks. As predicted, we found that basal levels of neuronal activity were reduced following a switch from one task to another and gradually returned to pre-switch baseline on subsequent trials. We failed to observe these effects in lateral intraparietal cortex (LIP, part of the dorsal fronto-parietal cortical attention network directly connected to CGp. These findings indicate that suppression of neuronal activity in CGp facilitates cognitive control, and suggest that activity in the default network reflects processes that directly compete with control processes elsewhere in the brain..

  1. Newly Identified CYP2C93 Is a Functional Enzyme in Rhesus Monkey, but Not in Cynomolgus Monkey

    OpenAIRE

    Uno, Yasuhiro; Uehara, Shotaro; Kohara, Sakae; Iwasaki, Kazuhide; Nagata, Ryoichi; Fukuzaki, Koichiro; Utoh, Masahiro; Murayama, Norie; Yamazaki, Hiroshi

    2011-01-01

    Cynomolgus monkey and rhesus monkey are used in drug metabolism studies due to their evolutionary closeness and physiological resemblance to human. In cynomolgus monkey, we previously identified cytochrome P450 (P450 or CYP) 2C76 that does not have a human ortholog and is partly responsible for species differences in drug metabolism between cynomolgus monkey and human. In this study, we report characterization of CYP2C93 cDNA newly identified in cynomolgus monkey and rhesus monkey. The CYP2C9...

  2. Hierarchical auditory processing directed rostrally along the monkey's supratemporal plane.

    Science.gov (United States)

    Kikuchi, Yukiko; Horwitz, Barry; Mishkin, Mortimer

    2010-09-29

    Connectional anatomical evidence suggests that the auditory core, containing the tonotopic areas A1, R, and RT, constitutes the first stage of auditory cortical processing, with feedforward projections from core outward, first to the surrounding auditory belt and then to the parabelt. Connectional evidence also raises the possibility that the core itself is serially organized, with feedforward projections from A1 to R and with additional projections, although of unknown feed direction, from R to RT. We hypothesized that area RT together with more rostral parts of the supratemporal plane (rSTP) form the anterior extension of a rostrally directed stimulus quality processing stream originating in the auditory core area A1. Here, we analyzed auditory responses of single neurons in three different sectors distributed caudorostrally along the supratemporal plane (STP): sector I, mainly area A1; sector II, mainly area RT; and sector III, principally RTp (the rostrotemporal polar area), including cortex located 3 mm from the temporal tip. Mean onset latency of excitation responses and stimulus selectivity to monkey calls and other sounds, both simple and complex, increased progressively from sector I to III. Also, whereas cells in sector I responded with significantly higher firing rates to the "other" sounds than to monkey calls, those in sectors II and III responded at the same rate to both stimulus types. The pattern of results supports the proposal that the STP contains a rostrally directed, hierarchically organized auditory processing stream, with gradually increasing stimulus selectivity, and that this stream extends from the primary auditory area to the temporal pole.

  3. Sensory experience modifies feature map relationships in visual cortex

    Science.gov (United States)

    Cloherty, Shaun L; Hughes, Nicholas J; Hietanen, Markus A; Bhagavatula, Partha S

    2016-01-01

    The extent to which brain structure is influenced by sensory input during development is a critical but controversial question. A paradigmatic system for studying this is the mammalian visual cortex. Maps of orientation preference (OP) and ocular dominance (OD) in the primary visual cortex of ferrets, cats and monkeys can be individually changed by altered visual input. However, the spatial relationship between OP and OD maps has appeared immutable. Using a computational model we predicted that biasing the visual input to orthogonal orientation in the two eyes should cause a shift of OP pinwheels towards the border of OD columns. We then confirmed this prediction by rearing cats wearing orthogonally oriented cylindrical lenses over each eye. Thus, the spatial relationship between OP and OD maps can be modified by visual experience, revealing a previously unknown degree of brain plasticity in response to sensory input. DOI: http://dx.doi.org/10.7554/eLife.13911.001 PMID:27310531

  4. Connectivity-based parcellation of the human orbitofrontal cortex.

    Science.gov (United States)

    Kahnt, Thorsten; Chang, Luke J; Park, Soyoung Q; Heinzle, Jakob; Haynes, John-Dylan

    2012-05-02

    The primate orbitofrontal cortex (OFC) is involved in reward processing, learning, and decision making. Research in monkeys has shown that this region is densely connected with higher sensory, limbic, and subcortical regions. Moreover, a parcellation of the monkey OFC into two subdivisions has been suggested based on its intrinsic anatomical connections. However, in humans, little is known about any functional subdivisions of the OFC except for a rather coarse medial/lateral distinction. Here, we used resting-state fMRI in combination with unsupervised clustering techniques to investigate whether OFC subdivisions can be revealed based on their functional connectivity profiles with other brain regions. Examination of different cluster solutions provided support for a parcellation into two parts as observed in monkeys, but it also highlighted a much finer hierarchical clustering of the orbital surface. Specifically, we identified (1) a medial, (2) a posterior-central, (3) a central, and (4-6) three lateral clusters spanning the anterior-posterior gradient. Consistent with animal tracing studies, these OFC clusters were connected to other cortical regions such as prefrontal, temporal, and parietal cortices but also subcortical areas in the striatum and the midbrain. These connectivity patterns provide important implications for identifying specific functional roles of OFC subdivisions for reward processing, learning, and decision making. Moreover, this parcellation schema can provide guidance to report results in future studies.

  5. Study of the striated nature of a glow discharge.; Estudio de la naturaleza estratificada de una descarga de resplandor.

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez A, M

    1995-10-01

    In an investigation in progress here, plasma diagnostics and detection of standing and moving striations is being made in a discharge in Argon at pressures of 2 x 10{sup -1} to 9 x 10{sup -1} mb and currents of 2 to 9 m-amp inside an discharge tube. Measurement of the temperature of the electrons, the concentration of electrons and the plasma potential are obtained in different places of the discharge by the double probe method, together with the computation system reported in [1]. In similar way an experimental work of the striated column in a discharge plasma to find the regimen of appearance of the standing and moving striations show some properties of moving striations (frequency and velocity) and standing striations. Two different oscilations are observed in motion in contrary directions along the discharge tube with a photomultiplier. (Author).

  6. Figure–ground organization and the emergence of proto-objects in the visual cortex

    OpenAIRE

    von der Heydt, Rüdiger

    2015-01-01

    A long history of studies of perception has shown that the visual system organizes the incoming information early on, interpreting the 2D image in terms of a 3D world and producing a structure that provides perceptual continuity and enables object-based attention. Recordings from monkey visual cortex show that many neurons, especially in area V2, are selective for border ownership. These neurons are edge selective and have ordinary classical receptive fields, but in addition their responses a...

  7. Differences between Neural Activity in Prefrontal Cortex and Striatum during Learning of Novel Abstract Categories

    OpenAIRE

    Antzoulatos, Evan G.; Miller, Earl K.

    2011-01-01

    Learning to classify diverse experiences into meaningful groups, like categories, is fundamental to normal cognition. To understand its neural basis, we simultaneously recorded from multiple electrodes in the lateral prefrontal cortex and dorsal striatum, two interconnected brain structures critical for learning. Each day, monkeys learned to associate novel, abstract dot-based categories with a right vs. left saccade. Early on, when they could acquire specific stimulus-response associations, ...

  8. Effects of muscarinic blockade in perirhinal cortex during visual recognition

    Science.gov (United States)

    Tang, Yi; Mishkin, Mortimer; Aigner, Thomas G.

    1997-01-01

    Stimulus recognition in monkeys is severely impaired by destruction or dysfunction of the perirhinal cortex and also by systemic administration of the cholinergic-muscarinic receptor blocker, scopolamine. These two effects are shown here to be linked: Stimulus recognition was found to be significantly impaired after bilateral microinjection of scopolamine directly into the perirhinal cortex, but not after equivalent injections into the laterally adjacent visual area TE or into the dentate gyrus of the overlying hippocampal formation. The results suggest that the formation of stimulus memories depends critically on cholinergic-muscarinic activation of the perirhinal area, providing a new clue to how stimulus representations are stored. PMID:9356507

  9. Dopamine D2 receptors in the cerebral cortex: Distribution and pharmacological characterization with [3H]raclopride

    International Nuclear Information System (INIS)

    Lidow, M.S.; Goldman-Rakic, P.S.; Rakic, P.; Innis, R.B.

    1989-01-01

    An apparent involvement of dopamine in the regulation of cognitive functions and the recognition of a widespread dopaminergic innervation of the cortex have focused attention on the identity of cortical dopamine receptors. However, only the presence and distribution of dopamine D 1 receptors in the cortex have been well documented. Comparable information on cortical D 2 sites is lacking. The authors report here the results of binding studied in the cortex and neostriatum of rat and monkey using the D 2 selective antagonist [ 3 H]raclopride. In both structures [ 3 H]raclopride bound in a sodium-dependent and saturable manner to a single population of sites with pharmacological profiles of dopamine D 2 receptors. D 2 sites were present in all regions of the cortex, although their density was much lower than in the neostriatum. The density of these sites in both monkey and, to a lesser extent, rat cortex displayed a rostral-caudal gradient with highest concentrations in the prefrontal and lowest concentrations in the occipital cortex, corresponding to dopamine levels in these areas. Thus, the present study established the presence and widespread distribution of dopamine D 2 receptors in the cortex

  10. Spontaneous high-gamma band activity reflects functional organization of auditory cortex in the awake macaque.

    Science.gov (United States)

    Fukushima, Makoto; Saunders, Richard C; Leopold, David A; Mishkin, Mortimer; Averbeck, Bruno B

    2012-06-07

    In the absence of sensory stimuli, spontaneous activity in the brain has been shown to exhibit organization at multiple spatiotemporal scales. In the macaque auditory cortex, responses to acoustic stimuli are tonotopically organized within multiple, adjacent frequency maps aligned in a caudorostral direction on the supratemporal plane (STP) of the lateral sulcus. Here, we used chronic microelectrocorticography to investigate the correspondence between sensory maps and spontaneous neural fluctuations in the auditory cortex. We first mapped tonotopic organization across 96 electrodes spanning approximately two centimeters along the primary and higher auditory cortex. In separate sessions, we then observed that spontaneous activity at the same sites exhibited spatial covariation that reflected the tonotopic map of the STP. This observation demonstrates a close relationship between functional organization and spontaneous neural activity in the sensory cortex of the awake monkey. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Somatosensory deficits in monkeys treated with misonidazole

    International Nuclear Information System (INIS)

    Maurissen, J.P.J.; Conroy, P.J.; Passalacqua, W.; Von Burg, R.; Weiss, B.; Sutherland, R.M.

    1981-01-01

    Misonidazole, a hypoxic cell radiosensitizer, can produce peripheral sensory disorders in humans. It has been studied in monkeys with a computer-controlled system for evaluating vibration sensitivity. Monkeys were trained to report when vibration was stimulating the finger tip. Sinusoidal vibrations of several frequencies were presented. Two monkeys were dosed with misonidazole and their vibration sensitivity tested. They received a dose of 3 g/m 2 (about 180 mg/kg) twice weekly over a period of 6 to 10 weeks. An amplitude-frequency detection function was determined for each monkey before and after drug treatment. An analysis of covariance comparing polynomial regressions was performed. A significant difference (p < 0.001) was found between control and experimental curves in both monkeys. Pharmacokinetic data indicated a half-life of the drug in blood of about 4 to 5 hr. The overall half-life for elimination did not increase throughout prolonged treatment with msonidazole. Neither motor nor sensory nerve conduction velocity was reduced after treatment

  12. The development of object recognition memory in rhesus macaques with neonatal lesions of the perirhinal cortex

    Directory of Open Access Journals (Sweden)

    Alyson Zeamer

    2015-02-01

    Full Text Available To investigate the role of the perirhinal cortex on the development of recognition measured by the visual paired-comparison (VPC task, infant monkeys with neonatal perirhinal lesions and sham-operated controls were tested at 1.5, 6, 18, and 48 months of age on the VPC task with color stimuli and intermixed delays of 10 s, 30 s, 60 s, and 120 s. Monkeys with neonatal perirhinal lesions showed an increase in novelty preference between 1.5 and 6 months of age similar to controls, although at these two ages, performance remained significantly poorer than that of control animals. With age, performance in animals with neonatal perirhinal lesions deteriorated as compared to that of controls. In contrast to the lack of novelty preference in monkeys with perirhinal lesions acquired in adulthood, novelty preference in the neonatally operated animals remained above chance at all delays and all ages. The data suggest that, although incidental recognition memory processes can be supported by the perirhinal cortex in early infancy, other temporal cortical areas may support these processes in the absence of a functional perirhinal cortex early in development. The neural substrates mediating incidental recognition memory processes appear to be more widespread in early infancy than in adulthood.

  13. Neuronal responses in visual area V2 (V2) of macaque monkeys with strabismic amblyopia.

    Science.gov (United States)

    Bi, H; Zhang, B; Tao, X; Harwerth, R S; Smith, E L; Chino, Y M

    2011-09-01

    Amblyopia, a developmental disorder of spatial vision, is thought to result from a cascade of cortical deficits over several processing stages beginning at the primary visual cortex (V1). However, beyond V1, little is known about how cortical development limits the visual performance of amblyopic primates. We quantitatively analyzed the monocular and binocular responses of V1 and V2 neurons in a group of strabismic monkeys exhibiting varying depths of amblyopia. Unlike in V1, the relative effectiveness of the affected eye to drive V2 neurons was drastically reduced in the amblyopic monkeys. The spatial resolution and the orientation bias of V2, but not V1, neurons were subnormal for the affected eyes. Binocular suppression was robust in both cortical areas, and the magnitude of suppression in individual monkeys was correlated with the depth of their amblyopia. These results suggest that the reduced functional connections beyond V1 and the subnormal spatial filter properties of V2 neurons might have substantially limited the sensitivity of the amblyopic eyes and that interocular suppression was likely to have played a key role in the observed alterations of V2 responses and the emergence of amblyopia.

  14. Monkey Bites among US Military Members, Afghanistan, 2011

    Science.gov (United States)

    Baker, Katheryn A.

    2012-01-01

    Bites from Macaca mulatta monkeys, native to Afghanistan, can cause serious infections. To determine risk for US military members in Afghanistan, we reviewed records for September–December 2011. Among 126 animal bites and exposures, 10 were monkey bites. Command emphasis is vital for preventing monkey bites; provider training and bite reporting promote postexposure treatment. PMID:23017939

  15. Basic math in monkeys and college students.

    Science.gov (United States)

    Cantlon, Jessica F; Brannon, Elizabeth M

    2007-12-01

    Adult humans possess a sophisticated repertoire of mathematical faculties. Many of these capacities are rooted in symbolic language and are therefore unlikely to be shared with nonhuman animals. However, a subset of these skills is shared with other animals, and this set is considered a cognitive vestige of our common evolutionary history. Current evidence indicates that humans and nonhuman animals share a core set of abilities for representing and comparing approximate numerosities nonverbally; however, it remains unclear whether nonhuman animals can perform approximate mental arithmetic. Here we show that monkeys can mentally add the numerical values of two sets of objects and choose a visual array that roughly corresponds to the arithmetic sum of these two sets. Furthermore, monkeys' performance during these calculations adheres to the same pattern as humans tested on the same nonverbal addition task. Our data demonstrate that nonverbal arithmetic is not unique to humans but is instead part of an evolutionarily primitive system for mathematical thinking shared by monkeys.

  16. Radiation-induced emesis in monkeys

    International Nuclear Information System (INIS)

    Mattsson, J.L.; Yochmowitz, M.G.

    1980-01-01

    To determine the emesis ED 50 for 60 Co radiation, 15 male rhesus monkeys were exposed to whole-body radiation doses ranging from 350 to 550 rad midline tissue dose. An up-and-down sequence of exposures was used. Step size between doses was 50 rad, and dose rate was 20 rad/min. There had been no access to food for 1 to 2 h. The ED 50 +- SE was found to be 446 +- 27 rad. To determine the effect of motion on emesis ED 50 , six more monkeys were exposed to 60 Co radiation as above, except that the chair in which they were seated was oscillated forward and backward 5 to 15 0 (pitch axis) at a variable rate not exceeding 0.3 Hz. Radioemesis ED 50 +- SE with motion was 258 +- 19 rad, a value significantly lower (P < 0.01) than for stationary monkeys

  17. Default Mode of Brain Function in Monkeys

    Science.gov (United States)

    Mantini, Dante; Gerits, Annelis; Nelissen, Koen; Durand, Jean-Baptiste; Joly, Olivier; Simone, Luciano; Sawamura, Hiromasa; Wardak, Claire; Orban, Guy A.; Buckner, Randy L.; Vanduffel, Wim

    2013-01-01

    Human neuroimaging has revealed a specific network of brain regions—the default-mode network (DMN)—that reduces its activity during goal-directed behavior. So far, evidence for a similar network in monkeys is mainly indirect, since, except for one positron emission tomography study, it is all based on functional connectivity analysis rather than activity increases during passive task states. Here, we tested whether a consistent DMN exists in monkeys using its defining property. We performed a meta-analysis of functional magnetic resonance imaging data collected in 10 awake monkeys to reveal areas in which activity consistently decreases when task demands shift from passive tasks to externally oriented processing. We observed task-related spatially specific deactivations across 15 experiments, implying in the monkey a functional equivalent of the human DMN. We revealed by resting-state connectivity that prefrontal and medial parietal regions, including areas 9/46d and 31, respectively, constitute the DMN core, being functionally connected to all other DMN areas. We also detected two distinct subsystems composed of DMN areas with stronger functional connections between each other. These clusters included areas 24/32, 8b, and TPOC and areas 23, v23, and PGm, respectively. Such a pattern of functional connectivity largely fits, but is not completely consistent with anatomical tract tracing data in monkeys. Also, analysis of afferent and efferent connections between DMN areas suggests a multisynaptic network structure. Like humans, monkeys increase activity during passive epochs in heteromodal and limbic association regions, suggesting that they also default to internal modes of processing when not actively interacting with the environment. PMID:21900574

  18. Cortico-cortical connections of areas 44 and 45B in the macaque monkey.

    Science.gov (United States)

    Frey, Stephen; Mackey, Scott; Petrides, Michael

    2014-04-01

    In the human brain, areas 44 and 45 constitute Broca's region, the ventrolateral frontal region critical for language production. The homologues of these areas in the macaque monkey brain have been established by direct cytoarchitectonic comparison with the human brain. The cortical areas that project monosynaptically to areas 44 and 45B in the macaque monkey brain require clarification. Fluorescent retrograde tracers were placed in cytoarchitectonic areas 44 and 45B of the macaque monkey, as well as in the anterior part of the inferior parietal lobule and the superior temporal gyrus. The results demonstrate that ipsilateral afferent connections of area 44 arise from local frontal areas, including rostral premotor cortical area 6, from secondary somatosensory cortex, the caudal insula, and the cingulate motor region. Area 44 is strongly linked with the anterior inferior parietal lobule (particularly area PFG and the adjacent anterior intraparietal sulcus). Input from the temporal lobe is limited to the fundus of the superior temporal sulcus extending caudal to the central sulcus. There is also input from the sulcal part of area Tpt in the upper bank of the superior temporal sulcus. Area 45B shares some of the connections of area 44, but can be distinguished from area 44 by input from the caudal inferior parietal lobule (area PG) and significant input from the part of the superior temporal sulcus that extends anterior to the central sulcus. Area 45B also receives input from visual association cortex that is not observed in area 44. The results have provided a clarification of the relative connections of areas 44 and 45B of the ventrolateral frontal region which, in the human brain, subserves certain aspects of language processing. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. No evidence for neo-oogenesis may link to ovarian senescence in adult monkey.

    Science.gov (United States)

    Yuan, Jihong; Zhang, Dongdong; Wang, Lei; Liu, Mengyuan; Mao, Jian; Yin, Yu; Ye, Xiaoying; Liu, Na; Han, Jihong; Gao, Yingdai; Cheng, Tao; Keefe, David L; Liu, Lin

    2013-11-01

    Female germline or oogonial stem cells transiently residing in fetal ovaries are analogous to the spermatogonial stem cells or germline stem cells (GSCs) in adult testes where GSCs and meiosis continuously renew. Oocytes can be generated in vitro from embryonic stem cells and induced pluripotent stem cells, but the existence of GSCs and neo-oogenesis in adult mammalian ovaries is less clear. Preliminary findings of GSCs and neo-oogenesis in mice and humans have not been consistently reproducible. Monkeys provide the most relevant model of human ovarian biology. We searched for GSCs and neo-meiosis in ovaries of adult monkeys at various ages, and compared them with GSCs from adult monkey testis, which are characterized by cytoplasmic staining for the germ cell marker DAZL and nuclear expression of the proliferative markers PCNA and KI67, and pluripotency-associated genes LIN28 and SOX2, and lack of nuclear LAMIN A, a marker for cell differentiation. Early meiocytes undergo homologous pairing at prophase I distinguished by synaptonemal complex lateral filaments with telomere perinuclear distribution. By exhaustive searching using comprehensive experimental approaches, we show that proliferative GSCs and neo-meiocytes by these specific criteria were undetectable in adult mouse and monkey ovaries. However, we found proliferative nongermline somatic stem cells that do not express LAMIN A and germ cell markers in the adult ovaries, notably in the cortex and granulosa cells of growing follicles. These data support the paradigm that adult ovaries do not undergo germ cell renewal, which may contribute significantly to ovarian senescence that occurs with age. Copyright © 2013 AlphaMed Press.

  20. MRI Overestimates Excitotoxic Amygdala Lesion Damage in Rhesus Monkeys

    Directory of Open Access Journals (Sweden)

    Benjamin M. Basile

    2017-06-01

    Full Text Available Selective, fiber-sparing excitotoxic lesions are a state-of-the-art tool for determining the causal contributions of different brain areas to behavior. For nonhuman primates especially, it is advantageous to keep subjects with high-quality lesions alive and contributing to science for many years. However, this requires the ability to estimate lesion extent accurately. Previous research has shown that in vivo T2-weighted magnetic resonance imaging (MRI accurately estimates damage following selective ibotenic acid lesions of the hippocampus. Here, we show that the same does not apply to lesions of the amygdala. Across 19 hemispheres from 13 rhesus monkeys, MRI assessment consistently overestimated amygdala damage as assessed by microscopic examination of Nissl-stained histological material. Two outliers suggested a linear relation for lower damage levels, and values of unintended amygdala damage from a previous study fell directly on that regression line, demonstrating that T2 hypersignal accurately predicts damage levels below 50%. For unintended damage, MRI estimates correlated with histological assessment for entorhinal cortex, perirhinal cortex and hippocampus, though MRI significantly overestimated the extent of that damage in all structures. Nevertheless, ibotenic acid injections routinely produced extensive intentional amygdala damage with minimal unintended damage to surrounding structures, validating the general success of the technique. The field will benefit from more research into in vivo lesion assessment techniques, and additional evaluation of the accuracy of MRI assessment in different brain areas. For now, in vivo MRI assessment of ibotenic acid lesions of the amygdala can be used to confirm successful injections, but MRI estimates of lesion extent should be interpreted with caution.

  1. Laparoscopic adrenal cortex

    International Nuclear Information System (INIS)

    Peyrolou, A.; Salom, A.; Harguindeguy; Taroco, L.; Ardao, G.; Broli, F. . E mail: andresssss@adinet.com.uy

    2005-01-01

    The paper presents the case of a female patient who carried an aldosterone-secreting tumor of adrenal cortex.In the analysis of diagnosis and para clinical examinations there is particular reference to the laparoscopic surgery mode of treatment.Diagnosis should be established on the basis of clinical and laboratory tests (hypopotassemia and hyperaldosteronism).Tumor topography was confirmed through CT scan, MRI and Scintiscan in left adrenal cortex.Resection was consequently made through laparoscopic surgery.The patients evolution was excellent from the surgical viewpoint,with I levels of blood pressure, potassium and aldosterone returned to normal

  2. Two-dimensional receptive-field organization in striate cortical neurons of the cat.

    Science.gov (United States)

    Sun, M; Bonds, A B

    1994-01-01

    The two-dimensional organization of receptive fields (RFs) of 44 cells in the cat visual cortex and four cells from the cat LGN was measured by stimulation with either dots or bars of light. The light bars were presented in different positions and orientations centered on the RFs. The RFs found were arbitrarily divided into four general types: Punctate, resembling DOG filters (11%); those resembling Gabor filters (9%); elongate (36%); and multipeaked-type (44%). Elongate RFs, usually found in simple cells, could show more than one excitatory band or bifurcation of excitatory regions. Although regions inhibitory to a given stimulus transition (e.g. ON) often coincided with regions excitatory to the opposite transition (e.g. OFF), this was by no means the rule. Measurements were highly repeatable and stable over periods of at least 1 h. A comparison between measurements made with dots and with bars showed reasonable matches in about 40% of the cases. In general, bar-based measurements revealed larger RFs with more structure, especially with respect to inhibitory regions. Inactivation of lower cortical layers (V-VI) by local GABA injection was found to reduce sharpness of detail and to increase both receptive-field size and noise in upper layer cells, suggesting vertically organized RF mechanisms. Across the population, some cells bore close resemblance to theoretically proposed filters, while others had a complexity that was clearly not generalizable, to the extent that they seemed more suited to detection of specific structures. We would speculate that the broadly varying forms of cat cortical receptive fields result from developmental processes akin to those that form ocular-dominance columns, but on a smaller scale.

  3. Analysis of prostate-specific antigen transcripts in chimpanzees, cynomolgus monkeys, baboons, and African green monkeys.

    Directory of Open Access Journals (Sweden)

    James N Mubiru

    Full Text Available The function of prostate-specific antigen (PSA is to liquefy the semen coagulum so that the released sperm can fuse with the ovum. Fifteen spliced variants of the PSA gene have been reported in humans, but little is known about alternative splicing in nonhuman primates. Positive selection has been reported in sex- and reproductive-related genes from sea urchins to Drosophila to humans; however, there are few studies of adaptive evolution of the PSA gene. Here, using polymerase chain reaction (PCR product cloning and sequencing, we study PSA transcript variant heterogeneity in the prostates of chimpanzees (Pan troglodytes, cynomolgus monkeys (Macaca fascicularis, baboons (Papio hamadryas anubis, and African green monkeys (Chlorocebus aethiops. Six PSA variants were identified in the chimpanzee prostate, but only two variants were found in cynomolgus monkeys, baboons, and African green monkeys. In the chimpanzee the full-length transcript is expressed at the same magnitude as the transcripts that retain intron 3. We have found previously unidentified splice variants of the PSA gene, some of which might be linked to disease conditions. Selection on the PSA gene was studied in 11 primate species by computational methods using the sequences reported here for African green monkey, cynomolgus monkey, baboon, and chimpanzee and other sequences available in public databases. A codon-based analysis (dN/dS of the PSA gene identified potential adaptive evolution at five residue sites (Arg45, Lys70, Gln144, Pro189, and Thr203.

  4. Canine distemper outbreak in rhesus monkeys, China.

    Science.gov (United States)

    Qiu, Wei; Zheng, Ying; Zhang, Shoufeng; Fan, Quanshui; Liu, Hua; Zhang, Fuqiang; Wang, Wei; Liao, Guoyang; Hu, Rongliang

    2011-08-01

    Since 2006, canine distemper outbreaks have occurred in rhesus monkeys at a breeding farm in Guangxi, People's Republic of China. Approximately 10,000 animals were infected (25%-60% disease incidence); 5%-30% of infected animals died. The epidemic was controlled by vaccination. Amino acid sequence analysis of the virus indicated a unique strain.

  5. Responsiveness in Behaving Monkeys and Human Subjects

    Science.gov (United States)

    1993-07-31

    Status of Current Research - Statement of Work Each study involving awake , behaving monkey neurophysiological recording used a behavioral paradigm that...anesthesia. A craniotomy was performed at approximately A+ 14.5mm. The recording chamber then was fixed to the skull at a lateral angle of 8’ from

  6. Nutritional and health status of woolly monkeys

    NARCIS (Netherlands)

    Ange-van Heugten, K.D.; Timmer, S.; Jansen, W.L.; Verstegen, M.W.A.

    2008-01-01

    Woolly monkeys (Lagothrix lagotricha and L. flavicauda) are threatened species in the wild and in captivity. Numerous zoological institutions have historically kept Lagothrix lagotricha spp., but only a few of them have succeeded in breeding populations. Therefore the majority of institutions that

  7. Canine Distemper Outbreak in Rhesus Monkeys, China

    Science.gov (United States)

    Qiu, Wei; Zheng, Ying; Zhang, Shoufeng; Fan, Quanshui; Liu, Hua; Zhang, Fuqiang; Wang, Wei; Liao, Guoyang

    2011-01-01

    Since 2006, canine distemper outbreaks have occurred in rhesus monkeys at a breeding farm in Guangxi, People’s Republic of China. Approximately 10,000 animals were infected (25%–60% disease incidence); 5%–30% of infected animals died. The epidemic was controlled by vaccination. Amino acid sequence analysis of the virus indicated a unique strain. PMID:21801646

  8. Computing Arm Movements with a Monkey Brainet.

    Science.gov (United States)

    Ramakrishnan, Arjun; Ifft, Peter J; Pais-Vieira, Miguel; Byun, Yoon Woo; Zhuang, Katie Z; Lebedev, Mikhail A; Nicolelis, Miguel A L

    2015-07-09

    Traditionally, brain-machine interfaces (BMIs) extract motor commands from a single brain to control the movements of artificial devices. Here, we introduce a Brainet that utilizes very-large-scale brain activity (VLSBA) from two (B2) or three (B3) nonhuman primates to engage in a common motor behaviour. A B2 generated 2D movements of an avatar arm where each monkey contributed equally to X and Y coordinates; or one monkey fully controlled the X-coordinate and the other controlled the Y-coordinate. A B3 produced arm movements in 3D space, while each monkey generated movements in 2D subspaces (X-Y, Y-Z, or X-Z). With long-term training we observed increased coordination of behavior, increased correlations in neuronal activity between different brains, and modifications to neuronal representation of the motor plan. Overall, performance of the Brainet improved owing to collective monkey behaviour. These results suggest that primate brains can be integrated into a Brainet, which self-adapts to achieve a common motor goal.

  9. Integrase of Mason-Pfizer monkey virus

    Czech Academy of Sciences Publication Activity Database

    Snášel, Jan; Krejčík, Zdeněk; Jenčová, Věra; Rosenberg, Ivan; Ruml, Tomáš; Alexandratos, J.; Gustchina, A.; Pichová, Iva

    2005-01-01

    Roč. 272, č. 1 (2005), s. 203-216 ISSN 1742-464X R&D Projects: GA AV ČR(CZ) IAA4055304 Institutional research plan: CEZ:AV0Z4055905 Keywords : integrase * Mason-Pfizer monkey virus * HIV-1 Subject RIV: CE - Biochemistry

  10. Distribution of cortical neurons projecting to the superior colliculus in macaque monkeys

    Directory of Open Access Journals (Sweden)

    Cerkevich CM

    2014-09-01

    Full Text Available Christina M Cerkevich,1 David C Lyon,2 Pooja Balaram,3 Jon H Kaas3 1Department of Neurobiology, University of Pittsburgh School of Medicine, Systems Neuroscience Institute, Pittsburgh, PA, USA; 2Department of Anatomy and Neurobiology, University of California, Irvine, CA, USA; 3Department of Psychology, Vanderbilt University, Nashville, TN, USA Abstract: To better reveal the pattern of corticotectal projections to the superficial layers of the superior colliculus (SC, we made a total of ten retrograde tracer injections into the SC of three macaque monkeys (Macaca mulatta. The majority of these injections were in the superficial layers of the SC, which process visual information. To isolate inputs to the purely visual layers in the superficial SC from those inputs to the motor and multisensory layers deeper in the SC, two injections were placed to include the intermediate and deep layers of the SC. In another case, an injection was placed in the medial pulvinar, a nucleus not known to be strongly connected with visual cortex, to identify possible projections from tracer spread past the lateral boundary of the SC. Four conclusions are supported by the results: 1 all early visual areas of cortex, including V1, V2, V3, and the middle temporal area, project to the superficial layers of the SC; 2 with the possible exception of the frontal eye field, few areas of cortex outside of the early visual areas project to the superficial SC, although many do, however, project to the intermediate and deep layers of the SC; 3 roughly matching retinotopy is conserved in the projections of visual areas to the SC; and 4 the projections from different visual areas are similarly dense, although projections from early visual areas appear somewhat denser than those of higher order visual areas in macaque cortex. Keywords: visual cortex, superior colliculus, frontal eye field, posterior parietal cortex, visual system

  11. Effect of carbamazepine (Tegretol) on seizure and EEG patterns in monkeys with alumina-induced focal motor and hippocampal foci.

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    David, J; Grewal, R S

    1976-12-01

    Qualitative and quantitative aspects of chronic carbamazepine (Tegretol) medication on focal seizures and associated interictal EEG abnormalities in Rhesus monkeys with alumina-induced foci in either the sensorimotor cortex or the hipocampus was investigated. In both groups of animals, carbamazepine produced qualitative control of visible seizures and reduced intracortical spike propagation, but did not cause complete normalization of the background EEG; quantitative indices, such as spike density and amount of paroxysmal discharge representative of abnormal EEG activity, were significantly reduced with respect to predrug values during medication and after cessation as well. Threshold to pentylenetetrazol was elevated by carbamazepine in both groups of epileptic monkeys. Aggressivity and other clinical manifestations in monekys with hippocampal foci were markedly reduced by carbamazepine.

  12. Peripheral refraction in normal infant rhesus monkeys

    Science.gov (United States)

    Hung, Li-Fang; Ramamirtham, Ramkumar; Huang, Juan; Qiao-Grider, Ying; Smith, Earl L.

    2008-01-01

    Purpose To characterize peripheral refractions in infant monkeys. Methods Cross-sectional data for horizontal refractions were obtained from 58 normal rhesus monkeys at 3 weeks of age. Longitudinal data were obtained for both the vertical and horizontal meridians from 17 monkeys. Refractive errors were measured by retinoscopy along the pupillary axis and at eccentricities of 15, 30, and 45 degrees. Axial dimensions and corneal power were measured by ultrasonography and keratometry, respectively. Results In infant monkeys, the degree of radial astigmatism increased symmetrically with eccentricity in all meridians. There were, however, initial nasal-temporal and superior-inferior asymmetries in the spherical-equivalent refractive errors. Specifically, the refractions in the temporal and superior fields were similar to the central ametropia, but the refractions in the nasal and inferior fields were more myopic than the central ametropia and the relative nasal field myopia increased with the degree of central hyperopia. With age, the degree of radial astigmatism decreased in all meridians and the refractions became more symmetrical along both the horizontal and vertical meridians; small degrees of relative myopia were evident in all fields. Conclusions As in adult humans, refractive error varied as a function of eccentricity in infant monkeys and the pattern of peripheral refraction varied with the central refractive error. With age, emmetropization occurred for both central and peripheral refractive errors resulting in similar refractions across the central 45 degrees of the visual field, which may reflect the actions of vision-dependent, growth-control mechanisms operating over a wide area of the posterior globe. PMID:18487366

  13. Early Stages of Melody Processing: Stimulus-Sequence and Task-Dependent Neuronal Activity in Monkey Auditory Cortical Fields A1 and R

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    Yin, Pingbo; Mishkin, Mortimer; Sutter, Mitchell; Fritz, Jonathan B.

    2008-01-01

    To explore the effects of acoustic and behavioral context on neuronal responses in the core of auditory cortex (fields A1 and R), two monkeys were trained on a go/no-go discrimination task in which they learned to respond selectively to a four-note target (S+) melody and withhold response to a variety of other nontarget (S−) sounds. We analyzed evoked activity from 683 units in A1/R of the trained monkeys during task performance and from 125 units in A1/R of two naive monkeys. We characterized two broad classes of neural activity that were modulated by task performance. Class I consisted of tone-sequence–sensitive enhancement and suppression responses. Enhanced or suppressed responses to specific tonal components of the S+ melody were frequently observed in trained monkeys, but enhanced responses were rarely seen in naive monkeys. Both facilitatory and suppressive responses in the trained monkeys showed a temporal pattern different from that observed in naive monkeys. Class II consisted of nonacoustic activity, characterized by a task-related component that correlated with bar release, the behavioral response leading to reward. We observed a significantly higher percentage of both Class I and Class II neurons in field R than in A1. Class I responses may help encode a long-term representation of the behaviorally salient target melody. Class II activity may reflect a variety of nonacoustic influences, such as attention, reward expectancy, somatosensory inputs, and/or motor set and may help link auditory perception and behavioral response. Both types of neuronal activity are likely to contribute to the performance of the auditory task. PMID:18842950

  14. The primary motor and premotor areas of the human cerebral cortex.

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    Chouinard, Philippe A; Paus, Tomás

    2006-04-01

    Brodmann's cytoarchitectonic map of the human cortex designates area 4 as cortex in the anterior bank of the precentral sulcus and area 6 as cortex encompassing the precentral gyrus and the posterior portion of the superior frontal gyrus on both the lateral and medial surfaces of the brain. More than 70 years ago, Fulton proposed a functional distinction between these two areas, coining the terms primary motor area for cortex in Brodmann area 4 and premotor area for cortex in Brodmann area 6. The parcellation of the cortical motor system has subsequently become more complex. Several nonprimary motor areas have been identified in the brain of the macaque monkey, and associations between anatomy and function in the human brain are being tested continuously using brain mapping techniques. In the present review, the authors discuss the unique properties of the primary motor area (M1), the dorsal portion of the premotor cortex (PMd), and the ventral portion of the premotor cortex (PMv). They end this review by discussing how the premotor areas influence M1.

  15. Circuit Mechanisms Governing Local vs. Global Motion Processing in Mouse Visual Cortex

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    Rune Rasmussen

    2017-12-01

    Full Text Available A withstanding question in neuroscience is how neural circuits encode representations and perceptions of the external world. A particularly well-defined visual computation is the representation of global object motion by pattern direction-selective (PDS cells from convergence of motion of local components represented by component direction-selective (CDS cells. However, how PDS and CDS cells develop their distinct response properties is still unresolved. The visual cortex of the mouse is an attractive model for experimentally solving this issue due to the large molecular and genetic toolbox available. Although mouse visual cortex lacks the highly ordered orientation columns of primates, it is organized in functional sub-networks and contains striate- and extrastriate areas like its primate counterparts. In this Perspective article, we provide an overview of the experimental and theoretical literature on global motion processing based on works in primates and mice. Lastly, we propose what types of experiments could illuminate what circuit mechanisms are governing cortical global visual motion processing. We propose that PDS cells in mouse visual cortex appear as the perfect arena for delineating and solving how individual sensory features extracted by neural circuits in peripheral brain areas are integrated to build our rich cohesive sensory experiences.

  16. Geologic continuous casting below continental and deep-sea detachment faults and at the striated extrusion of Sacsayhuaman, Peru

    Science.gov (United States)

    Spencer, J.E.

    1999-01-01

    In the common type of industrial continuous casting, partially molten metal is extruded from a vessel through a shaped orifice called a mold in which the metal assumes the cross-sectional form of the mold as it cools and solidifies. Continuous casting can be sustained as long as molten metal is supplied and thermal conditions are maintained. I propose that a similar process produced parallel sets of grooves in three geologic settings, as follows: (1) corrugated metamorphic core complexes where mylonized mid-crustal rocks were exhumed by movement along low-angle normal faults known as detachment faults; (2) corrugated submarine surfaces where ultramafic and mafic rocks were exhumed by normal faulting within oceanic spreading centers; and (3) striated magma extrusions exemplified by the famous grooved outcrops at the Inca fortress of Sacsayhuaman in Peru. In each case, rocks inferred to have overlain the corrugated surface during corrugation genesis molded and shaped a plastic to partially molten rock mass as it was extruded from a moderate- to high-temperature reservoir.

  17. Healthy and diseased striated muscle studied by analytical scanning electron microscopy with special reference to fibre type

    International Nuclear Information System (INIS)

    Wroblewski, R.

    1982-01-01

    X-ray microanalytical investigations of striated muscles in the scanning electron microscope are reviewed. The main part of the studies was performed on cryosections cut with a conventional cryostat operating at -20 degrees C to -40 degrees C. The preparation procedure including different types of attachment of the sections to the specimen holder is described in detail. The elemental changes in muscle are related to the muscle fibre type as demonstrated by histochemical methods or to histochemically demonstrated inclusions in diseased muscles. This is of great importance, because muscle disorders are often characterised by selective involvement of different muscle fibre types. The preparation methods of muscle for analytical scanning electron microscopy and the obtained results are compared with studies performed on thin cryo and epoxy sections, analysed in the transmission and scanning-transmission electron microscope. It is evident that X-ray microanalysis performed on thick cryosections provide a quick survey of the elemental composition of whole cells, and should be followed in interesting cases by close examination on the organelle level studied in thin cryosections in the transmission and scanning-transmission electron microscope

  18. Navigating actions through the rodent parietal cortex

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    Jonathan R. Whitlock

    2014-05-01

    Full Text Available The posterior parietal cortex (PPC participates in a manifold of cognitive functions, including visual attention, working memory, spatial processing and movement planning. Given the vast interconnectivity of PPC with sensory and motor areas, it is not surprising that neuronal recordings show that PPC often encodes mixtures of spatial information as well as the movements required to reach a goal. Recent work sought to discern the relative strength of spatial versus motor signaling in PPC by recording single unit activity in PPC of freely behaving rats during selective changes in either the spatial layout of the local environment or in the pattern of locomotor behaviors executed during navigational tasks. The results revealed unequivocally a predominant sensitivity of PPC neurons to locomotor action structure, with subsets of cells even encoding upcoming movements more than 1 second in advance. In light of these and other recent findings in the field, I propose that one of the key contributions of PPC to navigation is the synthesis of goal-directed behavioral sequences, and that the rodent PPC may serve as an apt system to investigate cellular mechanisms for spatial motor planning as traditionally studied in humans and monkeys.

  19. Dorsal premotor cortex is involved in switching motor plans

    Science.gov (United States)

    Pastor-Bernier, Alexandre; Tremblay, Elsa; Cisek, Paul

    2012-01-01

    Previous studies have shown that neural activity in primate dorsal premotor cortex (PMd) can simultaneously represent multiple potential movement plans, and that activity related to these movement options is modulated by their relative subjective desirability. These findings support the hypothesis that decisions about actions are made through a competition within the same circuits that guide the actions themselves. This hypothesis further predicts that the very same cells that guide initial decisions will continue to update their activities if an animal changes its mind. For example, if a previously selected movement option suddenly becomes unavailable, the correction will be performed by the same cells that selected the initial movement, as opposed to some different group of cells responsible for online guidance. We tested this prediction by recording neural activity in the PMd of a monkey performing an instructed-delay reach selection task. In the task, two targets were simultaneously presented and their border styles indicated whether each would be worth 1, 2, or 3 juice drops. In a random subset of trials (FREE), the monkey was allowed a choice while in the remaining trials (FORCED) one of the targets disappeared at the time of the GO signal. In FORCED-LOW trials the monkey was forced to move to the less valuable target and started moving either toward the new target (Direct) or toward the target that vanished and then curved to reach the remaining one (Curved). Prior to the GO signal, PMd activity clearly reflected the monkey's subjective preference, predicting his choices in FREE trials even with equally valued options. In FORCED-LOW trials, PMd activity reflected the switch of the monkey's plan as early as 100 ms after the GO signal, well before movement onset (MO). This confirms that the activity is not related to feedback from the movement itself, and suggests that PMd continues to participate in action selection even when the animal changes its mind on

  20. [Neuroanatomy of Frontal Association Cortex].

    Science.gov (United States)

    Takada, Masahiko

    2016-11-01

    The frontal association cortex is composed of the prefrontal cortex and the motor-related areas except the primary motor cortex (i.e., the so-called higher motor areas), and is well-developed in primates, including humans. The prefrontal cortex receives and integrates large bits of diverse information from the parietal, temporal, and occipital association cortical areas (termed the posterior association cortex), and paralimbic association cortical areas. This information is then transmitted to the primary motor cortex via multiple motor-related areas. Given these facts, it is likely that the prefrontal cortex exerts executive functions for behavioral control. The functional input pathways from the posterior and paralimbic association cortical areas to the prefrontal cortex are classified primarily into six groups. Cognitive signals derived from the prefrontal cortex are conveyed to the rostral motor-related areas to transform them into motor signals, which finally enter the primary motor cortex via the caudal motor-related areas. Furthermore, it has been shown that, similar to the primary motor cortex, areas of the frontal association cortex form individual networks (known as "loop circuits") with the basal ganglia and cerebellum via the thalamus, and hence are extensively involved in the expression and control of behavioral actions.

  1. Head Rotation Detection in Marmoset Monkeys

    Science.gov (United States)

    Simhadri, Sravanthi

    Head movement is known to have the benefit of improving the accuracy of sound localization for humans and animals. Marmoset is a small bodied New World monkey species and it has become an emerging model for studying the auditory functions. This thesis aims to detect the horizontal and vertical rotation of head movement in marmoset monkeys. Experiments were conducted in a sound-attenuated acoustic chamber. Head movement of marmoset monkey was studied under various auditory and visual stimulation conditions. With increasing complexity, these conditions are (1) idle, (2) sound-alone, (3) sound and visual signals, and (4) alert signal by opening and closing of the chamber door. All of these conditions were tested with either house light on or off. Infra-red camera with a frame rate of 90 Hz was used to capture of the head movement of monkeys. To assist the signal detection, two circular markers were attached to the top of monkey head. The data analysis used an image-based marker detection scheme. Images were processed using the Computation Vision Toolbox in Matlab. The markers and their positions were detected using blob detection techniques. Based on the frame-by-frame information of marker positions, the angular position, velocity and acceleration were extracted in horizontal and vertical planes. Adaptive Otsu Thresholding, Kalman filtering and bound setting for marker properties were used to overcome a number of challenges encountered during this analysis, such as finding image segmentation threshold, continuously tracking markers during large head movement, and false alarm detection. The results show that the blob detection method together with Kalman filtering yielded better performances than other image based techniques like optical flow and SURF features .The median of the maximal head turn in the horizontal plane was in the range of 20 to 70 degrees and the median of the maximal velocity in horizontal plane was in the range of a few hundreds of degrees per

  2. Alternative Splicing of AMPA subunits in Prefrontal Cortical Fields of Cynomolgus Monkeys following Chronic Ethanol Self-Administration

    Directory of Open Access Journals (Sweden)

    Glen eAcosta

    2012-01-01

    Full Text Available Functional impairment of the orbital and medial prefrontal cortex underlies deficits in executive control that characterize addictive disorders, including alcohol addiction. Previous studies indicate that alcohol alters glutamate neurotransmission and one substrate of these effects may be through the reconfiguration of the subunits constituting ionotropic glutamate receptor (iGluR complexes. Glutamatergic transmission is integral to cortico-cortical and cortico-subcortical communication and alcohol-induced changes in the abundance of the receptor subunits and/or their splice variants may result in critical functional impairments of prefrontal cortex in alcohol dependence. To this end, the effects of chronic ethanol self-administration on glutamate receptor ionotropic AMPA (GRIA subunit variant and kainate (GRIK subunit mRNA expression were studied in the orbitofrontal cortex (OFC, dorsolateral prefrontal cortex (DLPFC and anterior cingulate cortex (ACC of male cynomolgus monkeys. In DLPFC, total AMPA splice variant expression and total kainate receptor subunit expression were significantly decreased in alcohol drinking monkeys. Expression levels of GRIA3 flip and flop and GRIA4 flop mRNAs in this region were positively correlated with daily ethanol intake and blood ethanol concentrations averaged over the six months prior to necropsy. In OFC, AMPA subunit splice variant expression was reduced in the alcohol treated group. GRIA2 flop mRNA levels in this region were positively correlated with daily ethanol intake and blood ethanol concentrations averaged over the six months prior to necropsy. Results from these studies provide further evidence of transcriptional regulation of iGluR subunits in the primate brain following chronic alcohol self-administration. Additional studies examining the cellular localization of such effects in the framework of primate prefrontal cortical circuitry are warranted.

  3. Persistent neural activity in auditory cortex is related to auditory working memory in humans and nonhuman primates.

    Science.gov (United States)

    Huang, Ying; Matysiak, Artur; Heil, Peter; König, Reinhard; Brosch, Michael

    2016-07-20

    Working memory is the cognitive capacity of short-term storage of information for goal-directed behaviors. Where and how this capacity is implemented in the brain are unresolved questions. We show that auditory cortex stores information by persistent changes of neural activity. We separated activity related to working memory from activity related to other mental processes by having humans and monkeys perform different tasks with varying working memory demands on the same sound sequences. Working memory was reflected in the spiking activity of individual neurons in auditory cortex and in the activity of neuronal populations, that is, in local field potentials and magnetic fields. Our results provide direct support for the idea that temporary storage of information recruits the same brain areas that also process the information. Because similar activity was observed in the two species, the cellular bases of some auditory working memory processes in humans can be studied in monkeys.

  4. Postnatal Developmental Trajectories of Neural Circuits in the Primate Prefrontal Cortex: Identifying Sensitive Periods for Vulnerability to Schizophrenia

    Science.gov (United States)

    Hoftman, Gil D.; Lewis, David A.

    2011-01-01

    Schizophrenia is a disorder of cognitive neurodevelopment with characteristic abnormalities in working memory attributed, at least in part, to alterations in the circuitry of the dorsolateral prefrontal cortex. Various environmental exposures from conception through adolescence increase risk for the illness, possibly by altering the developmental trajectories of prefrontal cortical circuits. Macaque monkeys provide an excellent model system for studying the maturation of prefrontal cortical circuits. Here, we review the development of glutamatergic and γ-aminobutyric acid (GABA)-ergic circuits in macaque monkey prefrontal cortex and discuss how these trajectories may help to identify sensitive periods during which environmental exposures, such as those associated with increased risk for schizophrenia, might lead to the types of abnormalities in prefrontal cortical function present in schizophrenia. PMID:21505116

  5. The threshold for conscious report: Signal loss and response bias in visual and frontal cortex.

    Science.gov (United States)

    van Vugt, Bram; Dagnino, Bruno; Vartak, Devavrat; Safaai, Houman; Panzeri, Stefano; Dehaene, Stanislas; Roelfsema, Pieter R

    2018-05-04

    Why are some visual stimuli consciously detected, whereas others remain subliminal? We investigated the fate of weak visual stimuli in the visual and frontal cortex of awake monkeys trained to report stimulus presence. Reported stimuli were associated with strong sustained activity in the frontal cortex, and frontal activity was weaker and quickly decayed for unreported stimuli. Information about weak stimuli could be lost at successive stages en route from the visual to the frontal cortex, and these propagation failures were confirmed through microstimulation of area V1. Fluctuations in response bias and sensitivity during perception of identical stimuli were traced back to prestimulus brain-state markers. A model in which stimuli become consciously reportable when they elicit a nonlinear ignition process in higher cortical areas explained our results. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  6. Metabolism of lithocholic and chenodeoxycholic acids in the squirrel monkey

    International Nuclear Information System (INIS)

    Suzuki, H.; Hamada, M.; Kato, F.

    1985-01-01

    Metabolism of lithocholic acid (LCA) and chenodeoxycholic acid (CDCA) was studied in the squirrel monkey to clarify the mechanism of the lack of toxicity of CDCA in this animal. Radioactive LCA was administered to squirrel monkeys with biliary fistula. Most radioactivity was excreted in the bile in the form of unsulfated lithocholyltaurine. The squirrel monkey thus differs from humans and chimpanzees, which efficiently sulfate LCA, and is similar to the rhesus monkey and baboon in that LCA is poorly sulfated. When labeled CDCA was orally administered to squirrel monkeys, less than 20% of the dosed radioactivity was recovered as LCA and its further metabolites in feces over 3 days, indicating that bacterial metabolism of CDCA into LCA is strikingly less than in other animals and in humans. It therefore appears that LCA, known as a hepatotoxic secondary bile acid, is not accumulated in the squirrel monkey, not because of its rapid turnover through sulfation, but because of the low order of its production

  7. Hemorrhoids: an experimental model in monkeys

    Directory of Open Access Journals (Sweden)

    Plapler Hélio

    2006-01-01

    Full Text Available PURPOSE: Hemorrhoids are a matter of concern due to a painful outcome. We describe a simple, easy and reliable experimental model to produce hemorrhoids in monkeys. METHODS: 14 monkeys (Cebus apella were used. After general anesthesia, hemorrhoids were induced by ligation of the inferior hemorrhoidal vein, which is very alike to humans. The vein was located through a perianal incision, dissected and ligated with a 3-0 vicryl. The skin was sutured with a 4-0 catgut thread. Animals were kept in appropriate cages and evaluated daily. RESULTS: Nine days later there were hemorrhoidal piles in the anus in fifty percent (50% of the animals. Outcome was unremarkable. There was no bleeding and all animals showed no signs of pain or suffering. CONCLUSION: This is an affordable and reliable experimental model to induce hemorrhoids for experimental studies.

  8. Radioprotective effectiveness of adeturone in monkey experiments

    International Nuclear Information System (INIS)

    Nikolov, I.; Pantev, T.; Rogozkin, P.; Chertkov, K.; Dikovenko, E.; Kosarenkov, V.

    1976-01-01

    The radioprotective effect of adeturone (adenosine triphsophate salt of AET) was tested on 28 monkeys (Macaca mulata). The animals were gamma-irradiated (cobalt 60) with a dose of 680 R (17,6 R/min, LDsub(100/18)). Adeturone was administered intravenously for 5 minutes, from 6 to 15 minutes before irradiation in a dose of 150 mg/kg (1/2 of thr maximal tolerable dose). It was found that adeturone administration before the absolute lethal irradiation will ensure survival of 50 % of the monkeys. Radiation sickness in protected animals runs a milder course as shown by the duration of the latency period, the manifestation of the hemorrhagic syndrome, the leukopenia and erythrocytes in the peripheral blood. Some symptoms do not appear at all (diarrhoea) or develop later(hyperthermia, hypodynamia). (A.B.)

  9. Dramatic loss of Ube3A expression during aging of the mammalian cortex

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    Kate Williams

    2010-05-01

    Full Text Available Neurobiological studies of aging are beginning to link functional changes with a loss of experience-dependent plasticity. In the visual system, age-related functional changes include decreases in visual acuity, orientation selectivity, motion perception, and ocular dominance plasticity. A recent paper has shown that Ube3A, an E3 ubiquitin ligase that is absent in Angelman's Syndrome, is required for experience-dependent plasticity during development of the visual cortex. Knocking out Ube3A during development leads to rigidity of ocular dominance plasticity that is strikingly similar to the reduced plasticity seen in older animals. Furthermore, ubiquitin ligases have been linked with age-related neurodegenerative disorders and longevity. Ubiquitin ligases selectively mark proteins for degradation, and a balance between synaptic proteins and their degradation is important for neural transmission and plasticity. This led us to ask whether normal aging is characterized by a loss of Ube3A in the cortex. We used Western blot analysis in order to quantify Ube3A expression across the life span of humans, macaque monkeys, and cats. We found that Ube3A expression declines across the lifespan in human, monkey, and cat cortex. The losses were substantial (50-80% in all areas studied which includes V1, V3, V4, frontal, and auditory cortex. In addition, when compared with other synaptic proteins there was a selective loss of Ube3A in human cortex. The progressive loss of Ube3A expression during cortical aging is an important new finding. Furthermore, the selective loss of Ube3A in human cortex highlights a specific vulnerability in human brain aging that may signify a dramatic shift in cortical function and plasticity.

  10. Anatomical pathways for auditory memory II: information from rostral superior temporal gyrus to dorsolateral temporal pole and medial temporal cortex.

    Science.gov (United States)

    Muñoz-López, M; Insausti, R; Mohedano-Moriano, A; Mishkin, M; Saunders, R C

    2015-01-01

    Auditory recognition memory in non-human primates differs from recognition memory in other sensory systems. Monkeys learn the rule for visual and tactile delayed matching-to-sample within a few sessions, and then show one-trial recognition memory lasting 10-20 min. In contrast, monkeys require hundreds of sessions to master the rule for auditory recognition, and then show retention lasting no longer than 30-40 s. Moreover, unlike the severe effects of rhinal lesions on visual memory, such lesions have no effect on the monkeys' auditory memory performance. The anatomical pathways for auditory memory may differ from those in vision. Long-term visual recognition memory requires anatomical connections from the visual association area TE with areas 35 and 36 of the perirhinal cortex (PRC). We examined whether there is a similar anatomical route for auditory processing, or that poor auditory recognition memory may reflect the lack of such a pathway. Our hypothesis is that an auditory pathway for recognition memory originates in the higher order processing areas of the rostral superior temporal gyrus (rSTG), and then connects via the dorsolateral temporal pole to access the rhinal cortex of the medial temporal lobe. To test this, we placed retrograde (3% FB and 2% DY) and anterograde (10% BDA 10,000 mW) tracer injections in rSTG and the dorsolateral area 38 DL of the temporal pole. Results showed that area 38DL receives dense projections from auditory association areas Ts1, TAa, TPO of the rSTG, from the rostral parabelt and, to a lesser extent, from areas Ts2-3 and PGa. In turn, area 38DL projects densely to area 35 of PRC, entorhinal cortex (EC), and to areas TH/TF of the posterior parahippocampal cortex. Significantly, this projection avoids most of area 36r/c of PRC. This anatomical arrangement may contribute to our understanding of the poor auditory memory of rhesus monkeys.

  11. What do monkeys' music choices mean?

    Science.gov (United States)

    Lamont, Alexandra M

    2005-08-01

    McDermott and Hauser have recently shown that although monkeys show some types of preferences for sound, preferences for music are found only in humans. This suggests that music might be a relatively recent adaptation in human evolution. Here, I focus on the research methods used by McDermott and Hauser, and consider the findings in relation to infancy research and music psychology.

  12. Placental Transport of Zidovudine in the Rhesus Monkey

    OpenAIRE

    Ridgway III, Louis E.; King, Thomas S.; Henderson, George I.; Schenker, Steven; Schenken, Robert S.

    1993-01-01

    Objective: This study was undertaken to characterize the pharmacokinetics of zidovudine (ZDV) and ZDV-glucuronide (ZDVG) in the material and :fetal circulations of the rhesus monkey. Methods: Cannulas were placed in the maternal external jugular and the fetal internal jugular and carotid artery in 8 pregnant monkeys at .120–130 days gestation. ZDV (3.5 mg/kg) was administered to 5 monkeys and ZDVG (3.5 mg/kg) to 3 monkeys as single intravenous bolus infusions through the maternal catheter. Ma...

  13. Auditory short-term memory in the primate auditory cortex.

    Science.gov (United States)

    Scott, Brian H; Mishkin, Mortimer

    2016-06-01

    Sounds are fleeting, and assembling the sequence of inputs at the ear into a coherent percept requires auditory memory across various time scales. Auditory short-term memory comprises at least two components: an active ׳working memory' bolstered by rehearsal, and a sensory trace that may be passively retained. Working memory relies on representations recalled from long-term memory, and their rehearsal may require phonological mechanisms unique to humans. The sensory component, passive short-term memory (pSTM), is tractable to study in nonhuman primates, whose brain architecture and behavioral repertoire are comparable to our own. This review discusses recent advances in the behavioral and neurophysiological study of auditory memory with a focus on single-unit recordings from macaque monkeys performing delayed-match-to-sample (DMS) tasks. Monkeys appear to employ pSTM to solve these tasks, as evidenced by the impact of interfering stimuli on memory performance. In several regards, pSTM in monkeys resembles pitch memory in humans, and may engage similar neural mechanisms. Neural correlates of DMS performance have been observed throughout the auditory and prefrontal cortex, defining a network of areas supporting auditory STM with parallels to that supporting visual STM. These correlates include persistent neural firing, or a suppression of firing, during the delay period of the memory task, as well as suppression or (less commonly) enhancement of sensory responses when a sound is repeated as a ׳match' stimulus. Auditory STM is supported by a distributed temporo-frontal network in which sensitivity to stimulus history is an intrinsic feature of auditory processing. This article is part of a Special Issue entitled SI: Auditory working memory. Published by Elsevier B.V.

  14. (−)-EPICATECHIN IMPROVES MITOCHONDRIAL RELATED PROTEIN LEVELS AND AMELIORATES OXIDATIVE STRESS IN DYSTROPHIC DELTA SARCOGLYCAN NULL MOUSE STRIATED MUSCLE

    Science.gov (United States)

    Ramirez-Sanchez, Israel; De los Santos, Sergio; Gonzalez-Basurto, Silvia; Canto, Patricia; Mendoza-Lorenzo, Patricia; Palma-Flores, Carlos; Ceballos-Reyes, Guillermo; Villarreal, Francisco; Zentella-Dehesa, Alejandro; Coral-Vazquez, Ramon

    2014-01-01

    Muscular dystrophies (MD) are a group of heterogeneous genetic disorders characterized by progressive striated muscle wasting and degeneration. Although the genetic basis for many of these disorders has been identified, the exact mechanism for disease pathogenesis remains unclear. The presence of oxidative stress (OS) is known to contribute to the pathophysiology and severity of the MD. Mitochondrial dysfunction is observed in MD and likely represents an important determinant of increased OS. Experimental antioxidant therapies have been implemented with the aim of protecting against disease progression, but results from clinical trials have been disappointing. In this study, we explored the capacity of the cacao flavonoid (−)-epicatechin (Epi) to mitigate OS by acting as a positive regulator of mitochondrial structure/function endpoints and redox balance control systems in skeletal and cardiac muscles of dystrophic, δ-sarcoglycan (δ-SG) null mice. Wild type or δ-SG null 2.5 month old male mice were treated via oral gavage with either water (control animals) or Epi (1 mg/kg, twice/day) for 2 weeks. Results evidence a significant normalization of total protein carbonylation, recovery of reduced/oxidized glutathione (GSH/GSSG ratio) and enhanced superoxide dismutase 2, catalase and citrate synthase activities with Epi treatment. These effects were accompanied by increases in protein levels for thiolredoxin, glutathione peroxidase, superoxide dismutase 2, catalase and mitochondrial endpoints. Furthermore, we evidence decreases in heart and skeletal muscle fibrosis, accompanied with an improvement in skeletal muscle function with treatment. These results warrant the further investigation of Epi as a potential therapeutic agent to mitigate MD associated muscle degeneration. PMID:25284161

  15. The ‘Goldilocks Zone’ from a redox perspective - Adaptive versus deleterious responses to oxidative stress in striated muscle

    Directory of Open Access Journals (Sweden)

    Rick J Alleman

    2014-09-01

    Full Text Available Consequences of oxidative stress may be beneficial or detrimental in physiological systems. An organ system’s position on the ‘hormetic curve’ is governed by the source and temporality of reactive oxygen species (ROS production, proximity of ROS to moieties most susceptible to damage, and the capacity of the endogenous cellular ROS scavenging mechanisms. Most importantly, the resilience of the tissue (the capacity to recover from damage is a decisive factor, and this is reflected in the disparate response to ROS in cardiac and skeletal muscle. In myocytes, a high oxidative capacity invariably results in a significant ROS burden which in homeostasis, is rapidly neutralized by the robust antioxidant network. The up-regulation of key pathways in the antioxidant network is a central component of the hormetic response to ROS. Despite such adaptations, persistent oxidative stress over an extended time-frame (e.g. months to years inevitably leads to cumulative damages, maladaptation and ultimately the pathogenesis of chronic diseases. Indeed, persistent oxidative stress in heart and skeletal muscle has been repeatedly demonstrated to have causal roles in the etiology of heart disease and insulin resistance, respectively. Deciphering the mechanisms that underlie the divergence between adaptive and maladaptive responses to oxidative stress remains an active area of research for basic scientists and clinicians alike, as this would undoubtedly lead to novel therapeutic approaches. Here, we provide an overview of major types of ROS in striated muscle and the divergent adaptations that occur in response to them. Emphasis is placed on highlighting newly uncovered areas of research on this topic, with particular focus on the mitochondria, and the diverging roles that ROS play in muscle health (e.g., exercise or preconditioning and disease (e.g., cardiomyopathy, ischemia, metabolic syndrome.

  16. Impact of a nickel-reduced stainless steel implant on striated muscle microcirculation: a comparative in vivo study.

    Science.gov (United States)

    Kraft, C N; Burian, B; Perlick, L; Wimmer, M A; Wallny, T; Schmitt, O; Diedrich, O

    2001-12-05

    The impairment of skeletal muscle microcirculation by a biomaterial may have profound consequences. With moderately good physical and corrosion characteristics, implant-quality stainless steel is particularly popular in orthopedic surgery. However, due to the presence of a considerable amount of nickel in the alloy, concern has been voiced in respect to local tissue responses. More recently a stainless steel alloy with a significant reduction of nickel has become commercially available. We, therefore, studied in vivo nutritive perfusion and leukocytic response of striated muscle to this nickel-reduced alloy, and compared these results with those of the materials conventional stainless steel and titanium. Using the hamster dorsal skinfold chamber preparation and intravital microscopy, we could demonstrate that reduction of the nickel quantity in a stainless steel implant has a positive effect on local microvascular parameters. Although the implantation of a conventional stainless steel sample led to a distinct and persistent activation of leukocytes combined with disruption of the microvascular endothelial integrity, marked leukocyte extravasation, and considerable venular dilation, animals with a nickel-reduced stainless steel implant showed only a moderate increase of these parameters, with a clear tendency of recuperation. Titanium implants merely caused a transient increase of leukocyte-endothelial cell interaction within the first 120 min, and no significant change in macromolecular leakage, leukocyte extravasation, or venular diameter. Pending biomechanical and corrosion testing, nickel-reduced stainless steel may be a viable alternative to conventional implant-quality stainless steel for biomedical applications. Concerning tolerance by the local vascular system, titanium currently remains unsurpassed. Copyright 2001 John Wiley & Sons, Inc. J Biomed Mater Res 57: 404-412, 2001

  17. Decoding a Decision Process in the Neuronal Population of Dorsal Premotor Cortex.

    Science.gov (United States)

    Rossi-Pool, Román; Zainos, Antonio; Alvarez, Manuel; Zizumbo, Jerónimo; Vergara, José; Romo, Ranulfo

    2017-12-20

    When trained monkeys discriminate the temporal structure of two sequential vibrotactile stimuli, dorsal premotor cortex (DPC) showed high heterogeneity among its neuronal responses. Notably, DPC neurons coded stimulus patterns as broader categories and signaled them during working memory, comparison, and postponed decision periods. Here, we show that such population activity can be condensed into two major coding components: one that persistently represented in working memory both the first stimulus identity and the postponed informed choice and another that transiently coded the initial sensory information and the result of the comparison between the two stimuli. Additionally, we identified relevant signals that coded the timing of task events. These temporal and task-parameter readouts were shown to be strongly linked to the monkeys' behavior when contrasted to those obtained in a non-demanding cognitive control task and during error trials. These signals, hidden in the heterogeneity, were prominently represented by the DPC population response. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Distinct Roles for the Amygdala and Orbitofrontal Cortex in Representing the Relative Amount of Expected Reward.

    Science.gov (United States)

    Saez, Rebecca A; Saez, Alexandre; Paton, Joseph J; Lau, Brian; Salzman, C Daniel

    2017-07-05

    The same reward can possess different motivational meaning depending upon its magnitude relative to other rewards. To study the neurophysiological mechanisms mediating assignment of motivational meaning, we recorded the activity of neurons in the amygdala and orbitofrontal cortex (OFC) of monkeys during a Pavlovian task in which the relative amount of liquid reward associated with one conditioned stimulus (CS) was manipulated by changing the reward amount associated with a second CS. Anticipatory licking tracked relative reward magnitude, implying that monkeys integrated information about recent rewards to adjust the motivational meaning of a CS. Upon changes in relative reward magnitude, neural responses to reward-predictive cues updated more rapidly in OFC than amygdala, and activity in OFC but not the amygdala was modulated by recent reward history. These results highlight a distinction between the amygdala and OFC in assessing reward history to support the flexible assignment of motivational meaning to sensory cues. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Decoding stimulus features in primate somatosensory cortex during perceptual categorization

    Science.gov (United States)

    Alvarez, Manuel; Zainos, Antonio; Romo, Ranulfo

    2015-01-01

    Neurons of the primary somatosensory cortex (S1) respond as functions of frequency or amplitude of a vibrotactile stimulus. However, whether S1 neurons encode both frequency and amplitude of the vibrotactile stimulus or whether each sensory feature is encoded by separate populations of S1 neurons is not known, To further address these questions, we recorded S1 neurons while trained monkeys categorized only one sensory feature of the vibrotactile stimulus: frequency, amplitude, or duration. The results suggest a hierarchical encoding scheme in S1: from neurons that encode all sensory features of the vibrotactile stimulus to neurons that encode only one sensory feature. We hypothesize that the dynamic representation of each sensory feature in S1 might serve for further downstream processing that leads to the monkey’s psychophysical behavior observed in these tasks. PMID:25825711

  20. Distribution of glutamatergic, GABAergic, and glycinergic neurons in the auditory pathways of macaque monkeys.

    Science.gov (United States)

    Ito, T; Inoue, K; Takada, M

    2015-12-03

    Macaque monkeys use complex communication calls and are regarded as a model for studying the coding and decoding of complex sound in the auditory system. However, little is known about the distribution of excitatory and inhibitory neurons in the auditory system of macaque monkeys. In this study, we examined the overall distribution of cell bodies that expressed mRNAs for VGLUT1, and VGLUT2 (markers for glutamatergic neurons), GAD67 (a marker for GABAergic neurons), and GLYT2 (a marker for glycinergic neurons) in the auditory system of the Japanese macaque. In addition, we performed immunohistochemistry for VGLUT1, VGLUT2, and GAD67 in order to compare the distribution of proteins and mRNAs. We found that most of the excitatory neurons in the auditory brainstem expressed VGLUT2. In contrast, the expression of VGLUT1 mRNA was restricted to the auditory cortex (AC), periolivary nuclei, and cochlear nuclei (CN). The co-expression of GAD67 and GLYT2 mRNAs was common in the ventral nucleus of the lateral lemniscus (VNLL), CN, and superior olivary complex except for the medial nucleus of the trapezoid body, which expressed GLYT2 alone. In contrast, the dorsal nucleus of the lateral lemniscus, inferior colliculus, thalamus, and AC expressed GAD67 alone. The absence of co-expression of VGLUT1 and VGLUT2 in the medial geniculate, medial superior olive, and VNLL suggests that synaptic responses in the target neurons of these nuclei may be different between rodents and macaque monkeys. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  1. The anterior cingulate cortex

    Directory of Open Access Journals (Sweden)

    Pavlović D.M.

    2009-01-01

    Full Text Available The anterior cingulate cortex (ACC has a role in attention, analysis of sensory information, error recognition, problem solving, detection of novelty, behavior, emotions, social relations, cognitive control, and regulation of visceral functions. This area is active whenever the individual feels some emotions, solves a problem, or analyzes the pros and cons of an action (if it is a right decision. Analogous areas are also found in higher mammals, especially whales, and they contain spindle neurons that enable complex social interactions. Disturbance of ACC activity is found in dementias, schizophrenia, depression, the obsessive-compulsive syndrome, and other neuropsychiatric diseases.

  2. Regulating prefrontal cortex activation

    DEFF Research Database (Denmark)

    Aznar, Susana; Klein, Anders Bue

    2013-01-01

    The prefrontal cortex (PFC) is involved in mediating important higher-order cognitive processes such as decision making, prompting thereby our actions. At the same time, PFC activation is strongly influenced by emotional reactions through its functional interaction with the amygdala...... of emotion-based actions, such as addiction and other impulse-related behaviors. In this review, we give an overview of the 5-HT2A receptor distribution (neuronal, intracellular, and anatomical) along with its functional and physiological effect on PFC activation, and how that relates to more recent findings...... of a regulatory effect of the PFC on the emotional control of our actions....

  3. Monkey׳s short-term auditory memory nearly abolished by combined removal of the rostral superior temporal gyrus and rhinal cortices.

    Science.gov (United States)

    Fritz, Jonathan B; Malloy, Megan; Mishkin, Mortimer; Saunders, Richard C

    2016-06-01

    While monkeys easily acquire the rules for performing visual and tactile delayed matching-to-sample, a method for testing recognition memory, they have extraordinary difficulty acquiring a similar rule in audition. Another striking difference between the modalities is that whereas bilateral ablation of the rhinal cortex (RhC) leads to profound impairment in visual and tactile recognition, the same lesion has no detectable effect on auditory recognition memory (Fritz et al., 2005). In our previous study, a mild impairment in auditory memory was obtained following bilateral ablation of the entire medial temporal lobe (MTL), including the RhC, and an equally mild effect was observed after bilateral ablation of the auditory cortical areas in the rostral superior temporal gyrus (rSTG). In order to test the hypothesis that each of these mild impairments was due to partial disconnection of acoustic input to a common target (e.g., the ventromedial prefrontal cortex), in the current study we examined the effects of a more complete auditory disconnection of this common target by combining the removals of both the rSTG and the MTL. We found that the combined lesion led to forgetting thresholds (performance at 75% accuracy) that fell precipitously from the normal retention duration of ~30 to 40s to a duration of ~1 to 2s, thus nearly abolishing auditory recognition memory, and leaving behind only a residual echoic memory. This article is part of a Special Issue entitled SI: Auditory working memory. Published by Elsevier B.V.

  4. A neural correlate of working memory in the monkey primary visual cortex

    NARCIS (Netherlands)

    Lamme, V.A.F.; Suphr, H.; Spekreijse, H.

    2001-01-01

    The brain frequently needs to store information for short periods. In vision, this means that the perceptual correlate of a stimulus has to be maintained temporally once the stimulus has been removed from the visual scene. However, it is not known how the visual system transfers sensory information

  5. Neuronal correlate of pictorial short-term memory in the primate temporal cortexYasushi Miyashita

    Science.gov (United States)

    Miyashita, Yasushi; Chang, Han Soo

    1988-01-01

    It has been proposed that visual-memory traces are located in the temporal lobes of the cerebral cortex, as electric stimulation of this area in humans results in recall of imagery1. Lesions in this area also affect recognition of an object after a delay in both humans2,3 and monkeys4-7 indicating a role in short-term memory of images8. Single-unit recordings from the temporal cortex have shown that some neurons continue to fire when one of two or four colours are to be remembered temporarily9. But neuronal responses selective to specific complex objects10-18 , including hands10,13 and faces13,16,17, cease soon after the offset of stimulus presentation10-18. These results led to the question of whether any of these neurons could serve the memory of complex objects. We report here a group of shape-selective neurons in an anterior ventral part of the temporal cortex of monkeys that exhibited sustained activity during the delay period of a visual short-term memory task. The activity was highly selective for the pictorial information to be memorized and was independent of the physical attributes such as size, orientation, colour or position of the object. These observations show that the delay activity represents the short-term memory of the categorized percept of a picture.

  6. Evolution of posterior parietal cortex and parietal-frontal networks for specific actions in primates.

    Science.gov (United States)

    Kaas, Jon H; Stepniewska, Iwona

    2016-02-15

    Posterior parietal cortex (PPC) is an extensive region of the human brain that develops relatively late and is proportionally large compared with that of monkeys and prosimian primates. Our ongoing comparative studies have led to several conclusions about the evolution of this posterior parietal region. In early placental mammals, PPC likely was a small multisensory region much like PPC of extant rodents and tree shrews. In early primates, PPC likely resembled that of prosimian galagos, in which caudal PPC (PPCc) is visual and rostral PPC (PPCr) has eight or more multisensory domains where electrical stimulation evokes different complex motor behaviors, including reaching, hand-to-mouth, looking, protecting the face or body, and grasping. These evoked behaviors depend on connections with functionally matched domains in premotor cortex (PMC) and motor cortex (M1). Domains in each region compete with each other, and a serial arrangement of domains allows different factors to influence motor outcomes successively. Similar arrangements of domains have been retained in New and Old World monkeys, and humans appear to have at least some of these domains. The great expansion and prolonged development of PPC in humans suggest the addition of functionally distinct territories. We propose that, across primates, PMC and M1 domains are second and third levels in a number of parallel, interacting networks for mediating and selecting one type of action over others. © 2015 Wiley Periodicals, Inc.

  7. Coding the presence of visual objects in a recurrent neural network of visual cortex.

    Science.gov (United States)

    Zwickel, Timm; Wachtler, Thomas; Eckhorn, Reinhard

    2007-01-01

    Before we can recognize a visual object, our visual system has to segregate it from its background. This requires a fast mechanism for establishing the presence and location of objects independently of their identity. Recently, border-ownership neurons were recorded in monkey visual cortex which might be involved in this task [Zhou, H., Friedmann, H., von der Heydt, R., 2000. Coding of border ownership in monkey visual cortex. J. Neurosci. 20 (17), 6594-6611]. In order to explain the basic mechanisms required for fast coding of object presence, we have developed a neural network model of visual cortex consisting of three stages. Feed-forward and lateral connections support coding of Gestalt properties, including similarity, good continuation, and convexity. Neurons of the highest area respond to the presence of an object and encode its position, invariant of its form. Feedback connections to the lowest area facilitate orientation detectors activated by contours belonging to potential objects, and thus generate the experimentally observed border-ownership property. This feedback control acts fast and significantly improves the figure-ground segregation required for the consecutive task of object recognition.

  8. The Crossed Projection to the Striatum in Two Species of Monkey and in Humans: Behavioral and Evolutionary Significance.

    Science.gov (United States)

    Innocenti, Giorgio M; Dyrby, Tim B; Andersen, Kasper Winther; Rouiller, Eric M; Caminiti, Roberto

    2017-06-01

    The corpus callosum establishes the anatomical continuity between the 2 hemispheres and coordinates their activity. Using histological tracing, single axon reconstructions, and diffusion tractography, we describe a callosal projection to n caudatus and putamen in monkeys and humans. In both species, the origin of this projection is more restricted than that of the ipsilateral projection. In monkeys, it consists of thin axons (0.4-0.6 µm), appropriate for spatial and temporal dispersion of subliminal inputs. For prefrontal cortex, contralateral minus ipsilateral delays to striatum calculated from axon diameters and conduction distance are <2 ms in the monkey and, by extrapolation, <4 ms in humans. This delay corresponds to the performance in Poffenberger's paradigm, a classical attempt to estimate central conduction delays, with a neuropsychological task. In both species, callosal cortico-striatal projections originate from prefrontal, premotor, and motor areas. In humans, we discovered a new projection originating from superior parietal lobule, supramarginal, and superior temporal gyrus, regions engaged in language processing. This projection crosses in the isthmus the lesion of which was reported to dissociate syntax and prosody. The projection might originate from an overproduction of callosal projections in development, differentially pruned depending on species. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  9. Distinct neuronal interactions in anterior inferotemporal areas of macaque monkeys during retrieval of object association memory.

    Science.gov (United States)

    Hirabayashi, Toshiyuki; Tamura, Keita; Takeuchi, Daigo; Takeda, Masaki; Koyano, Kenji W; Miyashita, Yasushi

    2014-07-09

    In macaque monkeys, the anterior inferotemporal cortex, a region crucial for object memory processing, is composed of two adjacent, hierarchically distinct areas, TE and 36, for which different functional roles and neuronal responses in object memory tasks have been characterized. However, it remains unknown how the neuronal interactions differ between these areas during memory retrieval. Here, we conducted simultaneous recordings from multiple single-units in each of these areas while monkeys performed an object association memory task and examined the inter-area differences in neuronal interactions during the delay period. Although memory neurons showing sustained activity for the presented cue stimulus, cue-holding (CH) neurons, interacted with each other in both areas, only those neurons in area 36 interacted with another type of memory neurons coding for the to-be-recalled paired associate (pair-recall neurons) during memory retrieval. Furthermore, pairs of CH neurons in area TE showed functional coupling in response to each individual object during memory retention, whereas the same class of neuron pairs in area 36 exhibited a comparable strength of coupling in response to both associated objects. These results suggest predominant neuronal interactions in area 36 during the mnemonic processing, which may underlie the pivotal role of this brain area in both storage and retrieval of object association memory. Copyright © 2014 the authors 0270-6474/14/349377-12$15.00/0.

  10. An autoradiographic study of the projections of the central nucleus of the monkey amygdala

    International Nuclear Information System (INIS)

    Price, J.L.; Amaral, D.G.

    1981-01-01

    The efferent connections of the central nucleus of the monkey amygdala have been studied using the autoradiographic method for tracing axonal projections. Small injections of 3H-amino-acids which are largely confined to the central nucleus lead to the labeling of several brainstem nuclei as far caudally as the spinomedullary junction. A number of intra-amygdaloid connections between the basal and lateral nuclei of the amygdala and the central nucleus are also described. The present findings, taken together with recently reported widespread projections from the temporal association cortex to the amygdala, point out a potentially trisynaptic route between neocortical association regions and a variety of brainstem nuclei, many of which are related to autonomic function

  11. Monkeying around: Use of Survey Monkey as a Tool for School Social Work

    Science.gov (United States)

    Massat, Carol Rippey; McKay, Cassandra; Moses, Helene

    2009-01-01

    This article describes the use of an online survey tool called Survey Monkey, which can be used by school social workers and school social work educators for evaluation of practice, needs assessment, and program evaluation. Examples of questions are given. Principles of writing good survey questions are described. (Contains 2 tables and 1…

  12. Locomotor Anatomy and Behavior of Patas Monkeys (Erythrocebus patas with Comparison to Vervet Monkeys (Cercopithecus aethiops

    Directory of Open Access Journals (Sweden)

    Adrienne L. Zihlman

    2013-01-01

    Full Text Available Patas monkeys (Erythrocebus patas living in African savanna woodlands and grassland habitats have a locomotor system that allows them to run fast, presumably to avoid predators. Long fore- and hindlimbs, long foot bones, short toes, and a digitigrade foot posture were proposed as anatomical correlates with speed. In addition to skeletal proportions, soft tissue and whole body proportions are important components of the locomotor system. To further distinguish patas anatomy from other Old World monkeys, a comparative study based on dissection of skin, muscle, and bone from complete individuals of patas and vervet monkeys (Cercopithecus aethiops was undertaken. Analysis reveals that small adjustments in patas skeletal proportions, relative mass of limbs and tail, and specific muscle groups promote efficient sagittal limb motion. The ability to run fast is based on a locomotor system adapted for long distance walking. The patas’ larger home range and longer daily range than those of vervets give them access to highly dispersed, nutritious foods, water, and sleeping trees. Furthermore, patas monkeys have physiological adaptations that enable them to tolerate and dissipate heat. These features all contribute to the distinct adaptation that is the patas monkeys’ basis for survival in grassland and savanna woodland areas.

  13. Transmission of naturally occurring lymphoma in macaque monkeys.

    OpenAIRE

    Hunt, R D; Blake, B J; Chalifoux, L V; Sehgal, P K; King, N W; Letvin, N L

    1983-01-01

    Spontaneously occurring rhesus monkey lymphomas were transmitted into healthy rhesus monkeys by using tumor cell suspensions. The naturally arising tumors included an immunoblastic sarcoma and an undifferentiated lymphoma. Recipient animals developed undifferentiated lymphomas, poorly differentiated lymphomas, or parenchymal lymphoproliferative abnormalities suggestive of early lesions of lymphoma. Some of these animals developed such opportunistic infections as cytomegalovirus hepatitis and ...

  14. Evaluation of diabetes determinants in woolly monkeys (Lagothrix lagotricha)

    NARCIS (Netherlands)

    Ange-van Heugten, K.D.; Burns, R.; Verstegen, M.W.A.; Jansen, W.L.; Ferket, P.R.; Heugten, E.

    2007-01-01

    Woolly monkeys (Lagothrix lagotricha) are a threatened specie in the wild with limited successful management in captivity due to diagnosed hypertension and suspected diabetic conditions. Six woolly monkeys with known hypertension problems were tested to determine if diabetes mellitus and current

  15. Perceptual Learning: 12-Month-Olds' Discrimination of Monkey Faces

    Science.gov (United States)

    Fair, Joseph; Flom, Ross; Jones, Jacob; Martin, Justin

    2012-01-01

    Six-month-olds reliably discriminate different monkey and human faces whereas 9-month-olds only discriminate different human faces. It is often falsely assumed that perceptual narrowing reflects a permanent change in perceptual abilities. In 3 experiments, ninety-six 12-month-olds' discrimination of unfamiliar monkey faces was examined. Following…

  16. Effect of sound intensity on tonotopic fMRI maps in the unanesthetized monkey.

    Science.gov (United States)

    Tanji, Kazuyo; Leopold, David A; Ye, Frank Q; Zhu, Charles; Malloy, Megan; Saunders, Richard C; Mishkin, Mortimer

    2010-01-01

    The monkey's auditory cortex includes a core region on the supratemporal plane (STP) made up of the tonotopically organized areas A1, R, and RT, together with a surrounding belt and a lateral parabelt region. The functional studies that yielded the tonotopic maps and corroborated the anatomical division into core, belt, and parabelt typically used low-amplitude pure tones that were often restricted to threshold-level intensities. Here we used functional magnetic resonance imaging in awake rhesus monkeys to determine whether, and if so how, the tonotopic maps and the pattern of activation in core, belt, and parabelt are affected by systematic changes in sound intensity. Blood oxygenation level-dependent (BOLD) responses to groups of low- and high-frequency pure tones 3-4 octaves apart were measured at multiple sound intensity levels. The results revealed tonotopic maps in the auditory core that reversed at the putative areal boundaries between A1 and R and between R and RT. Although these reversals of the tonotopic representations were present at all intensity levels, the lateral spread of activation depended on sound amplitude, with increasing recruitment of the adjacent belt areas as the intensities increased. Tonotopic organization along the STP was also evident in frequency-specific deactivation (i.e. "negative BOLD"), an effect that was intensity-specific as well. Regions of positive and negative BOLD were spatially interleaved, possibly reflecting lateral inhibition of high-frequency areas during activation of adjacent low-frequency areas, and vice versa. These results, which demonstrate the strong influence of tonal amplitude on activation levels, identify sound intensity as an important adjunct parameter for mapping the functional architecture of auditory cortex.

  17. Upregulation of Aβ42 in the Brain and Bodily Fluids of Rhesus Monkeys with Aging.

    Science.gov (United States)

    Zhao, Qiao; Lu, Jing; Yao, Zitong; Wang, Shubo; Zhu, Liming; Wang, Ju; Chen, Baian

    2017-01-01

    The cerebral accumulation of amyloid beta (Aβ) is one of the key pathological hallmarks of Alzheimer's disease (AD). Aβ is also found in bodily fluids such as the cerebrospinal fluid (CSF) and plasma. However, the significance of Aβ accumulation in the brain and different bodily pools, as well as its correlation with aging and cerebral amyloid pathology, is not completely understood. To better understand this question, we selected the rhesus monkey, which is phylogenetically and physiologically highly similar to the human, as a model to study. We quantified the levels of the two main Aβ isoforms (Aβ42 and Aβ40) in different sections of the brain (frontal cortex, temporal cortex, and hippocampus) and bodily fluids (CSF and plasma) of rhesus monkeys at different developmental phases (young, 5-9 years of age; mature, 10-19 years of age; and old, 21-24 years of age). We found that the levels of neuronal and insoluble Aβ42 increased significantly in the brain with aging, suggesting that this specific isoform might be directly involved in aging and AD-like pathophysiology. There was no significant change in the Aβ40 level in the brain with aging. In addition, the Aβ42 level, but not the Aβ40 level, in both the CSF and plasma increased with aging. We also identified a positive correlation between Aβ42 in the CSF and plasma and Aβ42 in the brain. Taken collectively, our results indicate that there is an association between Aβ accumulation and age. These results support the increased incidence of AD with aging.

  18. The occipital cortex in detection and categorisation abilities: an fMRI study in hemianopia

    International Nuclear Information System (INIS)

    Perez, C.; Coubard, O.; Cavezian, C.; Gout, O.; Chokron, S.; Peyrin, C.; Andersson, F.; Doucet, G.

    2011-01-01

    Complete text of publication follows: Previous studies have shown that the right and left hemispheres are predominant for detection and categorization tasks, respectively. This asymmetry appears to be instantiated at a processing stage as early as the occipital cortex. The present study was intended to assess the cerebral network responsible for natural scenes perception in hemianopic patients suffering from an occipital cortex lesion. One Left and one Right hemianopic patient (LH or RH; respectively right and left occipital damage) were compared with 14 healthy controls in detection and categorisation tasks of natural scenes. Both tasks were performed in a 1.5 T scanner to collect anatomical and functional data. In healthy controls, occipital activation was observed in the extra-striate areas of both hemispheres in the detection task but only of the left hemisphere in the categorization task. The LH (patient showed a bilateral occipital activation in both tasks. while, the RH patient showed unilateral right (intact) occipital activation in both tasks. These results highlight the importance of the perceptual task (detection vs. categorization) on the hemispheric asymmetry. They also suggest that different cortical reorganisations take place depending on the occipital lesion side

  19. Radioimmunoassay of parathyroid hormone (parathyrin) in monkey and man

    International Nuclear Information System (INIS)

    Hargis, G.K.; Williams, G.A.; Reynolds, W.A.; Kawahara, W.; Jackson, B.; Bowser, E.N.; Pitkin, R.M.

    1977-01-01

    A radioimmunoassay for rhesus monkey and human innumoreactive parathyrin was developed in which a selected anti-bovine parathyrin antiserum, radioiodinated purified bovine parathyrin tracer, and human parathyroid tissue-culture media standards were used. The resulting data indicate that the method is sensitive, specific, accurate and reproducible; it is valid for both the rhesus monkey and the human; the serum immunoreactive parathyrin concentration of the monkey is essentially the same as that in man; monkey immunoreactive parathyrin responds to changes in serum calcium concentration similarly to that in man; and the rhesus monkey is therefore a suitable species in which to study parathyroid physiology, from which conclusions can be applied to the human

  20. Consolidation of visual associative long-term memory in the temporal cortex of primates.

    Science.gov (United States)

    Miyashita, Y; Kameyama, M; Hasegawa, I; Fukushima, T

    1998-01-01

    Neuropsychological theories have proposed a critical role for the interaction between the medial temporal lobe and the neocortex in the formation of long-term memory for facts and events, which has often been tested by learning of a series of paired words or figures in humans. We have examined neural mechanisms underlying the memory "consolidation" process by single-unit recording and molecular biological methods in an animal model of a visual pair-association task in monkeys. In our previous studies, we found that long-term associative representations of visual objects are acquired through learning in the neural network of the anterior inferior temporal (IT) cortex. In this article, we propose the hypothesis that limbic neurons undergo rapid modification of synaptic connectivity and provide backward signals that guide the reorganization of neocortical neural circuits. Two experiments tested this hypothesis: (1) we examined the role of the backward connections from the medial temporal lobe to the IT cortex by injecting ibotenic acid into the entorhinal and perirhinal cortices, which provided massive backward projections ipsilaterally to the IT cortex. We found that the limbic lesion disrupted the associative code of the IT neurons between the paired associates, without impairing the visual response to each stimulus. (2) We then tested the first half of this hypothesis by detecting the expression of immediate-early genes in the monkey temporal cortex. We found specific expression of zif268 during the learning of a new set of paired associates in the pair-association task, most intensively in area 36 of the perirhinal cortex. All these results with the visual pair-association task support our hypothesis and demonstrate that the consolidation process, which was first proposed on the basis of clinico-psychological evidence, can now be examined in primates using neurophysiolocical and molecular biological approaches. Copyright 1998 Academic Press.

  1. Resolving the organization of the third tier visual cortex in primates: a hypothesis-based approach.

    Science.gov (United States)

    Angelucci, Alessandra; Rosa, Marcello G P

    2015-01-01

    As highlighted by several contributions to this special issue, there is still ongoing debate about the number, exact location, and boundaries of the visual areas located in cortex immediately rostral to the second visual area (V2), i.e., the "third tier" visual cortex, in primates. In this review, we provide a historical overview of the main ideas that have led to four models of third tier cortex organization, which are at the center of today's debate. We formulate specific predictions of these models, and compare these predictions with experimental evidence obtained primarily in New World primates. From this analysis, we conclude that only one of these models (the "multiple-areas" model) can accommodate the breadth of available experimental evidence. According to this model, most of the third tier cortex in New World primates is occupied by two distinct areas, both representing the full contralateral visual quadrant: the dorsomedial area (DM), restricted to the dorsal half of the third visual complex, and the ventrolateral posterior area (VLP), occupying its ventral half and a substantial fraction of its dorsal half. DM belongs to the dorsal stream of visual processing, and overlaps with macaque parietooccipital (PO) area (or V6), whereas VLP belongs to the ventral stream and overlaps considerably with area V3 proposed by others. In contrast, there is substantial evidence that is inconsistent with the concept of a single elongated area V3 lining much of V2. We also review the experimental evidence from macaque monkey and humans, and propose that, once the data are interpreted within an evolutionary-developmental context, these species share a homologous (but not necessarily identical) organization of the third tier cortex as that observed in New World monkeys. Finally, we identify outstanding issues, and propose experiments to resolve them, highlighting in particular the need for more extensive, hypothesis-driven investigations in macaque and humans.

  2. Face Pareidolia in the Rhesus Monkey.

    Science.gov (United States)

    Taubert, Jessica; Wardle, Susan G; Flessert, Molly; Leopold, David A; Ungerleider, Leslie G

    2017-08-21

    Face perception in humans and nonhuman primates is rapid and accurate [1-4]. In the human brain, a network of visual-processing regions is specialized for faces [5-7]. Although face processing is a priority of the primate visual system, face detection is not infallible. Face pareidolia is the compelling illusion of perceiving facial features on inanimate objects, such as the illusory face on the surface of the moon. Although face pareidolia is commonly experienced by humans, its presence in other species is unknown. Here we provide evidence for face pareidolia in a species known to possess a complex face-processing system [8-10]: the rhesus monkey (Macaca mulatta). In a visual preference task [11, 12], monkeys looked longer at photographs of objects that elicited face pareidolia in human observers than at photographs of similar objects that did not elicit illusory faces. Examination of eye movements revealed that monkeys fixated the illusory internal facial features in a pattern consistent with how they view photographs of faces [13]. Although the specialized response to faces observed in humans [1, 3, 5-7, 14] is often argued to be continuous across primates [4, 15], it was previously unclear whether face pareidolia arose from a uniquely human capacity. For example, pareidolia could be a product of the human aptitude for perceptual abstraction or result from frequent exposure to cartoons and illustrations that anthropomorphize inanimate objects. Instead, our results indicate that the perception of illusory facial features on inanimate objects is driven by a broadly tuned face-detection mechanism that we share with other species. Published by Elsevier Ltd.

  3. Total lymphoid irradiation in rhesus monkeys

    International Nuclear Information System (INIS)

    Vriesendorp, H.M.; Maat, B.; Hogeweg, B.

    Total lymphoid irradiation (TLI) consists of three contiguous fields, a mantle, an inverted Y and a spleen field. TLI induces a state of immunosuppression in patients with Hodgkin disease or in small rodents. Infusion of allogeneic bone marrow cells into mice after TLI led to the development split haemopoietic chimerism and indefinite survival of skin grafts from the bone marrow donor. A protocol for TLI was developed for rhesus monkeys to attempt to verify these interesting observations in a pre-clinical animal model. (Auth.)

  4. Distribution and abundance of sacred monkeys in Igboland, southern Nigeria.

    Science.gov (United States)

    Baker, Lynne R; Tanimola, Adebowale A; Olubode, Oluseun S; Garshelis, David L

    2009-07-01

    Although primates are hunted on a global scale, some species are protected against harassment and killing by taboos or religious doctrines. Sites where the killing of sacred monkeys or the destruction of sacred groves is forbidden may be integral to the conservation of certain species. In 2004, as part of a distribution survey of Sclater's guenon (Cercopithecus sclateri) in southern Nigeria, we investigated reports of sacred monkeys in the Igbo-speaking region of Nigeria. We confirmed nine new sites where primates are protected as sacred: four with tantalus monkeys (Chlorocebus tantalus) and five with mona monkeys (Cercopithecus mona). During 2004-2006, we visited two communities (Akpugoeze and Lagwa) previously known to harbor sacred populations of Ce. sclateri to estimate population abundance and trends. We directly counted all groups and compared our estimates with previous counts when available. We also estimated the size of sacred groves and compared these with grove sizes reported in the literature. The mean size of the sacred groves in Akpugoeze (2.06 ha, n = 10) was similar to others in Africa south of the Sahel, but larger than the average grove in Lagwa (0.49 ha, n = 15). We estimated a total population of 124 Sclater's monkeys in 15 groups in Lagwa and 193 monkeys in 20 groups in Akpugoeze. The Akpugoeze population was relatively stable over two decades, although the proportion of infants declined, and the number of groups increased. As Sclater's monkey does not occur in any official protected areas, sacred populations are important to the species' long-term conservation. Despite the monkeys' destruction of human crops, most local people still adhere to the custom of not killing monkeys. These sites represent ideal locations in which to study the ecology of Sclater's monkey and human-wildlife interactions. (c) 2009 Wiley-Liss, Inc.

  5. Origins of the specialization for letters and numbers in ventral occipitotemporal cortex.

    Science.gov (United States)

    Hannagan, Thomas; Amedi, Amir; Cohen, Laurent; Dehaene-Lambertz, Ghislaine; Dehaene, Stanislas

    2015-07-01

    Deep in the occipitotemporal cortex lie two functional regions, the visual word form area (VWFA) and the number form area (NFA), which are thought to play a special role in letter and number recognition, respectively. We review recent progress made in characterizing the origins of these symbol form areas in children or adults, sighted or blind subjects, and humans or monkeys. We propose two non-mutually-exclusive hypotheses on the origins of the VWFA and NFA: the presence of a connectivity bias, and a sensitivity to shape features. We assess the explanatory power of these hypotheses, describe their consequences, and offer several experimental tests. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Information processing occurs via critical avalanches in a model of the primary visual cortex

    International Nuclear Information System (INIS)

    Bortolotto, G. S.; Girardi-Schappo, M.; Gonsalves, J. J.; Tragtenberg, M. H. R.; Pinto, L. T.

    2016-01-01

    We study a new biologically motivated model for the Macaque monkey primary visual cortex which presents power-law avalanches after a visual stimulus. The signal propagates through all the layers of the model via avalanches that depend on network structure and synaptic parameter. We identify four different avalanche profiles as a function of the excitatory postsynaptic potential. The avalanches follow a size-duration scaling relation and present critical exponents that match experiments. The structure of the network gives rise to a regime of two characteristic spatial scales, one of which vanishes in the thermodynamic limit. (paper)

  7. High baseline activity in inferior temporal cortex improves neural and behavioral discriminability during visual categorization

    Science.gov (United States)

    Emadi, Nazli; Rajimehr, Reza; Esteky, Hossein

    2014-01-01

    Spontaneous firing is a ubiquitous property of neural activity in the brain. Recent literature suggests that this baseline activity plays a key role in perception. However, it is not known how the baseline activity contributes to neural coding and behavior. Here, by recording from the single neurons in the inferior temporal cortex of monkeys performing a visual categorization task, we thoroughly explored the relationship between baseline activity, the evoked response, and behavior. Specifically we found that a low-frequency (baseline activity. This enhancement of the baseline activity was then followed by an increase in the neural selectivity and the response reliability and eventually a higher behavioral performance. PMID:25404900

  8. Word Recognition in Auditory Cortex

    Science.gov (United States)

    DeWitt, Iain D. J.

    2013-01-01

    Although spoken word recognition is more fundamental to human communication than text recognition, knowledge of word-processing in auditory cortex is comparatively impoverished. This dissertation synthesizes current models of auditory cortex, models of cortical pattern recognition, models of single-word reading, results in phonetics and results in…

  9. Operant conditioning of neural activity in freely behaving monkeys with intracranial reinforcement.

    Science.gov (United States)

    Eaton, Ryan W; Libey, Tyler; Fetz, Eberhard E

    2017-03-01

    Operant conditioning of neural activity has typically been performed under controlled behavioral conditions using food reinforcement. This has limited the duration and behavioral context for neural conditioning. To reward cell activity in unconstrained primates, we sought sites in nucleus accumbens (NAc) whose stimulation reinforced operant responding. In three monkeys, NAc stimulation sustained performance of a manual target-tracking task, with response rates that increased monotonically with increasing NAc stimulation. We recorded activity of single motor cortex neurons and documented their modulation with wrist force. We conditioned increased firing rates with the monkey seated in the training booth and during free behavior in the cage using an autonomous head-fixed recording and stimulating system. Spikes occurring above baseline rates triggered single or multiple electrical pulses to the reinforcement site. Such rate-contingent, unit-triggered stimulation was made available for periods of 1-3 min separated by 3-10 min time-out periods. Feedback was presented as event-triggered clicks both in-cage and in-booth, and visual cues were provided in many in-booth sessions. In-booth conditioning produced increases in single neuron firing probability with intracranial reinforcement in 48 of 58 cells. Reinforced cell activity could rise more than five times that of non-reinforced activity. In-cage conditioning produced significant increases in 21 of 33 sessions. In-cage rate changes peaked later and lasted longer than in-booth changes, but were often comparatively smaller, between 13 and 18% above non-reinforced activity. Thus intracranial stimulation reinforced volitional increases in cortical firing rates during both free behavior and a controlled environment, although changes in the latter were more robust. NEW & NOTEWORTHY Closed-loop brain-computer interfaces (BCI) were used to operantly condition increases in muscle and neural activity in monkeys by delivering

  10. Myostatin, a profibrotic factor and the main inhibitor of striated muscle mass, is present in the penile and vascular smooth muscle.

    Science.gov (United States)

    Kovanecz, I; Masouminia, M; Gelfand, R; Vernet, D; Rajfer, J; Gonzalez-Cadavid, N F

    2017-09-01

    Myostatin is present in striated myofibers but, except for myometrial cells, has not been reported within smooth muscle cells (SMC). We investigated in the rat whether myostatin is present in SMC within the penis and the vascular wall and, if so, whether it is transcriptionally expressed and associated with the loss of corporal SMC occurring in certain forms of erectile dysfunction (ED). Myostatin protein was detected by immunohistochemistry/fluorescence and western blots in the perineal striated muscles, and also in the SMC of the penile corpora, arteries and veins, and aorta. Myostatin was found in corporal SMC cultures, and its transcriptional expression (and its receptor) was shown there by DNA microarrays. Myostatin protein was measured by western blots in the penile shaft of rats subjected to bilateral cavernosal nerve resection (BCNR), that were left untreated, or treated (45 days) with muscle-derived stem cells (MDSC), or concurrent daily low-dose sildenafil. Myostatin was not increased by BCNR (compared with sham operated animals), but over expressed after treatment with MDSC. This was reduced by concurrent sildenafil. The presence of myostatin in corporal and vascular SMC, and its overexpression in the corpora by MDSC therapy, may have relevance for the stem cell treatment of corporal fibrosis and ED.

  11. Scleral Biomechanics in the Aging Monkey Eye

    Science.gov (United States)

    Girard, Michaël J. A.; Suh, J-K. Francis; Bottlang, Michael; Burgoyne, Claude F.; Downs, J. Crawford

    2010-01-01

    Purpose To investigate the age-related differences in the inhomogeneous, anisotropic, nonlinear biomechanical properties of posterior sclera from old (22.9 ± 5.3 years) and young (1.5 ± 0.7 years) rhesus monkeys. Methods The posterior scleral shell of each eye was mounted on a custom-built pressurization apparatus, then intraocular pressure (IOP) was elevated from 5 to 45 mmHg while the 3D displacements of the scleral surface were measured using speckle interferometry. Each scleral shell geometry was digitally reconstructed from data generated by a 3D digitizer (topography) and 20 MHz ultrasounds (thickness). An inverse finite element (FE) method incorporating a fiber-reinforced constitutive model was used to extract a unique set of biomechanical properties for each eye. Displacements, thickness, stress, strain, tangent modulus, structural stiffness, and preferred collagen fiber orientation were mapped for each posterior sclera. Results The model yielded 3-D deformations of posterior sclera that matched well with those observed experimentally. The posterior sclera exhibited inhomogeneous, anisotropic, nonlinear mechanical behavior. The sclera was significantly thinner (p = 0.038), and tangent modulus and structural stiffness were significantly higher in old monkeys (p biomechanics, and potentially contribute to age-related susceptibility to glaucomatous vision loss. PMID:19494203

  12. Explicit information reduces discounting behavior in monkeys

    Directory of Open Access Journals (Sweden)

    John ePearson

    2010-12-01

    Full Text Available Animals are notoriously impulsive in common laboratory experiments, preferring smaller, sooner rewards to larger, delayed rewards even when this reduces average reward rates. By contrast, the same animals often engage in natural behaviors that require extreme patience, such as food caching, stalking prey, and traveling long distances to high quality food sites. One possible explanation for this discrepancy is that standard laboratory delay discounting tasks artificially inflate impulsivity by subverting animals’ common learning strategies. To test this idea, we examined choices made by rhesus macaques in two variants of a standard delay discounting task. In the conventional variant, post-reward delays were uncued and adjusted to render total trial length constant; in the second, all delays were cued explicitly. We found that measured discounting was significantly reduced in the cued task, with discount rates well below those reported in studies using the standard uncued design. When monkeys had complete information, their decisions were more consistent with a strategy of reward rate maximization. These results indicate that monkeys, and perhaps other animals, are more patient than is normally assumed, and that laboratory measures of delay discounting may overstate impulsivity.

  13. Subarachnoid administration of iohexol in cynomolgus monkeys

    International Nuclear Information System (INIS)

    Drobeck, H.P.; Mayes, B.A.; Barbolt, T.A.; Fabian, R.J.; Kimball, J.P.; Slighter, R.R. Jr.

    1986-01-01

    A non-ionic diagnostic medium, iohexol, was administered by subarachnoid injection to groups of six cynomolgus monkeys and compared with the vehicle, physiologically normal saline, and/or saline of equal osmolality to determine its potential for increasing total protein and leucocyte levels in cerebrospinal fluid. Also investigated was the effect of repeated spinal taps not subsequently followed by the intrathecal injection of test or control articles. In the monkey, unlike man, low-level leucocyte counts were consistently observed following initial withdrawal of spinal fluid. Elevated leucocyte and total protein levels were observed in the present investigations one day to a week after intrathecal injection of radiopaque, vehicle or saline solution. Total protein returned to normal levels earlier than did leucocyte counts. However, repeated needle puncture alone was found to be sufficient to cause an elevation of leucocytes 3 to 4 times the baseline level, while inflammatory effects were observed histologically only when autopsy was performed soon after the final spinal tap. (orig.)

  14. Marmoset monkeys evaluate third-party reciprocity.

    Science.gov (United States)

    Kawai, Nobuyuki; Yasue, Miyuki; Banno, Taku; Ichinohe, Noritaka

    2014-05-01

    Many non-human primates have been observed to reciprocate and to understand reciprocity in one-to-one social exchanges. A recent study demonstrated that capuchin monkeys are sensitive to both third-party reciprocity and violation of reciprocity; however, whether this sensitivity is a function of general intelligence, evidenced by their larger brain size relative to other primates, remains unclear. We hypothesized that highly pro-social primates, even with a relatively smaller brain, would be sensitive to others' reciprocity. Here, we show that common marmosets discriminated between human actors who reciprocated in social exchanges with others and those who did not. Monkeys accepted rewards less frequently from non-reciprocators than they did from reciprocators when the non-reciprocators had retained all food items, but they accepted rewards from both actors equally when they had observed reciprocal exchange between the actors. These results suggest that mechanisms to detect unfair reciprocity in third-party social exchanges do not require domain-general higher cognitive ability based on proportionally larger brains, but rather emerge from the cooperative and pro-social tendencies of species, and thereby suggest this ability evolved in multiple primate lineages. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  15. Seeing is not feeling: posterior parietal but not somatosensory cortex engagement during touch observation.

    Science.gov (United States)

    Chan, Annie W-Y; Baker, Chris I

    2015-01-28

    Observing touch has been reported to elicit activation in human primary and secondary somatosensory cortices and is suggested to underlie our ability to interpret other's behavior and potentially empathy. However, despite these reports, there are a large number of inconsistencies in terms of the precise topography of activation, the extent of hemispheric lateralization, and what aspects of the stimulus are necessary to drive responses. To address these issues, we investigated the localization and functional properties of regions responsive to observed touch in a large group of participants (n = 40). Surprisingly, even with a lenient contrast of hand brushing versus brushing alone, we did not find any selective activation for observed touch in the hand regions of somatosensory cortex but rather in superior and inferior portions of neighboring posterior parietal cortex, predominantly in the left hemisphere. These regions in the posterior parietal cortex required the presence of both brush and hand to elicit strong responses and showed some selectivity for the form of the object or agent of touch. Furthermore, the inferior parietal region showed nonspecific tactile and motor responses, suggesting some similarity to area PFG in the monkey. Collectively, our findings challenge the automatic engagement of somatosensory cortex when observing touch, suggest mislocalization in previous studies, and instead highlight the role of posterior parietal cortex. Copyright © 2015 the authors 0270-6474/15/351468-13$15.00/0.

  16. Diverse coupling of neurons to populations in sensory cortex.

    Science.gov (United States)

    Okun, Michael; Steinmetz, Nicholas; Cossell, Lee; Iacaruso, M Florencia; Ko, Ho; Barthó, Péter; Moore, Tirin; Hofer, Sonja B; Mrsic-Flogel, Thomas D; Carandini, Matteo; Harris, Kenneth D

    2015-05-28

    A large population of neurons can, in principle, produce an astronomical number of distinct firing patterns. In cortex, however, these patterns lie in a space of lower dimension, as if individual neurons were "obedient members of a huge orchestra". Here we use recordings from the visual cortex of mouse (Mus musculus) and monkey (Macaca mulatta) to investigate the relationship between individual neurons and the population, and to establish the underlying circuit mechanisms. We show that neighbouring neurons can differ in their coupling to the overall firing of the population, ranging from strongly coupled 'choristers' to weakly coupled 'soloists'. Population coupling is largely independent of sensory preferences, and it is a fixed cellular attribute, invariant to stimulus conditions. Neurons with high population coupling are more strongly affected by non-sensory behavioural variables such as motor intention. Population coupling reflects a causal relationship, predicting the response of a neuron to optogenetically driven increases in local activity. Moreover, population coupling indicates synaptic connectivity; the population coupling of a neuron, measured in vivo, predicted subsequent in vitro estimates of the number of synapses received from its neighbours. Finally, population coupling provides a compact summary of population activity; knowledge of the population couplings of n neurons predicts a substantial portion of their n(2) pairwise correlations. Population coupling therefore represents a novel, simple measure that characterizes the relationship of each neuron to a larger population, explaining seemingly complex network firing patterns in terms of basic circuit variables.

  17. Grasp movement decoding from premotor and parietal cortex.

    Science.gov (United States)

    Townsend, Benjamin R; Subasi, Erk; Scherberger, Hansjörg

    2011-10-05

    Despite recent advances in harnessing cortical motor-related activity to control computer cursors and robotic devices, the ability to decode and execute different grasping patterns remains a major obstacle. Here we demonstrate a simple Bayesian decoder for real-time classification of grip type and wrist orientation in macaque monkeys that uses higher-order planning signals from anterior intraparietal cortex (AIP) and ventral premotor cortex (area F5). Real-time decoding was based on multiunit signals, which had similar tuning properties to cells in previous single-unit recording studies. Maximum decoding accuracy for two grasp types (power and precision grip) and five wrist orientations was 63% (chance level, 10%). Analysis of decoder performance showed that grip type decoding was highly accurate (90.6%), with most errors occurring during orientation classification. In a subsequent off-line analysis, we found small but significant performance improvements (mean, 6.25 percentage points) when using an optimized spike-sorting method (superparamagnetic clustering). Furthermore, we observed significant differences in the contributions of F5 and AIP for grasp decoding, with F5 being better suited for classification of the grip type and AIP contributing more toward decoding of object orientation. However, optimum decoding performance was maximal when using neural activity simultaneously from both areas. Overall, these results highlight quantitative differences in the functional representation of grasp movements in AIP and F5 and represent a first step toward using these signals for developing functional neural interfaces for hand grasping.

  18. Dissociation of item and source memory in rhesus monkeys.

    Science.gov (United States)

    Basile, Benjamin M; Hampton, Robert R

    2017-09-01

    Source memory, or memory for the context in which a memory was formed, is a defining characteristic of human episodic memory and source memory errors are a debilitating symptom of memory dysfunction. Evidence for source memory in nonhuman primates is sparse despite considerable evidence for other types of sophisticated memory and the practical need for good models of episodic memory in nonhuman primates. A previous study showed that rhesus monkeys confused the identity of a monkey they saw with a monkey they heard, but only after an extended memory delay. This suggests that they initially remembered the source - visual or auditory - of the information but forgot the source as time passed. Here, we present a monkey model of source memory that is based on this previous study. In each trial, monkeys studied two images, one that they simply viewed and touched and the other that they classified as a bird, fish, flower, or person. In a subsequent memory test, they were required to select the image from one source but avoid the other. With training, monkeys learned to suppress responding to images from the to-be-avoided source. After longer memory intervals, monkeys continued to show reliable item memory, discriminating studied images from distractors, but made many source memory errors. Monkeys discriminated source based on study method, not study order, providing preliminary evidence that our manipulation of retention interval caused errors due to source forgetting instead of source confusion. Finally, some monkeys learned to select remembered images from either source on cue, showing that they did indeed remember both items and both sources. This paradigm potentially provides a new model to study a critical aspect of episodic memory in nonhuman primates. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Intrinsic frequency biases and profiles across human cortex.

    Science.gov (United States)

    Mellem, Monika S; Wohltjen, Sophie; Gotts, Stephen J; Ghuman, Avniel Singh; Martin, Alex

    2017-11-01

    Recent findings in monkeys suggest that intrinsic periodic spiking activity in selective cortical areas occurs at timescales that follow a sensory or lower order-to-higher order processing hierarchy (Murray JD, Bernacchia A, Freedman DJ, Romo R, Wallis JD, Cai X, Padoa-Schioppa C, Pasternak T, Seo H, Lee D, Wang XJ. Nat Neurosci 17: 1661-1663, 2014). It has not yet been fully explored if a similar timescale hierarchy is present in humans. Additionally, these measures in the monkey studies have not addressed findings that rhythmic activity within a brain area can occur at multiple frequencies. In this study we investigate in humans if regions may be biased toward particular frequencies of intrinsic activity and if a full cortical mapping still reveals an organization that follows this hierarchy. We examined the spectral power in multiple frequency bands (0.5-150 Hz) from task-independent data using magnetoencephalography (MEG). We compared standardized power across bands to find regional frequency biases. Our results demonstrate a mix of lower and higher frequency biases across sensory and higher order regions. Thus they suggest a more complex cortical organization that does not simply follow this hierarchy. Additionally, some regions do not display a bias for a single band, and a data-driven clustering analysis reveals a regional organization with high standardized power in multiple bands. Specifically, theta and beta are both high in dorsal frontal cortex, whereas delta and gamma are high in ventral frontal cortex and temporal cortex. Occipital and parietal regions are biased more narrowly toward alpha power, and ventral temporal lobe displays specific biases toward gamma. Thus intrinsic rhythmic neural activity displays a regional organization but one that is not necessarily hierarchical. NEW & NOTEWORTHY The organization of rhythmic neural activity is not well understood. Whereas it has been postulated that rhythms are organized in a hierarchical manner across

  20. Dissecting the mechanisms of squirrel monkey (Saimiri boliviensis) social learning.

    Science.gov (United States)

    Hopper, Lm; Holmes, An; Williams, LE; Brosnan, Sf

    2013-01-01

    Although the social learning abilities of monkeys have been well documented, this research has only focused on a few species. Furthermore, of those that also incorporated dissections of social learning mechanisms, the majority studied either capuchins (Cebus apella) or marmosets (Callithrix jacchus). To gain a broader understanding of how monkeys gain new skills, we tested squirrel monkeys (Saimiri boliviensis) which have never been studied in tests of social learning mechanisms. To determine whether S. boliviensis can socially learn, we ran "open diffusion" tests with monkeys housed in two social groups (N = 23). Over the course of 10 20-min sessions, the monkeys in each group observed a trained group member retrieving a mealworm from a bidirectional task (the "Slide-box"). Two thirds (67%) of these monkeys both learned how to operate the Slide-box and they also moved the door significantly more times in the direction modeled by the trained demonstrator than the alternative direction. To tease apart the underlying social learning mechanisms we ran a series of three control conditions with 35 squirrel monkeys that had no previous experience with the Slide-box. The first replicated the experimental open diffusion sessions but without the inclusion of a trained model, the second was a no-information control with dyads of monkeys, and the third was a 'ghost' display shown to individual monkeys. The first two controls tested for the importance of social support (mere presence effect) and the ghost display showed the affordances of the task to the monkeys. The monkeys showed a certain level of success in the group control (54% of subjects solved the task on one or more occasions) and paired controls (28% were successful) but none were successful in the ghost control. We propose that the squirrel monkeys' learning, observed in the experimental open diffusion tests, can be best described by a combination of social learning mechanisms in concert; in this case, those

  1. Comment on "Monkey vocal tracts are speech-ready".

    Science.gov (United States)

    Lieberman, Philip

    2017-07-01

    Monkey vocal tracts are capable of producing monkey speech, not the full range of articulate human speech. The evolution of human speech entailed both anatomy and brains. Fitch, de Boer, Mathur, and Ghazanfar in Science Advances claim that "monkey vocal tracts are speech-ready," and conclude that "…the evolution of human speech capabilities required neural change rather than modifications of vocal anatomy." Neither premise is consistent either with the data presented and the conclusions reached by de Boer and Fitch themselves in their own published papers on the role of anatomy in the evolution of human speech or with the body of independent studies published since the 1950s.

  2. Loss of metabolites from monkey striatum during PET with FDOPA

    DEFF Research Database (Denmark)

    Cumming, P; Munk, O L; Doudet, D

    2001-01-01

    constants using data recorded during 240 min of FDOPA circulation in normal monkeys and in monkeys with unilateral 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) lesions. Use of the extended models increased the magnitudes of K(D)(i) and k(D)(3) in striatum; in the case of k(D)(3), variance...... of the estimate was substantially improved upon correction for metabolite loss. The rate constants for metabolite loss were higher in MPTP-lesioned monkey striatum than in normal striatum. The high correlation between individual estimates of k(Lin)(cl) and k(DA)(9) suggests that both rate constants reveal loss...

  3. Cerebral cortex modulation of pain

    Institute of Scientific and Technical Information of China (English)

    Yu-feng XIE; Fu-quan HUO; Jing-shi TANG

    2009-01-01

    Pain is a complex experience encompassing sensory-discriminative, affective-motivational and cognitiv e-emotional com-ponents mediated by different mechanisms. Contrary to the traditional view that the cerebral cortex is not involved in pain perception, an extensive cortical network associated with pain processing has been revealed using multiple methods over the past decades. This network consistently includes, at least, the anterior cingulate cortex, the agranular insular cortex, the primary (SⅠ) and secondary somatosensory (SⅡ) cortices, the ventrolateral orbital cortex and the motor cortex. These corti-cal structures constitute the medial and lateral pain systems, the nucleus submedius-ventrolateral orbital cortex-periaque-ductal gray system and motor cortex system, respectively. Multiple neurotransmitters, including opioid, glutamate, GABA and dopamine, are involved in the modulation of pain by these cortical structures. In addition, glial cells may also be in-volved in cortical modulation of pain and serve as one target for pain management research. This review discusses recent studies of pain modulation by these cerebral cortical structures in animals and human.

  4. Glacially striated, soft sediment surfaces on late Paleozoic tillite at São Luiz do Purunã, PR

    Directory of Open Access Journals (Sweden)

    Ivo Trosdtorf Jr.

    2005-06-01

    Full Text Available Striae and furrows found on the upper surfaces of three stratigraphically superposed decimetric beds of late Paleozoic lodgement tillite of the Itararé Subgroup in the northern Paraná Basin were engraved by ploughing of clasts and possibly also ice protuberances at the base of the glacier, on unconsolidated to partially consolidated sediment. Associated features indicate that the rheology of the bed varied from stiff during lodgement to soft and deformable during ploughing. Poor drainage of meltwater at the glacier-bed interface may have contributed to lower the strength of sediment to deformation. The deformed interval was probably generated during a single glacial phase or advance of a glacier grounding in a marine or lacustrine water body. Changes in the dynamics of the glacier involving slow and fast flow were correlated respectively with alternation of deposition and erosion. The proposed model is analogous to that of lodgement till complexes from the Pleistocene of the northern hemisphere. Retreat of the glacier was probably fast, followed by settling of muds on top of the upper striated and furrowed surface, and progradation of deltaic sands during post-glacial time.Estrias e sulcos encontrados sobre três camadas decimétricas, estratigraficamente superpostas, de tilito de alojamento neopaleozóico do Subgrupo Itararé, na porção norte da Bacia do Paraná, foram formados por aração de clastos e, possivelmente, por protuberâncias de gelo, na base da geleira. Feições associadas indicam que a reologia do sedimento variou de rígido, durante o alojamento, a inconsolidado e deformável durante a aração. A baixa drenagem da água de degelo na interface geleira-substrato pode ter contribuído para reduzir a resistência do sedimento à deformação. A sucessão acima foi gerada provavelmente durante uma única fase glacial ou avanço de geleira sobre corpo de água marinho ou lacustre. Mudanças na dinâmica da geleira envolvendo

  5. Theta coupling between V4 and prefrontal cortex predicts visual short-term memory performance.

    Science.gov (United States)

    Liebe, Stefanie; Hoerzer, Gregor M; Logothetis, Nikos K; Rainer, Gregor

    2012-01-29

    Short-term memory requires communication between multiple brain regions that collectively mediate the encoding and maintenance of sensory information. It has been suggested that oscillatory synchronization underlies intercortical communication. Yet, whether and how distant cortical areas cooperate during visual memory remains elusive. We examined neural interactions between visual area V4 and the lateral prefrontal cortex using simultaneous local field potential (LFP) recordings and single-unit activity (SUA) in monkeys performing a visual short-term memory task. During the memory period, we observed enhanced between-area phase synchronization in theta frequencies (3-9 Hz) of LFPs together with elevated phase locking of SUA to theta oscillations across regions. In addition, we found that the strength of intercortical locking was predictive of the animals' behavioral performance. This suggests that theta-band synchronization coordinates action potential communication between V4 and prefrontal cortex that may contribute to the maintenance of visual short-term memories.

  6. Temporal Sequence of Visuo-Auditory Interaction in Multiple Areas of the Guinea Pig Visual Cortex

    Science.gov (United States)

    Nishimura, Masataka; Song, Wen-Jie

    2012-01-01

    Recent studies in humans and monkeys have reported that acoustic stimulation influences visual responses in the primary visual cortex (V1). Such influences can be generated in V1, either by direct auditory projections or by feedback projections from extrastriate cortices. To test these hypotheses, cortical activities were recorded using optical imaging at a high spatiotemporal resolution from multiple areas of the guinea pig visual cortex, to visual and/or acoustic stimulations. Visuo-auditory interactions were evaluated according to differences between responses evoked by combined auditory and visual stimulation, and the sum of responses evoked by separate visual and auditory stimulations. Simultaneous presentation of visual and acoustic stimulations resulted in significant interactions in V1, which occurred earlier than in other visual areas. When acoustic stimulation preceded visual stimulation, significant visuo-auditory interactions were detected only in V1. These results suggest that V1 is a cortical origin of visuo-auditory interaction. PMID:23029483

  7. Anatomical pathways for auditory memory II: Information from rostral superior temporal gyrus to dorsolateral temporal pole and medial temporal cortex.

    Directory of Open Access Journals (Sweden)

    Monica eMunoz-Lopez

    2015-05-01

    Full Text Available Auditory recognition memory in non-human primates differs from recognition memory in other sensory systems. Monkeys learn the rule for visual and tactile delayed matching-to-sample within a few sessions, and then show one-trial recognition memory lasting 10-20 minutes. In contrast, monkeys require hundreds of sessions to master the rule for auditory recognition, and then show retention lasting no longer than 30-40 seconds. Moreover, unlike the severe effects of rhinal lesions on visual memory, such lesions have no effect on the monkeys’ auditory memory performance. It is possible, therefore, that the anatomical pathways differ. Long-term visual recognition memory requires anatomical connections from the visual association area TE with areas 35 and 36 of the perirhinal cortex (PRC. We examined whether there is a similar anatomical route for auditory processing, or that poor auditory recognition memory may reflect the lack of such a pathway. Our hypothesis is that an auditory pathway for recognition memory originates in the higher order processing areas of the rostral superior temporal gyrus (rSTG, and then connects via the dorsolateral temporal pole to access the rhinal cortex of the medial temporal lobe. To test this, we placed retrograde (3% FB and 2% DY and anterograde (10% BDA 10,000 MW tracer injections in rSTG and the dorsolateral area 38DL of the temporal pole. Results showed that area 38DL receives dense projections from auditory association areas Ts1, TAa, TPO of the rSTG, from the rostral parabelt and, to a lesser extent, from areas Ts2-3 and PGa. In turn, area 38DL projects densely to area 35 of PRC, entorhinal cortex, and to areas TH/TF of the posterior parahippocampal cortex. Significantly, this projection avoids most of area 36r/c of PRC. This anatomical arrangement may contribute to our understanding of the poor auditory memory of rhesus monkeys.

  8. Neuropeptide Y-immunoreactive neurons in the cerebral cortex of humans and other haplorrhine primates

    Science.gov (United States)

    Raghanti, Mary Ann; Conley, Tiffini; Sudduth, Jessica; Erwin, Joseph M.; Stimpson, Cheryl D.; Hof, Patrick R.; Sherwood, Chet C.

    2012-01-01

    We examined the distribution of neurons immunoreactive for neuropeptide Y (NPY) in the posterior part of the superior temporal cortex (Brodmann's area 22 or area Tpt) of humans and nonhuman haplorrhine primates. NPY has been implicated in learning and memory and the density of NPY-expressing cortical neurons and axons is reduced in depression, bipolar disorder, schizophrenia, and Alzheimer's disease. Due to the role that NPY plays in both cognition and neurodegenerative diseases, we tested the hypothesis that the density of cortical and interstitial neurons expressing NPY was increased in humans relative to other primate species. The study sample included great apes (chimpanzee and gorilla), Old World monkeys (pigtailed macaque, moor macaque, and baboon) and New World monkeys (squirrel monkey and capuchin). Stereologic methods were used to estimate the density of NPY-immunoreactive (-ir) neurons in layers I-VI of area Tpt and the subjacent white matter. Adjacent Nissl-stained sections were used to calculate local densities of all neurons. The ratio of NPY-ir neurons to total neurons within area Tpt and the total density of NPY-ir neurons within the white matter were compared among species. Overall, NPY-ir neurons represented only an average of 0.006% of the total neuron population. While there were significant differences among species, phylogenetic trends in NPY-ir neuron distributions were not observed and humans did not differ from other primates. However, variation among species warrants further investigation into the distribution of this neuromodulator system. PMID:23042407

  9. Transplantation of adult monkey neural stem cells into a contusion spinal cord injury model in rhesus macaque monkeys

    DEFF Research Database (Denmark)

    Nemati, Shiva Nemati; Jabbari, Reza; Hajinasrollah, Mostafa

    2014-01-01

    , therefore, to explore the efficacy of adult monkey NSC (mNSC) in a primate SCI model. MATERIALS AND METHODS: In this experimental study, isolated mNSCs were analyzed by flow cytometry, immunocytochemistry, and RT-PCR. Next, BrdU-labeled cells were transplanted into a SCI model. The SCI animal model...... on Tarlov's scale and our established behavioral tests for monkeys. CONCLUSION: Our findings have indicated that mNSCs can facilitate recovery in contusion SCI models in rhesus macaque monkeys. Additional studies are necessary to determine the im- provement mechanisms after cell transplantation....

  10. Callosal connections of dorso-lateral premotor cortex.

    Science.gov (United States)

    Marconi, B; Genovesio, A; Giannetti, S; Molinari, M; Caminiti, R

    2003-08-01

    This study investigated the organization of the callosal connections of the two subdivisions of the monkey dorsal premotor cortex (PMd), dorso-rostral (F7) and dorso-caudal (F2). In one animal, Fast blue and Diamidino yellow were injected in F7 and F2, respectively; in a second animal, the pattern of injections was reversed. F7 and F2 receive a major callosal input from their homotopic counterpart. The heterotopic connections of F7 originate mainly from F2, with smaller contingent from pre-supplementary motor area (pre-SMA, F6), area 8 (frontal eye fields), and prefrontal cortex (area 46), while those of F2 originate from F7, with smaller contributions from ventral premotor areas (F5, F4), SMA-proper (F3), and primary motor cortex (M1). Callosal cells projecting homotopically are mostly located in layers II-III, those projecting heterotopically occupy layers II-III and V-VI. A spectral analysis was used to characterize the spatial fluctuations of the distribution of callosal neurons, in both F7 and F2, as well as in adjacent cortical areas. The results revealed two main periodic components. The first, in the domain of the low spatial frequencies, corresponds to periodicities of cell density with peak-to-peak distances of approximately 10 mm, and suggests an arrangement of callosal cells in the form of 5-mm wide bands. The second corresponds to periodicities of approximately 2 mm, and probably reflects a 1-mm columnar-like arrangement. Coherency and phase analyses showed that, although similar in their spatial arrangements, callosal cells projecting to dorsal premotor areas are segregated in the tangential cortical domain.

  11. The reactivation of somatosensory cortex and behavioral recovery after sensory loss in mature primates

    Directory of Open Access Journals (Sweden)

    Hui-Xin eQi

    2014-05-01

    Full Text Available In our experiments, we removed a major source of activation of somatosensory cortex in mature monkeys by unilaterally sectioning the sensory afferents in the dorsal columns of the spinal cord at a high cervical level. At this level, the ascending branches of tactile afferents from the hand are cut, while other branches of these afferents remain intact to terminate on neurons in the dorsal horn of the spinal cord. Immediately after such a lesion, the monkeys seem relatively unimpaired in locomotion and often use the forelimb, but further inspection reveals that they prefer to use the unaffected hand in reaching for food. In addition, systematic testing indicates that they make more errors in retrieving pieces of food, and start using visual inspection of the rotated hand to confirm the success of the grasping of the food. Such difficulties are not surprising as a complete dorsal column lesion totally deactivates the contralateral hand representation in primary somatosensory cortex (area 3b. However, hand use rapidly improves over the first post-lesion weeks, and much of the hand representational territory in contralateral area 3b is reactivated by inputs from the hand in roughly a normal somatotopic pattern. Quantitative measures of single neuron response properties reveal that reactivated neurons respond to tactile stimulation on the hand with high firing rates and only slightly longer latencies. We conclude that preserved dorsal column afferents after nearly complete lesions contribute to the reactivation of cortex and the recovery of the behavior, but second-order sensory pathways in the spinal cord may also play an important role. Our microelectrode recordings indicate that these preserved first-order, and second-order pathways are initially weak and largely ineffective in activating cortex, but they are potentiated during the recovery process. Therapies that would promote this potentiation could usefully enhance recovery after spinal cord

  12. P1-27: Localizing Regions Activated by Surface Gloss in Macaque Visual Cortex by fMRI

    Directory of Open Access Journals (Sweden)

    Gouki Okazawa

    2012-10-01

    Full Text Available Surface properties of objects such as gloss provide important information about the states or materials of objects in our visual experiences. Previous studies have shown that there are cortical regions responding to shapes, colors, faces etc. in the macaque visual cortex. However, we still lack the information about where the surface properties are processed in the macaque visual cortex. In this study, we examined whether there are regions activated by surface gloss, an important surface property, in the macaque visual cortex by using functional magnetic resonance imaging (fMRI. We trained two monkeys to fixate on a small spot on the screen in MRI scanner, while the images of glossy and matte objects were presented. As a control condition for low-level image features, such as spatial frequency or luminance contrast, we generated scrambled images by locally randomizing the luminance phases of images using wavelet filters. By contrasting the responses to glossy images to those to matte and scrambled images, we found the activation in wide regions along the ventral visual pathway including V1, V2, V3, V4, and the posterior part of the inferior temporal (IT cortex. In one monkey, we also found the activations in the central part of IT cortex. In another control experiment, we manipulated the image contrasts and found that the responses in these regions cannot be explained simply by the image contrasts. These results suggest that surface gloss is processed along the ventral pathway and, in the IT cortex there are distinct regions processing surface gloss.

  13. Synthesis, characterization, and first successful monkey imaging studies of metabotropic glutamate receptor subtype 5 (mGluR5) PET radiotracers.

    Science.gov (United States)

    Hamill, Terence G; Krause, Stephen; Ryan, Christine; Bonnefous, Celine; Govek, Steve; Seiders, T Jon; Cosford, Nicholas D P; Roppe, Jeffrey; Kamenecka, Ted; Patel, Shil; Gibson, Raymond E; Sanabria, Sandra; Riffel, Kerry; Eng, Waisi; King, Christopher; Yang, Xiaoqing; Green, Mitchell D; O'Malley, Stacey S; Hargreaves, Richard; Burns, H Donald

    2005-06-15

    Three metabotropic glutamate receptor subtype 5 (mGluR5) PET tracers have been labeled with either carbon-11 or fluorine-18 and their in vitro and in vivo behavior in rhesus monkey has been characterized. Each of these tracers share the common features of high affinity for mGluR5 (0.08-0.23 nM vs. rat mGluR5) and moderate lipophilicity (log P 2.8-3.4). Compound 1b was synthesized using a Suzuki or Stille coupling reaction with [11C]MeI. Compounds 2b and 3b were synthesized by a SNAr reaction using a 3-chlorobenzonitrile precursor. Autoradiographic studies in rhesus monkey brain slices using 2b and 3b showed specific binding in cortex, caudate, putamen, amygdala, hippocampus, most thalamic nuclei, and lower binding in the cerebellum. PET imaging studies in monkey showed that all three tracers readily enter the brain and provide an mGluR5-specific signal in all gray matter regions, including the cerebellum. The specific signal observed in the cerebellum was confirmed by the autoradiographic studies and saturation binding experiments that showed tracer binding in the cerebellum of rhesus monkeys. In vitro metabolism studies using the unlabeled compounds showed that 1a, 2a, and 3a are metabolized slower by human liver microsomes than by monkey liver microsomes. In vivo metabolism studies showed 3b to be long-lived in rhesus plasma with only one other more polar metabolite observed. (c) 2005 Wiley-Liss, Inc.

  14. Maps of the Auditory Cortex.

    Science.gov (United States)

    Brewer, Alyssa A; Barton, Brian

    2016-07-08

    One of the fundamental properties of the mammalian brain is that sensory regions of cortex are formed of multiple, functionally specialized cortical field maps (CFMs). Each CFM comprises two orthogonal topographical representations, reflecting two essential aspects of sensory space. In auditory cortex, auditory field maps (AFMs) are defined by the combination of tonotopic gradients, representing the spectral aspects of sound (i.e., tones), with orthogonal periodotopic gradients, representing the temporal aspects of sound (i.e., period or temporal envelope). Converging evidence from cytoarchitectural and neuroimaging measurements underlies the definition of 11 AFMs across core and belt regions of human auditory cortex, with likely homology to those of macaque. On a macrostructural level, AFMs are grouped into cloverleaf clusters, an organizational structure also seen in visual cortex. Future research can now use these AFMs to investigate specific stages of auditory processing, key for understanding behaviors such as speech perception and multimodal sensory integration.

  15. Short parietal lobe connections of the human and monkey brain

    DEFF Research Database (Denmark)

    Catani, Marco; Robertsson, Naianna; Beyh, Ahmad

    2017-01-01

    projections were reconstructed for both species and results compared to identify similarities or differences in tract anatomy (i.e., trajectories and cortical projections). In addition, post-mortem dissections were performed in a human brain. The largest tract identified in both human and monkey brains...... and angular gyri of the inferior parietal lobule in humans but only to the supramarginal gyrus in the monkey brain. The third tract connects the postcentral gyrus to the anterior region of the superior parietal lobule and is more prominent in monkeys compared to humans. Finally, short U-shaped fibres...... and monkeys with some differences for those areas that have cytoarchitectonically distinct features in humans. The overall pattern of intraparietal connectivity supports the special role of the inferior parietal lobule in cognitive functions characteristic of humans....

  16. Thermoregulatory Responses of Febrile Monkeys During Microwave Exposure

    National Research Council Canada - National Science Library

    Adair, E

    1997-01-01

    .... In a controlled ambient temperature of 26 degrees C, autonomic mechanisms of heat production and heat loss were measured in febrile squirrel monkeys during 30-min exposures to 450 or 2450 MHz CW MW...

  17. Single subcutaneous dosing of cefovecin in rhesus monkeys (Macaca mulatta)

    DEFF Research Database (Denmark)

    Bakker, J.; Thuesen, Line Risager; Braskamp, G.

    2011-01-01

    was to determine whether cefovecin is a suitable antibiotic to prevent skin wound infection in rhesus monkeys. Therefore, the pharmacokinetics (PK) of cefovecin after a single subcutaneous injection at 8 mg/kg bodyweight in four rhesus monkeys (Macaca mulatta) and sensitivity of bacterial isolates from fresh skin...... wounds were determined. After administration, blood, urine, and feces were collected, and concentrations of cefovecin were determined. Further, the minimum inhibitory concentrations (MIC) for bacteria isolated from fresh skin wounds of monkeys during a health control program were determined. The mean...... maximum plasma concentration (C(max) ) of cefovecin was 78 µg/mL and was achieved after 57 min. The mean apparent long elimination half-life (t½) was 6.6 h and excretion occurred mainly via urine. The MIC for the majority of the bacteria examined was >100 µg/mL. The PK of cefovecin in rhesus monkeys...

  18. jMonkeyEngine 3.0 cookbook

    CERN Document Server

    Edén, Rickard

    2014-01-01

    If you are a jMonkey developer or a Java developer who is interested to delve further into the game making process to expand your skillset and create more technical games, then this book is perfect for you.

  19. Mechanism of toxicity of MPTP: A cause of Parkinsonism in human beings

    International Nuclear Information System (INIS)

    Denton, T.L.

    1988-01-01

    1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was found in 1983 to cause a syndrome virtually identical to Parkinson's Disease in humans and other primates. The symptoms, as in idiopathic Parkinson's syndrome, are due to destruction of dopaminergic neurons in the pars compacta of the substantia nigra resulting in depletion of dopamine in the basal ganglia. The mechanism of toxicity was investigated with a dopamine containing cell line, PC12, a MPTP resistant variant (MPTP r ), and synaptosomes from the striate cortex of mice, rats, guinea pigs and a monkey. The mechanism of acute effects was studied with membrane preparations from human and rat striate cortex. MPTP displaced [ 3 H]haloperidol from binding sites in human and rat striate cortex, but could not displace [ 3 H]flupenthixol, suggesting that MPTP is a D2 receptor ligand of equivalent potency in both species. MPTP was a competitive inhibitor of uptake of [ 3 H]dopamine in PC12 but did not accumulate in PC12 or in synaptosomes of rat, guinea pig, mouse or monkey striate cortex. 100 uM MPTP depleted catecholamine levels in PC12 cells by about 50%, without killing

  20. Chemosensory Learning in the Cortex

    Directory of Open Access Journals (Sweden)

    Edmund eRolls

    2011-09-01

    Full Text Available Taste is a primary reinforcer. Olfactory-taste and visual-taste association learning takes place in the primate including human orbitofrontal cortex to build representations of flavour. Rapid reversal of this learning can occur using a rule-based learning system that can be reset when an expected taste or flavour reward is not obtained, that is by negative reward prediction error, to which a population of neurons in the orbitofrontal cortex responds. The representation in the orbitofrontal cortex but not the primary taste or olfactory cortex is of the reward value of the visual / olfactory / taste / input as shown by devaluation experiments in which food is fed to satiety, and by correlations with the activations with subjective pleasantness ratings in humans. Sensory-specific satiety for taste, olfactory, visual, and oral somatosensory inputs produced by feeding a particular food to satiety are implemented it is proposed by medium-term synaptic adaptation in the orbitofrontal cortex. Cognitive factors, including word-level descriptions, modulate the representation of the reward value of food in the orbitofrontal cortex, and this effect is learned it is proposed by associative modification of top-down synapses onto neurons activated by bottom-up taste and olfactory inputs when both are active in the orbitofrontal cortex. A similar associative synaptic learning process is proposed to be part of the mechanism for the top-down attentional control to the reward value vs the sensory properties such as intensity of taste and olfactory inputs in the orbitofrontal cortex, as part of a biased activation theory of selective attention.

  1. Preference transitivity and symbolic representation in capuchin monkeys (Cebus apella.

    Directory of Open Access Journals (Sweden)

    Elsa Addessi

    Full Text Available BACKGROUND: Can non-human animals comprehend and employ symbols? The most convincing empirical evidence comes from language-trained apes, but little is known about this ability in monkeys. Tokens can be regarded as symbols since they are inherently non-valuable objects that acquire an arbitrarily assigned value upon exchange with an experimenter. Recent evidence suggested that capuchin monkeys, which diverged from the human lineage 35 million years ago, can estimate, represent and combine token quantities. A fundamental and open question is whether monkeys can reason about symbols in ways similar to how they reason about real objects. METHODOLOGY/PRINCIPAL FINDINGS: Here we examined this broad question in the context of economic choice behavior. Specifically, we assessed whether, in a symbolic context, capuchins' preferences satisfy transitivity--a fundamental trait of rational decision-making. Given three options A, B and C, transitivity holds true if A > or = B, B > or = C and A > or = C (where > or = indicates preference. In this study, we trained monkeys to exchange three types of tokens for three different foods. We then compared choices monkeys made between different types of tokens with choices monkeys made between the foods. Qualitatively, capuchins' preferences revealed by the way of tokens were similar to those measured with the actual foods. In particular, when choosing between tokens, monkeys displayed strict economic preferences and their choices satisfied transitivity. Quantitatively, however, values measured by the way of tokens differed systematically from those measured with the actual foods. In particular, for any pair of foods, the relative value of the preferred food increased when monkeys chose between the corresponding tokens. CONCLUSIONS/SIGNIFICANCE: These results indicate that indeed capuchins are capable of treating tokens as symbols. However, as they do so, capuchins experience the cognitive burdens imposed by symbolic

  2. Depth perception from moving cast shadow in macaque monkey.

    Science.gov (United States)

    Mizutani, Saneyuki; Usui, Nobuo; Yokota, Takanori; Mizusawa, Hidehiro; Taira, Masato; Katsuyama, Narumi

    2015-07-15

    In the present study, we investigate whether the macaque monkey can perceive motion in depth using a moving cast shadow. To accomplish this, we conducted two experiments. In the first experiment, an adult Japanese monkey was trained in a motion discrimination task in depth by binocular disparity. A square was presented on the display so that it appeared with a binocular disparity of 0.12 degrees (initial position), and moved toward (approaching) or away from (receding) the monkey for 1s. The monkey was trained to discriminate the approaching and receding motion of the square by GO/delayed GO-type responses. The monkey showed a significantly high accuracy rate in the task, and the performance was maintained when the position, color, and shape of the moving object were changed. In the next experiment, the change in the disparity was gradually decreased in the motion discrimination task. The results showed that the performance of the monkey declined as the distance of the approaching and receding motion of the square decreased from the initial position. However, when a moving cast shadow was added to the stimulus, the monkey responded to the motion in depth induced by the cast shadow in the same way as by binocular disparity; the reward was delivered randomly or given in all trials to prevent the learning of the 2D motion of the shadow in the frontal plane. These results suggest that the macaque monkey can perceive motion in depth using a moving cast shadow as well as using binocular disparity. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Monkey Feeding Assay for Testing Emetic Activity of Staphylococcal Enterotoxin.

    Science.gov (United States)

    Seo, Keun Seok

    2016-01-01

    Staphylococcal enterotoxins (SEs) are unique bacterial toxins that cause gastrointestinal toxicity as well as superantigenic activity. Since systemic administration of SEs induces superantigenic activity leading to toxic shock syndrome that may mimic enterotoxic activity of SEs such as vomiting and diarrhea, oral administration of SEs in the monkey feeding assay is considered as a standard method to evaluate emetic activity of SEs. This chapter summarizes and discusses practical considerations of the monkey feeding assay used in studies characterizing classical and newly identified SEs.

  4. Present and potential distribution of Snub-nosed Monkey

    DEFF Research Database (Denmark)

    Nüchel, Jonas; Bøcher, Peder Klith; Svenning, Jens-Christian

    are the Snub-nosed Monkeys (Rhinopithecus), a temperate-subtropical East Asian genus. We use species distribution modeling to assess the following question of key relevancy for conservation management of Rhinopithecus; 1. Which climatic factors determine the present distribution of Rhinopithecus within...... distribution of Rhinopithecus within the region, considering climate, habitat availability and the locations of nature reserves. Keywords: biodiversity, biogeography, conservation, China, snub-nosed monkey, rhinopithecus, primates, species distribution modeling...

  5. Control of Working Memory in Rhesus Monkeys (Macaca mulatta)

    Science.gov (United States)

    Tu, Hsiao-Wei; Hampton, Robert R.

    2014-01-01

    Cognitive control is critical for efficiently using the limited resources in working memory. It is well established that humans use rehearsal to increase the probability of remembering needed information, but little is known in nonhumans, with some studies reporting the absence of active control and others subject to alternative explanations. We trained monkeys in a visual matching-to-sample paradigm with a post-sample memory cue. Monkeys either saw a remember cue that predicted the occurrence of a matching test that required memory for the sample, or a forget cue that predicted a discrimination test that did not require memory of the sample. Infrequent probe trials on which monkeys were given tests of the type not cued on that trial were used to assess whether memory was under cognitive control. Our procedures controlled for reward expectation and for the surprising nature of the probes. Monkeys matched less accurately after forget cues, while discrimination accuracy was equivalent in the two cue conditions. We also tested monkeys with lists of two consecutive sample images that shared the same cue. Again, memory for expected memory tests was superior to that on unexpected tests. Together these results show that monkeys cognitively control their working memory. PMID:25436219

  6. Intrapericardial Denervation: Responses to Water Immersion in Rhesus Monkeys

    Science.gov (United States)

    McKeever, Kenneth H.; Keil, Lanny C.; Sandler, Harold

    1995-01-01

    Eleven anesthetized rhesus monkeys were used to study cardiovascular, renal, and endocrine alterations associated with 120 min of head-out water immersion. Five animals underwent complete intrapericardial denervation using the Randall technique, while the remaining six monkeys served as intact controls. Each animal was chronically instrumented with an electromagnetic flow probe on the ascending aorta, a strain gauge pressure transducer implanted in the apex of the left ventricle (LV), and electrocardiogram leads anchored to the chest wall and LV. During immersion, LV end-diastolic pressure, urine flow, glomerular filtration rate, sodium excretion, and circulating atrial natriuretic peptide (ANP) each increased (P less than 0.05) for intact and denervated monkeys. There were no alterations in free water clearance in either group during immersion, yet fractional excretion of free water increased (P less than 0.05) in the intact monkeys. Plasma renin activity (PRA) decreased (P less than 0.05) during immersion in intact monkeys but not the denervated animals. Plasma vasopressin (PVP) concentration decreased (P less than 0.05) during the first 30 min of immersion in both groups but was not distinguishable from control by 60 min of immersion in denervated monkeys. These data demonstrate that complete cardiac denervation does not block the rise in plasma ANP or prevent the natriuresis associated with head-out water immersion. The suppression of PVP during the first minutes of immersion after complete cardiac denervation suggests that extracardiac sensing mechanisms associated with the induced fluid shifts may be responsible for the findings.

  7. Spatiotemporal Spike Coding of Behavioral Adaptation in the Dorsal Anterior Cingulate Cortex.

    Directory of Open Access Journals (Sweden)

    Laureline Logiaco

    2015-08-01

    Full Text Available The frontal cortex controls behavioral adaptation in environments governed by complex rules. Many studies have established the relevance of firing rate modulation after informative events signaling whether and how to update the behavioral policy. However, whether the spatiotemporal features of these neuronal activities contribute to encoding imminent behavioral updates remains unclear. We investigated this issue in the dorsal anterior cingulate cortex (dACC of monkeys while they adapted their behavior based on their memory of feedback from past choices. We analyzed spike trains of both single units and pairs of simultaneously recorded neurons using an algorithm that emulates different biologically plausible decoding circuits. This method permits the assessment of the performance of both spike-count and spike-timing sensitive decoders. In response to the feedback, single neurons emitted stereotypical spike trains whose temporal structure identified informative events with higher accuracy than mere spike count. The optimal decoding time scale was in the range of 70-200 ms, which is significantly shorter than the memory time scale required by the behavioral task. Importantly, the temporal spiking patterns of single units were predictive of the monkeys' behavioral response time. Furthermore, some features of these spiking patterns often varied between jointly recorded neurons. All together, our results suggest that dACC drives behavioral adaptation through complex spatiotemporal spike coding. They also indicate that downstream networks, which decode dACC feedback signals, are unlikely to act as mere neural integrators.

  8. Prediction of Reach Goals in Depth and Direction from the Parietal Cortex

    Directory of Open Access Journals (Sweden)

    Matteo Filippini

    2018-04-01

    Full Text Available Summary: The posterior parietal cortex is well known to mediate sensorimotor transformations during the generation of movement plans, but its ability to control prosthetic limbs in 3D environments has not yet been fully demonstrated. With this aim, we trained monkeys to perform reaches to targets located at various depths and directions and tested whether the reach goal position can be extracted from parietal signals. The reach goal location was reliably decoded with accuracy close to optimal (>90%, and this occurred also well before movement onset. These results, together with recent work showing a reliable decoding of hand grip in the same area, suggest that this is a suitable site to decode the entire prehension action, to be considered in the development of brain-computer interfaces. : Filippini et al. show that it is possible to use parietal cortex activity to predict in which direction the arm will move and how far it will reach. This opens up the possibility of neural prostheses that can accurately guide reach and grasp using signals from this part of the brain. Keywords: neuroprosthetics, offline neural decoding, reaching in depth, monkey, V6A, machine learning, visuomotor transformations, hand guidance, prehension, robotics

  9. From rule to response: neuronal processes in the premotor and prefrontal cortex.

    Science.gov (United States)

    Wallis, Jonathan D; Miller, Earl K

    2003-09-01

    The ability to use abstract rules or principles allows behavior to generalize from specific circumstances (e.g., rules learned in a specific restaurant can subsequently be applied to any dining experience). Neurons in the prefrontal cortex (PFC) encode such rules. However, to guide behavior, rules must be linked to motor responses. We investigated the neuronal mechanisms underlying this process by recording from the PFC and the premotor cortex (PMC) of monkeys trained to use two abstract rules: "same" or "different." The monkeys had to either hold or release a lever, depending on whether two successively presented pictures were the same or different, and depending on which rule was in effect. The abstract rules were represented in both regions, although they were more prevalent and were encoded earlier and more strongly in the PMC. There was a perceptual bias in the PFC, relative to the PMC, with more PFC neurons encoding the presented pictures. In contrast, neurons encoding the behavioral response were more prevalent in the PMC, and the selectivity was stronger and appeared earlier in the PMC than in the PFC.

  10. Spatiotemporal Spike Coding of Behavioral Adaptation in the Dorsal Anterior Cingulate Cortex.

    Science.gov (United States)

    Logiaco, Laureline; Quilodran, René; Procyk, Emmanuel; Arleo, Angelo

    2015-08-01

    The frontal cortex controls behavioral adaptation in environments governed by complex rules. Many studies have established the relevance of firing rate modulation after informative events signaling whether and how to update the behavioral policy. However, whether the spatiotemporal features of these neuronal activities contribute to encoding imminent behavioral updates remains unclear. We investigated this issue in the dorsal anterior cingulate cortex (dACC) of monkeys while they adapted their behavior based on their memory of feedback from past choices. We analyzed spike trains of both single units and pairs of simultaneously recorded neurons using an algorithm that emulates different biologically plausible decoding circuits. This method permits the assessment of the performance of both spike-count and spike-timing sensitive decoders. In response to the feedback, single neurons emitted stereotypical spike trains whose temporal structure identified informative events with higher accuracy than mere spike count. The optimal decoding time scale was in the range of 70-200 ms, which is significantly shorter than the memory time scale required by the behavioral task. Importantly, the temporal spiking patterns of single units were predictive of the monkeys' behavioral response time. Furthermore, some features of these spiking patterns often varied between jointly recorded neurons. All together, our results suggest that dACC drives behavioral adaptation through complex spatiotemporal spike coding. They also indicate that downstream networks, which decode dACC feedback signals, are unlikely to act as mere neural integrators.

  11. P1-24: Neural Representation of Gloss in the Macaque Inferior Temporal Cortex

    Directory of Open Access Journals (Sweden)

    Akiko Nishio

    2012-10-01

    Full Text Available The variation of the appearance such as gloss provides one of the most important information for object recognition. However, little is known about the neural mechanisms related to the perception of gloss. We examined whether the neurons in the inferior temporal (IT cortex of the monkeys are coding gloss of objects. We made visual stimuli which have various surface reflectance properties, and tested responses of IT neurons to these stimuli while a monkey was performing a visual fixation task. We found that there exist neurons in the lower bank of the superior temporal sulcus that selectively responded to specific stimuli. The selectivity was largely maintained when the object shape or illumination condition was changed. In contrast, neural selectivity was lost when the pixels of objects were randomly rearranged. In the former manipulation of the stimuli, gloss perceptions were maintained, whereas in the latter manipulation, gloss perception was dramatically changed. These results indicate that these IT neurons selectively responded to gloss, not to the irrelevant local image features or average luminance or color. Next, to understand how the responses of gloss selective neurons are related to perceived gloss, responses of gloss selective neurons were mapped in perceptual gloss space in which glossiness changes uniformly. I found that responses of most gloss selective neurons can be explained by linear combinations of two parameters that are shown to be important for gloss perception. This result suggests that the responses of gloss selective neurons of IT cortex are closely related to gloss perception.

  12. Basal body and striated rootlet changes in primate macular retinal pigmented epithelium after low level diffuse argon laser radiation. Final report 1981-1982

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    Schuschereba, S.T.; Zwick, H.; Stuck, B.E.; Beatrice, E.S.

    1982-09-01

    Basal bodies or centrioles (BB - microtubule organizing centers) and striated rootlets (SR - bundles of 60 A action-like filaments) have a close association in primate retinal pigmented epithelial (RPE) cells. The frequency of occurrence of these structures was evaluated in the macular RPE after repeated exposure to low level diffuse argon laser radiation (DALR). The awake chaired animal's head was restrained and positioned near the center of the 0.75 m hemisphere which was diffusely irradiated with 514.5 nm laser radiation. The right eye of each subject was occluded during the two-hour exposure session. The first subject received 24 cumulative hours of exposure, the second, 40 hours and the third, 42 hours.

  13. Neurons in primary motor cortex engaged during action observation.

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    Dushanova, Juliana; Donoghue, John

    2010-01-01

    Neurons in higher cortical areas appear to become active during action observation, either by mirroring observed actions (termed mirror neurons) or by eliciting mental rehearsal of observed motor acts. We report the existence of neurons in the primary motor cortex (M1), an area that is generally considered to initiate and guide movement performance, responding to viewed actions. Multielectrode recordings in monkeys performing or observing a well-learned step-tracking task showed that approximately half of the M1 neurons that were active when monkeys performed the task were also active when they observed the action being performed by a human. These 'view' neurons were spatially intermingled with 'do' neurons, which are active only during movement performance. Simultaneously recorded 'view' neurons comprised two groups: approximately 38% retained the same preferred direction (PD) and timing during performance and viewing, and the remainder (62%) changed their PDs and time lag during viewing as compared with performance. Nevertheless, population activity during viewing was sufficient to predict the direction and trajectory of viewed movements as action unfolded, although less accurately than during performance. 'View' neurons became less active and contained poorer representations of action when only subcomponents of the task were being viewed. M1 'view' neurons thus appear to reflect aspects of a learned movement when observed in others, and form part of a broadly engaged set of cortical areas routinely responding to learned behaviors. These findings suggest that viewing a learned action elicits replay of aspects of M1 activity needed to perform the observed action, and could additionally reflect processing related to understanding, learning or mentally rehearsing action.

  14. Newly identified CYP2C93 is a functional enzyme in rhesus monkey, but not in cynomolgus monkey.

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    Yasuhiro Uno

    Full Text Available Cynomolgus monkey and rhesus monkey are used in drug metabolism studies due to their evolutionary closeness and physiological resemblance to human. In cynomolgus monkey, we previously identified cytochrome P450 (P450 or CYP 2C76 that does not have a human ortholog and is partly responsible for species differences in drug metabolism between cynomolgus monkey and human. In this study, we report characterization of CYP2C93 cDNA newly identified in cynomolgus monkey and rhesus monkey. The CYP2C93 cDNA contained an open reading frame of 490 amino acids approximately 84-86% identical to human CYP2Cs. CYP2C93 was located in the genomic region, which corresponded to the intergenic region in the human genome, indicating that CYP2C93 does not correspond to any human genes. CYP2C93 mRNA was expressed predominantly in the liver among 10 tissues analyzed. The CYP2C93 proteins heterologously expressed in Escherichia coli metabolized human CYP2C substrates, diclofenac, flurbiprofen, paclitaxel, S-mephenytoin, and tolbutamide. In addition to a normal transcript (SV1, an aberrantly spliced transcript (SV2 lacking exon 2 was identified, which did not give rise to a functional protein due to frameshift and a premature termination codon. Mini gene assay revealed that the genetic variant IVS2-1G>T at the splice site of intron 1, at least partly, accounted for the exon-2 skipping; therefore, this genotype would influence CYP2C93-mediated drug metabolism. SV1 was expressed in 6 of 11 rhesus monkeys and 1 of 8 cynomolgus monkeys, but the SV1 in the cynomolgus monkey was nonfunctional due to a rare null genotype (c.102T>del. These results suggest that CYP2C93 can play roles as a drug-metabolizing enzyme in rhesus monkeys (not in cynomolgus monkeys, although its relative contribution to drug metabolism has yet to be validated.

  15. Absorption, Distribution, and Excretion of 14C-APX001 after Single-Dose Administration to Rats and Monkeys

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    Mansbach, Robert; Shaw, Karen J; Hodges, Michael R; Coleman, Samantha; Fitzsimmons, Michael E

    2017-01-01

    Abstract Background APX001 is a small-molecule therapeutic agent in clinical development for the treatment of invasive fungal infections (IFI). Methods The absorption, distribution and excretion profiles of [14C]APX001-derived radioactivity were determined in rats (albino and pigmented) and monkeys. Rats (some implanted with bile duct cannulae) were administered a single 100 mg/kg oral dose or a 30 mg/kg intravenous (IV) dose. Monkeys were administered a single 6 mg/kg IV dose. Samples of blood, urine, feces and bile, as well as carcasses, were collected through 168 hours after dosing. Samples were analyzed for total radioactivity content by liquid scintillation counting, and carcasses were analyzed by quantitative whole-body autoradiography. Results [14C]APX001-derived radioactivity was rapidly and extensively absorbed and extensively distributed to most tissues for both routes of administration in both species. In rats, tissues with the highest radioactivity Cmax values included bile, abdominal fat, reproductive fat, subcutaneous fat, and liver, but radioactivity was also detected in tissues associated with IFI, including lung, brain and eye. In monkeys, the highest Cmax values were in bile, urine, uveal tract, bone marrow, abdominal fat, liver, and kidney cortex. Liver and kidney were the tissues with highest radioactivity, but as in the rat, radioactivity was also detected in lung, brain and eye tissues. In pigmented rats, radiocarbon was densely distributed into pigmented tissue and more slowly cleared than from other tissues. Mean recovery of radioactivity in rats was approximately 95–100%. In bile duct-intact rats, >90% of radioactivity was recovered in feces. In cannulated rats, biliary excretion of radioactivity was the major route of elimination and accounted for 88.8% of the dose, whereas urinary and fecal excretion of radioactivity was minor and accounted for 2.56% and 5.42% of the dose, respectively. In monkeys, the overall recovery of radioactivity

  16. Human left ventral premotor cortex mediates matching of hand posture to object use.

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    Guy Vingerhoets

    Full Text Available Visuomotor transformations for grasping have been associated with a fronto-parietal network in the monkey brain. The human homologue of the parietal monkey region (AIP has been identified as the anterior part of the intraparietal sulcus (aIPS, whereas the putative human equivalent of the monkey frontal region (F5 is located in the ventral part of the premotor cortex (vPMC. Results from animal studies suggest that monkey F5 is involved in the selection of appropriate hand postures relative to the constraints of the task. In humans, the functional roles of aIPS and vPMC appear to be more complex and the relative contribution of each region to grasp selection remains uncertain. The present study aimed to identify modulation in brain areas sensitive to the difficulty level of tool object - hand posture matching. Seventeen healthy right handed participants underwent fMRI while observing pictures of familiar tool objects followed by pictures of hand postures. The task was to decide whether the hand posture matched the functional use of the previously shown object. Conditions were manipulated for level of difficulty. Compared to a picture matching control task, the tool object - hand posture matching conditions conjointly showed increased modulation in several left hemispheric regions of the superior and inferior parietal lobules (including aIPS, the middle occipital gyrus, and the inferior temporal gyrus. Comparison of hard versus easy conditions selectively modulated the left inferior frontal gyrus with peak activity located in its opercular part (Brodmann area (BA 44. We suggest that in the human brain, vPMC/BA44 is involved in the matching of hand posture configurations in accordance with visual and functional demands.

  17. Reference frames for spatial frequency in face representation differ in the temporal visual cortex and amygdala.

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    Inagaki, Mikio; Fujita, Ichiro

    2011-07-13

    Social communication in nonhuman primates and humans is strongly affected by facial information from other individuals. Many cortical and subcortical brain areas are known to be involved in processing facial information. However, how the neural representation of faces differs across different brain areas remains unclear. Here, we demonstrate that the reference frame for spatial frequency (SF) tuning of face-responsive neurons differs in the temporal visual cortex and amygdala in monkeys. Consistent with psychophysical properties for face recognition, temporal cortex neurons were tuned to image-based SFs (cycles/image) and showed viewing distance-invariant representation of face patterns. On the other hand, many amygdala neurons were influenced by retina-based SFs (cycles/degree), a characteristic that is useful for social distance computation. The two brain areas also differed in the luminance contrast sensitivity of face-responsive neurons; amygdala neurons sharply reduced their responses to low luminance contrast images, while temporal cortex neurons maintained the level of their responses. From these results, we conclude that different types of visual processing in the temporal visual cortex and the amygdala contribute to the construction of the neural representations of faces.

  18. Structural and functional analyses of human cerebral cortex using a surface-based atlas

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    Van Essen, D. C.; Drury, H. A.

    1997-01-01

    We have analyzed the geometry, geography, and functional organization of human cerebral cortex using surface reconstructions and cortical flat maps of the left and right hemispheres generated from a digital atlas (the Visible Man). The total surface area of the reconstructed Visible Man neocortex is 1570 cm2 (both hemispheres), approximately 70% of which is buried in sulci. By linking the Visible Man cerebrum to the Talairach stereotaxic coordinate space, the locations of activation foci reported in neuroimaging studies can be readily visualized in relation to the cortical surface. The associated spatial uncertainty was empirically shown to have a radius in three dimensions of approximately 10 mm. Application of this approach to studies of visual cortex reveals the overall patterns of activation associated with different aspects of visual function and the relationship of these patterns to topographically organized visual areas. Our analysis supports a distinction between an anterior region in ventral occipito-temporal cortex that is selectively involved in form processing and a more posterior region (in or near areas VP and V4v) involved in both form and color processing. Foci associated with motion processing are mainly concentrated in a region along the occipito-temporal junction, the ventral portion of which overlaps with foci also implicated in form processing. Comparisons between flat maps of human and macaque monkey cerebral cortex indicate significant differences as well as many similarities in the relative sizes and positions of cortical regions known or suspected to be homologous in the two species.

  19. Wave aberrations in rhesus monkeys with vision-induced ametropias

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    Ramamirtham, Ramkumar; Kee, Chea-su; Hung, Li-Fang; Qiao-Grider, Ying; Huang, Juan; Roorda, Austin; Smith, Earl L.

    2007-01-01

    The purpose of this study was to investigate the relationship between refractive errors and high-order aberrations in infant rhesus monkeys. Specifically, we compared the monochromatic wave aberrations measured with a Shack-Hartman wavefront sensor between normal monkeys and monkeys with vision-induced refractive errors. Shortly after birth, both normal monkeys and treated monkeys reared with optically induced defocus or form deprivation showed a decrease in the magnitude of high-order aberrations with age. However, the decrease in aberrations was typically smaller in the treated animals. Thus, at the end of the lens-rearing period, higher than normal amounts of aberrations were observed in treated eyes, both hyperopic and myopic eyes and treated eyes that developed astigmatism, but not spherical ametropias. The total RMS wavefront error increased with the degree of spherical refractive error, but was not correlated with the degree of astigmatism. Both myopic and hyperopic treated eyes showed elevated amounts of coma and trefoil and the degree of trefoil increased with the degree of spherical ametropia. Myopic eyes also exhibited a much higher prevalence of positive spherical aberration than normal or treated hyperopic eyes. Following the onset of unrestricted vision, the amount of high-order aberrations decreased in the treated monkeys that also recovered from the experimentally induced refractive errors. Our results demonstrate that high-order aberrations are influenced by visual experience in young primates and that the increase in high-order aberrations in our treated monkeys appears to be an optical byproduct of the vision-induced alterations in ocular growth that underlie changes in refractive error. The results from our study suggest that the higher amounts of wave aberrations observed in ametropic humans are likely to be a consequence, rather than a cause, of abnormal refractive development. PMID:17825347

  20. Dissociation of Detection and Discrimination of Pure Tones following Bilateral Lesions of Auditory Cortex

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    Dykstra, Andrew R.; Koh, Christine K.; Braida, Louis D.; Tramo, Mark Jude

    2012-01-01

    It is well known that damage to the peripheral auditory system causes deficits in tone detection as well as pitch and loudness perception across a wide range of frequencies. However, the extent to which to which the auditory cortex plays a critical role in these basic aspects of spectral processing, especially with regard to speech, music, and environmental sound perception, remains unclear. Recent experiments indicate that primary auditory cortex is necessary for the normally-high perceptual acuity exhibited by humans in pure-tone frequency discrimination. The present study assessed whether the auditory cortex plays a similar role in the intensity domain and contrasted its contribution to sensory versus discriminative aspects of intensity processing. We measured intensity thresholds for pure-tone detection and pure-tone loudness discrimination in a population of healthy adults and a middle-aged man with complete or near-complete lesions of the auditory cortex bilaterally. Detection thresholds in his left and right ears were 16 and 7 dB HL, respectively, within clinically-defined normal limits. In contrast, the intensity threshold for monaural loudness discrimination at 1 kHz was 6.5±2.1 dB in the left ear and 6.5±1.9 dB in the right ear at 40 dB sensation level, well above the means of the control population (left ear: 1.6±0.22 dB; right ear: 1.7±0.19 dB). The results indicate that auditory cortex lowers just-noticeable differences for loudness discrimination by approximately 5 dB but is not necessary for tone detection in quiet. Previous human and Old-world monkey experiments employing lesion-effect, neurophysiology, and neuroimaging methods to investigate the role of auditory cortex in intensity processing are reviewed. PMID:22957087

  1. Functions of delay-period activity in the prefrontal cortex and mnemonic scotomas revisited

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    Shintaro eFunahashi

    2015-02-01

    Full Text Available Working memory is one of key concepts to understand functions of the prefrontal cortex. Delay-period activity is an important neural correlate to understand the role of working memory in prefrontal functions. The importance of delay-period activity is that this activity can encode not only visuospatial information but also a variety of information including non-spatial visual features, auditory and tactile stimuli, task rules, expected reward, and numerical quantity. This activity also participates in a variety of information processing including sensory-to-motor information transformation. These mnemonic features of delay-period activity enable to perform various important operations that the prefrontal cortex participates in, such as executive controls, and therefore, support the notion that working memory is an important function to understand prefrontal functions. On the other hand, although experiments using manual versions of the delayed-response task had revealed many important findings, an oculomotor version of this task enabled us to use multiple cue positions, exclude postural orientation during the delay period, and further prove the importance of mnemonic functions of the prefrontal cortex. In addition, monkeys with unilateral lesions exhibited specific impairment only in the performance of memory-guided saccades directed toward visual cues in the visual field contralateral to the lesioned hemisphere. This result indicates that memories for visuospatial coordinates in each hemifield are processed primarily in the contralateral prefrontal cortex. This result further strengthened the idea of mnemonic functions of the prefrontal cortex. Thus, the mnemonic functions of the prefrontal cortex and delay-period activity may not need to be reconsidered, but should be emphasized.

  2. Decision-making in the ventral premotor cortex harbinger of action

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    José L. ePardo-Vázquez

    2011-09-01

    Full Text Available Although the premotor cortex (PM was once viewed as the substrate of pure motor functions, soon it was realized that it was involved in higher brain functions. By this it is meant that the PM cortex functions would better be explained as motor set, preparation for limb movement or sensory guidance of movement rather than solely by a fixed link to motor performance. These findings, together with a better knowledge of the PM cortex histology and hodology in human and non-human primates prompted quantitative studies of this area combining behavioral tasks with electrophysiological recordings. In addition, the exploration of the PM cortex neurons with qualitative methods also suggested its participation in higher functions. Behavioral choices frequently depend on temporal cues, which together with knowledge of previous outcomes and expectancies are combined to decide and choose a behavioral action. In decision-making the knowledge about the consequences of decisions, either correct or incorrect, is fundamental because they can be used to adapt future behavior. The neuronal correlates of a decision process have been described in several cortical areas of primates. Among them, there is evidence that the monkey ventral premotor cortex (PMv, an anatomical and physiological well-differentiated area of the PM cortex, supports both perceptual decisions and performance monitoring. Here we review the evidence that the steps in a decision making process are encoded in the firing rate of the PMv neurons. This provides compelling evidence suggesting that the PMv is involved in the use of recent and long-term sensory memory to decide, execute and evaluate the outcomes of the subjects’ choices.

  3. Decision-Making in the Ventral Premotor Cortex Harbinger of Action

    Science.gov (United States)

    Pardo-Vazquez, Jose L.; Padron, Isabel; Fernandez-Rey, Jose; Acuña, Carlos

    2011-01-01

    Although the premotor (PM) cortex was once viewed as the substrate of pure motor functions, soon it was realized that it was involved in higher brain functions. By this it is meant that the PM cortex functions would better be explained as motor set, preparation for limb movement, or sensory guidance of movement rather than solely by a fixed link to motor performance. These findings, together with a better knowledge of the PM cortex histology and hodology in human and non-human primates prompted quantitative studies of this area combining behavioral tasks with electrophysiological recordings. In addition, the exploration of the PM cortex neurons with qualitative methods also suggested its participation in higher functions. Behavioral choices frequently depend on temporal cues, which together with knowledge of previous outcomes and expectancies are combined to decide and choose a behavioral action. In decision-making the knowledge about the consequences of decisions, either correct or incorrect, is fundamental because they can be used to adapt future behavior. The neuronal correlates of a decision process have been described in several cortical areas of primates. Among them, there is evidence that the monkey ventral premotor (PMv) cortex, an anatomical and physiological well-differentiated area of the PM cortex, supports both perceptual decisions and performance monitoring. Here we review the evidence that the steps in a decision-making process are encoded in the firing rate of the PMv neurons. This provides compelling evidence suggesting that the PMv is involved in the use of recent and long-term sensory memory to decide, execute, and evaluate the outcomes of the subjects’ choices. PMID:21991249

  4. Dissociation of detection and discrimination of pure tones following bilateral lesions of auditory cortex.

    Science.gov (United States)

    Dykstra, Andrew R; Koh, Christine K; Braida, Louis D; Tramo, Mark Jude

    2012-01-01

    It is well known that damage to the peripheral auditory system causes deficits in tone detection as well as pitch and loudness perception across a wide range of frequencies. However, the extent to which to which the auditory cortex plays a critical role in these basic aspects of spectral processing, especially with regard to speech, music, and environmental sound perception, remains unclear. Recent experiments indicate that primary auditory cortex is necessary for the normally-high perceptual acuity exhibited by humans in pure-tone frequency discrimination. The present study assessed whether the auditory cortex plays a similar role in the intensity domain and contrasted its contribution to sensory versus discriminative aspects of intensity processing. We measured intensity thresholds for pure-tone detection and pure-tone loudness discrimination in a population of healthy adults and a middle-aged man with complete or near-complete lesions of the auditory cortex bilaterally. Detection thresholds in his left and right ears were 16 and 7 dB HL, respectively, within clinically-defined normal limits. In contrast, the intensity threshold for monaural loudness discrimination at 1 kHz was 6.5 ± 2.1 dB in the left ear and 6.5 ± 1.9 dB in the right ear at 40 dB sensation level, well above the means of the control population (left ear: 1.6 ± 0.22 dB; right ear: 1.7 ± 0.19 dB). The results indicate that auditory cortex lowers just-noticeable differences for loudness discrimination by approximately 5 dB but is not necessary for tone detection in quiet. Previous human and Old-world monkey experiments employing lesion-effect, neurophysiology, and neuroimaging methods to investigate the role of auditory cortex in intensity processing are reviewed.

  5. Dissociation of detection and discrimination of pure tones following bilateral lesions of auditory cortex.

    Directory of Open Access Journals (Sweden)

    Andrew R Dykstra

    Full Text Available It is well known that damage to the peripheral auditory system causes deficits in tone detection as well as pitch and loudness perception across a wide range of frequencies. However, the extent to which to which the auditory cortex plays a critical role in these basic aspects of spectral processing, especially with regard to speech, music, and environmental sound perception, remains unclear. Recent experiments indicate that primary auditory cortex is necessary for the normally-high perceptual acuity exhibited by humans in pure-tone frequency discrimination. The present study assessed whether the auditory cortex plays a similar role in the intensity domain and contrasted its contribution to sensory versus discriminative aspects of intensity processing. We measured intensity thresholds for pure-tone detection and pure-tone loudness discrimination in a population of healthy adults and a middle-aged man with complete or near-complete lesions of the auditory cortex bilaterally. Detection thresholds in his left and right ears were 16 and 7 dB HL, respectively, within clinically-defined normal limits. In contrast, the intensity threshold for monaural loudness discrimination at 1 kHz was 6.5 ± 2.1 dB in the left ear and 6.5 ± 1.9 dB in the right ear at 40 dB sensation level, well above the means of the control population (left ear: 1.6 ± 0.22 dB; right ear: 1.7 ± 0.19 dB. The results indicate that auditory cortex lowers just-noticeable differences for loudness discrimination by approximately 5 dB but is not necessary for tone detection in quiet. Previous human and Old-world monkey experiments employing lesion-effect, neurophysiology, and neuroimaging methods to investigate the role of auditory cortex in intensity processing are reviewed.

  6. Cognitive Functions and Neurodevelopmental Disorders Involving the Prefrontal Cortex and Mediodorsal Thalamus

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    Zakaria Ouhaz

    2018-02-01

    Full Text Available The mediodorsal nucleus of the thalamus (MD has been implicated in executive functions (such as planning, cognitive control, working memory, and decision-making because of its significant interconnectivity with the prefrontal cortex (PFC. Yet, whilst the roles of the PFC have been extensively studied, how the MD contributes to these cognitive functions remains relatively unclear. Recently, causal evidence in monkeys has demonstrated that in everyday tasks involving rapid updating (e.g., while learning something new, making decisions, or planning the next move, the MD and frontal cortex are working in close partnership. Furthermore, researchers studying the MD in rodents have been able to probe the underlying mechanisms of this relationship to give greater insights into how the frontal cortex and MD might interact during the performance of these essential tasks. This review summarizes the circuitry and known neuromodulators of the MD, and considers the most recent behavioral, cognitive, and neurophysiological studies conducted in monkeys and rodents; in total, this evidence demonstrates that MD makes a critical contribution to cognitive functions. We propose that communication occurs between the MD and the frontal cortex in an ongoing, fluid manner during rapid cognitive operations, via the means of efference copies of messages passed through transthalamic routes; the conductance of these messages may be modulated by other brain structures interconnected to the MD. This is similar to the way in which other thalamic structures have been suggested to carry out forward modeling associated with rapid motor responding and visual processing. Given this, and the marked thalamic pathophysiology now identified in many neuropsychiatric disorders, we suggest that changes in the different subdivisions of the MD and their interconnections with the cortex could plausibly give rise to a number of the otherwise disparate symptoms (including changes to olfaction

  7. Serotonin shapes risky decision making in monkeys.

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    Long, Arwen B; Kuhn, Cynthia M; Platt, Michael L

    2009-12-01

    Some people love taking risks, while others avoid gambles at all costs. The neural mechanisms underlying individual variation in preference for risky or certain outcomes, however, remain poorly understood. Although behavioral pathologies associated with compulsive gambling, addiction and other psychiatric disorders implicate deficient serotonin signaling in pathological decision making, there is little experimental evidence demonstrating a link between serotonin and risky decision making, in part due to the lack of a good animal model. We used dietary rapid tryptophan depletion (RTD) to acutely lower brain serotonin in three macaques performing a simple gambling task for fluid rewards. To confirm the efficacy of RTD experiments, we measured total plasma tryptophan using high-performance liquid chromatography (HPLC) with electrochemical detection. Reducing brain serotonin synthesis decreased preference for the safe option in a gambling task. Moreover, lowering brain serotonin function significantly decreased the premium required for monkeys to switch their preference to the risky option, suggesting that diminished serotonin signaling enhances the relative subjective value of the risky option. These results implicate serotonin in risk-sensitive decision making and, further, suggest pharmacological therapies for treating pathological risk preferences in disorders such as problem gambling and addiction.

  8. Rhesus monkeys attribute perceptions to others.

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    Flombaum, Jonathan I; Santos, Laurie R

    2005-03-08

    Paramount among human cognitive abilities is the capacity to reason about what others think, want, and see--a capacity referred to as a theory of mind (ToM). Despite its importance in human cognition, the extent to which other primates share human ToM capacities has for decades remained a mystery. To date, primates [1, 2] have performed poorly in behavioral tasks that require ToM abilities, despite the fact that some macaques are known to encode social stimuli at the level of single neurons [3-5]. Here, we presented rhesus macaques with a more ecologically relevant ToM task in which subjects could "steal" a contested grape from one of two human competitors. In six experiments, monkeys selectively retrieved the grape from an experimenter who was incapable of seeing the grape rather than an experimenter who was visually aware. These results suggest that rhesus macaques possess an essential component of ToM: the ability to deduce what others perceive on the basis of where they are looking. These results converge with new findings illustrating the importance of competitive paradigms in apes [6]. Moreover, they raise the possibility that, in primates, cortical cells thought to encode where others are looking [7] may encode what those individuals see as well.

  9. Differential expression of secreted phosphoprotein 1 in the motor cortex among primate species and during postnatal development and functional recovery.

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    Tatsuya Yamamoto

    Full Text Available We previously reported that secreted phosphoprotein 1 (SPP1 mRNA is expressed in neurons whose axons form the corticospinal tract (CST of the rhesus macaque, but not in the corresponding neurons of the marmoset and rat. This suggests that SPP1 expression is involved in the functional or structural specialization of highly developed corticospinal systems in certain primate species. To further examine this hypothesis, we evaluated the expression of SPP1 mRNA in the motor cortex from three viewpoints: species differences, postnatal development, and functional/structural changes of the CST after a lesion of the lateral CST (l-CST at the mid-cervical level. The density of SPP1-positive neurons in layer V of the primary motor cortex (M1 was much greater in species with highly developed corticospinal systems (i.e., rhesus macaque, capuchin monkey, and humans than in those with less developed corticospinal systems (i.e., squirrel monkey, marmoset, and rat. SPP1-positive neurons in the macaque monkey M1 increased logarithmically in layer V during postnatal development, following a time course consistent with the increase in conduction velocity of the CST. After an l-CST lesion, SPP1-positive neurons increased in layer V of the ventral premotor cortex, in which compensatory changes in CST function/structure may occur, which positively correlated with the extent of finger dexterity recovery. These results further support the concept that the expression of SPP1 may reflect functional or structural specialization of highly developed corticospinal systems in certain primate species.

  10. Toward the restoration of hand use to a paralyzed monkey: brain-controlled functional electrical stimulation of forearm muscles.

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    Eric A Pohlmeyer

    2009-06-01

    Full Text Available Loss of hand use is considered by many spinal cord injury survivors to be the most devastating consequence of their injury. Functional electrical stimulation (FES of forearm and hand muscles has been used to provide basic, voluntary hand grasp to hundreds of human patients. Current approaches typically grade pre-programmed patterns of muscle activation using simple control signals, such as those derived from residual movement or muscle activity. However, the use of such fixed stimulation patterns limits hand function to the few tasks programmed into the controller. In contrast, we are developing a system that uses neural signals recorded from a multi-electrode array implanted in the motor cortex; this system has the potential to provide independent control of multiple muscles over a broad range of functional tasks. Two monkeys were able to use this cortically controlled FES system to control the contraction of four forearm muscles despite temporary limb paralysis. The amount of wrist force the monkeys were able to produce in a one-dimensional force tracking task was significantly increased. Furthermore, the monkeys were able to control the magnitude and time course of the force with sufficient accuracy to track visually displayed force targets at speeds reduced by only one-third to one-half of normal. Although these results were achieved by controlling only four muscles, there is no fundamental reason why the same methods could not be scaled up to control a larger number of muscles. We believe these results provide an important proof of concept that brain-controlled FES prostheses could ultimately be of great benefit to paralyzed patients with injuries in the mid-cervical spinal cord.

  11. S6-5: Visual Consciousness Tracked with Direct Intracranial Recording from Early and High-Level Visual Cortices in Humans and Monkeys

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    Naotsugu Tsuchiya

    2012-10-01

    Full Text Available Key insights about the neuronal correlates of consciousness have been gained by electrophysiological recording of single neurons from a particular area or by recording of indirect fMRI signals from the whole brain. However, if rapid interaction among neuronal populations in distant cortical areas is essential for consciousness, other methods such as intracranial electrocorticogram (ECoG that can attain both requirements are necessary. Here we report the results of ECoG experiments in three epilepsy patients and one monkey. We used Continuous Flash Suppression to investigate the neuronal activity when ‘invisible’ stimuli broke interocular suppression. We found that widespread activity in the visual cortex preceded up to 1–2 s before subjective reports of detection and that alpha-band activity in the visual cortex induced by the initial flashes predicted how long the suppression was going to last. We will discuss implication of these findings for the neuronal dynamics associated with consciousness.

  12. Construction and evaluation of novel rhesus monkey adenovirus vaccine vectors.

    Science.gov (United States)

    Abbink, Peter; Maxfield, Lori F; Ng'ang'a, David; Borducchi, Erica N; Iampietro, M Justin; Bricault, Christine A; Teigler, Jeffrey E; Blackmore, Stephen; Parenteau, Lily; Wagh, Kshitij; Handley, Scott A; Zhao, Guoyan; Virgin, Herbert W; Korber, Bette; Barouch, Dan H

    2015-02-01

    Adenovirus vectors are widely used as vaccine candidates for a variety of pathogens, including HIV-1. To date, human and chimpanzee adenoviruses have been explored in detail as vaccine vectors. The phylogeny of human and chimpanzee adenoviruses is overlapping, and preexisting humoral and cellular immunity to both are exhibited in human populations worldwide. More distantly related adenoviruses may therefore offer advantages as vaccine vectors. Here we describe the primary isolation and vectorization of three novel adenoviruses from rhesus monkeys. The seroprevalence of these novel rhesus monkey adenovirus vectors was extremely low in sub-Saharan Africa human populations, and these vectors proved to have immunogenicity comparable to that of human and chimpanzee adenovirus vaccine vectors in mice. These rhesus monkey adenoviruses phylogenetically clustered with the poorly described adenovirus species G and robustly stimulated innate immune responses. These novel adenoviruses represent a new class of candidate vaccine vectors. Although there have been substantial efforts in the development of vaccine vectors from human and chimpanzee adenoviruses, far less is known about rhesus monkey adenoviruses. In this report, we describe the isolation and vectorization of three novel rhesus monkey adenoviruses. These vectors exhibit virologic and immunologic characteristics that make them attractive as potential candidate vaccine vectors for both HIV-1 and other pathogens. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  13. Analogical reasoning in a capuchin monkey (Cebus apella).

    Science.gov (United States)

    Kennedy, Erica Hoy; Fragaszy, Dorothy M

    2008-05-01

    Previous evidence has suggested that analogical reasoning (recognizing similarities among object relations when the objects themselves are dissimilar) is limited to humans and apes. This study investigated whether capuchin monkeys (Cebus apella) can use analogical reasoning to solve a 3-dimensional search task. The task involved hiding a food item under 1 of 2 or 3 plastic cups of different sizes and then allowing subjects to search for food hidden under the cup of analogous size in their own set of cups. Four monkeys were exposed to a series of relational matching tasks. If subjects reached criterion on these tasks, they were exposed to relational transfer tasks involving novel stimuli. Three of the monkeys failed to reach criterion on the basic relational matching tasks and therefore were not tested further. One monkey, however, revealed above-chance performance on a series of transfer tasks with 3 novel stimuli. This evidence suggests that contrary to previous arguments, a member of a New World monkey species can solve an analogical problem. PsycINFO Database Record (c) 2008 APA, all rights reserved.

  14. [Monkey-pox, a model of emergent then reemergent disease].

    Science.gov (United States)

    Georges, A J; Matton, T; Courbot-Georges, M C

    2004-01-01

    The recent emergence of monkey pox in the United States of America highlights the problem (known for other infectious agents) of dissemination of pathogens outside their endemic area, and of subsequent global threats of variable gravity according to agents. It is a real emergency since monkey pox had been confined to Africa for several decades, where small epidemics occurred from time to time, monkey pox is a "miniature smallpox" which, in Africa, evolves on an endemic (zoonotic) mode with, as reservoirs, several species of wild rodents (mainly squirrels) and some monkey species. It can be accidentally transmitted to man then develops as epidemics, sometimes leading to death. The virus was imported in 2003 in the United States of America, via Gambia rats and wild squirrels (all African species), and infected prairie dogs (which are now in fashion as pets), then crossed the species barrier to man. In the United States of America, screening campaigns, epidemiological investigations, and subsequent treatments led to a rapid control of the epidemic, which is a model of emergent disease for this country. Therapeutic and preventive measures directly applicable to monkey pox are discussed. They can also be applied against other pox virus infections (including smallpox). The risk of criminal introduction of pox viruses is discussed since it is, more than ever, a real worldwide threat.

  15. Economic choices reveal probability distortion in macaque monkeys.

    Science.gov (United States)

    Stauffer, William R; Lak, Armin; Bossaerts, Peter; Schultz, Wolfram

    2015-02-18

    Economic choices are largely determined by two principal elements, reward value (utility) and probability. Although nonlinear utility functions have been acknowledged for centuries, nonlinear probability weighting (probability distortion) was only recently recognized as a ubiquitous aspect of real-world choice behavior. Even when outcome probabilities are known and acknowledged, human decision makers often overweight low probability outcomes and underweight high probability outcomes. Whereas recent studies measured utility functions and their corresponding neural correlates in monkeys, it is not known whether monkeys distort probability in a manner similar to humans. Therefore, we investigated economic choices in macaque monkeys for evidence of probability distortion. We trained two monkeys to predict reward from probabilistic gambles with constant outcome values (0.5 ml or nothing). The probability of winning was conveyed using explicit visual cues (sector stimuli). Choices between the gambles revealed that the monkeys used the explicit probability information to make meaningful decisions. Using these cues, we measured probability distortion from choices between the gambles and safe rewards. Parametric modeling of the choices revealed classic probability weighting functions with inverted-S shape. Therefore, the animals overweighted low probability rewards and underweighted high probability rewards. Empirical investigation of the behavior verified that the choices were best explained by a combination of nonlinear value and nonlinear probability distortion. Together, these results suggest that probability distortion may reflect evolutionarily preserved neuronal processing. Copyright © 2015 Stauffer et al.

  16. Responses of squirrel monkeys to their experimentally modified mobbing calls

    Science.gov (United States)

    Fichtel, Claudia; Hammerschmidt, Kurt

    2003-05-01

    Previous acoustic analyses suggested emotion-correlated changes in the acoustic structure of squirrel monkey (Saimiri sciureus) vocalizations. Specifically, calls given in aversive contexts were characterized by an upward shift in frequencies, often accompanied by an increase in amplitude. In order to test whether changes in frequencies or amplitude are indeed relevant for conspecific listeners, playback experiments were conducted in which either frequencies or amplitude of mobbing calls were modified. Latency and first orienting response were measured in playback experiments with six adult squirrel monkeys. After broadcasting yaps with increased frequencies or amplitude, squirrel monkeys showed a longer orienting response towards the speaker than after the corresponding control stimuli. Furthermore, after broadcasting yaps with decreased frequencies or amplitude, squirrel monkeys showed a shorter orienting response towards the speaker than after the corresponding manipulated calls with higher frequencies or amplitude. These results suggest that changes in frequencies or amplitude were perceived by squirrel monkeys, indicating that the relationship between call structure and the underlying affective state of the caller agreed with the listener's assessment of the calls. However, a simultaneous increase in frequencies and amplitude did not lead to an enhanced response, compared to each single parameter. Thus, from the receiver's perspective, both call parameters may mutually replace each other.

  17. Evaluation of monkey intraocular pressure by rebound tonometer

    Science.gov (United States)

    Yu, Wenhan; Cao, Guiqun; Qiu, Jinghua; Ma, Jia; Li, Ni; Yu, Man; Yan, Naihong; Chen, Lei; Pang, Iok-Hou

    2009-01-01

    Purpose To evaluate the usefulness of the TonoVet™ rebound tonometer in measuring intraocular pressure (IOP) of monkeys. Methods The accuracy of the TonoVet™ rebound tonometer was determined in cannulated eyes of anesthetized rhesus monkeys where IOP was controlled by adjusting the height of a connected perfusate reservoir. To assess the applicability of the equipment through in vivo studies, the diurnal fluctuation of IOP and effects of IOP-lowering compounds were evaluated in monkeys. Results IOP readings generated by the TonoVet™ tonometer correlated very well with the actual pressure in the cannulated monkey eye. The linear correlation had a slope of 0.922±0.014 (mean±SEM, n=4), a y-intercept of 3.04±0.61, and a correlation coefficient of r2=0.97. Using this method, diurnal IOP fluctuation of the rhesus monkey was demonstrated. The tonometer was also able to detect IOP changes induced by pharmacologically active compounds. A single topical ocular instillation (15 μg) of the rho kinase inhibitor, H1152, produced a 5–6 mmHg reduction (pmonkey eye. PMID:19898690

  18. Monkey brain damage from radiation in the therapeutic range

    International Nuclear Information System (INIS)

    Nakagaki, H.; Brunhart, G.; Kemper, T.L.; Caveness, W.F.

    1976-01-01

    Twelve Macaca mulatta monkeys received 200 rads of supervoltage radiation to the whole brain per day, 5 days a week. The course in four monkeys was 4 weeks for a total dose of 4000 rads; in four monkeys, 6 weeks for 6000 rads; and in four monkeys, 8 weeks for 8000 rads. Four unirradiated monkeys served as controls. One from each group, sacrificed at 6 and 12 months from start of irradiation, is reported here. The results from 4000 rads were negligible; those from 8000 rads, profound, with gross brain destruction. The results from 6000 rads, within the therapeutic range, included at 6 months punctate necrotic lesions, 1 mm or less, widely scattered but with a predilection for the forebrain white matter. The reaction to these lesions ranged from an early macrophage response to calcification. Some were accompanied by focal edema. There were occasional examples of vascular endothelial proliferation. In addition, there were patches of dilated capillaries or telangiectasia. Twelve months after 6000 rads there were a few mineralized lesions and innumerable minute deposits of calcium and iron. A more active process was suggested by widely disseminated areas of telangiectasia, 6 to 12 mm in extent. The clinical course from this exposure included papilledema from the third to the sixth month and depressed visual evoked response accompanied by delta activity in the electroencephalogram from the sixth to the twelfth month

  19. Integration of Visual and Proprioceptive Limb Position Information in Human Posterior Parietal, Premotor, and Extrastriate Cortex.

    Science.gov (United States)

    Limanowski, Jakub; Blankenburg, Felix

    2016-03-02

    The brain constructs a flexible representation of the body from multisensory information. Previous work on monkeys suggests that the posterior parietal cortex (PPC) and ventral premotor cortex (PMv) represent the position of the upper limbs based on visual and proprioceptive information. Human experiments on the rubber hand illusion implicate similar regions, but since such experiments rely on additional visuo-tactile interactions, they cannot isolate visuo-proprioceptive integration. Here, we independently manipulated the position (palm or back facing) of passive human participants' unseen arm and of a photorealistic virtual 3D arm. Functional magnetic resonance imaging (fMRI) revealed that matching visual and proprioceptive information about arm position engaged the PPC, PMv, and the body-selective extrastriate body area (EBA); activity in the PMv moreover reflected interindividual differences in congruent arm ownership. Further, the PPC, PMv, and EBA increased their coupling with the primary visual cortex during congruent visuo-proprioceptive position information. These results suggest that human PPC, PMv, and EBA evaluate visual and proprioceptive position information and, under sufficient cross-modal congruence, integrate it into a multisensory representation of the upper limb in space. The position of our limbs in space constantly changes, yet the brain manages to represent limb position accurately by combining information from vision and proprioception. Electrophysiological recordings in monkeys have revealed neurons in the posterior parietal and premotor cortices that seem to implement and update such a multisensory limb representation, but this has been difficult to demonstrate in humans. Our fMRI experiment shows that human posterior parietal, premotor, and body-selective visual brain areas respond preferentially to a virtual arm seen in a position corresponding to one's unseen hidden arm, while increasing their communication with regions conveying visual

  20. Robust tactile sensory responses in finger area of primate motor cortex relevant to prosthetic control

    Science.gov (United States)

    Schroeder, Karen E.; Irwin, Zachary T.; Bullard, Autumn J.; Thompson, David E.; Bentley, J. Nicole; Stacey, William C.; Patil, Parag G.; Chestek, Cynthia A.

    2017-08-01

    Objective. Challenges in improving the performance of dexterous upper-limb brain-machine interfaces (BMIs) have prompted renewed interest in quantifying the amount and type of sensory information naturally encoded in the primary motor cortex (M1). Previous single unit studies in monkeys showed M1 is responsive to tactile stimulation, as well as passive and active movement of the limbs. However, recent work in this area has focused primarily on proprioception. Here we examined instead how tactile somatosensation of the hand and fingers is represented in M1. Approach. We recorded multi- and single units and thresholded neural activity from macaque M1 while gently brushing individual finger pads at 2 Hz. We also recorded broadband neural activity from electrocorticogram (ECoG) grids placed on human motor cortex, while applying the same tactile stimulus. Main results. Units displaying significant differences in firing rates between individual fingers (p  sensory information was present in M1 to correctly decode stimulus position from multiunit activity above chance levels in all monkeys, and also from ECoG gamma power in two human subjects. Significance. These results provide some explanation for difficulties experienced by motor decoders in clinical trials of cortically controlled prosthetic hands, as well as the general problem of disentangling motor and sensory signals in primate motor cortex during dextrous tasks. Additionally, examination of unit tuning during tactile and proprioceptive inputs indicates cells are often tuned differently in different contexts, reinforcing the need for continued refinement of BMI training and decoding approaches to closed-loop BMI systems for dexterous grasping.

  1. Sensory-specific amnesia and hypoemotionality in humans and monkeys: gateway for developing a hodology of memory.

    Science.gov (United States)

    Ross, Elliott D

    2008-09-01

    Amnesia is a dramatic clinical syndrome caused by diverse pathologies and lesion localizations. Although amnesia is typically screened for by clinicians using verbal stimuli, amnestic syndromes have been described that do not impair verbal memory and may be confined to a single sensory system or a dominant or highly lateralized sensory function. Thus, the functional-anatomic basis for various types of amnestic disorders is complex and, in most instances, better understood as a disconnection syndrome rather than a primary processing deficit. Using the clinical disorder of sensory-specific visual amnesia in humans as a springboard, a hodological model for understanding the various types of amnestic syndromes encountered in the clinic and those produced by discrete experimental lesions in monkeys is offered. The model is then expanded to encompass memory functions, in general, including agnostic deficits and the role of prefrontal cortex in learning and remembering.

  2. Comparative plasma lipidome between human and cynomolgus monkey: are plasma polar lipids good biomarkers for diabetic monkeys?

    Directory of Open Access Journals (Sweden)

    Guanghou Shui

    Full Text Available BACKGROUND: Non-human primates (NHP are now being considered as models for investigating human metabolic diseases including diabetes. Analyses of cholesterol and triglycerides in plasma derived from NHPs can easily be achieved using methods employed in humans. Information pertaining to other lipid species in monkey plasma, however, is lacking and requires comprehensive experimental analysis. METHODOLOGIES/PRINCIPAL FINDINGS: We examined the plasma lipidome from 16 cynomolgus monkey, Macaca fascicularis, using liquid chromatography coupled with mass spectrometry (LC/MS. We established novel analytical approaches, which are based on a simple gradient elution, to quantify polar lipids in plasma including (i glycerophospholipids (phosphatidylcholine, PC; phosphatidylethanolamine, PE; phosphatidylinositol, PI; phosphatidylglycerol, PG; phosphatidylserine, PS; phosphatidic acid, PA; (ii sphingolipids (sphingomyelin, SM; ceramide, Cer; Glucocyl-ceramide, GluCer; ganglioside mannoside 3, GM3. Lipidomic analysis had revealed that the plasma of human and cynomolgus monkey were of similar compositions, with PC, SM, PE, LPC and PI constituting the major polar lipid species present. Human plasma contained significantly higher levels of plasmalogen PE species (p<0.005 and plasmalogen PC species (p<0.0005, while cynomolgus monkey had higher levels of polyunsaturated fatty acyls (PUFA in PC, PE, PS and PI. Notably, cynomolgus monkey had significantly lower levels of glycosphingolipids, including GluCer (p<0.0005 and GM(3 (p<0.0005, but higher level of Cer (p<0.0005 in plasma than human. We next investigated the biochemical alterations in blood lipids of 8 naturally occurring diabetic cynomolgus monkeys when compared with 8 healthy controls. CONCLUSIONS: For the first time, we demonstrated that the plasma of human and cynomolgus monkey were of similar compositions, but contained different mol distribution of individual molecular species. Diabetic monkeys

  3. MRI volumetry of prefrontal cortex

    Science.gov (United States)

    Sheline, Yvette I.; Black, Kevin J.; Lin, Daniel Y.; Pimmel, Joseph; Wang, Po; Haller, John W.; Csernansky, John G.; Gado, Mokhtar; Walkup, Ronald K.; Brunsden, Barry S.; Vannier, Michael W.

    1995-05-01

    Prefrontal cortex volumetry by brain magnetic resonance (MR) is required to estimate changes postulated to occur in certain psychiatric and neurologic disorders. A semiautomated method with quantitative characterization of its performance is sought to reliably distinguish small prefrontal cortex volume changes within individuals and between groups. Stereological methods were tested by a blinded comparison of measurements applied to 3D MR scans obtained using an MPRAGE protocol. Fixed grid stereologic methods were used to estimate prefrontal cortex volumes on a graphic workstation, after the images are scaled from 16 to 8 bits using a histogram method. In addition images were resliced into coronal sections perpendicular to the bicommissural plane. Prefrontal cortex volumes were defined as all sections of the frontal lobe anterior to the anterior commissure. Ventricular volumes were excluded. Stereological measurement yielded high repeatability and precision, and was time efficient for the raters. The coefficient of error was volumetry by stereology can yield accurate and repeatable measurements. Small frontal lobe volume reductions in patients with brain disorders such as depression and schizophrenia can be efficiently assessed using this method.

  4. Somato-motor haptic processing in posterior inner perisylvian region (SII/pIC of the macaque monkey.

    Directory of Open Access Journals (Sweden)

    Hiroaki Ishida

    Full Text Available The posterior inner perisylvian region including the secondary somatosensory cortex (area SII and the adjacent region of posterior insular cortex (pIC has been implicated in haptic processing by integrating somato-motor information during hand-manipulation, both in humans and in non-human primates. However, motor-related properties during hand-manipulation are still largely unknown. To investigate a motor-related activity in the hand region of SII/pIC, two macaque monkeys were trained to perform a hand-manipulation task, requiring 3 different grip types (precision grip, finger exploration, side grip both in light and in dark conditions. Our results showed that 70% (n = 33/48 of task related neurons within SII/pIC were only activated during monkeys' active hand-manipulation. Of those 33 neurons, 15 (45% began to discharge before hand-target contact, while the remaining neurons were tonically active after contact. Thirty-percent (n = 15/48 of studied neurons responded to both passive somatosensory stimulation and to the motor task. A consistent percentage of task-related neurons in SII/pIC was selectively activated during finger exploration (FE and precision grasping (PG execution, suggesting they play a pivotal role in control skilled finger movements. Furthermore, hand-manipulation-related neurons also responded when visual feedback was absent in the dark. Altogether, our results suggest that somato-motor neurons in SII/pIC likely contribute to haptic processing from the initial to the final phase of grasping and object manipulation. Such motor-related activity could also provide the somato-motor binding principle enabling the translation of diachronic somatosensory inputs into a coherent image of the explored object.

  5. Characterisation of the appearance of radioactive metabolites in monkey and human plasma from the 5-HT1A receptor radioligand, [carbonyl-11C]WAY-100635 - explanation of high signal contrast in PET and an aid to biomathematical modelling

    International Nuclear Information System (INIS)

    Osman, Safiye; Lundkvist, Camilla; Pike, Victor W.; Halldin, Christer; McCarron, Julie A.; Swahn, Carl-Gunnar; Farde, Lars; Ginovart, Nathalie; Luthra, Sajinder K.; Gunn, Roger N.; Bench, Christopher J.; Sargent, Peter A.; Grasby, Paul M.

    1998-01-01

    N-(2-(4-(2-Methoxy-phenyl)-1-piperazin-1-yl)ethyl)-N-(2-pyridyl) cyclohexanecarboxamide (WAY-100635), labelled in its amido carbonyl group with 11 C (t 1/2 = 20.4 min), is a promising radioligand for the study of brain 5-HT 1A receptors with positron emission tomography (PET). Thus, in PET experiments in six cynomolgus monkeys and seven healthy male volunteers, [carbonyl- 11 C]WAY-100635 was taken up avidly by brain. Radioactivity was retained in regions rich in 5-HT 1A receptors, such as occipital cortex, temporal cortex and raphe nuclei, but cleared rapidly from cerebellum, a region almost devoid of 5-HT 1A receptors. [Carbonyl- 11 C]WAY-100635 provides about 3- and 10-fold higher signal contrast (receptor-specific to nonspecific binding) than [O-methyl- 11 C]WAY-100635 in receptor-rich areas of monkey and human brain, respectively. To elucidate the effect of label position on radioligand behaviour and to aid in the future biomathematical interpretation of the kinetics of regional cerebral radioactivity uptake in terms of receptor-binding parameters, HPLC was used to measure [carbonyl- 11 C]WAY-100635 and its radioactive metabolites in plasma at various times after intravenous injection. Radioactivity cleared rapidly from monkey and human plasma. Parent radioligand represented 19% of the radioactivity in monkey plasma at 47 min and 8% of the radioactivity in human plasma at 40 min. [Carbonyl- 11 C]desmethyl-WAY-100635 was below detectable limits in monkey plasma and at most a very minor radioactive metabolite in human plasma. [ 11 C]Cyclohexanecarboxylic acid was identified as a significant radioactive metabolite. In human plasma this maximally represented 21% of the radioactivity at 10 min after radioligand injection. All other major radioactive metabolites in monkey and human plasma were even more polar. No-carrier-added [carbonyl- 11 C]cyclohexanecarboxylic acid was prepared in the laboratory and after intravenous administration into cynomolgus monkey was

  6. Neural Monkey: An Open-source Tool for Sequence Learning

    Directory of Open Access Journals (Sweden)

    Helcl Jindřich

    2017-04-01

    Full Text Available In this paper, we announce the development of Neural Monkey – an open-source neural machine translation (NMT and general sequence-to-sequence learning system built over the TensorFlow machine learning library. The system provides a high-level API tailored for fast prototyping of complex architectures with multiple sequence encoders and decoders. Models’ overall architecture is specified in easy-to-read configuration files. The long-term goal of the Neural Monkey project is to create and maintain a growing collection of implementations of recently proposed components or methods, and therefore it is designed to be easily extensible. Trained models can be deployed either for batch data processing or as a web service. In the presented paper, we describe the design of the system and introduce the reader to running experiments using Neural Monkey.

  7. Movement disorders induced in monkeys by chronic haloperidol treatment

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, B; Santelli, S; Lusink, G

    1977-01-01

    After several months of treatment, Cebus apella, Cebus albifrons, and Saimiri sciurea monkeys maintained on haloperidol, in doses of 0.5 or 1.0 mg/kg orally 5 days per week, began to display severe movement disorders, typically 1 to 6 h post-drug. Cebus monkeys exhibited violent, uncontrolled movements that flung the animals about the cage. Such episodes usually lasted only a few minutes, recurring several times during the period following drug ingestion. Writhing and bizarre postures dominated the response in S. sciurea. Cessation of drug treatment produced no distinctive after-effects. When tested as long as 508 days after the last administration, however, Cebus monkeys responded to haloperidol with several episodes of hyperkinesis, even at challenge doses considerably lower than those in the original treatment.

  8. Processing and Integration of Contextual Information in Monkey Ventrolateral Prefrontal Neurons during Selection and Execution of Goal-Directed Manipulative Actions.

    Science.gov (United States)

    Bruni, Stefania; Giorgetti, Valentina; Bonini, Luca; Fogassi, Leonardo

    2015-08-26

    The prefrontal cortex (PFC) is deemed to underlie the complexity, flexibility, and goal-directedness of primates' behavior. Most neurophysiological studies performed so far investigated PFC functions with arm-reaching or oculomotor tasks, thus leaving unclear whether, and to which extent, PFC neurons also play a role in goal-directed manipulative actions, such as those commonly used by primates during most of their daily activities. Here we trained two macaques to perform or withhold grasp-to-eat and grasp-to-place actions, depending on the combination of two subsequently presented cues: an auditory go/no-go cue (high/low tone) and a visually presented target (food/object). By varying the order of presentation of the two cues, we could segment and independently evaluate the processing and integration of contextual information allowing the monkey to make a decision on whether or not to act, and what action to perform. We recorded 403 task-related neurons from the ventrolateral prefrontal cortex (VLPFC): unimodal sensory-driven (37%), motor-related (21%), unimodal sensory-and-motor (23%), and multisensory (19%) neurons. Target and go/no-go selectivity characterized most of the recorded neurons, particularly those endowed with motor-related discharge. Interestingly, multisensory neurons appeared to encode a behavioral decision independently from the sensory modality of the stimulus allowing the monkey to make it: some of them reflected the decision to act or refraining from acting (56%), whereas others (44%) encoded the decision to perform (or withhold) a specific action (e.g., grasp-to-eat). Our findings indicate that VLPFC neurons play a role in the processing of contextual information underlying motor decision during goal-directed manipulative actions. We demonstrated that macaque ventrolateral prefrontal cortex (VLPFC) neurons show remarkable selectivity for different aspects of the contextual information allowing the monkey to select and execute goal

  9. Comparative imaging study on monkeys with hemi-parkinsonism

    International Nuclear Information System (INIS)

    Wang Wei; Yu Xiaoping; Mao Jun; Liu Sheng; Wang Xiaoyi; Peng Guangchun; Wang Ruiwen

    2003-01-01

    Objective: To study the imaging appearance of experimental Parkinson's disease (PD) and to evaluate the different medical imaging exams on PD. Methods: CT, MRI, SPECT (dopamine transporter imaging and regional cerebral blood flow imaging, DAT imaging and rCBF imaging), and PET (glucose metabolism imaging) were performed on 8 monkeys before and after the infusion of MPTP into unilateral internal carotid artery to develop hemi-Parkinsonism models. Results: Hemi-Parkinsonism models were successfully induced on all 8 monkeys. On DAT imaging, the uptake values of the lesioned striatums decreased obviously after the MPTP treatment and were lower than that of the contralateral ones. The glucose metabolic rates of the lesioned striatums and thalamus in PD models were lower, compared to that of the healthy monkeys and that of the contralateral sides of themselves. Neither DAT nor glucose metabolism abnormalities was found on both the contralateral sides of the healthy and PD monkeys. On MRI images before MPTP treatment, only 4 of 8 PD models showed hypointense in bilateral globus pallidus. No abnormal MRI findings occurred in the first 2 months after injection of MPTP. At tile third month, hypointense appeared in globus pallidus of three monkeys. Enlarged hyposignal region in globus pallidus were found in three models. Of the above 6 monkeys, two appeared hypointense in putamina. Substantia nigra demonstrated no abnormalities before and after MPTP treatment. All rCBF and CT images were normal. Conclusion: The decreased density of DAT and decreased glucose metabolism on experimental PD can be showed early by DAT imaging and glucose metabolism imaging, MRI can show abnormal signal in the basal ganglia of PD but it is later than DAT and glucose metabolism imaging. CT and rCBF find no abnormality on PD

  10. Socialization of adult owl monkeys (Aotus sp.) in Captivity.

    Science.gov (United States)

    Williams, Lawrence E; Coke, C S; Weed, J L

    2017-01-01

    Social housing has often been recommended as one-way to address the psychological well-being of captive non-human primates. Published reports have examined methods to socialize compatible animals by forming pairs or groups. Successful socialization rates vary depending on the species, gender, and environment. This study presents a retrospective look at pairing attempts in two species of owl monkeys, Aotus nancymaae and A. azarae, which live in monogamous pairs in the wild. The results of 477 pairing attempt conducted with captive, laboratory housed owl monkeys and 61 hr of behavioral observations are reported here. The greatest success pairing these owl monkeys occurred with opposite sex pairs, with an 82% success rate. Opposite sex pairs were more successful when females were older than males. Female-female pairs were more successful than male-male (MM) pairs (62% vs 40%). Successful pairs stayed together between 3 and 7 years before the animals were separated due to social incompatibility. Vigilance, eating, and sleeping during introductions significantly predicted success, as did the performance of the same behavior in both animals. The results of this analysis show that it is possible to give captive owl monkeys a social alternative even if species appropriate social partners (i.e., opposite sex partners) are not available. The focus of this report is a description of one potential way to enhance the welfare of a specific new world primate, the owl monkey, under laboratory conditions. More important is how the species typical social structure of owl monkeys in nature affects the captive management of this genus. Am. J. Primatol. 79:e22521, 2017. © 2015 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  11. Directional character of spreading of vasogenic cerebral edema after radiation damage in rhesus monkeys, and effects of removal of the primary lesion

    International Nuclear Information System (INIS)

    Wakisaka, Shinichiro; Iguchi, Takahiko; Nakagaki, Hiroyuki; Tanaka, Akira; Black, P.; O'Neill, R.R.; Caveness, W.F.

    1986-01-01

    Five pubescent rhesus monkeys were exposed to 35 Gy of orthovoltage x-irradiation in a single dose to the right visual cortex. Twenty to 36 weeks later the irradiated region broke down rather abruptly. Steep rise of cerebrospinal fluid (CSF) protein and lactic dehydrogenase (LDH) indicated disruption of blood brain barrier (BBB) and tissue breakdown. Visual evoked response (VER), funduscopic and clinical findings suggested disfunction of neural tissues and increased intracranial pressure. Extraordinary brain swelling and distortion were observed at the time of sacrifice. The most striking finding was that the ipsilateral middle and inferior temporal gyri, where radiation did not affect directly, were selectively swollen and edematous sparing the superior temporal gyrus. Corticocortical neuronal connections between visual cortex and inferior convexity of the temporal lobe has been demonstrated by Kuypers et al. Our previous studies also disclosed selective swelling of other remote visual association areas, i. e., ipsilateral lateral geniculate body and uncinate fasciculus. Thus, edema fluid might propagate from the site of the lesion through the anatomic pathways. In the group of monkeys, which received surgical removals of damaged right occipital lobes where BBB was disrupted, CSF protein and LDH drastically returned to the normal base line values after the surgery. Furthermore, no swelling of ipsilateral middle and inferior temporal gyri was observed in this group at the time of sacrifice, indicating that spreaded vasogenic edema could be subdued by removing the primary lesion. (author)

  12. Reproductive function of monkeys subjected to chronic irradiation

    International Nuclear Information System (INIS)

    Artem'eva, N.S.; Kosichenko, L.P.; Andreeva, A.V.; Zvereva, G.A.

    1976-01-01

    Marked functional disorders have been detected in reproductive glands of eight female monkeys (as compared to twelve control animals) subjected to protracted (up to eight years) irradiation (cumulative doses 826-3282 R). Irradiated monkeys exhibited a drastically decreased reproductive capacity, early menopause and sterility. Irradiation of preadolescent animals inhibited, in most cases, the puberty processes and disturbed sex cycles. Structural disorders in sex glands, inhibition of the processes of maturation and ovulation of folloculi, death of the mass of germ cells, atypical vegetations of the integmentary epithelium, sclerosing and cystic degeneration of the glandular tissue have been revealed

  13. "Zeroing" in on mathematics in the monkey brain.

    Science.gov (United States)

    Beran, Michael J

    2016-03-01

    A new study documented that monkeys showed selective neuronal responding to the concept of zero during a numerical task, and that there were two distinct classes of neurons that coded the absence of stimuli either through a discrete activation pattern (zero or not zero) or a continuous one for which zero was integrated with other numerosities in the relative rate of activity. These data indicate that monkeys, like humans, have a concept of zero that is part of their analog number line but that also may have unique properties compared to other numerosities.

  14. Functional analysis of aldehyde oxidase using expressed chimeric enzyme between monkey and rat.

    Science.gov (United States)

    Itoh, Kunio; Asakawa, Tasuku; Hoshino, Kouichi; Adachi, Mayuko; Fukiya, Kensuke; Watanabe, Nobuaki; Tanaka, Yorihisa

    2009-01-01

    Aldehyde oxidase (AO) is a homodimer with a subunit molecular mass of approximately 150 kDa. Each subunit consists of about 20 kDa 2Fe-2S cluster domain storing reducing equivalents, about 40 kDa flavine adenine dinucleotide (FAD) domain and about 85 kDa molybdenum cofactor (MoCo) domain containing a substrate binding site. In order to clarify the properties of each domain, especially substrate binding domain, chimeric cDNAs were constructed by mutual exchange of 2Fe-2S/FAD and MoCo domains between monkey and rat. Chimeric monkey/rat AO was referred to one with monkey type 2Fe-2S/FAD domains and a rat type MoCo domain. Rat/monkey AO was vice versa. AO-catalyzed 2-oxidation activities of (S)-RS-8359 were measured using the expressed enzyme in Escherichia coli. Substrate inhibition was seen in rat AO and chimeric monkey/rat AO, but not in monkey AO and chimeric rat/monkey AO, suggesting that the phenomenon might be dependent on the natures of MoCo domain of rat. A biphasic Eadie-Hofstee profile was observed in monkey AO and chimeric rat/monkey AO, but not rat AO and chimeric monkey/rat AO, indicating that the biphasic profile might be related to the properties of MoCo domain of monkey. Two-fold greater V(max) values were observed in monkey AO than in chimeric rat/monkey AO, and in chimeric monkey/rat AO than in rat AO, suggesting that monkey has the more effective electron transfer system than rat. Thus, the use of chimeric enzymes revealed that 2Fe-2S/FAD and MoCo domains affect the velocity and the quantitative profiles of AO-catalyzed (S)-RS-8359 2-oxidation, respectively.

  15. Encoding of Spatial Attention by Primate Prefrontal Cortex Neuronal Ensembles

    Science.gov (United States)

    Treue, Stefan

    2018-01-01

    Abstract Single neurons in the primate lateral prefrontal cortex (LPFC) encode information about the allocation of visual attention and the features of visual stimuli. However, how this compares to the performance of neuronal ensembles at encoding the same information is poorly understood. Here, we recorded the responses of neuronal ensembles in the LPFC of two macaque monkeys while they performed a task that required attending to one of two moving random dot patterns positioned in different hemifields and ignoring the other pattern. We found single units selective for the location of the attended stimulus as well as for its motion direction. To determine the coding of both variables in the population of recorded units, we used a linear classifier and progressively built neuronal ensembles by iteratively adding units according to their individual performance (best single units), or by iteratively adding units based on their contribution to the ensemble performance (best ensemble). For both methods, ensembles of relatively small sizes (n decoding performance relative to individual single units. However, the decoder reached similar performance using fewer neurons with the best ensemble building method compared with the best single units method. Our results indicate that neuronal ensembles within the LPFC encode more information about the attended spatial and nonspatial features of visual stimuli than individual neurons. They further suggest that efficient coding of attention can be achieved by relatively small neuronal ensembles characterized by a certain relationship between signal and noise correlation structures. PMID:29568798

  16. Medial-lateral organization of the orbitofrontal cortex.

    Science.gov (United States)

    Rich, Erin L; Wallis, Jonathan D

    2014-07-01

    Emerging evidence suggests that specific cognitive functions localize to different subregions of OFC, but the nature of these functional distinctions remains unclear. One prominent theory, derived from human neuroimaging, proposes that different stimulus valences are processed in separate orbital regions, with medial and lateral OFC processing positive and negative stimuli, respectively. Thus far, neurophysiology data have not supported this theory. We attempted to reconcile these accounts by recording neural activity from the full medial-lateral extent of the orbital surface in monkeys receiving rewards and punishments via gain or loss of secondary reinforcement. We found no convincing evidence for valence selectivity in any orbital region. Instead, we report differences between neurons in central OFC and those on the inferior-lateral orbital convexity, in that they encoded different sources of value information provided by the behavioral task. Neurons in inferior convexity encoded the value of external stimuli, whereas those in OFC encoded value information derived from the structure of the behavioral task. We interpret these results in light of recent theories of OFC function and propose that these distinctions, not valence selectivity, may shed light on a fundamental organizing principle for value processing in orbital cortex.

  17. Chronic marijuana smoke exposure in the rhesus monkey. IV: Neurochemical effects and comparison to acute and chronic exposure to delta-9-tetrahydrocannabinol (THC) in rats.

    Science.gov (United States)

    Ali, S F; Newport, G D; Scallet, A C; Paule, M G; Bailey, J R; Slikker, W

    1991-11-01

    THC is the major psychoactive constituent of marijuana and is known to produce psychopharmacological effects in humans. These studies were designed to determine whether acute or chronic exposure to marijuana smoke or THC produces in vitro or in vivo neurochemical alterations in rat or monkey brain. For the in vitro study, THC was added (1-100 nM) to membranes prepared from different regions of the rat brain and muscarinic cholinergic (MCh) receptor binding was measured. For the acute in vivo study, rats were injected IP with vehicle, 1, 3, 10, or 30 mg THC/kg and sacrificed 2 h later. For the chronic study, rats were gavaged with vehicle or 10 or 20 mg THC/kg daily, 5 days/week for 90 days and sacrificed either 24 h or 2 months later. Rhesus monkeys were exposed to the smoke of a single 2.6% THC cigarette once a day, 2 or 7 days a week for 1 year. Approximately 7 months after the last exposure, animals were sacrificed by overdose with pentobarbital for neurochemical analyses. In vitro exposure to THC produced a dose-dependent inhibition of MCh receptor binding in several brain areas. This inhibition of MCh receptor binding, however, was also observed with two other nonpsychoactive derivatives of marijuana, cannabidiol and cannabinol. In the rat in vivo study, we found no significant changes in MCh or other neurotransmitter receptor binding in hippocampus, frontal cortex or caudate nucleus after acute or chronic exposure to THC. In the monkey brain, we found no alterations in the concentration of neurotransmitters in caudate nucleus, frontal cortex, hypothalamus or brain stem.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Histological features of layers and sublayers in cortical visual areas V1 and V2 of chimpanzees, macaque monkeys, and humans

    Directory of Open Access Journals (Sweden)

    Balaram P

    2014-09-01

    Full Text Available Pooja Balaram, Nicole A Young, Jon H Kaas Department of Psychology, Vanderbilt University, Nashville, TN, USA Abstract: The layers and sublayers of primary visual cortex, or V1, in primates are easily distinguishable compared to those in other cortical areas, and are especially distinct in anthropoid primates – monkeys, apes, and humans – where they also vary in histological appearance. This variation in primate-specific specialization has led to a longstanding confusion over the identity of layer 4 and its proposed sublayers in V1. As the application of different histological markers relate to the issue of defining and identifying layers and sublayers, we applied four traditional and four more recent histological markers to brain sections of V1 and adjoining secondary visual cortex (V2 in macaque monkeys, chimpanzees, and humans in order to compare identifiable layers and sublayers in both cortical areas across these species. The use of Nissl, neuronal nuclear antigen (NeuN, Gallyas myelin, cytochrome oxidase (CO, acetylcholinesterase (AChE, nonphosphorylated neurofilament H (SMI-32, parvalbumin (PV, and vesicular glutamate transporter 2 (VGLUT2 preparations support the conclusion that the most popular scheme of V1 lamination, that of Brodmann, misidentifies sublayers of layer 3 (3Bβ and 3C as sublayers of layer 4 (4A and 4B, and that the specialized sublayer of layer 3 in monkeys, 3Bβ, is not present in humans. These differences in interpretation are important as they relate to the proposed functions of layer 4 in primate species, where layer 4 of V1 is a layer that receives and processes information from the visual thalamus, and layer 3 is a layer that transforms and distributes information to other cortical areas. Keywords: area 17, area 18, cortical layers, histology, immunohistochemistry

  19. Histological features of layers and sublayers in cortical visual areas V1 and V2 of chimpanzees, macaque monkeys, and humans.

    Science.gov (United States)

    Balaram, Pooja; Young, Nicole A; Kaas, Jon H

    2014-09-01

    The layers and sublayers of primary visual cortex, or V1, in primates are easily distinguishable compared to those in other cortical areas, and are especially distinct in anthropoid primates - monkeys, apes, and humans - where they also vary in histological appearance. This variation in primate-specific specialization has led to a longstanding confusion over the identity of layer 4 and its proposed sublayers in V1. As the application of different histological markers relate to the issue of defining and identifying layers and sublayers, we applied four traditional and four more recent histological markers to brain sections of V1 and adjoining secondary visual cortex (V2) in macaque monkeys, chimpanzees, and humans in order to compare identifiable layers and sublayers in both cortical areas across these species. The use of Nissl, neuronal nuclear antigen (NeuN), Gallyas myelin, cytochrome oxidase (CO), acetylcholinesterase (AChE), nonphosphorylated neurofilament H (SMI-32), parvalbumin (PV), and vesicular glutamate transporter 2 (VGLUT2) preparations support the conclusion that the most popular scheme of V1 lamination, that of Brodmann, misidentifies sublayers of layer 3 (3Bβ and 3C) as sublayers of layer 4 (4A and 4B), and that the specialized sublayer of layer 3 in monkeys, 3Bβ, is not present in humans. These differences in interpretation are important as they relate to the proposed functions of layer 4 in primate species, where layer 4 of V1 is a layer that receives and processes information from the visual thalamus, and layer 3 is a layer that transforms and distributes information to other cortical areas.

  20. [11C]CHIBA-1001 as a novel PET ligand for alpha7 nicotinic receptors in the brain: a PET study in conscious monkeys.

    Directory of Open Access Journals (Sweden)

    Kenji Hashimoto

    Full Text Available BACKGROUND: The alpha7 nicotinic acetylcholine receptors (nAChRs play an important role in the pathophysiology of neuropsychiatric diseases such as schizophrenia and Alzheimer's disease. However, there are currently no suitable positron emission tomography (PET radioligands for imaging alpha7 nAChRs in the intact human brain. Here we report the novel PET radioligand [11C]CHIBA-1001 for in vivo imaging of alpha7 nAChRs in the non-human primate brain. METHODOLOGY/PRINCIPAL FINDINGS: A receptor binding assay showed that CHIBA-1001 was a highly selective ligand at alpha7 nAChRs. Using conscious monkeys, we found that the distribution of radioactivity in the monkey brain after intravenous administration of [11C]CHIBA-1001 was consistent with the regional distribution of alpha7 nAChRs in the monkey brain. The distribution of radioactivity in the brain regions after intravenous administration of [11C]CHIBA-1001 was blocked by pretreatment with the selective alpha7 nAChR agonist SSR180711 (5.0 mg/kg. However, the distribution of [11C]CHIBA-1001 was not altered by pretreatment with the selective alpha4beta2 nAChR agonist A85380 (1.0 mg/kg. Interestingly, the binding of [11C]CHIBA-1001 in the frontal cortex of the monkey brain was significantly decreased by subchronic administration of the N-methyl-D-aspartate (NMDA receptor antagonist phencyclidine (0.3 mg/kg, twice a day for 13 days; which is a non-human primate model of schizophrenia. CONCLUSIONS/SIGNIFICANCE: The present findings suggest that [11C]CHIBA-1001 could be a novel useful PET ligand for in vivo study of the receptor occupancy and pathophysiology of alpha7 nAChRs in the intact brain of patients with neuropsychiatric diseases such as schizophrenia and Alzheimer's disease.

  1. One-trial memory for object-place associations after separate lesions of hippocampus and posterior parahippocampal region in the monkey.

    Science.gov (United States)

    Malkova, Ludise; Mishkin, Mortimer

    2003-03-01

    In earlier studies of one-trial spatial memory in monkeys (Parkinson et al., 1988; Angeli et al., 1993), severe and chronic memory impairment for both object-place association and place alone was found after ablation of the hippocampal formation. The results appeared to provide the first clear-cut evidence in the monkey of the essential role of the hippocampus in spatial memory, but that interpretation neglected the inclusion in the lesion of the underlying posterior parahippocampal region. To determine the separate contributions of the hippocampus and posterior parahippocampal region to these spatial forms of one-trial memory, we trained 10 rhesus monkeys, as before, to remember the spatial positions of either two different trial-unique objects overlying two of the wells in a three-well test tray (object-place trials) or simply two of the three wells (place trials). Six of the monkeys then received ibotenic acid lesions restricted to the hippocampal formation (group H), and the four others received selective ablations of the posterior parahippocampal region (group P), comprising mainly parahippocampal cortex, parasubiculum, and presubiculum. Group H was found to be completely unaffected postoperatively on both types of trials, whereas group P sustained an impairment on both types equal in magnitude to that observed after the combined lesions in the original studies. Thus, contrary to the previous interpretation, one-trial memory for object-place association and, perhaps more fundamentally, one-trial memory for two different places appear to be critically dependent not on the hippocampal formation but rather on the posterior parahippocampal region.

  2. Age- and brain region-dependent α-synuclein oligomerization is attributed to alterations in intrinsic enzymes regulating α-synuclein phosphorylation in aging monkey brains.

    Science.gov (United States)

    Chen, Min; Yang, Weiwei; Li, Xin; Li, Xuran; Wang, Peng; Yue, Feng; Yang, Hui; Chan, Piu; Yu, Shun

    2016-02-23

    We previously reported that the levels of α-syn oligomers, which play pivotal pathogenic roles in age-related Parkinson's disease (PD) and dementia with Lewy bodies, increase heterogeneously in the aging brain. Here, we show that exogenous α-syn incubated with brain extracts from older cynomolgus monkeys and in Lewy body pathology (LBP)-susceptible brain regions (striatum and hippocampus) forms higher amounts of phosphorylated and oligomeric α-syn than that in extracts from younger monkeys and LBP-insusceptible brain regions (cerebellum and occipital cortex). The increased α-syn phosphorylation and oligomerization in the brain extracts from older monkeys and in LBP-susceptible brain regions were associated with higher levels of polo-like kinase 2 (PLK2), an enzyme promoting α-syn phosphorylation, and lower activity of protein phosphatase 2A (PP2A), an enzyme inhibiting α-syn phosphorylation, in these brain extracts. Further, the extent of the age- and brain-dependent increase in α-syn phosphorylation and oligomerization was reduced by inhibition of PLK2 and activation of PP2A. Inversely, phosphorylated α-syn oligomers reduced the activity of PP2A and showed potent cytotoxicity. In addition, the activity of GCase and the levels of ceramide, a product of GCase shown to activate PP2A, were lower in brain extracts from older monkeys and in LBP-susceptible brain regions. Our results suggest a role for altered intrinsic metabolic enzymes in age- and brain region-dependent α-syn oligomerization in aging brains.

  3. The Functions of the Orbitofrontal Cortex

    Science.gov (United States)

    Rolls, Edmund T.

    2004-01-01

    The orbitofrontal cortex contains the secondary taste cortex, in which the reward value of taste is represented. It also contains the secondary and tertiary olfactory cortical areas, in which information about the identity and also about the reward value of odours is represented. The orbitofrontal cortex also receives information about the sight…

  4. Ketamine changes the local resting-state functional properties of anesthetized-monkey brain.

    Science.gov (United States)

    Rao, Jia-Sheng; Liu, Zuxiang; Zhao, Can; Wei, Rui-Han; Zhao, Wen; Tian, Peng-Yu; Zhou, Xia; Yang, Zhao-Yang; Li, Xiao-Guang

    2017-11-01

    Ketamine is a well-known anesthetic. 'Recreational' use of ketamine common induces psychosis-like symptoms and cognitive impairments. The acute and chronic effects of ketamine on relevant brain circuits have been studied, but the effects of single-dose ketamine administration on the local resting-state functional properties of the brain remain unknown. In this study, we aimed to assess the effects of single-dose ketamine administration on the brain local intrinsic properties. We used resting-state functional magnetic resonance imaging (rs-fMRI) to explore the ketamine-induced alterations of brain intrinsic properties. Seven adult rhesus monkeys were imaged with rs-fMRI to examine the fractional amplitude of low-frequency fluctuation (fALFF) and regional homogeneity (ReHo) in the brain before and after ketamine injection. Paired comparisons were used to detect the significantly altered regions. Results showed that the fALFF of the prefrontal cortex (p=0.046), caudate nucleus (left side, p=0.018; right side, p=0.025), and putamen (p=0.020) in post-injection stage significantly increased compared with those in pre-injection period. The ReHo of nucleus accumbens (p=0.049), caudate nucleus (p=0.037), and hippocampus (p=0.025) increased after ketamine injection, but that of prefrontal cortex decreased (pketamine administration can change the regional intensity and synchronism of brain activity, thereby providing evidence of ketamine-induced abnormal resting-state functional properties in primates. This evidence may help further elucidate the effects of ketamine on the cerebral resting status. Copyright © 2017. Published by Elsevier Inc.

  5. Reference values of clinical chemistry and hematology parameters in rhesus monkeys (Macaca mulatta).

    Science.gov (United States)

    Chen, Younan; Qin, Shengfang; Ding, Yang; Wei, Lingling; Zhang, Jie; Li, Hongxia; Bu, Hong; Lu, Yanrong; Cheng, Jingqiu

    2009-01-01

    Rhesus monkey models are valuable to the studies of human biology. Reference values for clinical chemistry and hematology parameters of rhesus monkeys are required for proper data interpretation. Whole blood was collected from 36 healthy Chinese rhesus monkeys (Macaca mulatta) of either sex, 3 to 5 yr old. Routine chemistry and hematology parameters, and some special coagulation parameters including thromboelastograph and activities of coagulation factors were tested. We presented here the baseline values of clinical chemistry and hematology parameters in normal Chinese rhesus monkeys. These data may provide valuable information for veterinarians and investigators using rhesus monkeys in experimental studies.

  6. Delayed response task performance as a function of age in cynomolgus monkeys (Macaca fascicularis)

    DEFF Research Database (Denmark)

    Darusman, H S; Call, J; Sajuthi, D

    2014-01-01

    We compared delayed response task performance in young, middle-aged, and old cynomolgus monkeys using three memory tests that have been used with non-human primates. Eighteen cynomolgus monkeys-6 young (4-9 years), 6 middle-aged (10-19 years), and 6 old (above 20 years)-were tested. In general......, the old monkeys scored significantly worse than did the animals in the two other age groups. Longer delays between stimulus presentation and response increased the performance differences between the old and younger monkeys. The old monkeys in particular showed signs of impaired visuo-spatial memory...

  7. Long term lung clearance and cellular retention of cadmium in rats and monkeys

    International Nuclear Information System (INIS)

    Oberdorster, G.; Cox, C.; Baggs, R.

    1987-01-01

    The paper describes experiments to determine the long term lung clearance and cellular retention of cadmium in rats and monkeys. The rats and monkeys were exposed to 109 Cd Cl 2 aerosols, and one monkey was exposed to 115 CdO particles. The thoracic activity of the respective Cd isotopes was measured with time after exposure, for both species. Accumulation of 109 Cd in the kidneys of the monkeys exposed to 109 Cd Cl 2 was also examined, and autoradiographs of lung sections of these monkeys were also prepared. The results showed that the cadmium accumulated differently in the lungs of the rats and primates. (U.K.)

  8. Emergence of Cryptosporidium hominis Monkey Genotype II and Novel Subtype Family Ik in the Squirrel Monkey (Saimiri sciureus) in China.

    Science.gov (United States)

    Liu, Xuehan; Xie, Na; Li, Wei; Zhou, Ziyao; Zhong, Zhijun; Shen, Liuhong; Cao, Suizhong; Yu, Xingming; Hu, Yanchuan; Chen, Weigang; Peng, Gangneng

    2015-01-01

    A single Cryptosporidium isolate from a squirrel monkey with no clinical symptoms was obtained from a zoo in Ya'an city, China, and was genotyped by PCR amplification and DNA sequencing of the small-subunit ribosomal RNA (SSU rRNA), 70-kDa heat shock protein (HSP70), Cryptosporidium oocyst wall protein, and actin genes. This multilocus genetic characterization determined that the isolate was Cryptosporidium hominis, but carried 2, 10, and 6 nucleotide differences in the SSU rRNA, HSP70, and actin loci, respectively, which is comparable to the variations at these loci between C. hominis and the previously reported monkey genotype (2, 3, and 3 nucleotide differences). Phylogenetic studies, based on neighbor-joining and maximum likelihood methods, showed that the isolate identified in the current study had a distinctly discordant taxonomic status, distinct from known C. hominis and also from the monkey genotype, with respect to the three loci. Restriction fragment length polymorphisms of the SSU rRNA gene obtained from this study were similar to those of known C. hominis but clearly differentiated from the monkey genotype. Further subtyping was performed by sequence analysis of the gene encoding the 60-kDa glycoprotein (gp60). Maximum homology of only 88.3% to C. hominis subtype IdA10G4 was observed for the current isolate, and phylogenetic analysis demonstrated that this particular isolate belonged to a novel C. hominis subtype family, IkA7G4. This study is the first to report C. hominis infection in the squirrel monkey and, based on the observed genetic characteristics, confirms a new C. hominis genotype, monkey genotype II. Thus, these results provide novel insights into genotypic variation in C. hominis.

  9. New kids on the block: The Popeye domain containing (POPDC) protein family acting as a novel class of cAMP effector proteins in striated muscle.

    Science.gov (United States)

    Brand, Thomas; Schindler, Roland

    2017-12-01

    The cyclic 3',5'-adenosine monophosphate (cAMP) signalling pathway constitutes an ancient signal transduction pathway present in prokaryotes and eukaryotes. Previously, it was thought that in eukaryotes three effector proteins mediate cAMP signalling, namely protein kinase A (PKA), exchange factor directly activated by cAMP (EPAC) and the cyclic-nucleotide gated channels. However, recently a novel family of cAMP effector proteins emerged and was termed the Popeye domain containing (POPDC) family, which consists of three members POPDC1, POPDC2 and POPDC3. POPDC proteins are transmembrane proteins, which are abundantly present in striated and smooth muscle cells. POPDC proteins bind cAMP with high affinity comparable to PKA. Presently, their biochemical activity is poorly understood. However, mutational analysis in animal models as well as the disease phenotype observed in patients carrying missense mutations suggests that POPDC proteins are acting by modulating membrane trafficking of interacting proteins. In this review, we will describe the current knowledge about this gene family and also outline the apparent gaps in our understanding of their role in cAMP signalling and beyond. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  10. Prefrontal Cortex Networks Shift from External to Internal Modes during Learning

    Science.gov (United States)

    Brincat, Scott L.

    2016-01-01

    As we learn about items in our environment, their neural representations become increasingly enriched with our acquired knowledge. But there is little understanding of how network dynamics and neural processing related to external information changes as it becomes laden with “internal” memories. We sampled spiking and local field potential activity simultaneously from multiple sites in the lateral prefrontal cortex (PFC) and the hippocampus (HPC)—regions critical for sensory associations—of monkeys performing an object paired-associate learning task. We found that in the PFC, evoked potentials to, and neural information about, external sensory stimulation decreased while induced beta-band (∼11–27 Hz) oscillatory power and synchrony associated with “top-down” or internal processing increased. By contrast, the HPC showed little evidence of learning-related changes in either spiking activity or network dynamics. The results suggest that during associative learning, PFC networks shift their resources from external to internal processing. SIGNIFICANCE STATEMENT As we learn about items in our environment, their representations in our brain become increasingly enriched with our acquired “top-down” knowledge. We found that in the prefrontal cortex, but not the hippocampus, processing of external sensory inputs decreased while internal network dynamics related to top-down processing increased. The results suggest that during learning, prefrontal cortex networks shift their resources from external (sensory) to internal (memory) processing. PMID:27629722

  11. The role of parietal cortex in the formation of colour and motion based concepts

    Directory of Open Access Journals (Sweden)

    Samuel William Cheadle

    2014-07-01

    Full Text Available Imaging evidence shows that separate subdivisions of parietal cortex, in and around the intraparietal sulcus (IPS, are engaged when stimuli are grouped according to colour and to motion (Zeki and Stutters 2013. Since grouping is an essential step in the formation of concepts, we wanted to learn whether parietal cortex is also engaged in the formation of concepts according to these two attributes. Using functional magnetic resonance imaging (fMRI, and choosing the recognition of concept-based colour or motion stimuli as our paradigm, we found that there was strong concept-related activity in and around the intraparietal sulcus (IPS, a region whose homologue in the macaque monkey is known to receive direct but segregated anatomical inputs from V4 and V5. Parietal activity related to colour concepts was juxtaposed but did not overlap with activity related to motion concepts, thus emphasizing the continuation of the segregation of colour and motion into the conceptual system. Concurrent retinotopic mapping experiments showed that within the parietal cortex, concept-related activity increases within later stage IPS areas.

  12. Laminar recordings in frontal cortex suggest distinct layers for maintenance and control of working memory.

    Science.gov (United States)

    Bastos, André M; Loonis, Roman; Kornblith, Simon; Lundqvist, Mikael; Miller, Earl K

    2018-01-30

    All of the cerebral cortex has some degree of laminar organization. These different layers are composed of neurons with distinct connectivity patterns, embryonic origins, and molecular profiles. There are little data on the laminar specificity of cognitive functions in the frontal cortex, however. We recorded neuronal spiking/local field potentials (LFPs) using laminar probes in the frontal cortex (PMd, 8A, 8B, SMA/ACC, DLPFC, and VLPFC) of monkeys performing working memory (WM) tasks. LFP power in the gamma band (50-250 Hz) was strongest in superficial layers, and LFP power in the alpha/beta band (4-22 Hz) was strongest in deep layers. Memory delay activity, including spiking and stimulus-specific gamma bursting, was predominately in superficial layers. LFPs from superficial and deep layers were synchronized in the alpha/beta bands. This was primarily unidirectional, with alpha/beta bands in deep layers driving superficial layer activity. The phase of deep layer alpha/beta modulated superficial gamma bursting associated with WM encoding. Thus, alpha/beta rhythms in deep layers may regulate the superficial layer gamma bands and hence maintenance of the contents of WM. Copyright © 2018 the Author(s). Published by PNAS.

  13. Cholinergic Modulation of Cortical Microcircuits Is Layer-Specific: Evidence from Rodent, Monkey and Human Brain

    Directory of Open Access Journals (Sweden)

    Joshua Obermayer

    2017-12-01

    Full Text Available Acetylcholine (ACh signaling shapes neuronal circuit development and underlies specific aspects of cognitive functions and behaviors, including attention, learning, memory and motivation. During behavior, activation of muscarinic and nicotinic acetylcholine receptors (mAChRs and nAChRs by ACh alters the activation state of neurons, and neuronal circuits most likely process information differently with elevated levels of ACh. In several brain regions, ACh has been shown to alter synaptic strength as well. By changing the rules for synaptic plasticity, ACh can have prolonged effects on and rearrange connectivity between neurons that outlasts its presence. From recent discoveries in the mouse, rat, monkey and human brain, a picture emerges in which the basal forebrain (BF cholinergic system targets the neocortex with much more spatial and temporal detail than previously considered. Fast cholinergic synapses acting on a millisecond time scale are abundant in the mammalian cerebral cortex, and provide BF cholinergic neurons with the possibility to rapidly alter information flow in cortical microcircuits. Finally, recent studies have outlined novel mechanisms of how cholinergic projections from the BF affect synaptic strength in several brain areas of the rodent brain, with behavioral consequences. This review highlights these exciting developments and discusses how these findings translate to human brain circuitries.

  14. Context-dependent representation of response-outcome in monkey prefrontal neurons.

    Science.gov (United States)

    Tsujimoto, Satoshi; Sawaguchi, Toshiyuki

    2005-07-01

    For behaviour to be purposeful, it is important to monitor the preceding behavioural context, particularly for factors regarding stimulus, response and outcome. The dorsolateral prefrontal cortex (DLPFC) appears to play a major role in such a context-dependent, flexible behavioural control system, and this area is likely to have a neuronal mechanism for such retrospective coding, which associates response-outcome with the information and/or neural systems that guided the response. To address this hypothesis, we recorded neuronal activity from the DLPFC of monkeys performing memory- and sensory-guided saccade tasks, each of which had two conditions with reward contingencies. We found that post-response activity of a subset of DLPFC neurons was modulated by three factors relating to earlier events: the direction of the immediately preceding response, its outcome (reward or non-reward) and the information type (memory or sensory) that guided the response. Such neuronal coding should play a role in associating response-outcome with information and/or neural systems used to guide behaviour - that is, 'retrospective monitoring' of behavioural context and/or neural systems used for guiding behaviour - thereby contributing to context-dependent, flexible control of behaviours.

  15. When vision guides movement: a functional imaging study of the monkey brain.

    Science.gov (United States)

    Gregoriou, Georgia G; Savaki, Helen E

    2003-07-01

    Goal-directed reaching requires a precise neural representation of the arm position and the target location. Parietal and frontal cortical areas rely on visual, somatosensory, and motor signals to guide the reaching arm to the desired position in space. To dissociate the regions processing these signals, we applied the quantitative [(14)C]-deoxyglucose method on monkeys reaching either in the light or in the dark. Nonvisual (somatosensory and memory-related) guidance of the arm, during reaching in the dark, induced activation of discrete regions in the parietal, premotor, and motor cortices. These included the dorsal part of the medial bank of the intraparietal sulcus, the ventral premotor area F4, the dorsal premotor area F2 below the superior precentral dimple, and the primary somatosensory and motor cortices. Additional parietal and premotor regions comprising the ventral intraparietal cortex, ventral premotor area F5, and the ventral part of dorsal premotor area F2 were activated by visual guidance of the arm during reaching in the light. This study provides evidence that different regions of the parieto-premotor circuit process the visual, somatosensory, and motor-memory-related signals which guide the moving arm.

  16. Neural mechanisms of transient neocortical beta rhythms: Converging evidence from humans, computational modeling, monkeys, and mice

    Science.gov (United States)

    Sherman, Maxwell A.; Lee, Shane; Law, Robert; Haegens, Saskia; Thorn, Catherine A.; Hämäläinen, Matti S.; Moore, Christopher I.; Jones, Stephanie R.

    2016-01-01

    Human neocortical 15–29-Hz beta oscillations are strong predictors of perceptual and motor performance. However, the mechanistic origin of beta in vivo is unknown, hindering understanding of its functional role. Combining human magnetoencephalography (MEG), computational modeling, and laminar recordings in animals, we present a new theory that accounts for the origin of spontaneous neocortical beta. In our MEG data, spontaneous beta activity from somatosensory and frontal cortex emerged as noncontinuous beta events typically lasting drive targeting proximal and distal dendrites of pyramidal neurons, where the defining feature of a beta event was a strong distal drive that lasted one beta period (∼50 ms). This beta mechanism rigorously accounted for the beta event profiles; several other mechanisms did not. The spatial location of synaptic drive in the model to supragranular and infragranular layers was critical to the emergence of beta events and led to the prediction that beta events should be associated with a specific laminar current profile. Laminar recordings in somatosensory neocortex from anesthetized mice and awake monkeys supported these predictions, suggesting this beta mechanism is conserved across species and recording modalities. These findings make several predictions about optimal states for perceptual and motor performance and guide causal interventions to modulate beta for optimal function. PMID:27469163

  17. PET measured evoked cerebral blood flow responses in an awake monkey

    International Nuclear Information System (INIS)

    Perlmutter, J.S.; Lich, L.L.; Margenau, W.; Buchholz, S.

    1991-01-01

    We have developed a method to measure task-related regional cerebral blood flow (BF) responses in an awake, trained monkey using positron emission tomography (PET) and H215O. We trained an animal with operant conditioning using only positive reinforcement to climb unassisted into a modified primate chair that was then positioned in the PET scanner. A special headholder and acrylic skull cap permitted precise placement and accurate repositioning. We measured BF qualitatively with bolus injection of H215O and 40-s scan. Each session included scans at rest interposed with scans during vibration of a forepaw. Regional responses were identified using subtraction image analysis. After global normalization, a resting image was subtracted on a pixel-by-pixel basis from a comparable image collected during vibration. The region of peak response occurred in contralateral sensorimotor cortex with a mean magnitude of 11.6% (+/- 3.2%) of the global mean value for 10 separate experiments, significantly greater than the mean qualitative BF change (0.4 +/- 3.6%; p less than 0.00001) in the same region for seven rest-rest pairs. This newly developed technique forms the basis for a wide variety of experiments

  18. Evaluating the habitat of the critically endangered Kipunji monkey ...

    African Journals Online (AJOL)

    Effective conservation of threatened species requires a good understanding of their habitat. Most primates are threatened by tropical forest loss. One population of the critically endangered kipunji monkey Rungwecebus kipunji occurs in a restricted part of one forest in southern Tanzania. This restricted range is something of ...

  19. Phylogenetic tests of a Cercopithecus monkey hybrid reveal X ...

    African Journals Online (AJOL)

    A captive Cercopithecus nictitans × C. cephus male was examined at loci on the X- and Y-chromosomes as a test of previously described phylogenetic methods for identifying hybrid Cercopithecus monkeys. The results confirm the reliability of such assays, indicating that they can be of immediate utility for studies of wild ...

  20. Food and Feeding Habits of Mona Monkey Cercopithecus Mona in ...

    African Journals Online (AJOL)

    The feeding habits of mona monkey Cercopithecus mona in Ayede/Isan forest reserve, Ayede, Ekiti State, Nigeria were studied for six months. Direct observation was used in the data collection. The study area was visited two days per week between 0600-1100hours and 1600-1800hours for the six months in the forest ...

  1. Discovery of a Cynomolgus Monkey Family With Retinitis Pigmentosa.

    Science.gov (United States)

    Ikeda, Yasuhiro; Nishiguchi, Koji M; Miya, Fuyuki; Shimozawa, Nobuhiro; Funatsu, Jun; Nakatake, Shunji; Fujiwara, Kohta; Tachibana, Takashi; Murakami, Yusuke; Hisatomi, Toshio; Yoshida, Shigeo; Yasutomi, Yasuhiro; Tsunoda, Tatsuhiko; Nakazawa, Toru; Ishibashi, Tatsuro; Sonoda, Koh-Hei

    2018-02-01

    To accelerate the development of new therapies, an inherited retinal degeneration model in a nonhuman primate would be useful to confirm the efficacy in preclinical studies. In this study, we describe the discovery of retinitis pigmentosa in a cynomolgus monkey (Macaca fascicularis) pedigree. First, screening with fundus photography was performed on 1443 monkeys at the Tsukuba Primate Research Center. Ophthalmic examinations, such as indirect ophthalmoscopy, ERGs using RETeval, and optic coherent tomography (OCT) measurement, were then performed to confirm diagnosis. Retinal degeneration with cystoid macular edema was observed in both eyes of one 14-year-old female monkey. In her examinations, the full-field ERGs were nonrecordable and the outer layer of the retina in the parafoveal area was not visible on OCT imaging. Moreover, less frequent pigmentary retinal anomalies also were observed in her 3-year-old nephew. His full-field ERGs were almost nonrecordable and the outer layer was not visible in the peripheral retina. His father was her cousin (the son of her mother's older brother) and his mother was her younger half-sibling sister with a different father. The hereditary nature is highly probable (autosomal recessive inheritance suspected). However, whole-exome analysis performed identified no pathogenic mutations in these monkeys.

  2. The Monkey Kid: A Personal Glimpse into the Cultural Revolution

    Directory of Open Access Journals (Sweden)

    Anita M. Andrew

    2011-04-01

    Full Text Available Wang, Xiao-Yen (Director/Writer, 'The Monkey Kid '(1995. San Francisco, Calif.: Beijing–San Francisco Film Group. Also released in France by Les Films du Parodoxe under the title, 'La Mome Singe '(1997. 95 minutes. Mandarin Chinese with English subtitles.

  3. GLP-1 receptor localization in monkey and human tissue

    DEFF Research Database (Denmark)

    Pyke, Charles; Heller, R Scott; Kirk, Rikke K

    2014-01-01

    and increase heart rate. Using a new monoclonal antibody for immunohistochemistry, we detected GLP-1 receptor (GLP-1R) in important target organs in humans and monkeys. In the pancreas, GLP-1R was predominantly localized in β-cells with a markedly weaker expression in acinar cells. Pancreatic ductal epithelial...

  4. Response of sublethally irradiated monkeys to a replicating viral antigen

    International Nuclear Information System (INIS)

    Hilmas, D.E.; Spertzel, R.O.

    1975-01-01

    Temporal effects of exposure to sublethal, total-body x radiation (400 R) on responses to vaccination with the attenuated Venezuelan equine encephalomyelitis vaccine virus, TC-83, were examined in rhesus monkeys. Viremia, often with delayed onset, was prolonged even when irradiation preceded vaccination by 28 days. Virus titers were increased, particularly in groups irradiated 4 or 7 days before vaccination. Delay in appearance of hemagglutination-inhibition and serum-neutralizing antibody correlated closely with persistence of viremia in irradiated-vaccinated monkeys. The temporal course of antibody response was markedly affected by the interval between irradiation and injection of this replicating antigen. With longer intervals between irradiation and vaccination, the somewhat depressed antibody responses approached normal or surpassed those of nonirradiated monkeys. Vaccination 14 days after radiation exposure resulted in lethality to 8 of 12 monkeys, apparently as a result of secondary infection. The additional lymphopenic stress due to the effect of TC-83, superimposed on the severely depressed hematopoietic competence at 14 days, undoubtedly contributed to this increased susceptibility to latent infection

  5. Call Combinations in Monkeys: Compositional or Idiomatic Expressions?

    Science.gov (United States)

    Arnold, Kate; Zuberbuhler, Klaus

    2012-01-01

    Syntax is widely considered the feature that most decisively sets human language apart from other natural communication systems. Animal vocalisations are generally considered to be holistic with few examples of utterances meaning something other than the sum of their parts. Previously, we have shown that male putty-nosed monkeys produce call…

  6. Toxoplasmosis in a colony of New World monkeys

    DEFF Research Database (Denmark)

    Dietz, H.H.; Henriksen, P.; Bille-Hansen, Vivi

    1997-01-01

    In a colony of New World monkeys five tamarins (Saguinus oedipus, Saguinus labiatus and Leontopithecus rosal. rosal.), three marmosets (Callithrix jacchus and Callithrix pygmaea) and one saki (Pithecia pithecia) died suddenly. The colony comprised 16 marmosets, 10 tamarins and three sakis. The ma...

  7. Risky business: rhesus monkeys exhibit persistent preferences for risky options.

    Science.gov (United States)

    Xu, Eric R; Kralik, Jerald D

    2014-01-01

    Rhesus monkeys have been shown to prefer risky over safe options in experiential decision-making tasks. These findings might be due, however, to specific contextual factors, such as small amounts of fluid reward and minimal costs for risk-taking. To better understand the factors affecting decision-making under risk in rhesus monkeys, we tested multiple factors designed to increase the stakes including larger reward amounts, distinct food items rather than fluid reward, a smaller number of trials per session, and risky options with greater variation that also included non-rewarded outcomes. We found a consistent preference for risky options, except when the expected value of the safe option was greater than the risky option. Thus, with equivalent mean utilities between the safe and risky options, rhesus monkeys appear to have a robust preference for the risky options in a broad range of circumstances, akin to the preferences found in human children and some adults in similar tasks. One account for this result is that monkeys make their choices based on the salience of the largest payoff, without integrating likelihood and value across trials. A related idea is that they fail to override an impulsive tendency to select the option with the potential to obtain the highest possible outcome. Our results rule out strict versions of both accounts and contribute to an understanding of the diversity of risky decision-making among primates.

  8. Servants, Managers and Monkeys: New Perspectives on Leadership

    Science.gov (United States)

    Buskey, Frederick C.

    2014-01-01

    In this article the author questions whether the understanding of teaching and leading is the same today as it was last year? The chances are that the concept of what it means to be a teacher and a leader has changed. After describing three leadership types: servants, managers, and monkeys, Buskey suggest several things that are needed to improve…

  9. Can monkeys make investments based on maximized pay-off?

    Directory of Open Access Journals (Sweden)

    Sophie Steelandt

    2011-03-01

    Full Text Available Animals can maximize benefits but it is not known if they adjust their investment according to expected pay-offs. We investigated whether monkeys can use different investment strategies in an exchange task. We tested eight capuchin monkeys (Cebus apella and thirteen macaques (Macaca fascicularis, Macaca tonkeana in an experiment where they could adapt their investment to the food amounts proposed by two different experimenters. One, the doubling partner, returned a reward that was twice the amount given by the subject, whereas the other, the fixed partner, always returned a constant amount regardless of the amount given. To maximize pay-offs, subjects should invest a maximal amount with the first partner and a minimal amount with the second. When tested with the fixed partner only, one third of monkeys learned to remove a maximal amount of food for immediate consumption before investing a minimal one. With both partners, most subjects failed to maximize pay-offs by using different decision rules with each partner' quality. A single Tonkean macaque succeeded in investing a maximal amount to one experimenter and a minimal amount to the other. The fact that only one of over 21 subjects learned to maximize benefits in adapting investment according to experimenters' quality indicates that such a task is difficult for monkeys, albeit not impossible.

  10. Structural study of Mason-Pfizer monkey virus protease

    Czech Academy of Sciences Publication Activity Database

    Veverka, V.; Bauerová, Helena; Hrabal, R.; Pichová, Iva

    2002-01-01

    Roč. 269, - (2002), s. 57-58 ISSN 0014-2956. [Meeting of the Federation of European Biochemical Societies /28./. 20.10.2002-25.10.2002, Istanbul] R&D Projects: GA ČR GA203/00/1241 Institutional research plan: CEZ:AV0Z4055905 Keywords : Mason-Pfizer monkey virus Subject RIV: CE - Biochemistry

  11. Monkeys Exhibit Prospective Memory in a Computerized Task

    Science.gov (United States)

    Evans, Theodore A.; Beran, Michael J.

    2012-01-01

    Prospective memory (PM) involves forming intentions, retaining those intentions, and later executing those intended responses at the appropriate time. Few studies have investigated this capacity in animals. Monkeys performed a computerized task that assessed their ability to remember to make a particular response if they observed a PM cue embedded…

  12. Play Initiating Behaviors and Responses in Red Colobus Monkeys

    Science.gov (United States)

    Worch, Eric A.

    2012-01-01

    Red colobus monkeys are playful primates, making them an important species in which to study animal play. The author examines play behaviors and responses in the species for its play initiation events, age differences in initiating frequency and initiating behavior, and the types of social play that result from specific initiating behaviors. Out…

  13. Dynamic ensemble coding of saccades in the monkey superior colliculus.

    NARCIS (Netherlands)

    Goossens, H.H.L.M.; Opstal, A.J. van

    2006-01-01

    The deeper layers of the midbrain superior colliculus (SC) contain a topographic motor map in which a localized population of cells is recruited for each saccade, but how the brain stem decodes the dynamic SC output is unclear. Here we analyze saccade-related responses in the monkey SC to test a new

  14. Monkey-derived monoclonal antibodies against Plasmodium falciparum

    International Nuclear Information System (INIS)

    Stanley, H.A.; Reese, R.T.

    1985-01-01

    A system has been developed that allows efficient production of monkey monoclonal antibodies from owl monkeys. Splenocytes or peripheral blood lymphocytes from monkeys immune to the human malarial parasite, Plasmodium falciparum, were fused with P3X63 Ag8.653 mouse myelomas. The resulting hybridomas were screened by an indirect fluorescent antibody test for the production of monkey monoclonal antibodies (mAb) reactive with P. falciparum. Most of the mAb reacted with the P. falciparum merozoites and immunoprecipitated a parasite-derived glycoprotein having a relative molecular weight of 185,000. These mAb gave a minimum of five different immunoprecipitation patterns, thus demonstrating that a large number of polypeptides obtained when parasitized erythrocytes are solubilized share epitopes with this large glycoprotein. In addition, mAb were obtained that reacted with antigens associated with the infected erythrocyte membrane. One of these mAb bound a M/sub r/ 95,000 antigen. Radioimmunoprecipitation assays using 125 T-antibodies were done

  15. Midcingulate cortex: Structure, connections, homologies, functions and diseases.

    Science.gov (United States)

    Vogt, Brent A

    2016-07-01

    Midcingulate cortex (MCC) has risen in prominence as human imaging identifies unique structural and functional activity therein and this is the first review of its structure, connections, functions and disease vulnerabilities. The MCC has two divisions (anterior, aMCC and posterior, pMCC) that represent functional units and the cytoarchitecture, connections and neurocytology of each is shown with immunohistochemistry and receptor binding. The MCC is not a division of anterior cingulate cortex (ACC) and the "dorsal ACC" designation is a misnomer as it incorrectly implies that MCC is a division of ACC. Interpretation of findings among species and developing models of human diseases requires detailed comparative studies which is shown here for five species with flat maps and immunohistochemistry (human, monkey, rabbit, rat, mouse). The largest neurons in human cingulate cortex are in layer Vb of area 24 d in pMCC which project to the spinal cord. This area is part of the caudal cingulate premotor area which is involved in multisensory orientation of the head and body in space and neuron responses are tuned for the force and direction of movement. In contrast, the rostral cingulate premotor area in aMCC is involved in action-reinforcement associations and selection based on the amount of reward or aversive properties of a potential movement. The aMCC is activated by nociceptive information from the midline, mediodorsal and intralaminar thalamic nuclei which evoke fear and mediates nocifensive behaviors. This subregion also has high dopaminergic afferents and high dopamine-1 receptor binding and is engaged in reward processes. Opposing pain/avoidance and reward/approach functions are selected by assessment of potential outcomes and error detection according to feedback-mediated, decision making. Parietal afferents differentially terminate in MCC and provide for multisensory control in an eye- and head-centric manner. Finally, MCC vulnerability in human disease confirms

  16. Distinct timescales of population coding across cortex.

    Science.gov (United States)

    Runyan, Caroline A; Piasini, Eugenio; Panzeri, Stefano; Harvey, Christopher D

    2017-08-03

    The cortex represents information across widely varying timescales. For instance, sensory cortex encodes stimuli that fluctuate over few tens of milliseconds, whereas in association cortex behavioural choices can require the maintenance of information over seconds. However, it remains poorly understood whether diverse timescales result mostly from features intrinsic to individual neurons or from neuronal population activity. This question remains unanswered, because the timescales of coding in populations of neurons have not been studied extensively, and population codes have not been compared systematically across cortical regions. Here we show that population codes can be essential to achieve long coding timescales. Furthermore, we find that the properties of population codes differ between sensory and association cortices. We compared coding for sensory stimuli and behavioural choices in auditory cortex and posterior parietal cortex as mice performed a sound localization task. Auditory stimulus information was stronger in auditory cortex than in posterior parietal cortex, and both regions contained choice information. Although auditory cortex and posterior parietal cortex coded information by tiling in time neurons that were transiently informative for approximately 200 milliseconds, the areas had major differences in functional coupling between neurons, measured as activity correlations that could not be explained by task events. Coupling among posterior parietal cortex neurons was strong and extended over long time lags, whereas coupling among auditory cortex neurons was weak and short-lived. Stronger coupling in posterior parietal cortex led to a population code with long timescales and a representation of choice that remained consistent for approximately 1 second. In contrast, auditory cortex had a code with rapid fluctuations in stimulus and choice information over hundreds of milliseconds. Our results reveal that population codes differ across cortex

  17. Synchronous Spike Patterns in Macaque Motor Cortex during an Instructed-Delay Reach-to-Grasp Task.

    Science.gov (United States)

    Torre, Emiliano; Quaglio, Pietro; Denker, Michael; Brochier, Thomas; Riehle, Alexa; Grün, Sonja

    2016-08-10

    The computational role of spike time synchronization at millisecond precision among neurons in the cerebral cortex is hotly debated. Studies performed on data of limited size provided experimental evidence that low-order correlations occur in relation to behavior. Advances in electrophysiological technology to record from hundreds of neurons simultaneously provide the opportunity to observe coordinated spiking activity of larger populations of cells. We recently published a method that combines data mining and statistical evaluation to search for significant patterns of synchronous spikes in massively parallel spike trains (Torre et al., 2013). The method solves the computational and multiple testing problems raised by the high dimensionality of the data. In the current study, we used our method on simultaneous recordings from two macaque monkeys engaged in an instructed-delay reach-to-grasp task to determine the emergence of spike synchronization in relation to behavior. We found a multitude of synchronous spike patterns aligned in both monkeys along a preferential mediolateral orientation in brain space. The occurrence of the patterns is highly specific to behavior, indicating that different behaviors are associated with the synchronization of different groups of neurons ("cell assemblies"). However, pooled patterns that overlap in neuronal composition exhibit no specificity, suggesting that exclusive cell assemblies become active during different behaviors, but can recruit partly identical neurons. These findings are consistent across multiple recording sessions analyzed across the two monkeys. Neurons in the brain communicate via electrical impulses called spikes. How spikes are coordinated to process information is still largely unknown. Synchronous spikes are effective in triggering a spike emission in receiving neurons and have been shown to occur in relation to behavior in a number of studies on simultaneous recordings of few neurons. We recently published

  18. Long-range traveling waves of activity triggered by local dichoptic stimulation in V1 of behaving monkeys

    Science.gov (United States)

    Yang, Zhiyong; Heeger, David J.; Blake, Randolph

    2014-01-01

    Traveling waves of cortical activity, in which local stimulation triggers lateral spread of activity to distal locations, have been hypothesized to play an important role in cortical function. However, there is conflicting physiological evidence for the existence of spreading traveling waves of neural activity triggered locally. Dichoptic stimulation, in which the two eyes view dissimilar monocular patterns, can lead to dynamic wave-like fluctuations in visual perception and therefore, provides a promising means for identifying and studying cortical traveling waves. Here, we used voltage-sensitive dye imaging to test for the existence of traveling waves of activity in the primary visual cortex of awake, fixating monkeys viewing dichoptic stimuli. We find clear traveling waves that are initiated by brief, localized contrast increments in one of the monocular patterns and then, propagate at speeds of ∼30 mm/s. These results demonstrate that under an appropriate visual context, circuitry in visual cortex in alert animals is capable of supporting long-range traveling waves triggered by local stimulation. PMID:25343785

  19. Task-Relevant Information Modulates Primary Motor Cortex Activity Before Movement Onset.

    Science.gov (United States)

    Calderon, Cristian B; Van Opstal, Filip; Peigneux, Philippe; Verguts, Tom; Gevers, Wim

    2018-01-01

    Monkey neurophysiology research supports the affordance competition hypothesis (ACH) proposing that cognitive information useful for action selection is integrated in sensorimotor areas. In this view, action selection would emerge from the simultaneous representation of competing action plans, in parallel biased by relevant task factors. This biased competition would take place up to primary motor cortex (M1). Although ACH is plausible in environments affording choices between actions, its relevance for human decision making is less clear. To address this issue, we designed an functional magnetic resonance imaging (fMRI) experiment modeled after monkey neurophysiology studies in which human participants processed cues conveying predictive information about upcoming button presses. Our results demonstrate that, as predicted by the ACH, predictive information (i.e., the relevant task factor) biases activity of primary motor regions. Specifically, first, activity before movement onset in contralateral M1 increases as the competition is biased in favor of a specific button press relative to activity in ipsilateral M1. Second, motor regions were more tightly coupled with fronto-parietal regions when competition between potential actions was high, again suggesting that motor regions are also part of the biased competition network. Our findings support the idea that action planning dynamics as proposed in the ACH are valid both in human and non-human primates.

  20. Parallel, multi-stage processing of colors, faces and shapes in macaque inferior temporal cortex

    Science.gov (United States)

    Lafer-Sousa, Rosa; Conway, Bevil R.

    2014-01-01

    Visual-object processing culminates in inferior temporal (IT) cortex. To assess the organization of IT, we measured fMRI responses in alert monkey to achromatic images (faces, fruit, bodies, places) and colored gratings. IT contained multiple color-biased regions, which were typically ventral to face patches and, remarkably, yoked to them, spaced regularly at four locations predicted by known anatomy. Color and face selectivity increased for more anterior regions, indicative of a broad hierarchical arrangement. Responses to non-face shapes were found across IT, but were stronger outside color-biased regions and face patches, consistent with multiple parallel streams. IT also contained multiple coarse eccentricity maps: face patches overlapped central representations; color-biased regions spanned mid-peripheral representations; and place-biased regions overlapped peripheral representations. These results suggest that IT comprises parallel, multi-stage processing networks subject to one organizing principle. PMID:24141314

  1. INCREASES IN FUNCTIONAL CONNECTIVITY BETWEEN PREFRONTAL CORTEX AND STRIATUM DURING CATEGORY LEARNING

    Science.gov (United States)

    Antzoulatos, Evan G.; Miller, Earl K.

    2014-01-01

    SUMMARY Functional connectivity between the prefrontal cortex (PFC) and striatum (STR) is thought critical for cognition, and has been linked to conditions like autism and schizophrenia. We recorded from multiple electrodes in PFC and STR while monkeys acquired new categories. Category learning was accompanied by an increase in beta-band synchronization of LFPs between, but not within, the PFC and STR. After learning, different pairs of PFC-STR electrodes showed stronger synchrony for one or the other category, suggesting category-specific functional circuits. This category-specific synchrony was also seen between PFC spikes and STR LFPs, but not the reverse, reflecting the direct monosynaptic connections from the PFC to STR. However, causal connectivity analyses suggested that the polysynaptic connections from STR to the PFC exerted a stronger overall influence. This supports models positing that the basal ganglia “train” the PFC. Category learning may depend on the formation of functional circuits between the PFC and STR. PMID:24930701

  2. High baseline activity in inferior temporal cortex improves neural and behavioral discriminability during visual categorization

    Directory of Open Access Journals (Sweden)

    Nazli eEmadi

    2014-11-01

    Full Text Available Spontaneous firing is a ubiquitous property of neural activity in the brain. Recent literature suggests that this baseline activity plays a key role in perception. However, it is not known how the baseline activity contributes to neural coding and behavior. Here, by recording from the single neurons in the inferior temporal cortex of monkeys performing a visual categorization task, we thoroughly explored the relationship between baseline activity, the evoked response, and behavior. Specifically we found that a low-frequency (< 8 Hz oscillation in the spike train, prior and phase-locked to the stimulus onset, was correlated with increased gamma power and neuronal baseline activity. This enhancement of the baseline activity was then followed by an increase in the neural selectivity and the response reliability and eventually a higher behavioral performance.

  3. Single-exposure visual memory judgments are reflected in inferotemporal cortex

    Science.gov (United States)

    Meyer, Travis

    2018-01-01

    Our visual memory percepts of whether we have encountered specific objects or scenes before are hypothesized to manifest as decrements in neural responses in inferotemporal cortex (IT) with stimulus repetition. To evaluate this proposal, we recorded IT neural responses as two monkeys performed a single-exposure visual memory task designed to measure the rates of forgetting with time. We found that a weighted linear read-out of IT was a better predictor of the monkeys’ forgetting rates and reaction time patterns than a strict instantiation of the repetition suppression hypothesis, expressed as a total spike count scheme. Behavioral predictions could be attributed to visual memory signals that were reflected as repetition suppression and were intermingled with visual selectivity, but only when combined across the most sensitive neurons. PMID:29517485

  4. Covert shift of attention modulates the value encoding in the orbitofrontal cortex.

    Science.gov (United States)

    Xie, Yang; Nie, Chechang; Yang, Tianming

    2018-03-13

    During value-based decision making, we often evaluate the value of each option sequentially by shifting our attention, even when the options are presented simultaneously. The orbitofrontal cortex (OFC) has been suggested to encode value during value-based decision making. Yet it is not known how its activity is modulated by attention shifts. We investigated this question by employing a passive viewing task that allowed us to disentangle effects of attention, value, choice and eye movement. We found that the attention modulated OFC activity through a winner-take-all mechanism. When we attracted the monkeys' attention covertly, the OFC neuronal activity reflected the reward value of the newly attended cue. The shift of attention could be explained by a normalization model. Our results strongly argue for the hypothesis that the OFC neuronal activity represents the value of the attended item. They provide important insights toward understanding the OFC's role in value-based decision making. © 2018, Xie et al.

  5. Neurons in Primary Motor Cortex Encode Hand Orientation in a Reach-to-Grasp Task.

    Science.gov (United States)

    Ma, Chaolin; Ma, Xuan; Fan, Jing; He, Jiping

    2017-08-01

    It is disputed whether those neurons in the primary motor cortex (M1) that encode hand orientation constitute an independent channel for orientation control in reach-to-grasp behaviors. Here, we trained two monkeys to reach forward and grasp objects positioned in the frontal plane at different orientation angles, and simultaneously recorded the activity of M1 neurons. Among the 2235 neurons recorded in M1, we found that 18.7% had a high correlation exclusively with hand orientation, 15.9% with movement direction, and 29.5% with both movement direction and hand orientation. The distributions of neurons encoding hand orientation and those encoding movement direction were not uniform but coexisted in the same region. The trajectory of hand rotation was reproduced by the firing patterns of the orientation-related neurons independent of the hand reaching direction. These results suggest that hand orientation is an independent component for the control of reaching and grasping activity.

  6. Dissecting contributions of prefrontal cortex and fusiform face area to face working memory.

    Science.gov (United States)

    Druzgal, T Jason; D'Esposito, Mark

    2003-08-15

    Interactions between prefrontal cortex (PFC) and stimulus-specific visual cortical association areas are hypothesized to mediate visual working memory in behaving monkeys. To clarify the roles for homologous regions in humans, event-related fMRI was used to assess neural activity in PFC and fusiform face area (FFA) of subjects performing a delay-recognition task for faces. In both PFC and FFA, activity increased parametrically with memory load during encoding and maintenance of face stimuli, despite quantitative differences in the magnitude of activation. Moreover, timing differences in PFC and FFA activation during memory encoding and retrieval implied a context dependence in the flow of neural information. These results support existing neurophysiological models of visual working memory developed in the nonhuman primate.

  7. Neuronal activity in primate prefrontal cortex related to goal-directed behavior during auditory working memory tasks.

    Science.gov (United States)

    Huang, Ying; Brosch, Michael

    2016-06-01

    Prefrontal cortex (PFC) has been documented to play critical roles in goal-directed behaviors, like representing goal-relevant events and working memory (WM). However, neurophysiological evidence for such roles of PFC has been obtained mainly with visual tasks but rarely with auditory tasks. In the present study, we tested roles of PFC in auditory goal-directed behaviors by recording local field potentials in the auditory region of left ventrolateral PFC while a monkey performed auditory WM tasks. The tasks consisted of multiple events and required the monkey to change its mental states to achieve the reward. The events were auditory and visual stimuli, as well as specific actions. Mental states were engaging in the tasks and holding task-relevant information in auditory WM. We found that, although based on recordings from one hemisphere in one monkey only, PFC represented multiple events that were important for achieving reward, including auditory and visual stimuli like turning on and off an LED, as well as bar touch. The responses to auditory events depended on the tasks and on the context of the tasks. This provides support for the idea that neuronal representations in PFC are flexible and can be related to the behavioral meaning of stimuli. We also found that engaging in the tasks and holding information in auditory WM were associated with persistent changes of slow potentials, both of which are essential for auditory goal-directed behaviors. Our study, on a single hemisphere in a single monkey, reveals roles of PFC in auditory goal-directed behaviors similar to those in visual goal-directed behaviors, suggesting that functions of PFC in goal-directed behaviors are probably common across the auditory and visual modality. This article is part of a Special Issue entitled SI: Auditory working memory. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Rhesus monkeys see who they hear: spontaneous cross-modal memory for familiar conspecifics.

    Directory of Open Access Journals (Sweden)

    Ikuma Adachi

    Full Text Available Rhesus monkeys gather much of their knowledge of the social world through visual input and may preferentially represent this knowledge in the visual modality. Recognition of familiar faces is clearly advantageous, and the flexibility and utility of primate social memory would be greatly enhanced if visual memories could be accessed cross-modally either by visual or auditory stimulation. Such cross-modal access to visual memory would facilitate flexible retrieval of the knowledge necessary for adaptive social behavior. We tested whether rhesus monkeys have cross-modal access to visual memory for familiar conspecifics using a delayed matching-to-sample procedure. Monkeys learned visual matching of video clips of familiar individuals to photographs of those individuals, and generalized performance to novel videos. In crossmodal probe trials, coo-calls were played during the memory interval. The calls were either from the monkey just seen in the sample video clip or from a different familiar monkey. Even though the monkeys were trained exclusively in visual matching, the calls influenced choice by causing an increase in the proportion of errors to the picture of the monkey whose voice was heard on incongruent trials. This result demonstrates spontaneous cross-modal recognition. It also shows that viewing videos of familiar monkeys activates naturally formed memories of real monkeys, validating the use of video stimuli in studies of social cognition in monkeys.

  9. Modulation of Neuronal Responses by Exogenous Attention in Macaque Primary Visual Cortex.

    Science.gov (United States)

    Wang, Feng; Chen, Minggui; Yan, Yin; Zhaoping, Li; Li, Wu

    2015-09-30

    Visual perception is influenced by attention deployed voluntarily or triggered involuntarily by salient stimuli. Modulation of visual cortical processing by voluntary or endogenous attention has been extensively studied, but much less is known about how involuntary or exogenous attention affects responses of visual cortical neurons. Using implanted microelectrode arrays, we examined the effects of exogenous attention on neuronal responses in the primary visual cortex (V1) of awake monkeys. A bright annular cue was flashed either around the receptive fields of recorded neurons or in the opposite visual field to capture attention. A subsequent grating stimulus probed the cue-induced effects. In a fixation task, when the cue-to-probe stimulus onset asynchrony (SOA) was visual fields weakened or diminished both the physiological and behavioral cueing effects. Our findings indicate that exogenous attention significantly modulates V1 responses and that the modulation strength depends on both novelty and task relevance of the stimulus. Significance statement: Visual attention can be involuntarily captured by a sudden appearance of a conspicuous object, allowing rapid reactions to unexpected events of significance. The current study discovered a correlate of this effect in monkey primary visual cortex. An abrupt, salient, flash enhanced neuronal responses, and shortened the animal's reaction time, to a subsequent visual probe stimulus at the same location. However, the enhancement of the neural responses diminished after repeated exposures to this flash if the animal was not required to react to the probe. Moreover, a second, simultaneous, flash at another location weakened the neuronal and behavioral effects of the first one. These findings revealed, beyond the observations reported so far, the effects of exogenous attention in the brain. Copyright © 2015 the authors 0270-6474/15/3513419-11$15.00/0.

  10. Neuronal activity in primate auditory cortex during the performance of audiovisual tasks.

    Science.gov (United States)

    Brosch, Michael; Selezneva, Elena; Scheich, Henning

    2015-03-01

    This study aimed at a deeper understanding of which cognitive and motivational aspects of tasks affect auditory cortical activity. To this end we trained two macaque monkeys to perform two different tasks on the same audiovisual stimulus and to do this with two different sizes of water rewards. The monkeys had to touch a bar after a tone had been turned on together with an LED, and to hold the bar until either the tone (auditory task) or the LED (visual task) was turned off. In 399 multiunits recorded from core fields of auditory cortex we confirmed that during task engagement neurons responded to auditory and non-auditory stimuli that were task-relevant, such as light and water. We also confirmed that firing rates slowly increased or decreased for several seconds during various phases of the tasks. Responses to non-auditory stimuli and slow firing changes were observed during both the auditory and the visual task, with some differences between them. There was also a weak task-dependent modulation of the responses to auditory stimuli. In contrast to these cognitive aspects, motivational aspects of the tasks were not reflected in the firing, except during delivery of the water reward. In conclusion, the present study supports our previous proposal that there are two response types in the auditory cortex that represent the timing and the type of auditory and non-auditory elements of a auditory tasks as well the association between elements. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  11. Seasonal changes in isoform composition of giant proteins of thick and thin filaments and titin (connectin) phosphorylation level in striated muscles of bears (Ursidae, Mammalia).

    Science.gov (United States)

    Salmov, N N; Vikhlyantsev, I M; Ulanova, A D; Gritsyna, Yu V; Bobylev, A G; Saveljev, A P; Makariushchenko, V V; Maksudov, G Yu; Podlubnaya, Z A

    2015-03-01

    Seasonal changes in the isoform composition of thick and thin filament proteins (titin, myosin heavy chains (MyHCs), nebulin), as well as in the phosphorylation level of titin in striated muscles of brown bear (Ursus arctos) and hibernating Himalayan black bear (Ursus thibetanus ussuricus) were studied. We found that the changes that lead to skeletal muscle atrophy in bears during hibernation are not accompanied by a decrease in the content of nebulin and intact titin-1 (T1) isoforms. However, a decrease (2.1-3.4-fold) in the content of T2 fragments of titin was observed in bear skeletal muscles (m. gastrocnemius, m. longissimus dorsi, m. biceps) during hibernation. The content of the stiffer N2B titin isoform was observed to increase relative to the content of its more compliant N2BA isoform in the left ventricles of hibernating bears. At the same time, in spite of the absence of decrease in the total content of T1 in the myocardium of hibernating brown bear, the content of T2 fragments decreased ~1.6-fold. The level of titin phosphorylation only slightly increased in the cardiac muscle of hibernating brown bear. In the skeletal muscles of brown bear, the level of titin phosphorylation did not vary between seasons. However, changes in the composition of MyHCs aimed at increasing the content of slow (I) and decreasing the content of fast (IIa) isoforms of this protein during hibernation of brown bear were detected. Content of MyHCs I and IIa in the skeletal muscles of hibernating Himalayan black bear corresponded to that in the skeletal muscles of hibernating brown bear.

  12. A novel conserved isoform of the ubiquitin ligase UFD2a/UBE4B is expressed exclusively in mature striated muscle cells.

    Directory of Open Access Journals (Sweden)

    Andrew L Mammen

    Full Text Available Yeast Ufd2p was the first identified E4 multiubiquitin chain assembly factor. Its vertebrate homologues later referred to as UFD2a, UBE4B or E4B were also shown to have E3 ubiquitin ligase activity. UFD2a function in the brain has been well established in vivo, and in vitro studies have shown that its activity is essential for proper condensation and segregation of chromosomes during mitosis. Here we show that 2 alternative splice forms of UFD2a, UFD2a-7 and -7/7a, are expressed sequentially during myoblast differentiation of C2C12 cell cultures and during cardiotoxin-induced regeneration of skeletal muscle in mice. UFD2a-7 contains an alternate exon 7, and UFD2a-7/7a, the larger of the 2 isoforms, contains an additional novel exon 7a. Analysis of protein or mRNA expression in mice and zebrafish revealed that a similar pattern of isoform switching occurs during developmental myogenesis of cardiac and skeletal muscle. In vertebrates (humans, rodents, zebrafish, UFD2a-7/7a is expressed only in mature striated muscle. This unique tissue specificity is further validated by the conserved presence of 2 muscle-specific splicing regulatory motifs located in the 3' introns of exons 7 and 7a. UFD2a interacts with VCP/p97, an AAA-type ATPase implicated in processes whose functions appear to be regulated, in part, through their interaction with one or more of 15 previously identified cofactors. UFD2a-7/7a did not interact with VCP/p97 in yeast 2-hybrid experiments, which may allow the ATPase to bind cofactors that facilitate its muscle-specific functions. We conclude that the regulated expression of these UFD2a isoforms most likely imparts divergent functions that are important for myogenisis.

  13. Placental Transport of Zidovudine in the Rhesus Monkey

    Science.gov (United States)

    King, Thomas S.; Henderson, George I.; Schenker, Steven; Schenken, Robert S.

    1993-01-01

    Objective: This study was undertaken to characterize the pharmacokinetics of zidovudine (ZDV) and ZDV-glucuronide (ZDVG) in the material and :fetal circulations of the rhesus monkey. Methods: Cannulas were placed in the maternal external jugular and the fetal internal jugular and carotid artery in 8 pregnant monkeys at .120–130 days gestation. ZDV (3.5 mg/kg) was administered to 5 monkeys and ZDVG (3.5 mg/kg) to 3 monkeys as single intravenous bolus infusions through the maternal catheter. Maternal and fetal blood , samples were collected every 20 min for the first 2 h and then every hour for the next 4 h. Maternal and fetal concentrations of ZDV and ZDVG were determined using high, performance liquid chromatography (HPLC) with ultraviolet (UV) detection. Results: In monkeys who received ZDV, the terminal half-life (T1/2) for ZDV was 37±15 and 33 ± 13 min in the maternal and fetal compartments, respectively. The apparent T1/2 for maternal ZDVG was 124 ± 44 and 142 ± 50 min in the maternal and fetal compartments, respectively. Peak levels of ZDV and ZDVG in the fetal compartment were reached 40 min after injection. The mean fetal/maternal concentration ratios for ZDV and ZDVG ranged from 0.20 ± 0.20 at 20 min to a maximum of 0.74 ± 1.0 at 120 min and from 0.28 ± 0.08 at 20 min to 1.4 ± 1.3 at 180 min, respectively. In monkeys who received ZDVG, the T1/2 for ZDWG in the maternal and fetal compartments was 47 ± 26 and 119 ± 164 min, respectively. ZDVG reached its peak in the fetal compartment at 60 min post-injection. The fetal/maternal rafio ranged from 0.08 ± 0.11 at 20 min to 4.2 ± 4.2 at 180 min post-injection. Conclusions: These data demonstrate that 1) ZDV and ZDVG rapidly cross the placenta to the fetal compartment, 2) ZDV crosses more rapidly than ZDVG, and 3) some metabolism of ZDV to ZDVG occurs in the fetal compartment. PMID:18475334

  14. Functional Imaging of Audio-Visual Selective Attention in Monkeys and Humans: How do Lapses in Monkey Performance Affect Cross-Species Correspondences?

    Science.gov (United States)

    Rinne, Teemu; Muers, Ross S; Salo, Emma; Slater, Heather; Petkov, Christopher I

    2017-06-01

    The cross-species correspondences and differences in how attention modulates brain responses in humans and animal models are poorly understood. We trained 2 monkeys to perform an audio-visual selective attention task during functional magnetic resonance imaging (fMRI), rewarding them to attend to stimuli in one modality while ignoring those in the other. Monkey fMRI identified regions strongly modulated by auditory or visual attention. Surprisingly, auditory attention-related modulations were much more restricted in monkeys than humans performing the same tasks during fMRI. Further analyses ruled out trivial explanations, suggesting that labile selective-attention performance was associated with inhomogeneous modulations in wide cortical regions in the monkeys. The findings provide initial insights into how audio-visual selective attention modulates the primate brain, identify sources for "lost" attention effects in monkeys, and carry implications for modeling the neurobiology of human cognition with nonhuman animals. © The Author 2017. Published by Oxford University Press.

  15. Functional Imaging of Audio–Visual Selective Attention in Monkeys and Humans: How do Lapses in Monkey Performance Affect Cross-Species Correspondences?

    Science.gov (United States)

    Muers, Ross S.; Salo, Emma; Slater, Heather; Petkov, Christopher I.

    2017-01-01

    Abstract The cross-species correspondences and differences in how attention modulates brain responses in humans and animal models are poorly understood. We trained 2 monkeys to perform an audio–visual selective attention task during functional magnetic resonance imaging (fMRI), rewarding them to attend to stimuli in one modality while ignoring those in the other. Monkey fMRI identified regions strongly modulated by auditory or visual attention. Surprisingly, auditory attention-related modulations were much more restricted in monkeys than humans performing the same tasks during fMRI. Further analyses ruled out trivial explanations, suggesting that labile selective-attention performance was associated with inhomogeneous modulations in wide cortical regions in the monkeys. The findings provide initial insights into how audio–visual selective attention modulates the primate brain, identify sources for “lost” attention effects in monkeys, and carry implications for modeling the neurobiology of human cognition with nonhuman animals. PMID:28419201

  16. Detection of stimulus deviance within primate primary auditory cortex: intracortical mechanisms of mismatch negativity (MMN) generation.

    Science.gov (United States)

    Javitt, D C; Steinschneider, M; Schroeder, C E; Vaughan, H G; Arezzo, J C

    1994-12-26

    Mismatch negativity (MMN) is a cognitive, auditory event-related potential (AEP) that reflects preattentive detection of stimulus deviance and indexes the operation of the auditory sensory ('echoic') memory system. MMN is elicited most commonly in an auditory oddball paradigm in which a sequence of repetitive standard stimuli is interrupted infrequently and unexpectedly by a physically deviant 'oddball' stimulus. Electro- and magnetoencephalographic dipole mapping studies have localized the generators of MMN to supratemporal auditory cortex in the vicinity of Heschl's gyrus, but have not determined the degree to which MMN reflects activation within primary auditory cortex (AI) itself. The present study, using moveable multichannel electrodes inserted acutely into superior temporal plane, demonstrates a significant contribution of AI to scalp-recorded MMN in the monkey, as reflected by greater response of AI to loud or soft clicks presented as deviants than to the same stimuli presented as repetitive standards. The MMN-like activity was localized primarily to supragranular laminae within AI. Thus, standard and deviant stimuli elicited similar degrees of initial, thalamocortical excitation. In contrast, responses within supragranular cortex were significantly larger to deviant stimuli than to standards. No MMN-like activity was detected in a limited number to passes that penetrated anterior and medial to AI. AI plays a well established role in the decoding of the acoustic properties of individual stimuli. The present study demonstrates that primary auditory cortex also plays an important role in processing the relationships between stimuli, and thus participates in cognitive, as well as purely sensory, processing of auditory information.

  17. Human-Rhesus Monkey conflict at Rampur Village under Monohardi Upazila in Narsingdi District of Bangladesh

    Directory of Open Access Journals (Sweden)

    M.F. Ahsan

    2014-06-01

    Full Text Available Human-Rhesus monkey conflicts were recorded at Rampur Village under Khidirpur Union Parishad of Monohardi upazila under Narsingdi District in Bangladesh from April to September 2012. There were three groups of Rhesus monkeys living in the area. The focal study group comprised 26 individuals (4 adult males, 6 adult females, 10 juveniles and 6 infants. The monkeys consumed parts of 10 plant species. From the questionnaire survey, it was found that the greatest damage caused by monkeys was on betel leaf vines and the least damage on vegetables. Eighty percent respondents opted to conserve the monkeys and 20% opined status quo. Some restricted areas (especially khas lands may be identified and planted with some fruit trees for survival of monkeys and for reducing conflicts with humans.

  18. Captive spider monkeys (Ateles geoffroyi) arm-raise to solicit allo-grooming.

    Science.gov (United States)

    Scheel, Matthew H; Edwards, Dori

    2012-03-01

    Old World monkeys solicit allo-grooming from conspecifics. However, there are relatively few studies of allo-grooming among spider monkeys, and descriptions of allo-grooming solicitation among spider monkeys are anecdotal. In this study, eighty-one hours of video, shot over eight weeks, captured 271 allo-grooming bouts among small groups of captive spider monkeys. Six of eight monkeys made heretofore unreported arm-raises that solicited higher than normal rates of allo-grooming. Allo-grooming bout durations following arm-raises also tended to be longer than bouts not preceded by arm-raises. The efficacy of the arm-raise at soliciting allo-grooming suggests spider monkeys are capable of intentional communication. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Phenobarbital treatments lower DDT body burden in rhesus monkeys

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, P.W.; Clark, C.R.; Gee, S.J.; Krieger, R.I.

    1981-01-01

    Decreased DDT, DDD, DDE in blood and DDA in urine followed phenobarbital treatments (10 mg/kg/day, 11 days, intramuscular (im)) in three male rhesus monkeys (Macaca mulatta). Animals were fed DDT diets containing up to 500 ppm DDT during a 3-year period. Induction of liver monooxygenases was confirmed by reduced in vivo antipyrine plasma half-life and increased in vitro oxidation rates of dihydroisodrin, p-nitroanisole and benz(alpha)pyrene by homogenates of liver obtained from closed needle biopsy. Chlorohydrocarbon blood levels significantly decreased during the induction period (days 1-11). Concentrations on day 28 were at or below pre-DDT exposure levels. Urine DDA gradually decreased in all monkeys from days 16 to 28.

  20. Metabolic alkalosis during immobilization in monkeys (M. nemestrina)

    Science.gov (United States)

    Young, D. R.; Yeh, I.; Swenson, R. S.

    1983-01-01

    The systemic and renal acid-base response of monkeys during ten weeks of immobilization was studied. By three weeks of immobilization, arterial pH and bicarbonate concentrations were elevated (chronic metabolic alkalosis). Net urinary acid excretion increased in immobilized animals. Urinary bicarbonate excretion decreased during the first three weeks of immobilization, and then returned to control levels. Sustained increases in urinary ammonium excretion were seen throughout the time duration of immobilization. Neither potassium depletion nor hypokalemia was observed. Most parameters returned promptly to the normal range during the first week of recovery. Factors tentatively associated with changes in acid-base status of monkeys include contraction of extracellular fluid volume, retention of bicarbonate, increased acid excretion, and possible participation of extrarenal buffers.

  1. Selection and Pairing of ’Normal’ Rhesus Monkeys (Macaca mulatta) for Research.

    Science.gov (United States)

    1978-11-08

    week intervals. Fecal bacteriological cultures did not detect any Salmonella or Shigella car- riers in the population. The male monkeys ranged in age...1Special Roert 78-6 LVEL•$ SELECTION AND PAIRING OF "NORMAL" RHESUS MONKEYS (Macaca mulatto) FOR RESEARC Matthew J. Kessler, James L. Kupper, James D...public release; distribution unlimited. SELECTION AND PAIRING OF "NORMAL" RHESUS MONKEYS (Macaca mulatta) FOR RESEARCH Matthew J. Kessler, James L

  2. Streptococcus oralis cerebral abscess following monkey bite in a 2-month-old infant.

    Science.gov (United States)

    Thiagarajan, Srinivasan; Krishnamurthy, Sriram; Raghavan, Renitha; Mahadevan, Subramanian; Madhugiri, Venkatesh S; Sistla, Sujatha

    2016-05-01

    Although cerebral abscesses caused by animal bites have been reported, they are extremely rare in infants and have not been described following monkey bite. A 55-day-old male infant presented with a multi-loculated Streptococcus oralis cerebral abscess following a monkey bite on the scalp. There was a clinical response to antibiotic therapy and repeated surgical aspiration followed by a ventriculoperitoneal shunt. This is the first report of a patient with a brain abscess following a monkey bite.

  3. Pathogenesis of Rift Valley Fever in Rhesus Monkeys: Role of Interferon Response

    Science.gov (United States)

    1990-01-01

    hemorrhagic fever characterized by epistaxis, petechial to purpuric cutaneous lesions, anorexia, and vomiting prior to death. The 14 remaining monkeys survived...DMI, FILE Copy Arch Virol (1990) 110: 195-212 Amhivesirology ( by Springer-Verlag 1990 00 N Pathogenesis of Rift Valley fever in rhesus monkeys: (NI...inoculated intravenously with Rift Valley fever (RVF) virus presented clinical disease syndromes similar to human cases of RVF. All 17 infected monkeys

  4. Habitat quality of the woolly spider monkey (Brachyteles hypoxanthus).

    Science.gov (United States)

    da Silva Júnior, Wilson Marcelo; Alves Meira-Neto, João Augusto; da Silva Carmo, Flávia Maria; Rodrigues de Melo, Fabiano; Santana Moreira, Leandro; Ferreira Barbosa, Elaine; Dias, Luiz Gustavo; da Silva Peres, Carlos Augusto

    2009-01-01

    This study examines how habitat structure affects the home range use of a group of Brachyteles hypoxanthus in the Brigadeiro State Park, Brazil. It has been reported that most of the annual feeding time of woolly spider monkeys is spent eating leaves, but they prefer fruits when available. We hypothesise that the protein-to-fibre ratio (PF; best descriptor of habitat quality for folivorous primates) is a better descriptor of habitat quality and abundance for these primates than the structural attributes of forests (basal area is the best descriptor of habitat quality for frugivorous primates of Africa and Asia). We evaluated plant community structure, successional status, and PF of leaf samples from the dominant tree populations, both within the core and from a non-core area of the home range of our study group. Forest structure was a combination of stem density and basal area of dominant tree populations. The core area had larger trees, a higher forest basal area, and higher stem density than the non-core area. Mean PF did not differ significantly between these sites, although PF was influenced by differences in tree regeneration guilds. Large-bodied monkeys could be favoured by later successional stages of forests because larger trees and denser stems prevent the need for a higher expenditure of energy for locomotion as a consequence of vertical travel when the crowns of trees are disconnected in early successional forests. Forest structure variables (such as basal area of trees) driven by succession influence woolly spider monkey abundance in a fashion similar to frugivorous monkeys of Asia and Africa, and could explain marked differences in ranging behaviour and home range use by B. hypoxanthus. Copyright 2009 S. Karger AG, Basel.

  5. Event-based proactive interference in rhesus monkeys.

    Science.gov (United States)

    Devkar, Deepna T; Wright, Anthony A

    2016-10-01

    Three rhesus monkeys (Macaca mulatta) were tested in a same/different memory task for proactive interference (PI) from prior trials. PI occurs when a previous sample stimulus appears as a test stimulus on a later trial, does not match the current sample stimulus, and the wrong response "same" is made. Trial-unique pictures (scenes, objects, animals, etc.) were used on most trials, except on trials where the test stimulus matched potentially interfering sample stimulus from a prior trial (1, 2, 4, 8, or 16 trials prior). Greater interference occurred when fewer trials separated interference and test. PI functions showed a continuum of interference. Delays between sample and test stimuli and intertrial intervals were manipulated to test how PI might vary as a function of elapsed time. Contrary to a similar study with pigeons, these time manipulations had no discernable effect on the monkey's PI, as shown by compete overlap of PI functions with no statistical differences or interactions. These results suggested that interference was strictly based upon the number of intervening events (trials with other pictures) without regard to elapsed time. The monkeys' apparent event-based interference was further supported by retesting with a novel set of 1,024 pictures. PI from novel pictures 1 or 2 trials prior was greater than from familiar pictures, a familiar set of 1,024 pictures. Moreover, when potentially interfering novel stimuli were 16 trials prior, performance accuracy was actually greater than accuracy on baseline trials (no interference), suggesting that remembering stimuli from 16 trials prior was a cue that this stimulus was not the sample stimulus on the current trial-a somewhat surprising conclusion particularly given monkeys.

  6. Pharmacokinetics of bisphenol A in neonatal and adult rhesus monkeys

    International Nuclear Information System (INIS)

    Doerge, Daniel R.; Twaddle, Nathan C.; Woodling, Kellie A.; Fisher, Jeffrey W.

    2010-01-01

    Bisphenol A (BPA) is a high-production volume industrial chemical used in the manufacture of polycarbonate plastic products and epoxy resin-based food can liners. The presence of BPA in urine of > 90% of Americans aged 6-60 is controversial because of the potential for endocrine disruption, particularly during perinatal development, as suggested by in vitro, experimental animal, and epidemiological studies. The current study used LC/MS/MS to measure serum pharmacokinetics of aglycone (active) and conjugated (inactive) BPA in adult and neonatal rhesus monkeys by oral (PND 5, 35, 70) and intravenous injection (PND 77) routes using d6-BPA to avoid sample contamination. The concentration-time profiles observed in adult monkeys following oral administration of 100 μg/kg bw were remarkably similar to those previously reported in human volunteers given a similar dose; moreover, minimal pharmacokinetic differences were observed between neonatal and adult monkeys for the receptor-active aglycone form of BPA. Circulating concentrations of BPA aglycone were quite low following oral administration (< 1% of total), which reflects the redundancy of active UDP-glucuronosyl transferase isoforms in both gut and liver. No age-related changes were seen in internal exposure metrics for aglycone BPA in monkeys, a result clearly different from developing rats where significant inverse age-related changes, based on immaturity of Phase II metabolism and renal excretion, were recently reported. These observations imply that any toxicological effect observed in rats from early postnatal exposures to BPA could over-predict those possible in primates of the same age, based on significantly higher internal exposures and overall immaturity at birth.

  7. Monkey alcohol tissue research resource: banking tissues for alcohol research.

    Science.gov (United States)

    Daunais, James B; Davenport, April T; Helms, Christa M; Gonzales, Steven W; Hemby, Scott E; Friedman, David P; Farro, Jonathan P; Baker, Erich J; Grant, Kathleen A

    2014-07-01

    An estimated 18 million adults in the United States meet the clinical criteria for diagnosis of alcohol abuse or alcoholism, a disorder ranked as the third leading cause of preventable death. In addition to brain pathology, heavy alcohol consumption is comorbid with damage to major organs including heart, lungs, liver, pancreas, and kidneys. Much of what is known about risk for and consequences of heavy consumption derive from rodent or retrospective human studies. The neurobiological effects of chronic intake in rodent studies may not easily translate to humans due to key differences in brain structure and organization between species, including a lack of higher-order cognitive functions, and differences in underlying prefrontal cortical neural structures that characterize the primate brain. Further, rodents do not voluntarily consume large quantities of ethanol (EtOH) and they metabolize it more rapidly than primates. The basis of the Monkey Alcohol Tissue Research Resource (MATRR) is that nonhuman primates, specifically monkeys, show a range of drinking excessive amounts of alcohol (>3.0 g/kg or a 12 drink equivalent per day) over long periods of time (12 to 30 months) with concomitant pathological changes in endocrine, hepatic, and central nervous system (CNS) processes. The patterns and range of alcohol intake that monkeys voluntarily consume parallel what is observed in humans with alcohol use disorders and the longitudinal experimental design spans stages of drinking from the EtOH-naïve state to early exposure through chronic abuse. Age- and sex-matched control animals self-administer an isocaloric solution under identical operant procedures. The MATRR is a unique postmortem tissue bank that provides CNS and peripheral tissues, and associated bioinformatics from monkeys that self-administer EtOH using a standardized experimental paradigm to the broader alcohol research community. This resource provides a translational platform from which we can better

  8. Autoprocessing of Mason-Pfizer monkey virus protease

    Czech Academy of Sciences Publication Activity Database

    Bauerová, Helena; Rumlová, Michaela; Hunter, E.; Ruml, T.; Pichová, Iva

    2001-01-01

    Roč. 77, č. 2 (2001), s. 131-133 ISSN 0168-1702 R&D Projects: GA ČR GA203/00/1241; GA AV ČR IAA4055904 Grant - others:Fogarty International Award(US) TW00050 Institutional research plan: CEZ:AV0Z4055905 Keywords : Mason-Pfizer monkey virus Subject RIV: CE - Biochemistry Impact factor: 1.806, year: 2001

  9. Capuchin monkeys do not show human-like pricing effects

    Science.gov (United States)

    Catapano, Rhia; Buttrick, Nicholas; Widness, Jane; Goldstein, Robin; Santos, Laurie R.

    2014-01-01

    Recent work in judgment and decision-making has shown that a good's price can have irrational effects on people's preferences. People tend to prefer goods that cost more money and assume that such expensive goods will be more effective, even in cases where the price of the good is itself arbitrary. Although much work has documented the existence of these pricing effects, unfortunately little work has addressed where these price effects come from in the first place. Here we use a comparative approach to distinguish between different accounts of this bias and to explore the origins of these effects. Specifically, we test whether brown capuchin monkeys (Cebus apella) are also susceptible to pricing effects within the context of an experimentally trained token economy. Using a capuchin population previously trained in a token market, we explored whether monkeys used price as an indicator of value across four experiments. Although monkeys demonstrated an understanding of which goods had which prices (consistently shifting preferences to cheaper goods when prices were increased), we observed no evidence that such price information affected their valuation of different kinds of goods. These results suggest that human pricing effects may involve more sophisticated human-unique cognitive capacities, such as an understanding of market forces and signaling. PMID:25520677

  10. Capuchin monkeys do not show human-like pricing effects

    Directory of Open Access Journals (Sweden)

    Rhia eCatapano

    2014-12-01

    Full Text Available Recent work in judgment and decision-making has shown that a good’s price can have irrational effects on people’s preferences. People tend to prefer goods that cost more money and assume that such expensive goods will be more effective, even in cases where the price of the good is itself arbitrary. Although much work has documented the existence of these pricing effects, unfortunately little work has addressed where these price effects come from in the first place. Here we use a comparative approach to distinguish between different accounts of this bias and to explore the origins of these effects. Specifically, we test whether brown capuchin monkeys (Cebus apella are also susceptible to pricing effects within the context of an experimentally trained token economy. Using a capuchin population previously trained in a token market, we explored whether monkeys used price as an indicator of value across four experiments. Although monkeys demonstrated an understanding of which goods had which prices (consistently shifting preferences to cheaper goods when prices were increased, we observed no evidence that such price information affected their valuation of different kinds of goods. These results suggest that human price effects may involve more sophisticated human-unique cognitive capacities, such as an understanding of market forces and signaling.

  11. [Blood plasma volume dynamics in monkeys during immersion].

    Science.gov (United States)

    Krotov, V P; Burkovskaia, T E; Dotsenko, M A; Gordeev, Iu V; Nosovskiĭ, A M; Chel'naia, N A

    2004-01-01

    Dynamics of blood plasma volume (PV) was studied with indirect methods (hematocrit count, hemoglobin, total protein and high-molecular protein) during 9-d immersion of monkeys Macaca mulatta. The animals were donned in waterproof suits, motor restrained in space seat liners and immersed down to the xiphisternum. Two monkeys were immersed in the bath at one time. The suits were changed every day under ketamine (10 mg/kg of body mass). There were two groups with 12 animals in each. The first group was kept in the bath 3 days and the second--9 days. Prior to the experiment, the animals had been trained to stay in the seat liner put down into the dry bath. It was shown that already two days of exposure to the hydrostatic forces (approximately 15 mm Hg) and absence of negative pressure breathing reduced PV by 18-20% on the average in all animals. Subsequent PV dynamics was individual by character; however, PV deficit persisted during 4 days of immersion in the whole group. In this period, albumin filtration was increased significantly, whereas high-molecular protein filtration was increased to a less degree. During the remaining days in immersion PV regained normal values. Ten days of readaptation (reclined positioning of monkeys brought back into cage) raised VP beyond baseline values. This phenomenon can be attributed to the necessity to provide appropriate venous return and sufficient blood supply of organs and tissues following extension of blood vessels capacity.

  12. Prenatal methylmercury exposure affects spatial vision in adult monkeys

    International Nuclear Information System (INIS)

    Burbacher, Thomas M.; Grant, Kimberly S.; Mayfield, David B.; Gilbert, Steven G.; Rice, Deborah C.

    2005-01-01

    Decades of research have demonstrated that exposure to methylmercury (MeHg), a ubiquitous environmental pollutant, can have both early and long-term neurobehavioral consequences in exposed offspring. The present study assessed visual functioning in adult macaque monkeys (Macaca fascicularis) exposed in utero to 0, 50, 70, or 90 μg/kg/day of MeHg hydroxide. Twenty-one full-term, normal birth weight offspring (9 controls, 12 exposed) were tested at approximately 11-14.5 years of age on a visual contrast sensitivity task. A forced-choice tracking procedure was utilized with spatial frequencies of 1, 4, 10, and 20 cycles per degree of visual angle. On each test session, a single spatial frequency was presented across five levels of contrast, each differing by 3 dB. Methylmercury-exposed monkeys exhibited reduced contrast sensitivity thresholds, particularly at the higher spatial frequencies. The degree of visual impairment was not related to MeHg body burden or clearance and almost half of the exposed animals were unimpaired. The results from this study demonstrate that chronic in utero MeHg exposure, at subclinical levels, is associated with permanent adverse effects on spatial vision in adult monkeys

  13. De novo DNA methylation during monkey pre-implantation embryogenesis.

    Science.gov (United States)

    Gao, Fei; Niu, Yuyu; Sun, Yi Eve; Lu, Hanlin; Chen, Yongchang; Li, Siguang; Kang, Yu; Luo, Yuping; Si, Chenyang; Yu, Juehua; Li, Chang; Sun, Nianqin; Si, Wei; Wang, Hong; Ji, Weizhi; Tan, Tao

    2017-04-01

    Critical epigenetic regulation of primate embryogenesis entails DNA methylome changes. Here we report genome-wide composition, patterning, and stage-specific dynamics of DNA methylation in pre-implantation rhesus monkey embryos as well as male and female gametes studied using an optimized tagmentation-based whole-genome bisulfite sequencing method. We show that upon fertilization, both paternal and maternal genomes undergo active DNA demethylation, and genome-wide de novo DNA methylation is also initiated in the same period. By the 8-cell stage, remethylation becomes more pronounced than demethylation, resulting in an increase in global DNA methylation. Promoters of genes associated with oxidative phosphorylation are preferentially remethylated at the 8-cell stage, suggesting that this mode of energy metabolism may not be favored. Unlike in rodents, X chromosome inactivation is not observed during monkey pre-implantation development. Our study provides the first comprehensive illustration of the 'wax and wane' phases of DNA methylation dynamics. Most importantly, our DNA methyltransferase loss-of-function analysis indicates that DNA methylation influences early monkey embryogenesis.

  14. Electrons at the monkey saddle: A multicritical Lifshitz point

    Science.gov (United States)

    Shtyk, A.; Goldstein, G.; Chamon, C.

    2017-01-01

    We consider two-dimensional interacting electrons at a monkey saddle with dispersion ∝px3-3 pxpy2 . Such a dispersion naturally arises at the multicritical Lifshitz point when three Van Hove saddles merge in an elliptical umbilic elementary catastrophe, which we show can be realized in biased bilayer graphene. A multicritical Lifshitz point of this kind can be identified by its signature Landau level behavior Em∝(Bm ) 3 /2 and related oscillations in thermodynamic and transport properties, such as de Haas-Van Alphen and Shubnikov-de Haas oscillations, whose period triples as the system crosses the singularity. We show, in the case of a single monkey saddle, that the noninteracting electron fixed point is unstable to interactions under the renormalization-group flow, developing either a superconducting instability or non-Fermi-liquid features. Biased bilayer graphene, where there are two non-nested monkey saddles at the K and K' points, exhibits an interplay of competing many-body instabilities, namely, s -wave superconductivity, ferromagnetism, and spin- and charge-density waves.

  15. Capuchin monkeys do not show human-like pricing effects.

    Science.gov (United States)

    Catapano, Rhia; Buttrick, Nicholas; Widness, Jane; Goldstein, Robin; Santos, Laurie R

    2014-01-01

    Recent work in judgment and decision-making has shown that a good's price can have irrational effects on people's preferences. People tend to prefer goods that cost more money and assume that such expensive goods will be more effective, even in cases where the price of the good is itself arbitrary. Although much work has documented the existence of these pricing effects, unfortunately little work has addressed where these price effects come from in the first place. Here we use a comparative approach to distinguish between different accounts of this bias and to explore the origins of these effects. Specifically, we test whether brown capuchin monkeys (Cebus apella) are also susceptible to pricing effects within the context of an experimentally trained token economy. Using a capuchin population previously trained in a token market, we explored whether monkeys used price as an indicator of value across four experiments. Although monkeys demonstrated an understanding of which goods had which prices (consistently shifting preferences to cheaper goods when prices were increased), we observed no evidence that such price information affected their valuation of different kinds of goods. These results suggest that human pricing effects may involve more sophisticated human-unique cognitive capacities, such as an understanding of market forces and signaling.

  16. Molecular characterization of Blastocystis isolates from children and rhesus monkeys in Kathmandu, Nepal.

    Science.gov (United States)

    Yoshikawa, Hisao; Wu, Zhiliang; Pandey, Kishor; Pandey, Basu Dev; Sherchand, Jeevan Bahadur; Yanagi, Tetsuo; Kanbara, Hiroji

    2009-03-23

    To investigate the possible transmission of Blastocystis organisms between local rhesus monkeys and children in Kathmandu, Nepal, we compared the subtype (ST) and sequence of Blastocystis isolates from children with gastrointestinal symptoms and local rhesus monkeys. Twenty and 10 Blastocystis isolates were established from 82 and 10 fecal samples obtained from children and monkeys, respectively. Subtype analysis with seven sequence-tagged site (STS) primers indicated that the prevalence of Blastocystis sp. ST1, ST2 and ST3 was 20%, 20% and 60% in the child isolates, respectively. In contrast to human isolates, ST3 was not found in monkey isolates and the prevalence of ST1 and ST2 was 50% and 70%, respectively, including three mixed STs1 and 2 and one isolate not amplified by any STS primers, respectively. Since Blastocystis sp. ST2 has been reported as the most dominant genotype in the survey of Blastocystis infection among the various monkey species, sequence comparison of the 150bp variable region of the small subunit rRNA (SSU rRNA) gene was conducted among ST2 isolates of humans and monkeys. Sequence alignment of 24 clones developed from ST2 isolates of 4 humans and 4 monkeys showed three distinct subgroups, defined as ST2A, ST2B and ST2C. These three subgroups were shared between the child and monkey isolates. These results suggest that the local rhesus monkeys are a possible source of Blastocystis sp. ST2 infection of humans in Kathmandu.

  17. A preliminary report on oral fat tolerance test in rhesus monkeys

    OpenAIRE

    Wu, Di; Liu, Qingsu; Wei, Shiyuan; Zhang, Yu Alex; Yue, Feng

    2014-01-01

    Background Oral fat tolerance test (OFTT) has been widely used to assess the postprandial lipemia in human beings, but there is few studies concerning OFTT in nonhuman primates. This study is designed to explore the feasibility of OFTT in rhesus monkeys. Methods In a cross-over study, a total of 8 adult female rhesus monkeys were fed with normal monkey diet (NND), high sugar high fat diet (HHD), and extremely high fat diet (EHD), respectively. Each monkey consumed NND, HHD and EHD respectivel...

  18. Allergic asthma induced in rhesus monkeys by house dust mite (Dermatophagoides farinae).

    Science.gov (United States)

    Schelegle, E S; Gershwin, L J; Miller, L A; Fanucchi, M V; Van Winkle, L S; Gerriets, J P; Walby, W F; Omlor, A M; Buckpitt, A R; Tarkington, B K; Wong, V J; Joad, J P; Pinkerton, K B; Wu, R; Evans, M J; Hyde, D M; Plopper, C G

    2001-01-01

    To establish whether allergic asthma could be induced experimentally in a nonhuman primate using a common human allergen, three female rhesus monkeys (Macaca mulatta) were sensitized with house dust mite (Dermatophagoides farinae) allergen (HDMA) by subcutaneous injection, followed by four intranasal sensitizations, and exposure to allergen aerosol 3 hours per day, 3 days per week for up to 13 weeks. Before aerosol challenge, all three monkeys skin-tested positive for HDMA. During aerosol challenge with HDMA, sensitized monkeys exhibited cough and rapid shallow breathing and increased airway resistance, which was reversed by albuterol aerosol treatment. Compared to nonsensitized monkeys, there was a fourfold reduction in the dose of histamine aerosol necessary to produce a 150% increase in airway resistance in sensitized monkeys. After aerosol challenge, serum levels of histamine were elevated in sensitized monkeys. Sensitized monkeys exhibited increased levels of HDMA-specific IgE in serum, numbers of eosinophils and exfoliated cells within lavage, and elevated CD25 expression on circulating CD4(+) lymphocytes. Intrapulmonary bronchi of sensitized monkeys had focal mucus cell hyperplasia, interstitial infiltrates of eosinophils, and thickening of the basement membrane zone. We conclude that a model of allergic asthma can be induced in rhesus monkeys using a protocol consisting of subcutaneous injection, intranasal instillation, and aerosol challenge with HDMA.

  19. Plasmodium simium/Plasmodium vivax infections in southern brown howler monkeys from the Atlantic Forest

    Directory of Open Access Journals (Sweden)

    Daniela Camargos Costa

    2014-08-01

    Full Text Available Blood infection by the simian parasite, Plasmodium simium, was identified in captive (n = 45, 4.4% and in wild Alouatta clamitans monkeys (n = 20, 35% from the Atlantic Forest of southern Brazil. A single malaria infection was symptomatic and the monkey presented clinical and haematological alterations. A high frequency of Plasmodium vivax-specific antibodies was detected among these monkeys, with 87% of the monkeys testing positive against P. vivax antigens. These findings highlight the possibility of malaria as a zoonosis in the remaining Atlantic Forest and its impact on the epidemiology of the disease.

  20. Modulation-Frequency-Specific Adaptation in Awake Auditory Cortex

    Science.gov (United States)

    Beitel, Ralph E.; Vollmer, Maike; Heiser, Marc A.; Schreiner, Christoph E.

    2015-01-01

    Amplitude modulations are fundamental features of natural signals, including human speech and nonhuman primate vocalizations. Because natural signals frequently occur in the context of other competing signals, we used a forward-masking paradigm to investigate how the modulation context of a prior signal affects cortical responses to subsequent modulated sounds. Psychophysical “modulation masking,” in which the presentation of a modulated “masker” signal elevates the threshold for detecting the modulation of a subsequent stimulus, has been interpreted as evidence of a central modulation filterbank and modeled accordingly. Whether cortical modulation tuning is compatible with such models remains unknown. By recording responses to pairs of sinusoidally amplitude modulated (SAM) tones in the auditory cortex of awake squirrel monkeys, we show that the prior presentation of the SAM masker elicited persistent and tuned suppression of the firing rate to subsequent SAM signals. Population averages of these effects are compatible with adaptation in broadly tuned modulation channels. In contrast, modulation context had little effect on the synchrony of the cortical representation of the second SAM stimuli and the tuning of such effects did not match that observed for firing rate. Our results suggest that, although the temporal representation of modulated signals is more robust to changes in stimulus context than representations based on average firing rate, this representation is not fully exploited and psychophysical modulation masking more closely mirrors physiological rate suppression and that rate tuning for a given stimulus feature in a given neuron's signal pathway appears sufficient to engender context-sensitive cortical adaptation. PMID:25878263

  1. Neuronal variability in orbitofrontal cortex during economic decisions.

    Science.gov (United States)

    Conen, Katherine E; Padoa-Schioppa, Camillo

    2015-09-01

    Neuroeconomic models assume that economic decisions are based on the activity of offer value cells in the orbitofrontal cortex (OFC), but testing this assertion has proven difficult. In principle, the decision made on a given trial should correlate with the stochastic fluctuations of these cells. However, this correlation, measured as a choice probability (CP), is small. Importantly, a neuron's CP reflects not only its individual contribution to the decision (termed readout weight), but also the intensity and the structure of correlated variability across the neuronal population (termed noise correlation). A precise mathematical relation between CPs, noise correlations, and readout weights was recently derived by Haefner and colleagues (Haefner RM, Gerwinn S, Macke JH, Bethge M. Nat Neurosci 16: 235-242, 2013) for a linear decision model. In this framework, concurrent measurements of noise correlations and CPs can provide quantitative information on how a population of cells contributes to a decision. Here we examined neuronal variability in the OFC of rhesus monkeys during economic decisions. Noise correlations had similar structure but considerably lower strength compared with those typically measured in sensory areas during perceptual decisions. In contrast, variability in the activity of individual cells was high and comparable to that recorded in other cortical regions. Simulation analyses based on Haefner's equation showed that noise correlations measured in the OFC combined with a plausible readout of offer value cells reproduced the experimental measures of CPs. In other words, the results obtained for noise correlations and those obtained for CPs taken together support the hypothesis that economic decisions are primarily based on the activity of offer value cells. Copyright © 2015 the American Physiological Society.

  2. Analysis of neural activity in human motor cortex -- Towards brain machine interface system

    Science.gov (United States)

    Secundo, Lavi

    The discovery of directional tuned neurons in the primary motor cortex has advanced motor research in several domains. For instance, in the area of brain machine interface (BMI), researchers have exploited the robust characteristic of tuned motor neurons to allow monkeys to learn control of various machines. In the first chapter of this work we examine whether this phenomena can be observed using the less invasive method of recording electrocorticographic signals (ECoG) from the surface of a human's brain. Our findings reveal that individual ECoG channels contain complex movement information about the neuronal population. While some ECoG channels are tuned to hand movement direction (direction specific channels), others are associated to movement but do not contain information regarding movement direction (non-direction specific channels). More specifically, directionality can vary temporally and by frequency within one channel. In addition, a handful of channels contain no significant information regarding movement at all. These findings strongly suggest that directional and non-directional regions of cortex can be identified with ECoG and provide solutions to decoding movement at the signal resolution provided by ECoG. In the second chapter we examine the influence of movement context on movement reconstruction accuracy. We recorded neuronal signals recorded from electro-corticography (ECoG) during performance of cued- and self-initiated movements. ECoG signals were used to train a reconstruction algorithm to reconstruct continuous hand movement. We found that both cued- and self-initiated movements could be reconstructed with similar accuracy from the ECoG data. However, while an algorithm trained on the cued task could reconstruct performance on a subsequent cued trial, it failed to reconstruct self-initiated arm movement. The same task-specificity was observed when the algorithm was trained with self-initiated movement data and tested on the cued task. Thus

  3. Do you see what I see? A comparative investigation of the Delboeuf illusion in humans (Homo sapiens), rhesus monkeys (Macaca mulatta), and capuchin monkeys (Cebus apella).

    Science.gov (United States)

    Parrish, Audrey E; Brosnan, Sarah F; Beran, Michael J

    2015-10-01

    Studying visual illusions is critical to understanding typical visual perception. We investigated whether rhesus monkeys (Macaca mulatta) and capuchin monkeys (Cebus apella) perceived the Delboeuf illusion in a similar manner as human adults (Homo sapiens). To test this, in Experiment 1, we presented monkeys and humans with a relative discrimination task that required subjects to choose the larger of 2 central dots that were sometimes encircled by concentric rings. As predicted, humans demonstrated evidence of the Delboeuf illusion, overestimating central dots when small rings surrounded them and underestimating the size of central dots when large rings surrounded them. However, monkeys did not show evidence of the illusion. To rule out an alternate explanation, in Experiment 2, we presented all species with an absolute classification task that required them to classify a central dot as "small" or "large." We presented a range of ring sizes to determine whether the Delboeuf illusion would occur for any dot-to-ring ratios. Here, we found evidence of the Delboeuf illusion in all 3 species. Humans and monkeys underestimated central dot size to a progressively greater degree with progressively larger rings. The Delboeuf illusion now has been extended to include capuchin monkeys and rhesus monkeys, and through such comparative investigations we can better evaluate hypotheses regarding illusion perception among nonhuman animals. (c) 2015 APA, all rights reserved).

  4. The Significance of Memory in Sensory Cortex.

    Science.gov (United States)

    Muckli, Lars; Petro, Lucy S

    2017-05-01

    Early sensory cortex is typically investigated in response to sensory stimulation, masking the contribution of internal signals. Recently, van Kerkoerle and colleagues reported that attention and memory signals segregate from sensory signals within specific layers of primary visual cortex, providing insight into the role of internal signals in sensory processing. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. The significance of memory in sensory cortex

    OpenAIRE

    Muckli, Lars; Petro, Lucy S.

    2017-01-01

    Early sensory cortex is typically investigated in response to sensory stimulation, masking the contribution of internal signals. Recently, van Kerkoerle and colleagues reported that attention and memory signals segregate from sensory signals within specific layers of primary visual cortex, providing insight into the role of internal signals in sensory processing.

  6. Visual Categorization and the Parietal Cortex

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    Jamie K Fitzgerald

    2012-05-01

    Full Text Available The primate brain is adept at rapidly grouping items and events into functional classes, or categories, in order to recognize the significance of stimuli and guide behavior. Higher cognitive functions have traditionally been considered the domain of frontal areas. However, increasing evidence suggests that parietal cortex is also involved in categorical and associative processes. Previous work showed that the parietal cortex is highly involved in spatial processing, attention and saccadic eye movement planning, and more recent studies have found decision-making signals in LIP. We recently found that a subdivision of parietal cortex, the lateral intraparietal area (LIP, reflects learned categories for multiple types of visual stimuli. Additionally, a comparison of categorization signals in parietal and frontal areas found stronger and earlier categorization signals in parietal cortex, arguing that parietal abstract association or category signals are unlikely to arise via feedback from prefrontal cortex (PFC.

  7. SV40 host-substituted variants: a new look at the monkey DNA inserts and recombinant junctions.

    Science.gov (United States)

    Singer, Maxine; Winocour, Ernest

    2011-04-10

    The available monkey genomic data banks were examined in order to determine the chromosomal locations of the host DNA inserts in 8 host-substituted SV40 variant DNAs. Five of the 8 variants contained more than one linked monkey DNA insert per tandem repeat unit and in all cases but one, the 19 monkey DNA inserts in the 8 variants mapped to different locations in the monkey genome. The 50 parental DNAs (32 monkey and 18 SV40 DNA segments) which spanned the crossover and flanking regions that participated in monkey/monkey and monkey/SV40 recombinations were characterized by substantial levels of microhomology of up to 8 nucleotides in length; the parental DNAs also exhibited direct and inverted repeats at or adjacent to the crossover sequences. We discuss how the host-substituted SV40 variants arose and the nature of the recombination mechanisms involved. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Binding kinetics of 11C-N-methyl piperidyl benzilate (11C-NMPB) in a rhesus monkey brain using the cerebellum as a reference region

    International Nuclear Information System (INIS)

    Itoh, Takashi; Tanaka, Masayasu; Suzuki, Kasutoshi; Kobayashi, Kaoru; Inoue, Osamu

    2005-01-01

    The binding kinetics of' 11 C-N-methyl piperidyl benzilate ( 11 C-NMPB) in rhesus monkey brain were studied using animal positron emission tomography (PET) (SHR2000). This study is intended to assess the validity of the method using the cerebellum as a reference region, and to evaluate the effects of anesthesia on 11 C -NMPB binding. Two monkeys, anesthetized with ketamine, received intravenous 11 C-NMPB alone (370-760 MBq, 11 C-NMPB accumulated densely in the striatum and cerebral cortex with time. In contrast, the tracer accumulation significantly decreased with increased doses of nonradioactive NMPB. In the cerebellum, on the other hand, the accumulation of 11 C-NMPB remained low and the tracer was slowly eliminated from the brain following the injection. 11 C-NMPB binding in the cerebellum was barely affected by the increased dose of nonradioactive NMPB. We thus concluded that the specific 11 C-NMPB binding was negligible in the cerebellum, and performed simplified evaluation of 11 C-NMPB binding in each brain region by a graphical method using the cerebellum as a reference region. PET was conducted 26 times, in total both in ketamine-anesthetized and awake monkeys (n=3 each). Measurements of 11 C-NMPB binding showed good run-to-run reproducibility within individual animals. When 11 C-NMPB binding was compared between ketamine-treated and awake animals, a significant increase in 11 C-NMPB binding was observed in the striatum but not in other brain regions of ketamine-treated animals. (author)

  9. Neonatal lesions of orbital frontal areas 11/13 in monkeys alter goal-directed behavior but spare fear conditioning and safety signal learning.

    Directory of Open Access Journals (Sweden)

    Andy M Kazama

    2014-03-01

    Full Text Available Recent studies in monkeys have demonstrated that damage to the lateral subfields of orbital frontal cortex (OFC areas 11/13 yields profound changes in flexible modulation of goal-directed behaviors and a lack in fear regulation. Yet, little consideration has been placed on its role in emotional and social development throughout life. The current study investigated the effects of neonatal lesions of the OFC on the flexible modulation of goal-directed behaviors and fear responses in monkeys. Infant monkeys received neonatal lesions of OFC areas 11/13 or sham-lesions during the first post-natal week. Modulation of goal-directed behaviors was measured with a devaluation task at 3-4 years and 6-7 years. Modulation of fear reactivity by safety signals was assessed with the AX+/BX- potentiated-startle paradigm at 6-7 years. Similar to adult-onset OFC lesions, selective neonatal lesions of OFC areas 11/13 yielded a failure to modulate behavioral responses guided by changes in reward value, but spared the ability to modulate fear responses in the presence of safety signals. These results suggest that these areas play a critical role in the development of behavioral adaptation during goal-directed behaviors, but not, or less so, in the development of the ability to process emotionally salient stimuli and to modulate emotional reactivity using environmental contexts, which could be supported by other OFC subfields, such as the most ventromedial subfields (i.e. areas 14/25. Given similar impaired decision-making abilities and spared modulation of fear followed both neonatal lesions of either OFC areas 11 and 13 or amygdala (Kazama et al., 2012; Kazama & Bachevalier, 2013, the present results suggest that interactions between these two neural structures play a critical role in the development of behavioral adaptation; an ability essential for the self-regulation of emotion and behavior that assures the maintenance of successful social relationships.

  10. Reward value-based gain control: divisive normalization in parietal cortex.

    Science.gov (United States)

    Louie, Kenway; Grattan, Lauren E; Glimcher, Paul W

    2011-07-20

    The representation of value is a critical component of decision making. Rational choice theory assumes that options are assigned absolute values, independent of the value or existence of other alternatives. However, context-dependent choice behavior in both animals and humans violates this assumption, suggesting that biological decision processes rely on comparative evaluation. Here we show that neurons in the monkey lateral intraparietal cortex encode a relative form of saccadic value, explicitly dependent on the values of the other available alternatives. Analogous to extra-classical receptive field effects in visual cortex, this relative representation incorporates target values outside the response field and is observed in both stimulus-driven activity and baseline firing rates. This context-dependent modulation is precisely described by divisive normalization, indicating that this standard form of sensory gain control may be a general mechanism of cortical computation. Such normalization in decision circuits effectively implements an adaptive gain control for value coding and provides a possible mechanistic basis for behavioral context-dependent violations of rationality.

  11. Transformation of a virtual action plan into a motor plan in the premotor cortex.

    Science.gov (United States)

    Nakayama, Yoshihisa; Yamagata, Tomoko; Tanji, Jun; Hoshi, Eiji

    2008-10-08

    Before preparing to initiate a forthcoming motion, we often acquire information about the future action without specifying actual motor parameters. The information for planning an action at this conceptual level can be provided with verbal commands or nonverbal signals even before the associated motor targets are visible. Under these conditions, the information signifying a virtual action plan must be transformed to information that can be used for constructing a motor plan to initiate specific movements. To determine whether the premotor cortex is involved in this process, we examined neuronal activity in the dorsal premotor cortex (PMd) of monkeys performing a behavioral task designed to isolate the behavioral stages of the acquisition of information for a future action and the construction of a motor plan. We trained the animals to receive a symbolic instruction (color and shape of an instruction cue) to determine whether to select the right or left of targets to reach, despite the physical absence of targets. Subsequently, two targets appeared on a screen at different locations. The animals then determined the correct target (left or right) based on the previous instruction and prepared to initiate a reaching movement to an actual target. The experimental design dissociated the selection of the right/left at an abstract level (action plan) from the physical motor plan. Here, we show that activity of individual PMd neurons initially reflects a virtual action plan transcending motor specifics, before these neurons contribute to a transformation process that leads to activity encoding a motor plan.

  12. The neurophysiology of figure-ground segregation in primary visual cortex.

    Science.gov (United States)

    Lamme, V A

    1995-02-01

    The activity of neurons in the primary visual cortex of the awake macaque monkey was recorded while the animals were viewing full screen arrays of either oriented line segments or moving random dots. A square patch of the screen was made to perceptually pop out as a circumscribed figure by virtue of differences between the orientation or the direction of motion of the texture elements within that patch and the surround. The animals were trained to identify the figure patches by making saccadic eye movements towards their positions. Almost every cell gave a significantly larger response to elements belonging to the figure than to similar elements belonging to the background. The figure-ground response enhancement was present along the entire extent of the patch and was absent as soon as the receptive field was outside the patch. The strength of the effect had no relation with classical receptive field properties like orientation or direction selectivity or receptive field size. The response enhancement had a latency of 30-40 msec relative to the onset of the neuronal response itself. The results show that context modulation within primary visual cortex has a highly sophisticated nature, putting the image features the cells are responding to into their fully evaluated perceptual context.

  13. Motivation and Affective Judgments Differentially Recruit Neurons in the Primate Dorsolateral Prefrontal and Anterior Cingulate Cortex

    Science.gov (United States)

    Amemori, Ken-ichi; Amemori, Satoko

    2015-01-01

    The judgment of whether to accept or to reject an offer is determined by positive and negative affect related to the offer, but affect also induces motivational responses. Rewarding and aversive cues influence the firing rates of many neurons in primate prefrontal and cingulate neocortical regions, but it still is unclear whether neurons in these regions are related to affective judgment or to motivation. To address this issue, we recorded simultaneously the neuronal spike activities of single units in the dorsolateral prefrontal cortex (dlPFC) and the anterior cingulate cortex (ACC) of macaque monkeys as they performed approach–avoidance (Ap–Av) and approach–approach (Ap–Ap) decision-making tasks that can behaviorally dissociate affective judgment and motivation. Notably, neurons having activity correlated with motivational condition could be distinguished from neurons having activity related to affective judgment, especially in the Ap–Av task. Although many neurons in both regions exhibited similar, selective patterns of task-related activity, we found a larger proportion of neurons activated in low motivational conditions in the dlPFC than in the ACC, and the onset of this activity was significantly earlier in the dlPFC than in the ACC. Furthermore, the temporal onsets of affective judgment represented by neuronal activities were significantly slower in the low motivational conditions than in the other conditions. These findings suggest that motivation and affective judgment both recruit dlPFC and ACC neurons but with differential degrees of involvement and timing. PMID:25653353

  14. Multiple functional attributes of glucose-monitoring neurons in the medial orbitofrontal (ventrolateral prefrontal) cortex.

    Science.gov (United States)

    Szabó, István; Hormay, Edina; Csetényi, Bettina; Nagy, Bernadett; Lénárd, László; Karádi, Zoltán

    2018-02-01

    Multiple functional attributes of glucose-monitoring neurons in the medial orbitofrontal (ventrolateral prefrontal) cortex. NEUROSCI BIOBEHAV REV 73(1) XXX-XXX, 2017.- Special chemosensory cells, the glucose-monitoring (GM) neurons, reportedly involved in the central feeding control, exist in the medial orbitofrontal (ventrolateral prefrontal) cortex (mVLPFC). Electrophysiological, metabolic and behavioral studies reveal complex functional attributes of these cells and raise their homeostatic significance. Single neuron recordings, by means of the multibarreled microelectrophoretic technique, elucidate differential sensitivities of limbic forebrain neurons in the rat and the rhesus monkey to glucose and other chemicals, whereas gustatory stimulations demonstrate their distinct taste responsiveness. Metabolic examinations provide evidence for alteration of blood glucose level in glucose tolerance test and elevation of plasma triglyceride concentration after destruction of the local GM cells by streptozotocin (STZ). In behavioral studies, STZ microinjection into the mVLPFC fails to interfere with the acquisition of saccharin conditioned taste avoidance, does cause, however, taste perception deficit in taste reactivity tests. Multiple functional attributes of GM neurons in the mVLPFC, within the frame of the hierarchically organized central GM neuronal network, appear to play important role in the maintenance of the homeostatic balance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Neuronal correlate of visual associative long-term memory in the primate temporal cortex

    Science.gov (United States)

    Miyashita, Yasushi

    1988-10-01

    In human long-term memory, ideas and concepts become associated in the learning process1. No neuronal correlate for this cognitive function has so far been described, except that memory traces are thought to be localized in the cerebral cortex; the temporal lobe has been assigned as the site for visual experience because electric stimulation of this area results in imagery recall,2 and lesions produce deficits in visual recognition of objects3-9. We previously reported that in the anterior ventral temporal cortex of monkeys, individual neurons have a sustained activity that is highly selective for a few of the 100 coloured fractal patterns used in a visual working-memory task10. Here I report the development of this selectivity through repeated trials involving the working memory. The few patterns for which a neuron was conjointly selective were frequently related to each other through stimulus-stimulus association imposed during training. The results indicate that the selectivity acquired by these cells represents a neuronal correlate of the associative long-term memory of pictures.

  16. The serotonin transporter in rhesus monkey brain: comparison of DASB and citalopram binding sites

    Energy Technology Data Exchange (ETDEWEB)

    Zeng Zhizhen [Imaging Department, Merck Research Laboratories, West Point, PA 19486 (United States)]. E-mail: zhizhen_zeng@merck.com; Chen, T.-B. [Imaging Department, Merck Research Laboratories, West Point, PA 19486 (United States); Miller, Patricia J. [Imaging Department, Merck Research Laboratories, West Point, PA 19486 (United States); Dean, Dennis [Labeled Compound Synthesis Group, Drug Metabolism, Merck Research Laboratories, Rahway, NJ 07065-0900 (United States); Tang, Y.S. [Labeled Compound Synthesis Group, Drug Metabolism, Merck Research Laboratories, Rahway, NJ 07065-0900 (United States); Sur, Cyrille [Imaging Department, Merck Research Laboratories, West Point, PA 19486 (United States); Williams, David L. [Imaging Department, Merck Research Laboratories, West Point, PA 19486 (United States)

    2006-05-15

    We have characterized the interaction of the serotonin transporter ligand [{sup 3}H]-N,N-dimethyl-2-(2-amino-4-cyanophenylthio)-benzylamine (DASB) with rhesus monkey brain in vitro using tissue homogenate binding and autoradiographic mapping. [{sup 3}H]-DASB, a tritiated version of the widely used [{sup 11}C] positron emission tomography tracer, was found to selectively bind to a single population of sites with high affinity (K {sub d}=0.20{+-}0.04 nM). The serotonin transporter density (B {sub max}) obtained for rhesus frontal cortex was found to be 66{+-}8 fmol/mg protein using [{sup 3}H]-DASB, similar to the B {sub max} value obtained using the reference radioligand [{sup 3}H]-citalopram, a well-characterized and highly selective serotonin reuptake inhibitor (83{+-}22 fmol/mg protein). Specific binding sites of both [{sup 3}H]-DASB and [{sup 3}H]-citalopram were similarly and nonuniformly distributed throughout the rhesus central nervous system, in a pattern consistent with serotonin transporter localization reported for human brain. Regional serotonin transporter densities, estimated from optical densities of the autoradiographic images, were well correlated between the two radioligands. Finally, DASB and fluoxetine showed dose-dependent full inhibition of [{sup 3}H]-citalopram binding in a competition autoradiographic study, with K {sub i} values in close agreement with those obtained from rhesus brain homogenates. This side-by-side comparison of [{sup 3}H]-DASB and [{sup 3}H]-citalopram binding sites in rhesus tissue homogenates and in adjacent rhesus brain slices provides additional support for the use of [{sup 11}C]-DASB to assess the availability and distribution of serotonin transporters in nonhuman primates.

  17. Deep brain stimulation of the bilateral nucleus accumbens in normal rhesus monkey.

    Science.gov (United States)

    Li, Nan; Gao, Li; Wang, Xue-lian; Chen, Lei; Fang, Wei; Ge, Shun-nan; Gao, Guo-dong

    2013-01-09

    The nucleus accumbens (NAc) has been considered as a novel target of deep brain stimulation (DBS) for intractable psychiatric disorders. Quite a few questions exist about this new treatment, and might be explored in nonhuman primate models. There are several reports on DBS of brain nucleus other than NAc in nonhuman primates. Therefore, we stereotactically implanted the electrodes into bilateral NAc under the guidance of MRI using a clinical Leksell stereotactic system in normal rhesus monkeys. NAc could be recognized as the area of continuity between the caudate nucleus and putamen in the coronal sections, which is beneath the internal capsule, and the gray matter nucleus between the ventromedial prefrontal cortex and anterior commissure in axial sections, which is medial to the putamen. NAc is mainly at a point 2.0-3.0 mm inferior, 3.0-4.0 mm anterior, and 4.5-5.5 mm lateral to the anterior commissure. The electrodes were implanted accurately and connected to an implantable pulse generator subcutaneously. After recovery from surgery, stimulation with a variety of parameters was trialed, and continuous stimulation at 90 μs, 3.5 V, 160, or 60 Hz was administered individually for 7 days. The behaviors and spontaneous locomotor activity of the animals did not change significantly during stimulation. This is the first report on DBS of NAc in nonhuman primates to the best of our knowledge. Bilateral electrical stimulation of NAc is a safe treatment. This model could be helpful in further studies on the clinical use of NAc stimulation for psychiatric disorders and for a better understanding of the functions of this nucleus.

  18. Cholinergic and serotonergic modulation of visual information processing in monkey V1.

    Science.gov (United States)

    Shimegi, Satoshi; Kimura, Akihiro; Sato, Akinori; Aoyama, Chisa; Mizuyama, Ryo; Tsunoda, Keisuke; Ueda, Fuyuki; Araki, Sera; Goya, Ryoma; Sato, Hiromichi

    2016-09-01

    The brain dynamically changes its input-output relationship depending on the behavioral state and context in order to optimize information processing. At the molecular level, cholinergic/monoaminergic transmitters have been extensively studied as key players for the state/context-dependent modulation of brain function. In this paper, we review how cortical visual information processing in the primary visual cortex (V1) of macaque monkey, which has a highly differentiated laminar structure, is optimized by serotonergic and cholinergic systems by examining anatomical and in vivo electrophysiological aspects to highlight their similarities and distinctions. We show that these two systems have a similar layer bias for axonal fiber innervation and receptor distribution. The common target sites are the geniculorecipient layers and geniculocortical fibers, where the appropriate gain control is established through a geniculocortical signal transformation. Both systems exert activity-dependent response gain control across layers, but in a manner consistent with the receptor subtype. The serotonergic receptors 5-HT1B and 5HT2A modulate the contrast-response curve in a manner consistent with bi-directional response gain control, where the sign (facilitation/suppression) is switched according to the firing rate and is complementary to the other. On the other hand, cholinergic nicotinic/muscarinic receptors exert mono-directional response gain control without a sign reversal. Nicotinic receptors increase the response magnitude in a multiplicative manner, while muscarinic receptors exert both suppressive and facilitative effects. We discuss the implications of the two neuromodulator systems in hierarchical visual signal processing in V1 on the basis of the developed laminar structure. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. The serotonin transporter in rhesus monkey brain: comparison of DASB and citalopram binding sites

    International Nuclear Information System (INIS)

    Zeng Zhizhen; Chen, T.-B.; Miller, Patricia J.; Dean, Dennis; Tang, Y.S.; Sur, Cyrille; Williams, David L.

    2006-01-01

    We have characterized the interaction of the serotonin transporter ligand [ 3 H]-N,N-dimethyl-2-(2-amino-4-cyanophenylthio)-benzylamine (DASB) with rhesus monkey brain in vitro using tissue homogenate binding and autoradiographic mapping. [ 3 H]-DASB, a tritiated version of the widely used [ 11 C] positron emission tomography tracer, was found to selectively bind to a single population of sites with high affinity (K d =0.20±0.04 nM). The serotonin transporter density (B max ) obtained for rhesus frontal cortex was found to be 66±8 fmol/mg protein using [ 3 H]-DASB, similar to the B max value obtained using the reference radioligand [ 3 H]-citalopram, a well-characterized and highly selective serotonin reuptake inhibitor (83±22 fmol/mg protein). Specific binding sites of both [ 3 H]-DASB and [ 3 H]-citalopram were similarly and nonuniformly distributed throughout the rhesus central nervous system, in a pattern consistent with serotonin transporter localization reported for human brain. Regional serotonin transporter densities, estimated from optical densities of the autoradiographic images, were well correlated between the two radioligands. Finally, DASB and fluoxetine showed dose-dependent full inhibition of [ 3 H]-citalopram binding in a competition autoradiographic study, with K i values in close agreement with those obtained from rhesus brain homogenates. This side-by-side comparison of [ 3 H]-DASB and [ 3 H]-citalopram binding sites in rhesus tissue homogenates and in adjacent rhesus brain slices provides additional support for the use of [ 11 C]-DASB to assess the availability and distribution of serotonin transporters in nonhuman primates

  20. Different sensitivities to competitive inhibition of benzodiazepine receptor binding of {sup 11}C-iomazenil and {sup 11}C-flumazenil in rhesus monkey brain

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Osamu; Hosoi, Rie; Kobayashi, Kaoru [Osaka Univ., Suita (Japan). Medical School; Itoh, Takashi; Gee, A.; Suzuki, Kazutoshi

    2001-04-01

    The in vivo binding kinetics of {sup 11}C-iomazenil were compared with those of {sup 11}C-flumazenil binding in rhesus monkey brain. The monkey was anesthetized with ketamine and intravenously injected with either {sup 11}C-iomazenil or {sup 11}C-flumazenil in combination with the coadministration of different doses of non-radioactive flumazenil (0, 5 and 20 {mu}g/kg). The regional distribution of {sup 11}C-iomazenil in the brain was similar to that of {sup 11}C-flumazenil, but the sensitivity of {sup 11}C-iomazenil binding to competitive inhibition by non-radioactive flumazenil was much less than that of {sup 11}C-flumazenil binding. A significant reduction in {sup 11}C-flumazenil binding in the cerebral cortex was observed with 20 {mu}g/kg of flumazenil, whereas a relatively smaller inhibition of {sup 11}C-iomazenil binding in the same region was observed with the same dose of flumazenil. These results suggest that {sup 11}C-flumazenil may be a superior radiotracer for estimating benzodiazepine receptor occupancy in the intact brain. (author)

  1. Age-related reduction in microcolumnar structure correlates with cognitive decline in ventral but not dorsal area 46 of the rhesus monkey.

    Science.gov (United States)

    Cruz, L; Roe, D L; Urbanc, B; Inglis, A; Stanley, H E; Rosene, D L

    2009-02-18

    The age-related decline in cognitive function that is observed in normal aging monkeys and humans occurs without significant loss of cortical neurons. This suggests that cognitive impairment results from subtle, sub-lethal changes in the cortex. Recently, changes in the structural coherence in mini- or microcolumns without loss of neurons have been linked to loss of function. Here we use a density map method to quantify microcolumnar structure in both banks of the sulcus principalis (prefrontal cortical area 46) of 16 (ventral) and 19 (dorsal) behaviorally tested female rhesus monkeys from 6 to 33 years of age. While total neuronal density does not change with age in either of these banks, there is a significant age-related reduction in the strength of microcolumns in both regions on the order of 40%. This likely reflects a subtle but definite loss of organization in the structure of the cortical microcolumn. The reduction in strength in ventral area 46 correlates with cognitive impairments in learning and memory while the reduction in dorsal area 46 does not. This result is congruent with published data attributing cognitive functions to ventral area 46 that are similar to our particular cognitive battery which does not optimally tap cognitive functions attributed to dorsal area 46. While the exact mechanisms underlying this loss of microcolumnar organization remain to be determined, it is plausible that they reflect age-related alterations in dendritic and/or axonal organization which alter connectivity and may contribute to age-related declines in cognitive performance.

  2. Differences in behaviour and physiology between adult surrogate-reared and mother-reared Cynomolgous monkeys (Macaca fascicularis)

    NARCIS (Netherlands)

    Luijk, I.A.F. van; Timmermans, P.J.A.; Sweep, C.G.J.; Willems, J.; Vossen, J.M.H.

    2000-01-01

    Previous studies of the effects of rearing conditions on exploratory behaviour revealed that 80% of monkeys reared in peer groups with surrogate mothers developed neophobia, whereas only 15 % of mother-reared monkeys did. Young surrogate-reared and, especially, isolated rhesus monkeys are known to

  3. No effects of dioxin singly on limb malformations in macaque monkeys through epidemiological and treated studies

    Energy Technology Data Exchange (ETDEWEB)

    Asaoka, Kazuo; Iida, Hiroko [Kyoto Univ. (Japan). Primate Research Insitute, Dept. of Molecular and Cellular Biochemistry; Watanabe, Kunio [Kyoto Univ. (Japan). Primate Research Institute, Field Research Center; Goda, Hiroshi [Towa Kagaku Co., Ltd. (Japan); Ihara, Toshio; Nagata, Ryoichi [Shin Nippon Biomedical Laboratories, Ltd. (Japan). Safety Research Facility; Yasuda, Mineo [Hiroshima International Univ. (Japan). Fac. of Health Sciences, Dept. of Clinical Engineering; Kubata, Shunichiro [Tokyo Univ. (Japan). Dept. of Life Science, Graduate School of Arts and Sciences

    2004-09-15

    Human populations exposed with highly dioxin were suspected to be caused immunological dysfunctions, carcinogenesis, and developmental and reproductive dysfunctions. Because of species resemblances, the dioxin effects have been investigating using monkeys as a model for assessment of dioxin exposure on human health. Since 1957 the limb malformations of monkeys in Japan have been reported. The higher frequency of them was found in provisional groups of monkeys who were given the same kind of food for human. The chromosomal abnormalities are excluded from the factor for the congenital limb malformations that are still producing in Japan. In this study, the relations between dioxin and the limb malformations of macaque monkeys were estimated by the epidemiological and administered researches. The dioxin levels in monkeys were measured at two districts that one has the provisional groups including monkeys with limb malformations and the other has breeding groups never seeing the malformations for a long time. TEQ was calculated by the levels of dioxin isomers in the monkeys and the values show no difference between the two places and between the individuals with and without the limb malformations. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) was administered via subcutaneous to pregnant rhesus monkeys from the day 20 of gestation to the day 90 after birth. The exposed babies, including the offspring and died in neonatal, had observed normal limbs in the range of 30-300 ng TCDD /kg of body weight.

  4. Rod photoreceptors express GPR55 in the adult vervet monkey retina

    DEFF Research Database (Denmark)

    Bouskila, Joseph; Javadi, Pasha; Casanova, Christian

    2013-01-01

    . Yet, its formal classification is still a matter of debate. CB1R and CB2R expression patterns are well described for rodent and monkey retinas. In the monkey retina, CB1R has been localized in its neural (cone photoreceptor, horizontal, bipolar, amacrine and ganglion cells) and CB2R in glial...

  5. Stimulus Similarity and Encoding Time Influence Incidental Recognition Memory in Adult Monkeys with Selective Hippocampal Lesions

    Science.gov (United States)

    Zeamer, Alyson; Meunier, Martine; Bachevalier, Jocelyne

    2011-01-01

    Recognition memory impairment after selective hippocampal lesions in monkeys is more profound when measured with visual paired-comparison (VPC) than with delayed nonmatching-to-sample (DNMS). To clarify this issue, we assessed the impact of stimuli similarity and encoding duration on the VPC performance in monkeys with hippocampal lesions and…

  6. Macaque monkeys can learn token values from human models through vicarious reward.

    Science.gov (United States)

    Bevacqua, Sara; Cerasti, Erika; Falcone, Rossella; Cervelloni, Milena; Brunamonti, Emiliano; Ferraina, Stefano; Genovesio, Aldo

    2013-01-01

    Monkeys can learn the symbolic meaning of tokens, and exchange them to get a reward. Monkeys can also learn the symbolic value of a token by observing conspecifics but it is not clear if they can learn passively by observing other actors, e.g., humans. To answer this question, we tested two monkeys in a token exchange paradigm in three experiments. Monkeys learned token values through observation of human models exchanging them. We used, after a phase of object familiarization, different sets of tokens. One token of each set was rewarded with a bit of apple. Other tokens had zero value (neutral tokens). Each token was presented only in one set. During the observation phase, monkeys watched the human model exchange tokens and watched them consume rewards (vicarious rewards). In the test phase, the monkeys were asked to exchange one of the tokens for food reward. Sets of three tokens were used in the first experiment and sets of two tokens were used in the second and third experiments. The valuable token was presented with different probabilities in the observation phase during the first and second experiments in which the monkeys exchanged the valuable token more frequently than any of the neutral tokens. The third experiments examined the effect of unequal probabilities. Our results support the view that monkeys can learn from non-conspecific actors through vicarious reward, even a symbolic task like the token-exchange task.

  7. Plasma disappearance, urine excretion, and tissue distribution of ribavirin in rats and rhesus monkeys

    International Nuclear Information System (INIS)

    Ferrara, E.A.; Oishi, J.S.; Wannemacher, R.W. Jr.; Stephen, E.L.

    1981-01-01

    Ribavirin has been shown to have broad-spectrum antiviral. To study its tissue distribution and disappearance rate, a single dose of 10 mg/kg which contained 10 microCi of [14C]ribavirin was injected intravenously into rhesus monkeys and intramuscularly into m