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Sample records for water maze task

  1. Endogenous anxiety and stress responses in water maze and Barnes maze spatial memory tasks

    Science.gov (United States)

    Harrison, F.E.; Hosseini, A.H.; McDonald, M.P.

    2009-01-01

    The effects of abnormally high or low stress on learning are well established. The Barnes maze and Morris water maze are two commonly-used tests of spatial memory, of which the water maze is considered more stressful; however, until now this has not been demonstrated empirically. In the present study, mice matched for performance on commonly-used anxiety tasks were trained on either the Barnes maze or water maze or received no cognitive testing. Water-maze training induced greater increases in plasma corticosterone than did Barnes maze training, assessed 30 min. after the final session. Importantly, spatial learning was inversely correlated with corticosterone levels in the water maze but not the Barnes maze, suggesting that performance on the water maze may be more affected by test-induced stress even within wild-type subjects of the same age and gender. These findings are important when considering the appropriate cognitive tasks for any experiment in which stress responses may differ systematically across groups. PMID:18996418

  2. Variants of the Morris water maze task to comparatively assess human and rodent place navigation.

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    Schoenfeld, Robby; Schiffelholz, Thomas; Beyer, Christian; Leplow, Bernd; Foreman, Nigel

    2017-03-01

    Performance in the Morris water maze has been widely used in routine behavioural studies of rodents. Since the advent of computer-based virtual environments, adaptations of the water maze have become available for human research. Despite decades of comparative neuroscience, formal comparisons of human and animal place navigation performance are rare. We studied 36 subjects, 18 young male mice in a Morris water maze and 18 male students in a virtual version. Quantitative measures (escape latencies, distances and platform crossings) indicated no discernable differences between human and rodent performance, reinforcing the task's general validity and its implied cross-species comparability. However, we extracted, using an a priori free classification method, qualitatively different movement patterns for mice and humans, patterns that reflect the probable strategy that individuals might have been using to solve the task. Our results indicated young male students to have most likely solved the maze by means of spatial strategies whereas mice were observed more often to have adopted non-spatial strategies. These differences could be attributed to differences in our maze setups (spatial cues, task instruction, training protocol, motivation) and gave further hints that maze learning depends on many factors. In summary performance on both spatial tasks was equivalent in humans and mice but the kind of maze learning that was used to achieve maximum performance was different. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Effects of Acute or Chronic Ethanol Exposure during Adolescence on Behavioral Inhibition and Efficiency in a Modified Water Maze Task

    OpenAIRE

    Acheson, Shawn K.; Craig Bearison; M Louise Risher; Abdelwahab, Sabri H.; Wilson, Wilkie A.; H Scott Swartzwelder

    2013-01-01

    Ethanol is well known to adversely affect frontal executive functioning, which continues to develop throughout adolescence and into young adulthood. This is also a developmental window in which ethanol is misused by a significant number of adolescents. We examined the effects of acute and chronic ethanol exposure during adolescence on behavioral inhibition and efficiency using a modified water maze task. During acquisition, rats were trained to find a stable visible platform onto which they c...

  4. Effects of acute or chronic ethanol exposure during adolescence on behavioral inhibition and efficiency in a modified water maze task.

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    Shawn K Acheson

    Full Text Available Ethanol is well known to adversely affect frontal executive functioning, which continues to develop throughout adolescence and into young adulthood. This is also a developmental window in which ethanol is misused by a significant number of adolescents. We examined the effects of acute and chronic ethanol exposure during adolescence on behavioral inhibition and efficiency using a modified water maze task. During acquisition, rats were trained to find a stable visible platform onto which they could escape. During the test phase, the stable platform was converted to a visible floating platform (providing no escape and a new hidden platform was added in the opposite quadrant. The hidden platform was the only means of escape during the test phase. In experiment 1, adolescent animals received ethanol (1.0 g/kg 30 min before each session during the test phase. In experiment 2, adolescent animals received chronic intermittent ethanol (5.0 g/kg for 16 days (PND30 To PND46 prior to any training in the maze. At PND72, training was initiated in the same modified water maze task. Results from experiment 1 indicated that acute ethanol promoted behavioral disinhibition and inefficiency. Experiment 2 showed that chronic intermittent ethanol during adolescence appeared to have no lasting effect on behavioral disinhibition or new spatial learning during adulthood. However, chronic ethanol did promote behavioral inefficiency. In summary, results indicate that ethanol-induced promotion of perseverative behavior may contribute to the many adverse behavioral sequelae of alcohol intoxication in adolescents and young adults. Moreover, the long-term effect of adolescent chronic ethanol exposure on behavioral efficiency is similar to that observed after chronic exposure in humans.

  5. A Preliminary Study of Functional Brain Activation among Marijuana Users during Performance of a Virtual Water Maze Task

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    Jennifer Tropp Sneider

    2013-01-01

    Full Text Available Numerous studies have reported neurocognitive impairments associated with chronic marijuana use. Given that the hippocampus contains a high density of cannabinoid receptors, hippocampal-mediated cognitive functions, including visuospatial memory, may have increased vulnerability to chronic marijuana use. Thus, the current study examined brain activation during the performance of a virtual analogue of the classic Morris water maze task in 10 chronic marijuana (MJ users compared to 18 nonusing (NU comparison subjects. Imaging data were acquired using blood oxygen level-dependent (BOLD functional MRI at 3.0 Tesla during retrieval (hidden platform and motor control (visible platform conditions. While task performance on learning trials was similar between groups, MJ users demonstrated a deficit in memory retrieval. For BOLD fMRI data, NU subjects exhibited greater activation in the right parahippocampal gyrus and cingulate gyrus compared to the MJ group for the Retrieval-Motor Control contrast (NU > MJ. These findings suggest that hypoactivation in MJ users may be due to differences in the efficient utilization of neuronal resources during the retrieval of memory. Given the paucity of data on visuospatial memory function in MJ users, these findings may help elucidate the neurobiological effects of marijuana on brain activation during memory retrieval.

  6. Learning strategy preference of 5XFAD transgenic mice depends on the sequence of place/spatial and cued training in the water maze task.

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    Cho, Woo-Hyun; Park, Jung-Cheol; Chung, ChiHye; Jeon, Won Kyung; Han, Jung-Soo

    2014-10-15

    Learning strategy preference was assessed in 5XFAD mice, which carry 5 familial Alzheimer's disease (AD) mutations. Mice were sequentially trained in cued and place/spatial versions of the water maze task. After training, a strategy preference test was conducted in which mice were required to choose between the spatial location where the platform had previously been during the place/spatial training, and a visible platform in a new location. 5XFAD and non-transgenic control mice showed equivalent escape performance in both training tasks. However, in the strategy preference test, 5XFAD mice preferred a cued strategy relative to control mice. When the training sequence was presented in the reverse order (i.e., place/spatial training before cued training), 5XFAD mice showed impairments in place/spatial training, but no differences in cued training or in the strategy preference test comparing to control. Analysis of regional Aβ42 deposition in brains of 5XFAD mice showed that the hippocampus, which is involved in the place/spatial learning strategy, had the highest levels of Aβ42 and the dorsal striatum, which is involved in cued learning strategy, showed a small increase in Aβ42 levels. The effect of training protocol order on performance, and regional differences in Aβ42 deposition observed in 5XFAD mice, suggest differential functional recruitment of brain structures related to learning in healthy and AD individuals. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Nicotine interacts with sex in affecting rat choice between "look-out" and "navigational" cognitive styles in the Morris water maze place learning task.

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    Kanit, L; Taşkiran, D; Furedy, J J; Kulali, B; McDonald, R; Pöğün, S

    1998-07-15

    The effect of sex and nicotine on cognitive style was examined in rats using a water maze task that allows differentiation between cognitive ability and style. During the 12-day acquisition period with the platform in the same location (either visible or hidden) there were no effects or interactions attributable to nicotine and sex, either in terms of learning rate or asymptotic latency. On the final test day the platform was visible and shifted in its location, and on the first trial the new location was proximal to the rats starting position, in contrast to the more distal location of the platform during the previous acquisition days. This platform relocation presented the rats with a choice between two competing cognitive styles: using local visual (look-out) cues vs. navigational cues. Performance on the test day yielded a nicotine x sex interaction, such that only saline-treated female rats showed a clear preference for the perceptual-proximal look-out cognitive style by swimming straight to the newly-relocated visible platform with mean escape latency that approximated the limits of swimming speed. The other three groups did not differ from each other, and preferred navigational cues. The results show that male and female rats use different strategies in problem solving, and that nicotine shifts the female pattern to that of the male.

  8. Second Language Learning with the Story Maze Task: Examining the Training Effect of Weaving through Stories

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    Enkin, Elizabeth

    2016-01-01

    The maze task is a psycholinguistic experimental procedure that measures real-time incremental sentence processing. The task has recently been tested as a language learning tool with promising results. Therefore, the present study examines the merits of a contextualized version of this task: the story maze. The findings are consistent with…

  9. Sensitivity of modified Biel-maze task, compared with Y-maze task, to measure spatial learning and memory deficits of ethanol teratogenicity in the guinea pig.

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    Dobson, Christine C; Mongillo, Daniel L; Poklewska-Koziell, Margo; Winterborn, Andrew; Brien, James F; Reynolds, James N

    2012-07-15

    Ethanol consumption during pregnancy can produce a variety of teratogenic effects in offspring, termed Fetal Alcohol Spectrum Disorders (FASD). The most debilitating and permanent consequence of chronic prenatal ethanol exposure (CPEE) is neurobehavioral teratogenicity, which often manifests as cognitive and behavioral impairments, including deficits in spatial learning and memory. This study tested the hypothesis that a modified dry-land version of the multi-choice Biel-maze task is more sensitive than the rewarded-alternation Y-maze task for the determination of spatial learning and memory deficits of ethanol teratogenicity. Pregnant guinea pigs received ethanol (4 g/kg maternal body weight/day) or isocaloric-sucrose/pair-feeding (control) for 5days/week throughout gestation. CPEE resulted in ethanol neurobehavioral teratogenicity in offspring, as demonstrated by increased spontaneous locomotor activity at postnatal day (PD) 10 and decreased brain weight at euthanasia (PD 150-200). On PD 21, offspring were randomly assigned to one of two tasks to assess spatial learning and memory performance: a dry-land version of the Biel maze or a rewarded-alternation Y-maze. Animals were habituated to the environment of their assigned task and performance of each CPEE or control offspring was measured. In the modified Biel maze, CPEE and control offspring were not different for percent completed trials or time to complete a trial. However, CPEE offspring made more errors (reversals and entering dead ends) in the Biel maze, demonstrating impaired spatial learning and memory. In contrast, CPEE offspring did not have impaired performance of the rewarded-alternation Y-maze task. Therefore, the modified dry-land version of the Biel-maze task, which measures cognitive performance using a complex multi-choice design, is more sensitive in demonstrating CPEE-induced spatial learning and memory deficits compared with a simple, rewarded-alternation Y-maze task. Copyright © 2012

  10. The maze task: measuring forced incremental sentence processing time.

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    Forster, Kenneth I; Guerrera, Christine; Elliot, Lisa

    2009-02-01

    The maze task is an online measure of sentence processing time that provides an alternative to the standard moving window version of self-paced reading. Rather than each word of the sentence being presented in succession, two words are presented at the same time, and the participant must choose which word is a grammatical continuation of the sentence. This procedure forces the reader into an incremental mode of processing in which each word must be fully integrated with the preceding context before the next word can be considered. Previous research with this technique has not considered whether it is sufficiently sensitive to syntactic complexity effects or to garden path effects. Four experiments are reported demonstrating that reliable differences in processing time for subject relatives and object relatives can be obtained, and that this technique generates garden path effects that correspond closely with the data from eyetracking experiments, but without the spillover effects that are sometimes obtained with eyetracking. It is also shown that the task is sensitive to word frequency effects, producing estimates well in excess of those found with eyetracking.

  11. Using the Morris water maze to assess spatial learning and memory in weanling mice.

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    Barnhart, Christopher D; Yang, Dongren; Lein, Pamela J

    2015-01-01

    Mouse models have been indispensable for elucidating normal and pathological processes that influence learning and memory. A widely used method for assessing these cognitive processes in mice is the Morris water maze, a classic test for examining spatial learning and memory. However, Morris water maze studies with mice have principally been performed using adult animals, which preclude studies of critical neurodevelopmental periods when the cellular and molecular substrates of learning and memory are formed. While weanling rats have been successfully trained in the Morris water maze, there have been few attempts to test weanling mice in this behavioral paradigm even though mice offer significant experimental advantages because of the availability of many genetically modified strains. Here, we present experimental evidence that weanling mice can be trained in the Morris water maze beginning on postnatal day 24. Maze-trained weanling mice exhibit significant improvements in spatial learning over the training period and results of the probe trial indicate the development of spatial memory. There were no sex differences in the animals' performance in these tasks. In addition, molecular biomarkers of synaptic plasticity are upregulated in maze-trained mice at the transcript level. These findings demonstrate that the Morris water maze can be used to assess spatial learning and memory in weanling mice, providing a potentially powerful experimental approach for examining the influence of genes, environmental factors and their interactions on the development of learning and memory.

  12. Reversible Hippocampal Lesions Disrupt Water Maze Performance during Both Recent and Remote Memory Tests

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    Broadbent, Nicola J.; Squire, Larry R.; Clark, Robert E.

    2006-01-01

    Conventional lesion methods have shown that damage to the rodent hippocampus can impair previously acquired spatial memory in tasks such as the water maze. In contrast, work with reversible lesion methods using a different spatial task has found remote memory to be spared. To determine whether the finding of spared remote spatial memory depends on…

  13. Memory-Enhancing Activity of Palmatine in Mice Using Elevated Plus Maze and Morris Water Maze

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    Dinesh Dhingra

    2012-01-01

    Full Text Available The present study was designed to evaluate the effect of palmatine on memory of Swiss young male albino mice. Palmatine (0.1, 0.5, 1 mg/kg, i.p. and physostigmine (0.1 mg/kg, i.p. per se were administered for 10 successive days to separate groups of mice. Effect of drugs on learning and memory of mice was evaluated using elevated plus maze and Morris water maze. Brain acetylcholinesterase activity was also estimated. Effect of palmatine on scopolamine- and diazepam-induced amnesia was also investigated. Palmatine (0.5 and 1 mg/kg and physostigmine significantly improved learning and memory of mice, as indicated by decrease in transfer latency using elevated plus maze, and decrease in escape latency during training and increase in time spent in target quadrant during retrieval using Morris water maze. The drugs did not show any significant effect on locomotor activity of the mice. Memory-enhancing activity of palmatine (1 mg/kg was comparable to physostigmine. Palmatine (1 mg/kg significantly reversed scopolamine- and diazepam-induced amnesia in mice. Palmatine and physostigmine also significantly reduced brain acetylcholinesterase activity of mice. Thus, palmatine showed memory-enhancing activity in mice probably by inhibiting brain acetylcholinesterase activity, through involvement of GABA-benzodiazepine pathway, and due to its antioxidant activity.

  14. Age-dependent effects of developmental lead exposure on performance in the Morris water maze.

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    Jett, D A; Kuhlmann, A C; Farmer, S J; Guilarte, T R

    1997-01-01

    The neurobehavioral toxicity of developmental exposure to lead (Pb) was investigated by conducting tests of spatial learning in the Morris water maze. Female Long-Evans rats were exposed to 0 or 250 ppm Pb acetate in the diet beginning 10 days prior to breeding and continued throughout gestation and lactation. Pups were weaned onto the same diets as the dams at postnatal day 20 (PN20). Increased levels of Pb were detected in the hippocampus of the 250 ppm Pb acetate group relative to controls. The highest concentration of Pb measured in the hippocampus was at PN21 with decreasing levels at older ages. In the Morris Water Maze, a statistically significant (p water maze at any age. These initial studies indicate an impairment of performance in the swim task in PN21 rats exposed to Pb during development. The age-dependent effect of Pb in this learning paradigm is consistent with previous studies in experimental animals and with the observation that children are more susceptible to Pb-induced cognitive deficits than adults. The Morris water maze may be useful for studying the effects of Pb on learning and memory, and their neurochemical basis.

  15. A Wireless EEG Recording Method for Rat Use inside the Water Maze.

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    Pinnell, Richard C; Almajidy, Rand K; Kirch, Robert D; Cassel, Jean C; Hofmann, Ulrich G

    2016-01-01

    With the continued miniaturisation of portable embedded systems, wireless EEG recording techniques are becoming increasingly prevalent in animal behavioural research. However, in spite of their versatility and portability, they have seldom been used inside water-maze tasks designed for rats. As such, a novel 3D printed implant and waterproof connector is presented, which can facilitate wireless water-maze EEG recordings in freely-moving rats, using a commercial wireless recording system (W32; Multichannel Systems). As well as waterproofing the wireless system, battery, and electrode connector, the implant serves to reduce movement-related artefacts by redistributing movement-related forces away from the electrode connector. This implant/connector was able to successfully record high-quality LFP in the hippocampo-striatal brain regions of rats as they undertook a procedural-learning variant of the double-H water-maze task. Notably, there were no significant performance deficits through its use when compared with a control group across a number of metrics including number of errors and speed of task completion. Taken together, this method can expand the range of measurements that are currently possible in this diverse area of behavioural neuroscience, whilst paving the way for integration with more complex behaviours.

  16. A Wireless EEG Recording Method for Rat Use inside the Water Maze.

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    Richard C Pinnell

    Full Text Available With the continued miniaturisation of portable embedded systems, wireless EEG recording techniques are becoming increasingly prevalent in animal behavioural research. However, in spite of their versatility and portability, they have seldom been used inside water-maze tasks designed for rats. As such, a novel 3D printed implant and waterproof connector is presented, which can facilitate wireless water-maze EEG recordings in freely-moving rats, using a commercial wireless recording system (W32; Multichannel Systems. As well as waterproofing the wireless system, battery, and electrode connector, the implant serves to reduce movement-related artefacts by redistributing movement-related forces away from the electrode connector. This implant/connector was able to successfully record high-quality LFP in the hippocampo-striatal brain regions of rats as they undertook a procedural-learning variant of the double-H water-maze task. Notably, there were no significant performance deficits through its use when compared with a control group across a number of metrics including number of errors and speed of task completion. Taken together, this method can expand the range of measurements that are currently possible in this diverse area of behavioural neuroscience, whilst paving the way for integration with more complex behaviours.

  17. The effect of sub-anesthetic and anesthetic ketamine on water maze memory acquisition, consolidation and retrieval.

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    Moosavi, Maryam; Yadollahi Khales, Golnaz; Rastegar, Karim; Zarifkar, Asadollah

    2012-02-29

    Ketamine, a non-selective inhibitor of NMDA (N-methyl-D-aspartate) channels is used in anesthetic or sub-anesthetic doses to induce analgesia, amnesia, to suppress fear, anxiety and depression. Although the ketamine's effect on memory acquisition is known, its effects on other aspects of memory are controversial. Morris water maze is a task which assesses spatial learning and memory. This study was aimed to assess the ketamine's differential effect on water maze memory acquisition, consolidation and retrieval. Male Sprague-Dawley rats (250-350 g) were trained in water maze single training session. 24h later a probe trial which was consisted of a single trial without platform was done. To assess the effect of ketamine on water maze memory acquisition it was administered before training; to assess its effect on memory consolidation it was administered immediately after training and to assess its effect on memory retrieval it was injected before probe trial. Ketamine both in sub-anesthetic and anesthetic doses impaired water maze memory acquisition, its anesthetic dose but not sub-anesthetic dose impaired memory consolidation and on retrieval stage, both doses deteriorated memory retrieval. It seems that NMDA receptor activity is not just necessary during water maze memory acquisition but also their post-learning reactivation is required to maintain memory consolidation and retrieval. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Intrahippocampal administration of lead (Pb) impairs performance of rats in the Morris water maze.

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    Jett, D A; Kuhlmann, A C; Guilarte, T R

    1997-01-01

    We examined spatial learning in the Morris water maze after daily acute bilateral micro-injection of 13.9 ng sodium acetate (NaAc) or 37.9 ng lead acetate (PbAc) in 1 microliter volumes into the dorsal hippocampus of normal adult rats. After six days of injections and water maze training, rats injected with NaAc were able to find a hidden platform in 8.3 s, and those injected with PbAc were significantly slower (15.2 s; p water maze.

  19. A Wireless EEG Recording Method for Rat Use inside the Water Maze

    National Research Council Canada - National Science Library

    Pinnell, Richard C; Almajidy, Rand K; Kirch, Robert D; Cassel, Jean C; Hofmann, Ulrich G

    2016-01-01

    .... As such, a novel 3D printed implant and waterproof connector is presented, which can facilitate wireless water-maze EEG recordings in freely-moving rats, using a commercial wireless recording system (W32...

  20. Effects of morphine dependence on the performance of rats in reference and working versions of the water maze.

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    Miladi Gorji, Hossein; Rashidy-Pour, Ali; Fathollahi, Yaghoub

    2008-02-27

    Numerous studies have dealt with the role of opiate system in tasks aimed at measurement of cognitive behavior, but the role of morphine dependence on learning and memory is still controversial. In this study chronic exposure to morphine was employed to evaluate learning ability and spatial short-term memory (working memory) and long-term memory (reference memory) in the water maze task. Male albino rats were made dependent by chronic administration of morphine in drinking water that lasted at least 21 days. In Experiment 1, the performance of animals was evaluated in reference memory version of the water maze. Rats were submitted to a session of 6 trials for 6 consecutive days to find the submerged platform that was located in the center of a quadrant. Latency and traveled distance to find the platform were measured as indexes of learning. Memory retention was tested 24 h after the last training session in a probe trial (60 s) in which there was no platform and the time spent in each quadrant of the water maze was recorded. Results indicated that latency and traveled distance to find the platform were same in control and dependent rats during training days, but during the probe test morphine-dependent group spent significantly less time in the target quadrant. In Experiment 2, training on working memory version of the water maze task was started. Only two trials per day were given until the performance of animals was stabilized (at least 5 days). Final test was done at day 6. Acquisition-retention interval was 75 min. No significant differences were found on acquisition and retention trials between morphine and control groups. Our findings indicate that chronic exposure to morphine did not impair learning ability, but partially impaired retention of spatial long-term (reference) memory. Moreover, dependence on morphine did not affect either acquisition or retention of spatial short (working) memory.

  1. An old test for new neurons: refining the Morris water maze to study the functional relevance of adult hippocampal neurogenesis

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    Alexander eGarthe

    2013-05-01

    Full Text Available The Morris water maze represents the de-facto standard for testing hippocampal function in laboratory rodents. In the field of adult hippocampal neurogenesis, however, using this paradigm to assess the functional relevance of the new neurons yielded surprisingly inconsistent results. While some authors found aspects of water maze performance to be linked to adult neurogenesis, others obtained different results or could not demonstrate any effect of manipulating adult neurogenesis.In this review we discuss evidence that the large diversity of protocols and setups used is an important aspect in interpreting the differences in the results that have been obtained. Even simple parameters such as pool size, number and configuration of visual landmarks, or number of trials can become highly relevant for getting the new neurons involved at all. Sets of parameters are often chosen with implicit or explicit concepts in mind and these might lead to different views on the function of adult-generated neurons.We propose that the classical parameters usually used to measure spatial learning performance in the water maze might not be particularly well suited to sensitively and specifically detect the supposedly highly specific functional changes elicited by the experimental modulation of adult hippocampal neurogenesis. As adult neurogenesis is supposed to affect specific aspects of information processing only in the hippocampus, any claim for a functional relevance of the new neurons has to be based on hippocampus-specific parameters. We also placed a special emphasis on the fact that the DG facilitates the differentiation between contexts as opposed to just differentiating places.In conclusion, while the Morris water maze has proven to be one of the most effective testing paradigms to assess hippocampus-dependent spatial learning, new and more specific questions ask for new parameters. Therefore, the full potential of the water maze task remains to be tapped.

  2. Rats in a levered T-maze task show evidence of time-place discriminations in two different measures.

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    Deibel, Scott H; Lehr, Andrew B; Maloney, Chelsea; Ingram, Matthew L; Lewis, Leanna M; Chaulk, Anne-Marie P; Chaulk, Pam D; Skinner, Darlene M; Thorpe, Christina M

    2017-06-01

    It is difficult for rats to learn to go to an arm of a T-maze to receive food that is dependent on the time of day, unless the amount of food in each daily session is different. In the same task, rats show evidence of time-place discriminations if they are required to press levers in the arms of the T-maze, but learning is only evident when the first lever press is considered, and not the first arm visited. These data suggest that rats struggle to use time as a discriminative stimulus unless the rewards/events differ in some dimension, or unless the goal locations can be visited prior to making a response. If both of these conditions are met in the same task, it might be possible to compare time-place learning in two different measures that essentially indicate performance before and after entering the arms of the T-maze. In the present study, we investigated time-place learning in rats with a levered T-maze task in which the amounts of food varied depending on the time of day. The first arm choices and first lever presses both indicated that the rats had acquired time-place discriminations, and both of these measures became significantly different from chance during the same block. However, there were subtle differences between the two measures, which suggest that time-place discrimination is aided by visiting the goal locations.

  3. Language control in bilingual language comprehension: evidence from the maze task

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    XIN eWANG

    2015-08-01

    Full Text Available Most empirical evidence on switch costs is based on bilingual production and interpreted as a result of inhibitory control. It is unclear whether such a top-down control process exists in language switching during comprehension. This study investigates whether a non-lexical switch cost is involved in reading code-switched sentences and its relation to language dominance with cross-script bilingual readers. A maze task is adopted in order to separate top-down inhibitory effects, from lexical effects driven by input. The key findings are: 1 switch costs were observed in both L1-L2 and L2-L1 directions; 2 these effects were driven by two mechanisms: lexical activation and inhibitory control; 3 language dominance modulated the lexical effects, but did not affect the inhibitory effects. These results suggest that a language control mechanism is involved in bilingual reading, even though the control process is not driven by selection as in production. At the theoretical level, these results lend support for the Inhibitory Control model during language switching in comprehension; while the BIA/BIA+ model needs to incorporate a top-down control mechanism to be able to explain the current findings.

  4. Effects of zolpidem on sedation, anxiety, and memory in the plus-maze discriminative avoidance task.

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    Zanin, Karina A; Patti, Camilla L; Sanday, Leandro; Fernandes-Santos, Luciano; Oliveira, Larissa C; Poyares, Dalva; Tufik, Sergio; Frussa-Filho, Roberto

    2013-04-01

    Zolpidem (Zolp), a hypnotic drug prescribed to treat insomnia, may have negative effects on memory, but reports are inconsistent. We examined the effects of acute doses of Zolp (2, 5, or 10 mg/kg, i.p.) on memory formation (learning, consolidation, and retrieval) using the plus-maze discriminative avoidance task. Mice were acutely treated with Zolp 30 min before training or testing. In addition, the effects of Zolp and midazolam (Mid; a classic benzodiazepine) on consolidation at different time points were examined. The possible role of state dependency was investigated using combined pre-training and pre-test treatments. Zolp produced a dose-dependent sedative effect, without modifying anxiety-like behavior. The pre-training administration of 5 or 10 mg/kg resulted in retention deficits. When administered immediately after training or before testing, memory was preserved. Zolp post-training administration (2 or 3 h) impaired subsequent memory. There was no participation of state dependency phenomenon in the amnestic effects of Zolp. Similar to Zolp, Mid impaired memory consolidation when administered 1 h after training. Amnestic effects occurred when Zolp was administered either before or 2-3 h after training. These memory deficits are not related to state dependency. Moreover, Zolp did not impair memory retrieval. Notably, the memory-impairing effects of Zolp are similar to those of Mid, with the exception of the time point at which the drug can modify consolidation. Finally, the memory effects were unrelated to sedation or anxiolysis.

  5. Language control in bilingual language comprehension: evidence from the maze task.

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    Wang, Xin

    2015-01-01

    Most empirical evidence on switch costs is based on bilingual production and interpreted as a result of inhibitory control. It is unclear whether such a top-down control process exists in language switching during comprehension. This study investigates whether a non-lexical switch cost is involved in reading code-switched sentences and its relation to language dominance with cross-script bilingual readers. A maze task is adopted in order to separate top-down inhibitory effects, from lexical effects driven by input. The key findings are: (1) switch costs were observed in both L1-L2 and L2-L1 directions; (2) these effects were driven by two mechanisms: lexical activation and inhibitory control; (3) language dominance modulated the lexical effects, but did not affect the inhibitory effects. These results suggest that a language control mechanism is involved in bilingual reading, even though the control process is not driven by selection as in production. At the theoretical level, these results lend support for the Inhibitory Control model during language switching in comprehension; while the BIA/BIA+ model needs to incorporate a top-down control mechanism to be able to explain the current findings.

  6. Spatial Memory in the Morris Water Maze and Activation of Cyclic AMP Response Element-Binding (CREB) Protein within the Mouse Hippocampus

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    Porte, Yves; Buhot, Marie Christine; Mons, Nicole E.

    2008-01-01

    We investigated the spatio-temporal dynamics of learning-induced cAMP response element-binding protein activation/phosphorylation (pCREB) in mice trained in a spatial reference memory task in the water maze. Using immunohistochemistry, we examined pCREB immunoreactivity (pCREB-ir) in hippocampal CA1 and CA3 and related brain structures. During the…

  7. "Despair" induced by extinction trials in the water maze: relationship with measures of anxiety in aged and adult rats.

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    Schulz, Daniela; Huston, Joseph P; Buddenberg, Tim; Topic, Bianca

    2007-03-01

    We have previously reported that extinction of escape behavior in the water maze due to the removal of the platform coincided with the development of behavioral "despair" in aged and adult rats, as assessed by immobility. The present study examines further predictions derived from the hypothesis that the withholding of reinforcement induces behaviors akin to depression. We tested for correlations between extinction performance and immobility, as well as between immobility and measures of anxiety in aged and adult rats. Age comparisons were also performed on these variables. Forty aged and 29 adult male Wistar rats (24 and 3 months old, respectively) were examined in the open field, black/white box and elevated-plus maze followed by 6 days of training in the water maze hidden platform task and 8 days of extinction without the platform. Indices of immobility increased over trials of extinction, with the aged showing higher levels, earlier onsets and larger slope increases of immobility than the adults. A lower resistance-to-extinction was predictive of more "despair" in both age groups. Between-group differences in the open field, black/white box and elevated-plus maze indicated that the aged showed more anxiety-like behavior than the adults and/or explored these environments less. Within the aged group, indicators of fearfulness in the three tests were predictive of higher levels of "despair". The extinction-despair model is held to provide the promise of a conceptual and empirical model of human depression that is the consequence of withdrawal of reinforcement.

  8. Spontaneous Recovery of Human Spatial Memory in a Virtual Water Maze

    Science.gov (United States)

    Luna, David; Martínez, Héctor

    2015-01-01

    The occurrence of spontaneous recovery in human spatial memory was assessed using a virtual environment. In Experiment 1, spatial memory was established by training participants to locate a hidden platform in a virtual water maze using a set of four distal landmarks. In Experiment 2, after learning about the location of a hidden platform, the…

  9. Morris Water Maze Test: Optimization for Mouse Strain and Testing Environment.

    Science.gov (United States)

    Weitzner, Daniel S; Engler-Chiurazzi, Elizabeth B; Kotilinek, Linda A; Ashe, Karen Hsiao; Reed, Miranda Nicole

    2015-06-22

    The Morris water maze (MWM) is a commonly used task to assess hippocampal-dependent spatial learning and memory in transgenic mouse models of disease, including neurocognitive disorders such as Alzheimer's disease. However, the background strain of the mouse model used can have a substantial effect on the observed behavioral phenotype, with some strains exhibiting superior learning ability relative to others. To ensure differences between transgene negative and transgene positive mice can be detected, identification of a training procedure sensitive to the background strain is essential. Failure to tailor the MWM protocol to the background strain of the mouse model may lead to under- or over- training, thereby masking group differences in probe trials. Here, a MWM protocol tailored for use with the F1 FVB/N x 129S6 background is described. This is a frequently used background strain to study the age-dependent effects of mutant P301L tau (rTg(TauP301L)4510 mice) on the memory deficits associated with Alzheimer's disease. Also described is a strategy to re-optimize, as dictated by the particular testing environment utilized.

  10. Prenatal toluene exposure impairs performance in the Morris Water Maze in adolescent rats.

    Science.gov (United States)

    Callan, S P; Hannigan, J H; Bowen, S E

    2017-02-07

    Volatile organic solvent abuse continues to be a worldwide health problem, including the neurobehavioral teratogenic sequelae of toluene abuse during pregnancy. Although abuse levels of prenatal toluene exposure can lead to a Fetal Solvent Syndrome, there is little research examining these effects on memory. Consumption of toluene can have detrimental effects on the developing hippocampus which could lead to specific spatial learning and memory deficits. This study used a rat model to determine how prenatal exposure to abuse levels of toluene would affect performance in a spatial learning and memory task, the Morris Water Maze (MWM). Pregnant Sprague-Dawley rats were exposed to 0, 8000 or 12,000ppm (ppm) of toluene for 15min twice daily from gestation day 8 (GD8) through GD20. Male and female offspring (N=104) were observed in the MWM for 5days beginning on postnatal day (PN) 28 and again on PN44. While prenatal toluene-exposed animals did not differ in initial acquisition in the MWM, rats prenatally exposed to 12,000ppm toluene displayed performance deficits during a probe trial and in reversal learning on PN44. Overall, this study indicates that prenatal exposure to repeated inhaled abuse patterns of high concentrations of toluene can impair spatial memory function that persists into adolescence. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  11. Ageing and spatial reversal learning in humans: findings from a virtual water maze.

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    Schoenfeld, R; Foreman, N; Leplow, B

    2014-08-15

    Deterioration in spatial memory with normal ageing is well accepted. Animal research has shown spatial reversal learning to be most vulnerable to pathological changes in the brain, but this has never been tested in humans. We studied ninety participants (52% females, 20-80 yrs) in a virtual water maze with a reversal learning procedure. Neuropsychological functioning, mood and personality were assessed to control moderator effects. For data analysis, participants were subdivided post hoc into groups aged 20-24, 25-34, 35-44, 45-64 and 65-80 yrs. Initial spatial learning occurred in all age groups but 65-80-yrs-olds never reached the level of younger participants. When tested for delayed recall of spatial memory, younger people frequented the target area but those over 65 yrs did not. In spatial reversal learning, age groups over 45 yrs were deficient and the 65-80-yrs-olds showed no evidence of reversal. Spatial measures were associated with neuropsychological functioning. Extraversion and measures of depression moderated the age effect on the learning index with older introverted and non-depressed individuals showing better results. Measures of anxiety moderated the age effect on reversal learning with older people having higher anxiety scores showing a preserved reversal learning capability. Results confirmed age to be a major factor in spatial tasks but further showed neuropsychological functioning, psycho-affective determinants and personality traits to be significant predictors of individual differences. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Effects of caffeine on learning and memory in rats tested in the Morris water maze

    Directory of Open Access Journals (Sweden)

    M.E.M. Angelucci

    2002-10-01

    Full Text Available We studied some of the characteristics of the improving effect of the non-specific adenosine receptor antagonist, caffeine, using an animal model of learning and memory. Groups of 12 adult male Wistar rats receiving caffeine (0.3-30 mg/kg, ip, in 0.1 ml/100 g body weight administered 30 min before training, immediately after training, or 30 min before the test session were tested in the spatial version of the Morris water maze task. Post-training administration of caffeine improved memory retention at the doses of 0.3-10 mg/kg (the rats swam up to 600 cm less to find the platform in the test session, P<=0.05 but not at the dose of 30 mg/kg. Pre-test caffeine administration also caused a small increase in memory retrieval (the escape path of the rats was up to 500 cm shorter, P<=0.05. In contrast, pre-training caffeine administration did not alter the performance of the animals either in the training or in the test session. These data provide evidence that caffeine improves memory retention but not memory acquisition, explaining some discrepancies among reports in the literature.

  13. Effects of caffeine on learning and memory in rats tested in the Morris water maze.

    Science.gov (United States)

    Angelucci, M E M; Cesário, C; Hiroi, R H; Rosalen, P L; Da Cunha, C

    2002-10-01

    We studied some of the characteristics of the improving effect of the non-specific adenosine receptor antagonist, caffeine, using an animal model of learning and memory. Groups of 12 adult male Wistar rats receiving caffeine (0.3-30 mg/kg, ip, in 0.1 ml/100 g body weight) administered 30 min before training, immediately after training, or 30 min before the test session were tested in the spatial version of the Morris water maze task. Post-training administration of caffeine improved memory retention at the doses of 0.3-10 mg/kg (the rats swam up to 600 cm less to find the platform in the test session, Pcaffeine administration also caused a small increase in memory retrieval (the escape path of the rats was up to 500 cm shorter, Pcaffeine administration did not alter the performance of the animals either in the training or in the test session. These data provide evidence that caffeine improves memory retention but not memory acquisition, explaining some discrepancies among reports in the literature.

  14. Cognitive and Neural Determinants of Response Strategy in the Dual-Solution Plus-Maze Task

    Science.gov (United States)

    De Leonibus, Elvira; Costantini, Vivian J. A.; Massaro, Antonio; Mandolesi, Georgia; Vanni, Valentina; Luvisetto, Siro; Pavone, Flaminia; Oliverio, Alberto; Mele, Andrea

    2011-01-01

    Response strategy in the dual-solution plus maze is regarded as a form of stimulus-response learning. In this study, by using an outcome devaluation procedure, we show that it can be based on both action-outcome and stimulus-response habit learning, depending on the amount of training that the animals receive. Furthermore, we show that…

  15. Fractal dimensions: A new paradigm to assess spatial memory and learning using Morris water maze.

    Science.gov (United States)

    Singh, Surjeet; Kaur, Harpreet; Sandhir, Rajat

    2016-02-15

    Morris water maze has been widely used for analysis of cognitive functions and relies on the time taken by animal to find the platform i.e. escape latency as a parameter to quantify spatial memory and learning. However, escape latency is confounded by swimming speed which is not necessarily a cognitive factor. Rather, path length may be a more appropriate and reliable parameter to assess spatial learning. This paper presents fractal dimension as a new paradigm to assess spatial memory and learning in animals. Male wistar rats were administrated with pentylenetetrazole and scopolamine to induce chronic epilepsy and dementia respectively. Fractal dimension of the random path followed by the animals on Morris water maze was analyzed and statistically compared among different experimental groups; the results suggest that fractal dimension is more reliable and accurate parameter to assess cognitive deficits compared to escape latency. Thus, the present study suggests that fractal dimensions could be used as an independent parameter to assess spatial memory and learning in animals using Morris water maze. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Effects of rolipram and zaprinast on learning and memory in the Morris water maze and radial arm maze tests in naive mice.

    Science.gov (United States)

    Akar, F; Mutlu, O; Celikyurt, I K; Ulak, G; Erden, F; Bektas, E; Tanyeri, P

    2015-02-01

    Inhibition of phosphodiesterase 5 (PDE) improved recognition memory and counteracted spatial learning impairment induced by nitric oxide synthase (NOS) inhibition in recent studies. Aim of this study was to investigate effects of rolipram, a PDE4 inhibitor and zaprinast, a PDE5 inhibitor, on learning and memory in Morris water maze (MWM) and radial arm maze (RAM) tests in naive mice. Male Balb-c mice were treated subchronically with zaprinast (3 and 10 mg/kg) and rolipram (0.05 and 0.1 mg/kg) for 6 days in the MWM test and acutely before the retention trial of radial arm maze test. Rolipram (0.05 and 0.1 mg/kg) significantly decreased escape latency between 2(nd) and 5(th) sessions, while zaprinast (10 mg/kg) significantly decreased escape latency only in 2(nd) session. Rolipram (0.05 and 0.1 mg/kg) and zaprinast (10 mg/kg) significantly increased time spent in escape platform's quadrant in probe trial of MWM test; only rolipram decreased mean distance to platform, while zaprinast had no effect on mean distance to platform. Zaprinast (3 and 10 mg/kg) significantly decreased number of errors compared to control group, while rolipram (0.05 and 0.1mg/kg) had no effect on number of errors in retention trial of RAM test. Rolipram (0.05 and 0.1 mg/kg) and zaprinast (10 mg/kg) significantly decreased time spent to complete retention trial (latency) compared to control group. Our study revealed that both zaprinast and rolipram enhanced spatial memory in MWM, while zaprinast seems to have more memory enhancing effects compared to rolipram in radial arm maze test. © Georg Thieme Verlag KG Stuttgart · New York.

  17. Post-acquisition hippocampal NMDA receptor blockade sustains retention of spatial reference memory in Morris water maze.

    Science.gov (United States)

    Shinohara, Keisuke; Hata, Toshimichi

    2014-02-01

    Several studies have demonstrated that the hippocampal N-methyl-D-aspartate type glutamate receptors (NMDARs) are necessary for the acquisition but not the retention of spatial reference memory. In contrast, a few studies have shown that post-acquisition repetitive intraperitoneal injections of an NMDAR antagonist facilitate the retention of spatial reference memory in a radial maze task. In the present study, we investigated the role of hippocampal NMDARs in the retention of spatial reference memories in Morris water maze. In Experiment 1, 24 h after training (4 trials/day for 4 days), D-AP5 was chronically infused into the hippocampus of rats for 5 days. In the subsequent probe test (seven days after training), we found that rats infused with D-AP5 spent a significantly longer time in the target quadrant compared to chance level, whereas rats in the control group did not. In Experiment 2, D-AP5 was infused into the hippocampus 1 (immediate) or 7 (delayed) days after the training session. In the probe test, following the retention interval of 13 days, immediate infusion facilitated the performance in a manner similar to Experiment 1, whereas the delayed infusion did not. These findings suggest that hippocampal NMDARs play an important role in the deterioration of spatial reference memory. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Differential Endocannabinoid Regulation of Extinction in Appetitive and Aversive Barnes Maze Tasks

    Science.gov (United States)

    Harloe, John P.; Thorpe, Andrew J.; Lichtman, Aron H.

    2008-01-01

    CB[subscript 1] receptor-compromised animals show profound deficits in extinguishing learned behavior from aversive conditioning tasks, but display normal extinction learning in appetitive operant tasks. However, it is difficult to discern whether the differential involvement of the endogenous cannabinoid system on extinction results from the…

  19. Looking ahead? Computerized maze task performance by chimpanzees (Pan troglodytes), rhesus monkeys (Macaca mulatta), capuchin monkeys (Cebus apella), and human children (Homo sapiens).

    Science.gov (United States)

    Beran, Michael J; Parrish, Audrey E; Futch, Sara E; Evans, Theodore A; Perdue, Bonnie M

    2015-05-01

    Human and nonhuman primates are not mentally constrained to the present. They can remember the past and-at least to an extent-anticipate the future. Anticipation of the future ranges from long-term prospection such as planning for retirement to more short-term future-oriented cognition such as planning a route through a maze. Here we tested a great ape species (chimpanzees), an Old World monkey species (rhesus macaques), a New World monkey species (capuchin monkeys), and human children on a computerized maze task. All subjects had to move a cursor through a maze to reach a goal at the bottom of the screen. For best performance on the task, subjects had to "plan ahead" to the end of the maze to move the cursor in the correct direction, avoid traps, and reverse directions if necessary. Mazes varied in difficulty. Chimpanzees were better than both monkey species, and monkeys showed a particular deficit when moving away from the goal or changing directions was required. Children showed a similar pattern to monkeys regarding the effects of reversals and moves away from the goal, but their overall performance in terms of correct maze completion was similar to the chimpanzees. The results highlight similarities as well as differences in planning across species and the role that inhibitory control may play in future-oriented cognition in primates. (c) 2015 APA, all rights reserved).

  20. [Analysis of variance of repeated data measured by water maze with SPSS].

    Science.gov (United States)

    Qiu, Hong; Jin, Guo-qin; Jin, Ru-feng; Zhao, Wei-kang

    2007-01-01

    To introduce the method of analyzing repeated data measured by water maze with SPSS 11.0, and offer a reference statistical method to clinical and basic medicine researchers who take the design of repeated measures. Using repeated measures and multivariate analysis of variance (ANOVA) process of the general linear model in SPSS and giving comparison among different groups and different measure time pairwise. Firstly, Mauchly's test of sphericity should be used to judge whether there were relations among the repeatedly measured data. If any (PSPSS statistical package is available to fulfil this process.

  1. Mapping immediate-early gene activity in the rat after place learning in a water-maze: the importance of matched control conditions.

    Science.gov (United States)

    Shires, K L; Aggleton, J P

    2008-09-01

    The expression of two immediate-early genes (IEGs), Zif268 and c-Fos, was quantified in hippocampal subregions and related structures following spatial learning in the Morris water-maze. A critical feature was the novel control protocol alongside more standard controls, the purpose of which was to test whether hippocampal activity is set automatically when traversing an environment or whether it is dependent on reaching a specific goal using learning that requires the hippocampus (i.e. task dependent). The new control protocol (Procedural Task) made it possible to match swim time, swim distance and learning to escape from water with that of the experimental (Working Memory) group. Unlike the Working Memory group, the Procedural Task animals showed no evidence of learning the absolute platform location during the test session. While the Working Memory rats showed c-Fos increases relative to the Procedural Task controls in the frontal and parahippocampal cortices, hippocampal levels did not differ. Again, for Zif268 there was no evidence of a relative increase of hippocampal activity in the Working Memory group. In fact, hippocampal Zif268 showed evidence of a relative decrease, even though the spatial working memory task is hippocampal dependent. The study not only highlighted the shortcomings of other control procedures used in water-maze studies (free-swimming or home cage control), but also indicated that the expression of these IEGs in the hippocampus is not a direct predictor of explicit spatial location learning. Rather, the activity in combinations of regions, including prefrontal cortex, provides a stronger correlate of water-maze learning.

  2. Modafinil and Memory: Effects of Modafinil on Morris Water Maze Learning and Pavlovian Fear Conditioning

    Science.gov (United States)

    Shuman, Tristan; Wood, Suzanne C.; Anagnostaras, Stephan G.

    2010-01-01

    Modafinil has been shown to promote wakefulness and some studies suggest the drug can improve cognitive function. Because of many similarities, the mechanism of action may be comparable to classical psychostimulants, although the exact mechanisms of modafinil’s actions in wakefulness and cognitive enhancement are unknown. The current study aims to further examine the effects of modafinil as a cognitive enhancer on hippocampus-dependent memory in mice. A high dose of modafinil (75 mg/kg, i.p.) given before training improved acquisition on a Morris water maze. When given only before testing, modafinil did not affect water maze performance. We also examined modafinil (0.075 – 75 mg/kg) on Pavlovian fear conditioning. A low dose of pre-training modafinil (0.75 mg/kg) enhanced memory of contextual fear conditioning (tested off-drug one week later) while a high dose (75 mg/kg) disrupted memory. Pre-training modafinil did not affect cued conditioning at any dose tested, and immediate post-training modafinil had no effect on either cued or contextual fear. These results suggest that modafinil’s effects of memory are more selective than amphetamine or cocaine, and specific to hippocampus-dependent memory. PMID:19331449

  3. Water Associated Zero Maze: A novel rat test for long term traumatic re-experiencing

    Directory of Open Access Journals (Sweden)

    Gilad eRitov

    2014-01-01

    Full Text Available Often, freezing and startle behaviors in the context of a previously experienced stress are taken as an indication of posttraumatic stress disorder (PTSD-like symptoms in rats. However, PTSD is characterized by large individual variations of symptoms. In order to take into consideration the complex and long term distinctive variations in effects of trauma exposure additional behavioral measures are required.The current study used a novel behavioral test, the Water Associated Zero Maze (WAZM. This test was planned to enable a formation of an association between the context of the maze and an underwater trauma or swim stress in order to examine the impact of exposure to the context which immediately precedes a stressful or a traumatic experience on rat's complex behavior. Rats were exposed to the WAZM and immediately after to an underwater trauma or short swim. One month later rats were re-exposed to the context of the WAZM while their behavior was video recorded. Furthermore, c-Fos expression in the amygdala was measured 90 min after this exposure.The results of the current study indicate that the WAZM can be used to discern behavioral changes measured a long time after the actual traumatic or stressful events. Furthermore, the behavioral changes detected were accompanied by changes of c-Fos expression in the amygdala of exposed rats. We suggest that the WAZM can be used to model traumatic memories re-experiencing in rodent models of human stress-related pathologies such as PTSD.

  4. 5-HTT Deficiency Affects Neuroplasticity and Increases Stress Sensitivity Resulting in Altered Spatial Learning Performance in the Morris Water Maze but Not in the Barnes Maze

    Science.gov (United States)

    Karabeg, Margherita M.; Grauthoff, Sandra; Kollert, Sina Y.; Weidner, Magdalena; Heiming, Rebecca S.; Jansen, Friederike; Popp, Sandy; Kaiser, Sylvia; Lesch, Klaus-Peter; Sachser, Norbert

    2013-01-01

    The purpose of this study was to evaluate whether spatial hippocampus-dependent learning is affected by the serotonergic system and stress. Therefore, 5-HTT knockout (-/-), heterozygous (+/-) and wildtype (+/+) mice were subjected to the Barnes maze (BM) and the Morris water maze (WM), the latter being discussed as more aversive. Additionally, immediate early gene (IEG) expression, hippocampal adult neurogenesis (aN), and blood plasma corticosterone were analyzed. While the performance of 5-HTT-/- mice in the BM was undistinguishable from both other genotypes, they performed worse in the WM. However, in the course of the repeated WM trials 5-HTT-/- mice advanced to wildtype level. The experience of a single trial of either the WM or the BM resulted in increased plasma corticosterone levels in all genotypes. After several trials 5-HTT-/- mice exhibited higher corticosterone concentrations compared with both other genotypes in both tests. Corticosterone levels were highest in 5-HTT-/- mice tested in the WM indicating greater aversiveness of the WM and a greater stress sensitivity of 5-HTT deficient mice. Quantitative immunohistochemistry in the hippocampus revealed increased cell counts positive for the IEG products cFos and Arc as well as for proliferation marker Ki67 and immature neuron marker NeuroD in 5-HTT-/- mice compared to 5-HTT+/+ mice, irrespective of the test. Most differences were found in the suprapyramidal blade of the dentate gyrus of the septal hippocampus. Ki67-immunohistochemistry revealed a genotype x environment interaction with 5-HTT genotype differences in naïve controls and WM experience exclusively yielding more Ki67-positive cells in 5-HTT+/+ mice. Moreover, in 5-HTT-/- mice we demonstrate that learning performance correlates with the extent of aN. Overall, higher baseline IEG expression and increased an in the hippocampus of 5-HTT-/- mice together with increased stress sensitivity may constitute the neurobiological correlate of raised

  5. Rapid learning of magnetic compass direction by C57BL/6 mice in a 4-armed 'plus' water maze.

    Directory of Open Access Journals (Sweden)

    John B Phillips

    Full Text Available Magnetoreception has been demonstrated in all five vertebrate classes. In rodents, nest building experiments have shown the use of magnetic cues by two families of molerats, Siberian hamsters and C57BL/6 mice. However, assays widely used to study rodent spatial cognition (e.g. water maze, radial arm maze have failed to provide evidence for the use of magnetic cues. Here we show that C57BL/6 mice can learn the magnetic direction of a submerged platform in a 4-armed (plus water maze. Naïve mice were given two brief training trials. In each trial, a mouse was confined to one arm of the maze with the submerged platform at the outer end in a predetermined alignment relative to magnetic north. Between trials, the training arm and magnetic field were rotated by 180(° so that the mouse had to swim in the same magnetic direction to reach the submerged platform. The directional preference of each mouse was tested once in one of four magnetic field alignments by releasing it at the center of the maze with access to all four arms. Equal numbers of responses were obtained from mice tested in the four symmetrical magnetic field alignments. Findings show that two training trials are sufficient for mice to learn the magnetic direction of the submerged platform in a plus water maze. The success of these experiments may be explained by: (1 absence of alternative directional cues (2, rotation of magnetic field alignment, and (3 electromagnetic shielding to minimize radio frequency interference that has been shown to interfere with magnetic compass orientation of birds. These findings confirm that mice have a well-developed magnetic compass, and give further impetus to the question of whether epigeic rodents (e.g., mice and rats have a photoreceptor-based magnetic compass similar to that found in amphibians and migratory birds.

  6. Use of an eight-arm radial water maze to assess working and reference memory following neonatal brain injury.

    Science.gov (United States)

    Penley, Stephanie C; Gaudet, Cynthia M; Threlkeld, Steven W

    2013-12-04

    Working and reference memory are commonly assessed using the land based radial arm maze. However, this paradigm requires pretraining, food deprivation, and may introduce scent cue confounds. The eight-arm radial water maze is designed to evaluate reference and working memory performance simultaneously by requiring subjects to use extra-maze cues to locate escape platforms and remedies the limitations observed in land based radial arm maze designs. Specifically, subjects are required to avoid the arms previously used for escape during each testing day (working memory) as well as avoid the fixed arms, which never contain escape platforms (reference memory). Re-entries into arms that have already been used for escape during a testing session (and thus the escape platform has been removed) and re-entries into reference memory arms are indicative of working memory deficits. Alternatively, first entries into reference memory arms are indicative of reference memory deficits. We used this maze to compare performance of rats with neonatal brain injury and sham controls following induction of hypoxia-ischemia and show significant deficits in both working and reference memory after eleven days of testing. This protocol could be easily modified to examine many other models of learning impairment.

  7. Distinct epigenetic and gene expression changes in rat hippocampal neurons after Morris water maze training

    Directory of Open Access Journals (Sweden)

    Sylvia D. eCarter

    2015-06-01

    Full Text Available Gene transcription and translation in the hippocampus is of critical importance in hippocampus-dependent memory formation, including during Morris water maze (MWM learning. Previous work using gene deletion models has shown that the immediate-early genes (IEGs c-Fos, Egr-1 and Arc are crucial for such learning. Recently, we reported that induction of IEGs in sparse dentate gyrus neurons requires ERK MAPK signaling and downstream formation of a distinct epigenetic histone mark (i.e. phospho-acetylated histone H3. Until now, this signaling, epigenetic and gene transcriptional pathway has not been comprehensively studied in the MWM model. Therefore, we conducted a detailed study of the phosphorylation of ERK1/2 and serine10 in histone H3 (H3S10p and induction of IEGs in the hippocampus of MWM trained rats and matched controls. MWM training evoked consecutive waves of ERK1/2 phosphorylation and H3S10 phosphorylation, as well as c-Fos, Egr-1 and Arc induction in sparse hippocampal neurons. The observed effects were most pronounced in the dentate gyrus. A positive correlation was found between the average latency to find the platform and the number of H3S10p-positive dentate gyrus neurons. Furthermore, chromatin immuno-precipitation (ChIP revealed a significantly increased association of phospho-acetylated histone H3 (H3K9ac-S10p with the gene promoters of c-Fos and Egr-1, but not Arc, after MWM exposure compared with controls. Surprisingly, however, we found very little difference between IEG responses (regarding both protein and mRNA in MWM-trained rats compared with matched swim controls. We conclude that exposure to the water maze evokes ERK MAPK activation, distinct epigenetic changes and IEG induction predominantly in sparse dentate gyrus neurons. It appears, however, that a specific role for IEGs in the learning aspect of MWM training may become apparent in downstream AP-1- and Egr-1-regulated (second wave genes and Arc-dependent effector

  8. PWZ-029, AN INVERSE AGONIST SELECTIVE FOR α5 GABAA RECEPTORS, IMPROVES OBJECT RECOGNITION, BUT NOT WATER-MAZE MEMORY IN NORMAL AND SCOPOLAMINE-TREATED RATS

    Science.gov (United States)

    Milić, Marija; Timić, Tamara; Joksimović, Srd̄an; Biawat, Poonam; Rallapalli, Sundari; Divljaković, Jovana; Radulović, Tamara; Cook, James M.; Savić, Miroslav M.

    2013-01-01

    Inverse agonism at the benzodiazepine site of α5 subunit-containing GABAA receptors is an attractive approach for the development of putative cognition-enhancing compounds, which are still far from clinical application. Several ligands with binding and/or functional selectivity for α5 GABAA receptors have been synthesized and tested in a few animal models. PWZ-029 is an α5 GABAA selective inverse agonist whose memory enhancing effects were demonstrated in the passive avoidance task in rats and in Pavlovian fear conditioning in mice. In the present study we investigated the effects of PWZ-029 administration in novel object recognition test and Morris water maze, in normal and scopolamine-treated rats. All the three doses of PWZ-029 (2, 5 and 10 mg/kg) improved object recognition after the 24-h delay period, as shown by significant differences between the exploration times of the novel and old object, and the respective discrimination indices. PWZ-029 (2 mg/kg) also successfully reversed the 0.3 mg/kg scopolamine-induced deficit in recognition memory after the 1-h delay. In the Morris water maze test, PWZ-029 (5, 10 and 15 mg/kg) did not significantly influence swim patterns, either during five acquisition days or during the treatment-free probe trial. PWZ-029 (2, 5 and 10 mg/kg) also proved to be ineffective in the reversal of the 1 mg/kg scopolamine-induced memory impairment in the water maze. The present mixed results encourage use of a variety of tests and experimental conditions in order to increase the predictability of preclinical testing of selective α5 GABAA inverse agonists. PMID:23261875

  9. PWZ-029, an inverse agonist selective for α₅ GABAA receptors, improves object recognition, but not water-maze memory in normal and scopolamine-treated rats.

    Science.gov (United States)

    Milić, Marija; Timić, Tamara; Joksimović, Srđan; Biawat, Poonam; Rallapalli, Sundari; Divljaković, Jovana; Radulović, Tamara; Cook, James M; Savić, Miroslav M

    2013-03-15

    Inverse agonism at the benzodiazepine site of α(5) subunit-containing GABA(A) receptors is an attractive approach for the development of putative cognition-enhancing compounds, which are still far from clinical application. Several ligands with binding and/or functional selectivity for α(5) GABA(A) receptors have been synthesized and tested in a few animal models. PWZ-029 is an α(5) GABA(A) selective inverse agonist whose memory enhancing effects were demonstrated in the passive avoidance task in rats and in Pavlovian fear conditioning in mice. In the present study we investigated the effects of PWZ-029 administration in novel object recognition test and Morris water maze, in normal and scopolamine-treated rats. All the three doses of PWZ-029 (2, 5 and 10 mg/kg) improved object recognition after the 24-h delay period, as shown by significant differences between the exploration times of the novel and old object, and the respective discrimination indices. PWZ-029 (2 mg/kg) also successfully reversed the 0.3 mg/kg scopolamine-induced deficit in recognition memory after the 1-h delay. In the Morris water maze test, PWZ-029 (5, 10 and 15 mg/kg) did not significantly influence swim patterns, either during five acquisition days or during the treatment-free probe trial. PWZ-029 (2, 5 and 10 mg/kg) also proved to be ineffective in the reversal of the 1mg/kg scopolamine-induced memory impairment in the water maze. The present mixed results encourage use of a variety of tests and experimental conditions in order to increase the predictability of preclinical testing of selective α(5) GABA(A) inverse agonists. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Midazolam impairs acquisition and retrieval, but not consolidation of reference memory in the Morris water maze.

    Science.gov (United States)

    Timić, Tamara; Joksimović, Srđan; Milić, Marija; Divljaković, Jovana; Batinić, Bojan; Savić, Miroslav M

    2013-03-15

    Amnesia is one of the most discussed properties of the benzodiazepine class of drugs. The effects of benzodiazepines on human memory are usually anterograde, while changes in retrograde memory functions were seldom reported. Such inconsistent findings have prompted numerous animal studies investigating the influences of these positive modulators of inhibitory neurotransmission on different stages of memory. Among the benzodiazepines, memory effects of midazolam are of special interest due to its many and varied clinical applications. The present Morris water maze study in adult male Wistar rats was performed in three experiments in which midazolam was administered at doses of 0.5, 1 and 2 mg/kg intraperitoneally, before or immediately after each of five daily learning sessions, with two trials in a session, as well as before the probe test. Midazolam impaired acquisition and subsequent retention of spatial learning of the position of the hidden platform even at a pre-training dose of 0.5 mg/kg. This low dose was not associated with impairment of the procedural component of learning, manifested by increased time spent in the periphery of the pool. The lack of midazolam effect on consolidation has not been confounded by the observed below-chance performance of the control group since our additional experiment using diazepam also administered immediately after each of five learning sessions has revealed a similar pattern of results. Finally, midazolam administered before the probe test impaired retrieval of reference memory at all tested doses. Hence, induction of retrograde, besides anterograde amnesia should be kept in mind as a possibility when midazolam is used in clinical settings. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Molecular mechanisms for the destabilization and restabilization of reactivated spatial memory in the Morris water maze

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    Kim Ryang

    2011-02-01

    Full Text Available Abstract Background Memory retrieval is not a passive process. Recent studies have shown that reactivated memory is destabilized and then restabilized through gene expression-dependent reconsolidation. Molecular studies on the regulation of memory stability after retrieval have focused almost exclusively on fear memory, especially on the restabilization process of the reactivated fear memory. We previously showed that, similarly with fear memories, reactivated spatial memory undergoes reconsolidation in the Morris water maze. However, the underlying molecular mechanisms by which reactivated spatial memory is destabilized and restabilized remain poorly understood. In this study, we investigated the molecular mechanism that regulates the stability of the reactivated spatial memory. Results We first showed that pharmacological inactivation of the N-methyl-D-aspartate glutamate receptor (NMDAR in the hippocampus or genetic inhibition of cAMP-responsible element binding protein (CREB-mediated transcription disrupted reactivated spatial memory. Finally, we showed that pharmacological inhibition of cannabinoid receptor 1 (CB1 and L-type voltage gated calcium channels (LVGCCs in the hippocampus blocked the disruption of the reactivated spatial memory by the inhibition of protein synthesis. Conclusions Our findings indicated that the reactivated spatial memory is destabilized through the activation of CB1 and LVGCCs and then restabilized through the activation of NMDAR- and CREB-mediated transcription. We also suggest that the reactivated spatial memory undergoes destabilization and restabilization in the hippocampus, through similar molecular processes as those for reactivated contextual fear memories, which require CB1 and LVGCCs for destabilization and NMDAR and CREB for restabilization.

  12. Non-spatial pre-training in the water maze as a clinically relevant model for evaluating learning and memory in experimental TBI.

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    Wagner, Amy K; Brayer, Samuel W; Hurwitz, Max; Niyonkuru, Christian; Zou, Huichao; Failla, Michelle; Arenth, Patricia; Manole, Mioara D; Skidmore, Elizabeth; Thiels, Edda

    2013-11-01

    Explicit and implicit learning and memory networks exist where each network can facilitate or inhibit cognition. Clinical evidence suggests that implicit networks are relatively preserved after traumatic brain injury (TBI). Non-spatial pre-training (NSPT) in the Morris Water Maze (MWM) provides the necessary behavioral components to complete the task, while limiting the formation of spatial maps. Our study utilized NSPT in the MWM to assess implicit and explicit learning and memory system deficits in the controlled cortical impact (CCI) model of TBI. 76 adult male Sprague-Dawley rats were divided: CCI vs. sham surgery, NSPT vs. No-NSPT, and cued vs. non-cued groups. NSPT occurred for 4d prior to surgery (dynamic hidden platform location, extra-maze cues covered, static pool entry point). Acquisition (d14-18), Probe/Visible Platform (d19), and Reversal (d20-21) trials were conducted with or without extra-maze cues. Novel time allocation and search strategy selection metrics were utilized. Results indicated implicit and explicit learning/memory networks are distinguishable in the MWM. In the cued condition, NSPT reduced thigmotaxis, improved place learning, and largely eliminated the apparent injury-induced deficits typically observed between untrained CCI and sham rats. However, among NSPT groups, incorporation of cues into search strategy selection for CCI rats was relatively impaired compared to shams. Non-cued condition performance showed sham/NSPT and CCI/NSPT rats perform similarly, suggesting implicit memory networks are largely intact 2weeks after CCI. Place learning differences between CCI/NSPT and sham/NSPT rats more accurately reflect spatial deficits in our CCI model compared to untrained controls. These data suggest NSPT as a clinically relevant construct for evaluating potential neurorestorative and neuroprotective therapies. These findings also support development of non-spatial cognitive training paradigms for evaluating rehabilitation relevant

  13. Effect of a water-maze procedure on the redox mechanisms in brain parts of aged rats

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    Natalia Andreevna Krivova

    2015-03-01

    Full Text Available The Morris water maze (MWM is a tool for assessment of age-related cognitive deficits. In our work, MWM was used for appraisal of cognitive deficits in 11-month-old rats and investigation of the effect exerted by training in the Morris water maze on the redox mechanisms in rat brain parts. Young adult (3-month-old and aged (11-month-old male rats were trained in the water maze. Intact animals of the corresponding age were used as the reference groups. The level of pro- and antioxidant capacity in brain tissue homogenates was assessed using the chemiluminescence method.Cognitive deficits were found in 11-month-old rats: at the first day of training they showed only 30% of successful MWM trials. However, at the last training day the percentage of successful trials was equal for young adult and aged animals. This indicates that cognitive deficits in aged rats can be reversed by MWM training. Therewith, the MWM spatial learning procedure itself produces changes in different processes of redox homeostasis in 11-month-old and 3-month-old rats as compared to intact animals. Young adult rats showed a decrease in prooxidant capacity in all brain parts, while 11-month-old rats demonstrated an increase in antioxidant capacity in the olfactory bulb, pons + medulla oblongata and frontal lobe cortex. Hence, the MWM procedure activates the mechanisms that restrict the oxidative stress in brain parts. The obtained results may be an argument for further development of the animal training procedures aimed to activate the mechanisms responsible for age-related cognitive deficits. This may be useful not only for the development of training procedures applicable to human patients with age-related cognitive impairments, but also for their rehabilitation.

  14. Identifying the appropriate time for deep brain stimulation to achieve spatial memory improvement on the Morris water maze.

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    Jeong, Da Un; Lee, Jihyeon; Chang, Won Seok; Chang, Jin Woo

    2017-03-07

    The possibility of using deep brain stimulation (DBS) for memory enhancement has recently been reported, but the precise underlying mechanisms of its effects remain unknown. Our previous study suggested that spatial memory improvement by medial septum (MS)-DBS may be associated with cholinergic regulation and neurogenesis. However, the affected stage of memory could not be distinguished because the stimulation was delivered during the execution of all memory processes. Therefore, this study was performed to determine the stage of memory affected by MS-DBS. Rats were administered 192 IgG-saporin to lesion cholinergic neurons. Stimulation was delivered at different times in different groups of rats: 5 days before the Morris water maze test (pre-stimulation), 5 days during the training phase of the Morris water maze test (training-stimulation), and 2 h before the Morris water maze probe test (probe-stimulation). A fourth group of rats was lesioned but received no stimulation. These four groups were compared with a normal (control) group. The most effective memory restoration occurred in the pre-stimulation group. Moreover, the pre-stimulation group exhibited better recall of the platform position than the other stimulation groups. An increase in the level of brain derived neurotrophic factor (BDNF) was observed in the pre-stimulation group; this increase was maintained for 1 week. However, acetylcholinesterase activity in the pre-stimulation group was not significantly different from the lesion group. Memory impairment due to cholinergic denervation can be improved by DBS. The improvement is significantly correlated with the up-regulation of BDNF expression and neurogenesis. Based on the results of this study, the use of MS-DBS during the early stage of disease may restore spatial memory impairment.

  15. [Sleep deprivation effect upon spatial memory consolidation in rats after one-day learning in a Morris water maze].

    Science.gov (United States)

    Dorokhov, V B; Kozhedub, R G; Arsen'ev, G N; Kozhechkin, S N; Ukraintseva, Iu V; Kulikov, M A; Manolov, A I; Koval'zon, V M

    2011-01-01

    The effect of sleep deprivation by 'carousel' method on spatial memory consolidation in a Morris water maze was studied in Wistar male rats after one-day learning (in accordance to a protocol by Frick et al., 2000). It was found that after fast 3-hr learning the memory trace retains during 24-hr. Twenty four hour sleep deprivation followed learning impaired consolidation of spatial memory. So the rat model of a one-day learning is suitable for the studying of neurophysiological mechanisms of sleep deprivation effects on spatial memory consolidation.

  16. EFFECTS OF 5, 7-DIHYDROXYTRYPTAMINE-INDUCED DEPLETION OF BRAIN SEROTONIN ON RADIAL ARM-MAZE TASK IN RATS

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    Vasile Hefco

    2005-08-01

    Full Text Available Adult rats pretreated with desipramine (25 mg/kg i.p.30 min before anesthesia in order to protect noradrenergic system, were subjected to intracerebroventriculare injection of 5, 7 –dihydroxytryptamine (5, 7-DHT, 150 μg, 4.5 μl/ventricle, a chronic neurotoxin of the central serotonergic function. After 1.5 months later, we assessed the working memory and reference memory in radial 8 arm-mazes. Serotonergic depletion impaired more significantly shortterm memory tested by means of the average working memory errors, entries to repeat and average time taken to consume all five baits during 12 days training. Long-term memory, explored by means of reference memory errors, was less impaired. It is concluded that serotonin, among other neurotransmitters, play one important role in cognitive functions, including learning and memory.

  17. Interactive effects of ethanol and nicotine on learning, anxiety, and locomotion in C57BL/6 mice in the plus-maze discriminative avoidance task.

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    Gulick, Danielle; Gould, Thomas J

    2009-09-01

    Alcohol and nicotine both alter learning, locomotion, and anxiety, yet no study has directly examined the interactive effects of these drugs across these behaviors within subjects. Such a comparison would determine if the drugs produce independent effects on each behavior. The plus-maze discriminative avoidance task (PMDAT) allows within-subject measurement of these behaviors. For training, each mouse explored the elevated plus-maze for 5 min and each time a mouse entered the aversive enclosed arm, a light and white noise were turned on. For testing, each mouse was returned to the center of the maze and, for 3 min, the time in each arm or in the center area was recorded. No cues were turned on during testing. The effects of ethanol (0.6-2.6 g/kg 15 min before training) and nicotine (0.045-0.18 mg/kg 5 min before training), alone or in combination, on behavior were examined. Ethanol dose-dependently decreased anxiety, increased locomotion, and decreased learning but different doses altered each behavior. Nicotine dose-dependently increased anxiety and locomotion and decreased learning but different doses altered each behavior. Nicotine (0.09 mg/kg) reversed ethanol-associated changes in learning (1.0 and 1.4 g/kg), locomotion (1.4 g/kg), and anxiety (1.4 g/kg). The effects of nicotine or ethanol on learning occurred at different doses than those that altered anxiety or locomotion, suggesting that the drug effects on learning are independent of the effects on anxiety and locomotion. With combined administration, nicotine reduced ethanol-associated deficits in learning and changes in anxiety and locomotion.

  18. Crocin improves spatial learning and memory deficits in the Morris water maze via attenuating cortical oxidative damage in diabetic rats.

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    Ahmadi, M; Rajaei, Z; Hadjzadeh, M A; Nemati, H; Hosseini, M

    2017-03-06

    The purpose of the current study was to examine the influence of crocin on improving spatial memory deficits and cerebral oxidative damage in streptozotocin-induced diabetic rats. Crocin was administered intraperitoneally daily at doses of 15, 30 and 60mg/kg for 6 weeks. Spatial memory performance was measured in rats by the Morris water maze paradigm. Lipid peroxidation and total thiol levels as parameters of oxidative stress were assessed in the cerebral cortex at the end of week 6. Diabetic rats showed spatial learning and memory deficits in the Morris water maze which was accompanied by increased lipid peroxidation levels in the cerebral cortex. By contrast, chronic treatment with crocin (15, 30 and 60mg/kg, ip, 6 weeks) improved cognitive performance and lowered hyperglycaemia and oxidative stress in diabetic rats. In conclusion, the results suggest that beneficial effects of crocin on streptozotocin-induced memory dysfunction may be attributed to its antidiabetic and antioxidant activity, which could find clinical use in treating cognitive dysfunction in diabetics. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Curcuma comosa improves learning and memory function on ovariectomized rats in a long-term Morris water maze test

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    Su, Jian; Sripanidkulchai, Kittisak; Wyss, J. Michael; Sripanidkulchai, Bungorn

    2010-01-01

    Aim of the study Curcuma comosa extract and some purified compounds from this plant have been reported to have estrogenic-like effects, and estrogen improves learning in some animals and potentially in postmenopausal women; therefore, this study tested the hypothesis that Curcuma comosa and estrogen have similar beneficial effects on spatial learning and memory. Materials and methods Curcuma comosa hexane extract, containing 0.165 mg of (4E,6E)-1,7-diphenylhepta-4,6-dien-3-one per mg of the crude extract, was orally administered to ovariectomized Wistar rats at the doses of 250 or 500 mg/kg body weight. 17β-estradiol (10 μg/kg body weight, subcutaneously) was used as a positive control. Thirty days after the initiation of treatment, animals were tested in a Morris water maze for spatial learning and memory. They were re-tested every 30 days and a final probe trial was run on day 119. Results Compared to control rats, OVX rats displayed significant memory impairment for locating the platform in the water maze from day 67 after the surgery, onward. In contrast, OVX rats treated with either Curcuma comosa or estrogen were significantly protected from this decline in cognitive function. Further, the protection of cognitive effects by Curcuma comosa was larger at higher dose. Conclusions These results suggest that long-term treatment with Curcuma comosa has beneficial effects on learning and memory function in rats. PMID:20420894

  20. Search strategy selection in the Morris water maze indicates allocentric map formation during learning that underpins spatial memory formation.

    Science.gov (United States)

    Rogers, Jake; Churilov, Leonid; Hannan, Anthony J; Renoir, Thibault

    2017-03-01

    Using a Matlab classification algorithm, we demonstrate that a highly salient distal cue array is required for significantly increased likelihoods of spatial search strategy selection during Morris water maze spatial learning. We hypothesized that increased spatial search strategy selection during spatial learning would be the key measure demonstrating the formation of an allocentric map to the escape location. Spatial memory, as indicated by quadrant preference for the area of the pool formally containing the hidden platform, was assessed as the main measure that this allocentric map had formed during spatial learning. Our C57BL/6J wild-type (WT) mice exhibit quadrant preference in the highly salient cue paradigm but not the low, corresponding with a 120% increase in the odds of a spatial search strategy selection during learning. In contrast, quadrant preference remains absent in serotonin 1A receptor (5-HT 1A R) knockout (KO) mice, who exhibit impaired search strategy selection during spatial learning. Additionally, we also aimed to assess the impact of the quality of the distal cue array on the spatial learning curves of both latency to platform and path length using mixed-effect regression models and found no significant associations or interactions. In contrast, we demonstrated that the spatial learning curve for search strategy selection was absent during training in the low saliency paradigm. Therefore, we propose that allocentric search strategy selection during spatial learning is the learning parameter in mice that robustly indicates the formation of a cognitive map for the escape goal location. These results also suggest that both latency to platform and path length spatial learning curves do not discriminate between allocentric and egocentric spatial learning and do not reliably predict spatial memory formation. We also show that spatial memory, as indicated by the absolute time in the quadrant formerly containing the hidden platform alone (without

  1. Chronic prenatal caffeine exposure impairs novel object recognition and radial arm maze behaviors in adult rats.

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    Soellner, Deborah E; Grandys, Theresa; Nuñez, Joseph L

    2009-12-14

    In this report, we demonstrate that chronic prenatal exposure to a moderate dose of caffeine disrupts novel object recognition and radial arm maze behaviors in adult male and female rats. Pregnant dams were administered either tap water or 75 mg/L caffeinated tap water throughout gestation. Oral self-administration in the drinking water led to an approximate maternal intake of 10mg/kg/day, equivalent to 2-3 cups of coffee/day in humans based on a metabolic body weight conversion. In adulthood, the offspring underwent testing on novel object recognition, radial arm maze, and Morris water maze tasks. Prenatal caffeine exposure was found to impair 24-h memory retention in the novel object recognition task and impair both working and reference memory in the radial arm maze. However, prenatal caffeine exposure did not alter Morris water maze performance in either a simple water maze procedure or in an advanced water maze procedure that included reversal and working memory paradigms. These findings demonstrate that chronic oral intake of caffeine throughout gestation can alter adult cognitive behaviors in rats.

  2. Sex Differences in a Human Analogue of the Radial Arm Maze: The ''17-Box Maze Test''

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    Rahman, Q.; Abrahams, S.; Jussab, F.

    2005-01-01

    This study investigated sex differences in spatial memory using a human analogue of the Radial Arm Maze: a revision on the Nine Box Maze originally developed by Abrahams, Pickering, Polkey, and Morris (1997) called the 17-Box Maze Test herein. The task encourages allocentric spatial processing, dissociates object from spatial memory, and…

  3. Hippocampal-dependent spatial memory in the water maze is preserved in an experimental model of temporal lobe epilepsy in rats.

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    Marion Inostroza

    Full Text Available Cognitive impairment is a major concern in temporal lobe epilepsy (TLE. While different experimental models have been used to characterize TLE-related cognitive deficits, little is known on whether a particular deficit is more associated with the underlying brain injuries than with the epileptic condition per se. Here, we look at the relationship between the pattern of brain damage and spatial memory deficits in two chronic models of TLE (lithium-pilocarpine, LIP and kainic acid, KA from two different rat strains (Wistar and Sprague-Dawley using the Morris water maze and the elevated plus maze in combination with MRI imaging and post-morten neuronal immunostaining. We found fundamental differences between LIP- and KA-treated epileptic rats regarding spatial memory deficits and anxiety. LIP-treated animals from both strains showed significant impairment in the acquisition and retention of spatial memory, and were unable to learn a cued version of the task. In contrast, KA-treated rats were differently affected. Sprague-Dawley KA-treated rats learned less efficiently than Wistar KA-treated animals, which performed similar to control rats in the acquisition and in a probe trial testing for spatial memory. Different anxiety levels and the extension of brain lesions affecting the hippocampus and the amydgala concur with spatial memory deficits observed in epileptic rats. Hence, our results suggest that hippocampal-dependent spatial memory is not necessarily affected in TLE and that comorbidity between spatial deficits and anxiety is more related with the underlying brain lesions than with the epileptic condition per se.

  4. Hippocampal proteoglycans brevican and versican are linked to spatial memory of Sprague-Dawley rats in the morris water maze.

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    Saroja, Sivaprakasam R; Sase, Ajinkya; Kircher, Susanne G; Wan, Jia; Berger, Johannes; Höger, Harald; Pollak, Arnold; Lubec, Gert

    2014-09-01

    Proteoglycans (PGs) are major constituents of the extracellular matrix and have recently been proposed to contribute to synaptic plasticity. Hippocampal PGs have not yet been studied or linked to memory. The aim of the study, therefore, was to isolate and characterize rat hippocampal PGs and determine their possible role in spatial memory. PGs were extracted from rat hippocampi by anion-exchange chromatography and analyzed by nano LC-MS/MS. Twenty male Sprague-Dawley rats were tested in the morris water maze. PGs agrin, amyloid beta A4 protein, brevican, glypican-1, neurocan, phosphacan, syndecan-4, and versican were identified in the hippocampi. Brevican and versican levels in the membrane fraction were higher in the trained group, correlating with the time spent in the target quadrant. α-amino-3-hydroxy-5-methylisoxazole-4-propionate receptor GluR1 was co-precipitated with brevican and versican. Levels for a receptor complex containing GluR1 was higher in trained while GluR2 and GluR3-containing complex levels were higher in yoked rats. The findings provide information about the PGs present in the rat hippocampus, demonstrating that versican and brevican are linked to memory retrieval in the morris water maze and that PGs interact with α-amino-3-hydroxy-5-methylisoxazole-4-propionate receptor GluR1, which is linked to memory retrieval. Proteoglycans (PGs) are major constituents of the extracellular matrix of the brain and were proposed to contribute to synaptic plasticity. This report addressed PGs in rat hippocampus and suggests that PGs brevican and versican are linked to spatial memory, and form a complex with the GluR1 subunit of the AMPA receptor, a key signaling molecule in memory mechanisms. © 2014 International Society for Neurochemistry.

  5. Early-life exposure to noise reduces mPFC astrocyte numbers and T-maze alternation/discrimination task performance in adult male rats

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    Yaveth Ruvalcaba-Delgadillo

    2015-01-01

    Full Text Available In this experiment, we evaluated the long-term effects of noise by assessing both astrocyte changes in medial prefrontal cortex (mPFC and mPFC-related alternation/discrimination tasks. Twenty-one-day-old male rats were exposed during a period of 15 days to a standardized rats′ audiogram-fitted adaptation of a human noisy environment. We measured serum corticosterone (CORT levels at the end of the exposure and periodically registered body weight gain. In order to evaluate the long-term effects of this exposure, we assessed the rats′ performance on the T-maze apparatus 3 months later. Astrocyte numbers and proliferative changes in mPFC were also evaluated at this stage. We found that environmental noise (EN exposure significantly increased serum CORT levels and negatively affected the body weight gain curve. Accordingly, enduring effects of noise were demonstrated on mPFC. The ability to solve alternation/discrimination tasks was reduced, as well as the number of astroglial cells. We also found reduced cytogenesis among the mPFC areas evaluated. Our results support the idea that early exposure to environmental stressors may have long-lasting consequences affecting complex cognitive processes. These results also suggest that glial changes may become an important element behind the cognitive and morphological alterations accompanying the PFC changes seen in some stress-related pathologies.

  6. The beneficial effects of olibanum on memory deficit induced by hypothyroidism in adult rats tested in Morris water maze.

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    Hosseini, Mahmoud; Hadjzadeh, Mosa Al-Reza; Derakhshan, Mohammad; Havakhah, Shahrzad; Rassouli, Fatemeh Behnam; Rakhshandeh, Hassan; Saffarzadeh, Fatema

    2010-03-01

    Functional consequences of hypothyroidism include impaired learning and memory and inability to produce long-term potentiation (LTP) in hippocampus. Olibanum has been used for variety of therapeutic purposes. In traditional medicine, oilbanum is used to enhance learning and memory. In the present study the effect of olibanum on memory deficit in hypothyroid rats was investigated. Male wistar rats were divided into four groups and treated for 180 days. Group 1 received tap drinking water while in group 2, 0.03% methimazol was added to drinking water. Group 3 and 4 were treated with 0.03% methimazole as well as 100 and 500 mg/kg olibanum respectively. The animals were tested in Morris water maze. The swimming speed was significantly lower and the distance and time latency were higher in group 2 compared with group 1. In groups 3 and 4 the swimming speed was significantly higher while, the length of the swim path and time latency were significantly lower in comparison with group 2. It is concluded that methimazole-induced hypothyroidism impairs learning and memory in adult rats which could be prevented by using olibanum.

  7. The flexible use of multiple cue relationships in spatial navigation : A comparison of water maze performance following hippocampal, medial septal, prefrontal cortex, or posterior parietal cortex lesions

    NARCIS (Netherlands)

    Compton, DM; Griffith, HR; McDaniel, WF; Foster, RA; Davis, BK

    Rats prepared with lesions of the prefrontal cortex, posterior parietal cortex, hippocampus, or medial septal area were tested for acquisition of a number of variations of the open-field water maze using a version of place learning assessment described by Eichenbaum, Stewart, and Morris (1991).

  8. Spatial and Reversal Learning in the Morris Water Maze Are Largely Resistant to Six Hours of REM Sleep Deprivation Following Training

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    Walsh, Christine M.; Booth, Victoria; Poe, Gina R.

    2011-01-01

    This first test of the role of REM (rapid eye movement) sleep in reversal spatial learning is also the first attempt to replicate a much cited pair of papers reporting that REM sleep deprivation impairs the consolidation of initial spatial learning in the Morris water maze. We hypothesized that REM sleep deprivation following training would impair…

  9. Bidirectional changes in water-maze learning following recombinant adenovirus-associated viral vector (rAAV)-mediated brain-derived neurotrophic factor expression in the rat hippocampus.

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    Pietropaolo, Susanna; Paterna, Jean-Charles; Büeler, Hansruedi; Feldon, Joram; Yee, Benjamin K

    2007-09-01

    Alterations in hippocampal brain-derived neurotrophic factor (BDNF) expression have been implicated in the pathogenesis of emotional and cognitive dysfunction. Here, we induced BDNF overexpression in the rat hippocampus using recombinant adenovirus-associated viral (rAAV) vectors, and studied its long-term (2 months postinduction) effects on anxiety-related behaviour, exploration in the open field, and spatial learning in the water maze. Although the treatment successfully led to substantial elevation of hippocampal BDNF levels, its effect on spatial learning was bidirectional: a subset of rAAV-induced BDNF-overexpressing rats performed well above control level, whereas the rest were clearly impaired. This behavioural distinction corresponded to two markedly different levels of BDNF overexpression. The increase in dorsal hippocampal BDNF content achieved in the 'water-maze-impaired' subgroup was twice that attained in the 'water-maze-improved' rats. Although neither subgroup of rAAV-induced BDNF-overexpressing rats differed from controls in the open field, the 'water-maze-impaired' subgroup also showed a significant anxiolytic effect. Our results suggest that hippocampal BDNF elevation significantly affects cognitive and emotional behaviours, but the direction and magnitude of the effects critically depend on the precise levels of overexpression. This factor must be taken into account in future studies examining the functional consequences of hippocampal BDNF overexpression.

  10. Mouse genetic differences in voluntary wheel running, adult hippocampal neurogenesis and learning on the multi-strain-adapted plus water maze.

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    Merritt, Jennifer R; Rhodes, Justin S

    2015-03-01

    Moderate levels of aerobic exercise broadly enhance cognition throughout the lifespan. One hypothesized contributing mechanism is increased adult hippocampal neurogenesis. Recently, we measured the effects of voluntary wheel running on adult hippocampal neurogenesis in 12 different mouse strains, and found increased neurogenesis in all strains, ranging from 2- to 5-fold depending on the strain. The purpose of this study was to determine the extent to which increased neurogenesis from wheel running is associated with enhanced performance on the water maze for 5 of the 12 strains, chosen based on their levels of neurogenesis observed in the previous study (C57BL/6 J, 129S1/SvImJ, B6129SF1/J, DBA/2 J, and B6D2F1/J). Mice were housed with or without a running wheels for 30 days then tested for learning and memory on the plus water maze, adapted for multiple strains, and rotarod test of motor performance. The first 10 days, animals were injected with BrdU to label dividing cells. After behavioral testing animals were euthanized to measure adult hippocampal neurogenesis using standard methods. Levels of neurogenesis depended on strain but all mice had a similar increase in neurogenesis in response to exercise. All mice acquired the water maze but performance depended on strain. Exercise improved water maze performance in all strains to a similar degree. Rotarod performance depended on strain. Exercise improved rotarod performance only in DBA/2 J and B6D2F1/J mice. Taken together, results demonstrate that despite different levels of neurogenesis, memory performance and motor coordination in these mouse strains, all strains have the capacity to increase neurogenesis and improve learning on the water maze through voluntary wheel running. Published by Elsevier B.V.

  11. Effects of NOS inhibitors on the benzodiazepines-induced memory impairment of mice in the modified elevated plus-maze task.

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    Orzelska, Jolanta; Talarek, Sylwia; Listos, Joanna; Fidecka, Sylwia

    2013-05-01

    The aim of the present study was to examine the effects of nitric oxide synthase (NOS) inhibitors on responses, elicited by benzodiazepines (BZs) in a modified elevated plus-maze task in mice. It was shown that acute doses of diazepam (DZ; 1 and 2 mg/kg) and flunitrazepam (FNZ; 0.05, 0.1 and 0.2 mg/kg) significantly increased the time of transfer latency (TL2) in a retention trial, thus confirming memory impairing effects of BZs. l-NAME (N(G)-nitro-l-arginine methyl ester; 200 mg/kg), a non-selective inhibitor of NOS, and 7-NI (7-nitroindazole; 40 mg/kg), a selective inhibitor of NOS, further intensified DZ-induced memory impairment. On the other hand, L-NAME (50, 100 and 200 mg/kg) and 7-NI (10, 20 and 40 mg/kg) prevented FNZ-induced memory compromising process. The results of this study indicated that suppressed NO synthesis enhanced DZ-induced but prevented FNZ-induced memory impairment. Taken together, these findings could suggest NO involvement in BZs-induced impairment of memory processes. The precise mechanism of these controversial effects, however, remains elusive. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Interactive effects of a protein kinase AII inhibitor and testosterone on spatial learning in the Morris water maze.

    Science.gov (United States)

    Khorshidahmad, Tina; Tabrizian, Kaveh; Vakilzadeh, Gelareh; Nikbin, Parmida; Moradi, Shahla; Hosseini-Sharifabad, Ali; Roghani, Ali; Naghdi, Nasser; Sharifzadeh, Mohammad

    2012-03-17

    Neurohormones such as testosterone (TE) are important in modulation of learning and memory. In the present study, we investigated the interactive effects of pre-training bilateral intra-hippocampal infusions of testosterone and H-89, a selective PKAII inhibitor, on spatial acquisition in the Morris water maze (MWM). Different doses of TE (20, 40 and 80 μg/side) and H-89 (5 and 10 μM/side) were administered 30 min before start of the training each day. Control animals received bilateral intra-hippocampal infusions of DMSO as vehicle for TE and H-89. Animals were trained for 4 days and each day included one block of four trials. The results of this study showed that bilateral infusion of TE (40 and 80 μg/side) or H-89 (10 μM/side) impaired spatial learning as indicated by significant increases in escape latency and traveled distance compared to the control group. Although pre-training bilateral infusions of a low concentration of either TE (20 μg/side) or H-89 (5 μM/side) into the CA1 region of the hippocampus did not affect learning capabilities, but the combination of the low doses of the drugs led to significant deficits in spatial acquisition. Overall, our data suggest that spatial acquisition was affected by PKAII inhibition or TE administration. Moreover, when co-administered, these drugs had a negative synergistic impact on acquisition. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Effects of ventral pallidal D1 dopamine receptor activation on memory consolidation in morris water maze test.

    Science.gov (United States)

    Péczely, László; Ollmann, Tamás; László, Kristóf; Kovács, Anita; Gálosi, Rita; Szabó, Adám; Karádi, Zoltán; Lénárd, László

    2014-11-01

    In the present experiments, in adult male Wistar rats, the effect of microinjection of the D1 dopamine receptor agonist SKF38393 into the ventral pallidum on memory consolidation, as well as on resistance of the resulting memory trace against extinction were investigated in Morris water maze test. SKF38393 was applied in three doses (0.1, 1.0 or 5.0μg in 0.4μl physiological saline, respectively). To clarify whether the effect of the agonist was specific, in a separate group of animals, the D1 dopamine receptor antagonist SCH23390 (5.0μg in 0.4μl physiological saline) was administered 15min prior to 1.0μg agonist treatment. In another group of animals, the same dose of antagonist was applied by itself. The two lower doses (0.1 and 1.0μg) of the agonist accelerated memory consolidation relative to controls and increased the stability of the consolidated memory trace against extinction. Antagonist pretreatment eliminated the effects of the agonist, thus confirming that the effect was selectively specific to D1 dopamine receptors. Our findings indicate that the ventral pallidal D1 dopamine receptors are intimately involved in the control of the consolidation processes of spatial memory. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. A working memory "theory of relativity": elasticity in temporal, spatial, and modality dimensions conserves item capacity in radial maze, verbal tasks, and other cognition.

    Science.gov (United States)

    Glassman, R B

    1999-03-15

    It is remarkable that working memory (WM) capacity for numbers of items remains modest, at approximately 7+/-2 (the so-called "magical number"), across a wide variety of kinds of material. Indeed, consideration of radial maze studies together with more traditional memory research shows that WM capacity remains fairly constant whether the items are verbal or visuospatial, and that this same capacity is true of other species as of humans. In contrast to their limited numerousness, WM items are extremely flexible in ways that are here brought under the heading of "dimensionality." Therefore, the physical items represented in WM, can vary widely in any quantitative characteristic and in the temporal pace at which they are encountered. Combinatorial considerations suggest that WM numerousness results from evolution of a middle ground between a sterile parsimony and an overwhelming excess, for organizing neurocognitive associations. Such natural selection seems likely to have worked opportunistically to yield diverse characteristics of neuronal tissue, from subcellular components to properties of ensembles, which converge on the required cognitive properties of WM. Priming and implicit memory may play supporting roles with WM. These intermediate-term memory phenomena allow certain kinds of background information to be accumulated at higher volume than seems possible from the textbook, "modal model" of memory. By expediting attentional focus on subsets of information already in long-term memory, priming may help WM chunks to emerge in limited number as appropriately scaled "figures" from the primed "ground." The larger neuronal dynamic patterns that embody these cognitive phenomena must regulate their microscopic component systems, automatically selecting those having parameters of temporal persistence, rhythm, and connectivity patterns that are pertinent to the current task. Relevant neural phenomena may include "Hebbian" associativity and persistence of firing patterns

  15. Stable, Long-Term, Spatial Memory in Young and Aged Rats Achieved with a One Day Morris Water Maze Training Protocol

    Science.gov (United States)

    Barrientos, Ruth M.; Kitt, Meagan M.; D'Angelo, Heather M.; Watkins, Linda R.; Rudy, Jerry W.; Maier, Steven F.

    2016-01-01

    Here, we present data demonstrating that a 1 d Morris water maze training protocol is effective at producing stable, long-term spatial memory in both young (3 mo old) and aged (24 mo old) F344xBN rats. Four trials in each of four sessions separated by a 2.5 h ISI produced robust selective search for the platform 1 and 4 d after training, in both…

  16. Lego Mindstorm Maze Runner

    OpenAIRE

    Drakonakis, Konstantinos; Mentzelopoulos, Panagiotis

    2014-01-01

    This project describes a method for solving mazes using a path finding algorithm, specifically DFS. Its input consists of the NXT lego robot along with a color sensor and a colored ball, the constructed maze and a text (.txt) file that describes the structure of the maze. Subsequently, the output of our program in order of execution is the identification of the provided colored ball, the calculation of the maze's solution (path) and the actual movement of the robot through the maze carrying t...

  17. Comparative studies using the Morris water maze to assess spatial memory deficits in two transgenic mouse models of Alzheimer's disease.

    Science.gov (United States)

    Edwards, Stephen R; Hamlin, Adam S; Marks, Nicola; Coulson, Elizabeth J; Smith, Maree T

    2014-10-01

    Evaluation of the efficacy of novel therapeutics for potential treatment of Alzheimer's disease (AD) requires an animal model that develops age-related cognitive deficits reproducibly between independent groups of investigators. Herein we assessed comparative temporal changes in spatial memory function in two commercially available transgenic mouse models of AD using the Morris water maze (MWM), incorporating both visible and hidden platform training. Individual cohorts of cDNA-based 'line 85'-derived double-transgenic mice coexpressing the 'Swedish' mutation of amyloid precursor protein (APPSwe) and the presenillin 1 (PS1) 'dE9' mutation were assessed in the MWM at mean ages of 3.6, 9.3 and 14.8 months. We found significant deficits in spatial memory retention in APPSwe/PS1dE9 mice aged 3.6 months and robust deficits in spatial memory acquisition and retention in APPSwe/PS1dE9 mice aged 9.3 months, with a further significant decline by age 14.8 months. β-Amyloid deposits were present in brain sections by 7.25 months of age. In contrast, MWM studies with individual cohorts (aged 4-21 months) of single-transgenic genomic-based APPSwe mice expressing APPSwe on a yeast artificial chromosomal (YAC) construct showed no significant deficits in spatial memory acquisition until 21 months of age. There were no significant deficits in spatial memory retention up to 21 months of age and β-amyloid deposits were not present in brain sections up to 24 months of age. These data, generated using comprehensive study designs, show that APPSwe/PS1dE9 but not APPSwe YAC mice appear to provide a suitably robust model of AD for efficacy assessment of novel AD treatments in development. © 2014 Wiley Publishing Asia Pty Ltd.

  18. Levodopa improves learning and memory ability on global cerebral ischemia-reperfusion injured rats in the Morris water maze test.

    Science.gov (United States)

    Wang, Wenzhu; Liu, Lixu; Jiang, Peng; Chen, Chen; Zhang, Tong

    2017-01-01

    Previous studies have shown that levodopa (L-dopa) for 1-7days improved the consciousness level of certain patients who suffered from ischemia-reperfusion injury and were comatose for a long time period after cerebral resuscitation treatment. It also has an awakening effect on patients with disorders of consciousness. This study aimed to investigate whether L-dopa, which is used clinically to treat Parkinson's disease, might also ameliorate the behavior of rats following global cerebral ischemia-reperfusion injury. Fifty-six healthy adult male Sprague-Dawley rats were randomly divided into four groups: shamoperated, global cerebral ischemia mode, 25mg/kg/d L-dopa intervention, and 50mg/kg/d L-dopa intervention. The level of consciousness and modified neurological severity score (NSS) of the rats in each group were measured before reperfusion and 6, 24, and 72h and 1-4 weeks after reperfusion. The Morris water maze test was used to assess behavior of rats 1 week after reperfusion and 2 weeks after reperfusion in each group. The results showed that after global cerebral ischemiareperfusion injury, neurological deficits of rats are severe, and space exploration capacity and learning and memory capacity are significantly decreased. L-dopa can shorten the duration of coma in rats following global cerebral ischemia-reperfusion injury and improve the symptoms of neurological deficits and advanced learning and memory. In the range of the selected doses, the relationship between L-dopa and improvement of the neurological behavior in rats was not dose-dependent. Dopamine may be useful for treating severe ischemia-reperfusion brain injury. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  19. Early protein malnutrition changes learning and memory in spaced but not in condensed trials in the Morris water-maze.

    Science.gov (United States)

    Valadares, Camila Tavares; de Sousa Almeida, Sebastião

    2005-02-01

    Early protein malnutrition induces structural, neurochemical and functional changes in the central nervous system leading to alterations in cognitive and behavioral development of rats. The aim of the present study was to investigate the effects of protein malnutrition during lactation on acquisition and retention of spatial information using different training procedures (spaced x condensed trials). Rats treated with 16% (well-nourished) or 6% (malnourished) protein diets during the lactation phase and nutritionally recovered until 70 days of age were tested in the Morris water-maze in procedures of 1 trial/day (spaced trials), 4, 8, 12 trials/day (intermediate density) and 24 trials/day (condensed trials), completing 24 trials at the end of training. Seven and 28 days after the training the animals were tested again in just one trial to assess long-term memory. The results showed that protein malnutrition caused deficits on the spatial learning and memory in spaced but not in intermediate and condensed trials procedure. Seven and 28 days after the training there was an increase in the latency to find the platform but only malnourished animals submitted to 1 trial/day had significantly higher latency as compared with well-nourished controls. One of the possible hypotheses is that the effect protein malnutrition only in the procedure of spaced trials could be due to deficits in memory consolidation. It is suggested that these deficits can be the result of alterations produced by protein malnutrition in the hippocampal formation or in long-lasting emotional and/or motivational aspects of the rat's behavior.

  20. Divergence in Morris Water Maze-Based Cognitive Performance under Chronic Stress Is Associated with the Hippocampal Whole Transcriptomic Modification in Mice

    Science.gov (United States)

    Jung, Seung H.; Brownlow, Milene L.; Pellegrini, Matteo; Jankord, Ryan

    2017-01-01

    Individual susceptibility determines the magnitude of stress effects on cognitive function. The hippocampus, a brain region of memory consolidation, is vulnerable to stressful environments, and the impact of stress on hippocampus may determine individual variability in cognitive performance. Therefore, the purpose of this study was to define the relationship between the divergence in spatial memory performance under chronically unpredictable stress and an associated transcriptomic alternation in hippocampus, the brain region of spatial memory consolidation. Multiple strains of BXD (B6 × D2) recombinant inbred mice went through a 4-week chronic variable stress (CVS) paradigm, and the Morris water maze (MWM) test was conducted during the last week of CVS to assess hippocampal-dependent spatial memory performance and grouped animals into low and high performing groups based on the cognitive performance. Using hippocampal whole transcriptome RNA-sequencing data, differential expression, PANTHER analysis, WGCNA, Ingenuity's upstream regulator analysis in the Ingenuity Pathway Analysis® and phenotype association analysis were conducted. Our data identified multiple genes and pathways that were significantly associated with chronic stress-associated cognitive modification and the divergence in hippocampal dependent memory performance under chronic stress. Biological pathways associated with memory performance following chronic stress included metabolism, neurotransmitter and receptor regulation, immune response and cellular process. The Ingenuity's upstream regulator analysis identified 247 upstream transcriptional regulators from 16 different molecule types. Transcripts predictive of cognitive performance under high stress included genes that are associated with a high occurrence of Alzheimer's and cognitive impairments (e.g., Ncl, Eno1, Scn9a, Slc19a3, Ncstn, Fos, Eif4h, Copa, etc.). Our results show that the variable effects of chronic stress on the hippocampal

  1. Effects of training in the Morris water maze on the spatial learning acquisition and VAChT expression in male rats

    Directory of Open Access Journals (Sweden)

    N Naghdi

    2011-05-01

    Full Text Available "n  "n  Background and the purpose of the study: It has been well established that cholinergic pathway plays an important role in learning and memory processes. The present study was designed to evaluate the effects of Morris water maze (MWM training on spatial memory acquisition and expression of the vesicular acetylcholine transporter (VAChT in male rats. "n  Methods: In this study, training trials of all groups of animals were conducted in the MWM task. Rats received one training session consisting of four trials per day which continued for another four consecutive days. Controls received visible platform MWM training. The escape latency, the traveled distance and swimming speed for each rat were recorded and used to evaluate the performance of the animal during training period. For evaluation of expression of VAChT protein levels, brain tissues from animals in each experiment were obtained immediately after the last trial on the related experimental day and processed for immunohistochemistry staining and western blotting analysis. "n  Results: There was a significant difference between animals subjected to one day training and those receiving four days of training in escape latency and travel distance. There were an apparent increase in VAChT immunoreactivity in the medial septal area (MSA and CA1 region of the hippocampus in one day and four day trained animals compared with controls (visible group. Quantitative immunostaining analysis by optical density measurements in the CA1 region and evaluation of immunopositive neurons in medial septal area of brain sections confirmed qualitative findings. Assessment of VAChT protein level expression in hippocampus by western blotting evaluation showed the same pattern of immunohistochemistry results. "n  Conclusion: Overall, results of this study reveal changes in cholinergic neuron activity in different stages of training in the MWM task. Data suggest that there is a significant level of

  2. Electric Current Solves Mazes

    Science.gov (United States)

    Ayrinhac, Simon

    2014-01-01

    We present in this work a demonstration of the maze-solving problem with electricity. Electric current flowing in a maze as a printed circuit produces Joule heating and the right way is instantaneously revealed with infrared thermal imaging. The basic properties of electric current can be discussed in this context, with this challenging question:…

  3. The Double-H Maze: A Robust Behavioral Test for Learning and Memory in Rodents.

    Science.gov (United States)

    Kirch, Robert D; Pinnell, Richard C; Hofmann, Ulrich G; Cassel, Jean-Christophe

    2015-07-08

    Spatial cognition research in rodents typically employs the use of maze tasks, whose attributes vary from one maze to the next. These tasks vary by their behavioral flexibility and required memory duration, the number of goals and pathways, and also the overall task complexity. A confounding feature in many of these tasks is the lack of control over the strategy employed by the rodents to reach the goal, e.g., allocentric (declarative-like) or egocentric (procedural) based strategies. The double-H maze is a novel water-escape memory task that addresses this issue, by allowing the experimenter to direct the type of strategy learned during the training period. The double-H maze is a transparent device, which consists of a central alleyway with three arms protruding on both sides, along with an escape platform submerged at the extremity of one of these arms. Rats can be trained using an allocentric strategy by alternating the start position in the maze in an unpredictable manner (see protocol 1; §4.7), thus requiring them to learn the location of the platform based on the available allothetic cues. Alternatively, an egocentric learning strategy (protocol 2; §4.8) can be employed by releasing the rats from the same position during each trial, until they learn the procedural pattern required to reach the goal. This task has been proven to allow for the formation of stable memory traces. Memory can be probed following the training period in a misleading probe trial, in which the starting position for the rats alternates. Following an egocentric learning paradigm, rats typically resort to an allocentric-based strategy, but only when their initial view on the extra-maze cues differs markedly from their original position. This task is ideally suited to explore the effects of drugs/perturbations on allocentric/egocentric memory performance, as well as the interactions between these two memory systems.

  4. Scopolamine disrupts place navigation in rats and humans: a translational validation of the Hidden Goal Task in the Morris water maze and a real maze for humans

    Czech Academy of Sciences Publication Activity Database

    Laczó, J.; Marková, H.; Lobellová, Veronika; Gažová, I.; Pařízková, M.; Cerman, J.; Nekovářová, Tereza; Valeš, Karel; Klovrzová, S.; Harrison, J.; Windisch, M.; Vlček, Kamil; Svoboda, Jan; Hort, J.; Stuchlík, Aleš

    2017-01-01

    Roč. 234, č. 4 (2017), s. 535-547 ISSN 0033-3158 R&D Projects: GA ČR(CZ) GBP304/12/G069; GA MŠk(CZ) LH14053 Institutional support: RVO:67985823 Keywords : spatial orientation * scopolamine * acetylcholinesterase inhibitor * human * rat Subject RIV: FH - Neurology Impact factor: 3.308, year: 2016

  5. Analysis of the stress response in rats trained in the water-maze: differential expression of corticotropin-releasing hormone, CRH-R1, glucocorticoid receptors and brain-derived neurotrophic factor in limbic regions.

    Science.gov (United States)

    Aguilar-Valles, Argel; Sánchez, Edith; de Gortari, Patricia; Balderas, Israela; Ramírez-Amaya, Víctor; Bermúdez-Rattoni, Federico; Joseph-Bravo, Patricia

    2005-01-01

    Glucocorticoids and corticotropin-releasing hormone (CRH) are key regulators of stress responses. Different types of stress activate the CRH system; in hypothalamus, CRH expression and release are increased by physical or psychological stressors while in amygdala, preferentially by psychological stress. Learning and memory processes are modulated by glucocorticoids and stress at different levels. To characterize the kind of stress provoked by a hippocampal-dependent task such as spatial learning, we compared the expression profile of glucocorticoid receptor (GR), pro-CRH and CRH-R1 mRNAs (analyzed by RT-PCR), in amygdala, hippocampus and hypothalamus and quantified serum corticosterone levels by radioimmunoassay at different stages of training. mRNA levels of brain-derived neurotrophic factor (BDNF) were also quantified due to its prominent role in learning and memory processes. Male Wistar rats trained for 1, 3 or 5 days in the Morris water-maze (10 trials/day) were sacrificed 5-60 min the after last trial. A strong stress response occurred at day one in both yoked and trained animals (increased corticosterone and hypothalamic pro-CRH and CRH-R1 mRNA levels); changes gradually diminished as the test progressed. In amygdala, pro-CRH mRNA levels decreased while those of BDNF augmented when stress was highest, in yoked and trained animals. Hippocampi, of both yoked and trained groups, had decreased levels of GR mRNA on days 1 and 3, normalizing by day 5, while those of pro-CRH and CRH-R1 increased after the 3rd day. Increased gene expression, specifically due to spatial learning, occurred only for hippocampal BDNF since day 3. These results show that the Morris water-maze paradigm induces a strong stress response that is gradually attenuated. Inhibition of CRH expression in amygdala suggests that the stress inflicted is of physical but not of psychological nature and could lead to reduced fear or anxiety.

  6. Lack of protection of monoamine oxidase B-deficient mice from age-related spatial learning deficits in the Morris water maze.

    Science.gov (United States)

    Holschneider, D P; Scremin, O U; Chen, K; Shih, J C

    1999-01-01

    Monoamine oxidase B (MAO-B) increases in brain in response to aging and neurodegeneration. Whether such increases represent a risk factor to further neuronal damage or simply represent epiphenomena remains unclear. L-deprenyl, an inhibitor of MAO-B, has been shown to improve learning in aged rodents. However, recent data suggests this may occur through mechanisms independent of its enzymatic inhibition. This study investigates visualspatial learning of MAO-B deficient mice and examines what effects absence of MAO-B has on age-related cognitive decline. Learning was tested in the Morris Water Maze in male transgenic MAO-B knockout mice (KO) ages 2 months (n = 9), 7 months (n = 7), and 17 months (n = 8). Performance was compared to that of wild type (WT) littermates. Animals were given four 60 second trials per day with the submerged platform in the "North" position. Animals received 7 days of learning in which they were introduced into the pool facing the wall, alternating between the "East" and "West" positions. A single probe trial followed on day 8, followed by continuation of the original learning paradigm on days 9 and 10. Subsequently, the platform position was changed to the diagonally opposite quadrant and learning continued on days 11-13, followed by a cue phase in which the platform was made visible. Total distance traveled and latency to the platform was increased in 7- and 17- month old mice, most significantly at the beginning of the acquisition phase. This effect reappeared again in 17- month old mice during the reversal phase. No predominant genotypic differences in latency or distance were observed during any phase of the experiment. Our results show that presence or absence of MAO-B does not appear to alter performance in the Morris water maze. Furthermore, presence or absence of MAO-B does not provide protection from the age-dependent deficits in spatial learning.

  7. A room with a view and a polarizing cue: individual differences in the stimulus control of place navigation and passive latent learning in the water maze.

    Science.gov (United States)

    Devan, Bryan D; Petri, Herbert L; Mishkin, Mortimer; Stouffer, Eric M; Bowker, Jonna L; Yin, Ping-Bo; Buffalari, Deanne M; Olds, James L

    2002-07-01

    We investigated individual differences in the stimulus control of navigational behavior in the water maze by comparing measures of place learning in one environment to measures of latent learning (via passive placement on the goal platform) in a novel environment. In the first experiment, 12 rats were trained to find a slightly submerged hidden platform at a fixed location in room A for 10 days (4 trials/day). Fast and slow place learners were identified by their mean escape latency and cumulative distance to the goal during acquisition. The same animals were then given a 2-min passive placement on the submerged platform in room B. Latent learning was assessed by the animal's escape latency on a single swim trial immediately following the placement in room B. The results showed that the good latent learners in room B were not necessarily the fast place learners in room A. This weak correlation may be related to the fact that some rats swam near the area in room B that corresponded to the former goal location in room A relative to a common polarizing cue (i.e., the door/entrance to both rooms). When the view of the door was blocked in a second experiment a significant positive correlation between place acquisition and the latent learning test was obtained, although escape performance following passive placement was not improved. These findings suggest that while place navigation and latent learning via passive placement may involve some common cognitive-spatial function, other associative (S-S and/or S-R) processes that occur during place navigation/active movement may be required for animals to exhibit truly accurate navigational behavior characteristic of asymptotic escape performance in the water maze. Additional implications for neurobiological studies using a procedural pretraining design are discussed. Copyright 2002 Elsevier Science (USA).

  8. The honeycomb maze provides a novel test to study hippocampal-dependent spatial navigation.

    Science.gov (United States)

    Wood, Ruth A; Bauza, Marius; Krupic, Julija; Burton, Stephen; Delekate, Andrea; Chan, Dennis; O'Keefe, John

    2018-02-01

    Here we describe the honeycomb maze, a behavioural paradigm for the study of spatial navigation in rats. The maze consists of 37 platforms that can be raised or lowered independently. Place navigation requires an animal to go to a goal platform from any of several start platforms via a series of sequential choices. For each, the animal is confined to a raised platform and allowed to choose between two of the six adjacent platforms, the correct one being the platform with the smallest angle to the goal-heading direction. Rats learn rapidly and their choices are influenced by three factors: the angle between the two choice platforms, the distance from the goal, and the angle between the correct platform and the direction of the goal. Rats with hippocampal damage are impaired in learning and their performance is affected by all three factors. The honeycomb maze represents a marked improvement over current spatial navigation tests, such as the Morris water maze, because it controls the choices of the animal at each point in the maze, provides the ability to assess knowledge of the goal direction from any location, enables the identification of factors influencing task performance and provides the possibility for concomitant single-cell recording.

  9. Electroacupuncture Treatment Improves Learning-Memory Ability and Brain Glucose Metabolism in a Mouse Model of Alzheimer’s Disease: Using Morris Water Maze and Micro-PET

    Directory of Open Access Journals (Sweden)

    Jing Jiang

    2015-01-01

    Full Text Available Introduction. Alzheimer’s disease (AD causes progressive hippocampus dysfunctions leading to the impairment of learning and memory ability and low level of uptake rate of glucose in hippocampus. What is more, there is no effective treatment for AD. In this study, we evaluated the beneficial and protective effects of electroacupuncture in senescence-accelerated mouse prone 8 (SAMP8. Method. In the electroacupuncture paradigm, electroacupuncture treatment was performed once a day for 15 days on 7.5-month-old SAMP8 male mice. In the normal control paradigm and AD control group, 7.5-month-old SAMR1 male mice and SAMP8 male mice were grabbed and bandaged while electroacupuncture group therapy, in order to ensure the same treatment conditions, once a day, 15 days. Results. From the Morris water maze (MWM test, we found that the treatment of electroacupuncture can improve the spatial learning and memory ability of SAMP8 mouse, and from the micro-PET test, we proved that after the electroacupuncture treatment the level of uptake rate of glucose in hippocampus was higher than normal control group. Conclusion. These results suggest that the treatment of electroacupuncture may provide a viable treatment option for AD.

  10. The creativity maze

    DEFF Research Database (Denmark)

    Bourgeois-Bougrine, Samira; Glaveanu, Vlad Petre; Botella, Marion

    2014-01-01

    The present article aims to address a current gap in our understanding of creativity in screenplay writing by focusing on the cognitive, conative, affective, and environmental factors that come into play at different stages in the creative process. It reports a study employing in-depth interviews...... and or treatment), and, finally, intense periods of writing and rewriting the script. These 3 stages, and, in particular, the multiple and concrete decisions to be taken within each one of them, support a vision of the creative process in this domain metaphorically conceptualized as crossing a maze. Creators...

  11. Physical exercise counteracts MPTP-induced changes in neural precursor cell proliferation in the hippocampus and restores spatial learning but not memory performance in the water maze.

    Science.gov (United States)

    Klein, C; Rasińska, J; Empl, L; Sparenberg, M; Poshtiban, A; Hain, E G; Iggena, D; Rivalan, M; Winter, Y; Steiner, B

    2016-07-01

    Parkinson's disease (PD) is characterized by a continuous loss of dopaminergic neurons in the substantia nigra, which not only leads to characteristic motor symptoms but also to cognitive impairments. Physical exercise has been shown to improve hippocampus-dependent cognitive functions in PD patients. Animal studies have demonstrated the involvement of adult hippocampal neurogenesis in exercise-induced improvements of visuo-spatial learning and memory. Here, we investigated the direct impact of voluntary wheel running on hippocampal neurogenesis and spatial learning and memory in the Morris water maze (MWM) using the1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. We also analyzed striatal and hippocampal dopamine transmission and mRNA expression levels of dopamine receptors. We show that MPTP-induced spatial learning deficits were alleviated by short-term physical exercise but not MPTP-induced spatial memory impairments in either exercise intervention group. Neural precursor proliferation was transiently altered in MPTP-treated mice, while the cell survival was increased by exercise. Dopamine was progressively depleted by MPTP and its turnover altered by exercise. In addition, gene expression of dopamine receptor D1/D5 was transiently upregulated following MPTP treatment but not affected by physical exercise. Our findings suggest that physical exercise benefits spatial learning but not memory performance in the MWM after MPTP-induced dopamine depletion by restoring precursor cell proliferation in the hippocampus and influencing dopamine transmission. This adds to the understanding of cognitive decline and mechanisms for potential improvements by physical exercise in PD patients. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. [Application of the method of one-day learning in a Morris water maze to analyse the effects of sleep deprivation on memory trace recall 24 hours later, after learning].

    Science.gov (United States)

    Dorokhov, V B; Kozhedub, R G; Arsenyev, G N; Bukhgolts, O I; Marchenko, V G; Puchkova, A N

    2014-01-01

    The proposed model of a one-day spatial learning is of interest in research of how sleep influences the hippocamp-dependent memory consolidation. We have studied the influence of a one-day total sleep deprivation on spatial memory consolidation in hooded rats after a one-day learning in the Morris water maze according to Feldman et al. [2010] protocol. According to it rats had to find a submerged platform that was alternatively marked by a flag or completely invisible to an animal. In a previous study [Dorokhov et al., 2011] we have used another one-day learning protocol [Frick et al., 2000] and Wistar rats and have demonstrated a large interindividual variance in learning parameters and sleep deprivation effects on memory consolidation. In this study we confirm previously acquired results on negative impact of sleep deprivation on spatial memory consolidation. To demonstrate the effects of sleep deprivation on the results of one-day learning we are using for the first time an evaluation of the time spent by an animal in the area of the platform placement and corresponding areas in the other quadrants of the water maze.

  13. Harmine treatment enhances short-term memory in old rats: Dissociation of cognition and the ability to perform the procedural requirements of maze testing.

    Science.gov (United States)

    Mennenga, Sarah E; Gerson, Julia E; Dunckley, Travis; Bimonte-Nelson, Heather A

    2015-01-01

    Harmine is a naturally occurring monoamine oxidase inhibitor that has recently been shown to selectively inhibit the dual-specificity tyrosine-(Y)-phosphorylation-regulated kinase 1A (DYRK1A). We investigated the cognitive effects of 1mg (low) Harmine and 5mg (high) Harmine using the delayed-match-to-sample (DMS) asymmetrical 3-choice water maze task to evaluate spatial working and recent memory, and the Morris water maze task (MM) to test spatial reference memory. Animals were also tested on the visible platform task, a water-escape task with the same motor, motivational, and reinforcement components as the other tasks used to evaluate cognition, but differing in its greater simplicity and that the platform was visible above the surface of the water. A subset of the Harmine-high treated animals showed clear motor impairments on all behavioral tasks, and the visible platform task confirmed a lack of competence to perform the procedural components of water maze testing. After excluding animals from the high dose group that could not perform the procedural components of a swim task, it was revealed that both high- and low-dose treatment with Harmine enhanced performance on the latter portion of DMS testing, but had no effect on MM performance. Thus, this study demonstrates the importance of confirming motor and visual competence when studying animal cognition, and verifies the one-day visible platform task as a reliable measure of ability to perform the procedural components necessary for completion of a swim task. Copyright © 2014. Published by Elsevier Inc.

  14. Spatial learning in a Z-maze by cerebellar mutant mice.

    Science.gov (United States)

    Lalonde, R; Filali, M; Bensoula, A N; Monnier, C; Guastavino, J M

    1996-01-01

    Two types of cerebellar mutant mice (staggerer and lurcher) were evaluated during 5-day acquisition of a spatial learning task in a Z-maze filled with water. Although the number of errors and escape latencies decreased in normal mice, the acquisition of the cerebellar mutants was impaired but not abolished. These results indicate that the cerebellum has a role in spatial learning. Mice with cerebellar dysfunction take a more indirect route toward a goal during the course of swimming, when ataxic symptoms are no longer in evidence.

  15. Maze navigation by honeybees: learning path regularity.

    Science.gov (United States)

    Zhang, S; Mizutani, A; Srinivasan, M V

    2000-01-01

    We investigated the ability of honeybees to learn mazes of four types: constant-turn mazes, in which the appropriate turn is always in the same direction in each decision chamber; zig-zag mazes, in which the appropriate turn is alternately left and right in successive decision chambers; irregular mazes, in which there is no readily apparent pattern to the turns; and variable irregular mazes, in which the bees were trained to learn several irregular mazes simultaneously. The bees were able to learn to navigate all four types of maze. Performance was best in the constant-turn mazes, somewhat poorer in the zig-zag mazes, poorer still in the irregular mazes, and poorest in the variable irregular mazes. These results demonstrate that bees do not navigate such mazes simply by memorizing the entire sequence of appropriate turns. Rather, performance in the various configurations depends on the existence of regularity in the structure of the maze and on the ease with which this regularity is recognized and learned.

  16. Sex difference in cue strategy in a modified version of the Morris water task: correlations between brain and behaviour.

    Science.gov (United States)

    Keeley, Robin J; Tyndall, Amanda V; Scott, Gavin A; Saucier, Deborah M

    2013-01-01

    Sex differences in spatial memory function have been reported with mixed results in the literature, with some studies showing male advantages and others showing no differences. When considering estrus cycle in females, results are mixed at to whether high or low circulating estradiol results in an advantage in spatial navigation tasks. Research involving humans and rodents has demonstrated males preferentially employ Euclidean strategies and utilize geometric cues in order to spatially navigate, whereas females employ landmark strategies and cues in order to spatially navigate. This study used the water-based snowcone maze in order to assess male and female preference for landmark or geometric cues, with specific emphasis placed on the effects of estrus cycle phase for female rat. Performance and preference for the geometric cue was examined in relation to total hippocampal and hippocampal subregions (CA1&2, CA3 and dentate gyrus) volumes and entorhinal cortex thickness in order to determine the relation between strategy and spatial performance and brain area size. The study revealed that males outperformed females overall during training trials, relied on the geometric cue when the platform was moved and showed significant correlations between entorhinal cortex thickness and spatial memory performance. No gross differences in behavioural performance was observed within females when accounting for cyclicity, and only total hippocampal volume was correlated with performance during the learning trials. This study demonstrates the sex-specific use of cues and brain areas in a spatial learning task.

  17. Phosphorylation of tyrosine receptor kinase B in the dorsal striatum and dorsal hippocampus is associated with response learning in a water plus maze.

    Science.gov (United States)

    Pahng, Amanda R; Colombo, Paul J

    2017-02-01

    The dorsal hippocampus and dorsal striatum have dissociable roles in learning and memory that are related to region-specific changes in proteins necessary for neuronal plasticity and memory formation. There is additional evidence that the hippocampus and striatum can interact during memory formation. Phosphorylation of tyrosine receptor kinase B is important for memory formation in the hippocampus, but whether or not it has a role in striatum-dependent learning, or in interactions between the hippocampus and striatum, has not been examined. In the present study, we tested the hypothesis that response training increases pTrkB in the dorsal striatum, but decreases pTrkB in dorsal hippocampus, due to an interaction between the systems during memory formation. Results show a significant decrease in pTrkB levels in the dorsal hippocampus of rats trained on the response task compared with swim controls. Response training did not increase pTrkB levels in the dorsal striatum. Positive correlations were found between response learning and the total area of cells expressing pTrkB in the dorsal striatum, while no correlations were found in swim controls. Our results partially support our hypothesis and indicate that response learning is associated with a decrease in hippocampal pTrkB, while phosphorylation of TrkB in the dorsal striatum remains constant. This indicates that suppression of hippocampal pTrkB during response learning may be involved in striatum-dependent memory formation. Additionally, our findings suggest that activation of TrkB in a sparse arrangement of cells may be associated with faster acquisition of a response task. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  18. Emotional and Cognitive Information Processing: Relations to Behavioral Performance and Hippocampal Long-Term Potentiation In Vivo during a Spatial Water Maze Training in Rats

    Science.gov (United States)

    Schulz, Kristina; Korz, Volker

    2010-01-01

    Emotionality as well as cognitive abilities contribute to the acquisition and retrieval of memories as well as to the consolidation of long-term potentiation (LTP), a cellular model of memory formation. However, little is known about the timescale and relative contribution of these processes. Therefore, we tested the effects of weak water maze…

  19. fMRI hippocampal activity during a virtual radial arm maze.

    Science.gov (United States)

    Astur, Robert S; St Germain, Sarah A; Baker, Elizabeth K; Calhoun, Vince; Pearlson, Godfrey D; Constable, R Todd

    2005-09-01

    Numerous studies have shown that the hippocampus is critical for spatial memory. Within nonhuman research, a task often used to assess spatial memory is the radial arm maze. Because of the spatial nature of this task, this maze is often used to assess the function of the hippocampus. Our goal was to extrapolate this task to humans and examine whether healthy undergraduates utilize their hippocampus while performing a virtual reality version of the radial arm maze task. Thirteen undergraduates performed a virtual radial arm maze during functional magnetic resonance imaging. The brain maps of activity reveal bilateral hippocampal BOLD signal changes during the performance of this task. However, paradoxically, this BOLD signal change decreases during the spatial memory component of the task. Additionally, we note frontal cortex activity reflective of working memory circuits. These data reveal that, as predicted by the rodent literature, the hippocampus is involved in performing the virtual radial arm maze in humans. Hence, this virtual reality version may be used to assess the integrity of hippocampus so as to predict risk or severity in a variety of psychiatric disorders.

  20. Navigating a Maze with Balance Board and Wiimote

    Science.gov (United States)

    Fikkert, Wim; Hoeijmakers, Niek; van der Vet, Paul; Nijholt, Anton

    Input from the lower body in human-computer interfaces can be beneficial, enjoyable and even entertaining when users are expected to perform tasks simultaneously. Users can navigate a virtual (game) world or even an (empirical) dataset while having their hands free to issue commands. We compared the Wii Balance Board to a hand-held Wiimote for navigating a maze and found that users completed this task slower with the Balance Board. However, the Balance Board was considered more intuitive, easy to learn and ‘much fun’.

  1. Exploring the T-Maze: Evolving Learning-Like Robot Behaviors using CTRNNs

    OpenAIRE

    Blynel, J.; Floreano, D.

    2003-01-01

    This paper explores the capabilities of continuous time recurrent neural networks (CTRNNs) to display reinforcement learning-like abilities on a set of T-Maze and double T-Maze navigation tasks, where the robot has to locate and "remember'' the position of a reward-zone. The "learning'' comes about without modifications of synapse strengths, but simply from internal network dynamics, as proposed by [12]. Neural controllers are evolved in simulation and in the simple case evalua...

  2. [Glass maze in women's leadership].

    Science.gov (United States)

    Barberá Heredia, Ester; Ramos López, Amparo; Candela Agulló, Carlos

    2011-04-01

    Psychological gender discrimination explanations have changed over the past thirty years, becoming more complex in order to obtain a better understanding of the social reality. At the present moment, one of the most interesting research areas is the one referring to the 'glass maze' phenomenon in women's management careers. The main purpose of this work is to reveal the theoretical evolution in an attempt to explain the leadership study from a gender perspective. The consecutive hypotheses, starting with the labour sexual division idea, are becoming more interactive in order to understand the current labour-social situation. Social psychology has underlined the role of beliefs, observed via gender stereotyped roles, prejudiced attitudes against women, sexist and neo-sexist ideology, or masculine, feminine and androgynous identity development. New psychological interpretations insist on the variability of the gender concept, where gender is sometimes observed through men and women's behaviours, and other times through those behaviour expectations. But gender is mainly observed though the power relations between men and women during social interactions in labour organizations.

  3. Effect of Water Immersion on Dual-task Performance: Implications for Aquatic Therapy.

    Science.gov (United States)

    Schaefer, Sydney Y; Louder, Talin J; Foster, Shayla; Bressel, Eadric

    2016-09-01

    Much is known about cardiovascular and biomechanical responses to exercise during water immersion, yet an understanding of the higher-order neural responses to water immersion is unclear. The purpose of this study was to compare cognitive and motor performance between land and water environments using a dual-task paradigm, which served as an indirect measure of cortical processing. A quasi-experimental crossover research design is used. Twenty-two healthy participants (age = 24.3 ± 5.24 years) and a single-case patient (age = 73) with mild cognitive impairment performed a cognitive (auditory vigilance) and motor (standing balance) task separately (single-task condition) and simultaneously (dual-task condition) on land and in chest-deep water. Listening errors from the auditory vigilance task and centre of pressure (CoP) area for the balance task measured cognitive and motor performance, respectively. Listening errors for the single-task and dual-task conditions were 42% and 45% lower for the water than land condition, respectively (effect size [ES] = 0.38 and 0.55). CoP area for the single-task and dual-task conditions, however, were 115% and 164% lower on land than in water, respectively, and were lower (≈8-33%) when balancing concurrently with the auditory vigilance task compared with balancing alone, regardless of environment (ES = 0.23-1.7). This trend was consistent for the single-case patient. Participants tended to make fewer 'cognitive' errors while immersed chest-deep in water than on land. These same participants also tended to display less postural sway under dual-task conditions, but more in water than on land. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  4. Effect of crude extract and its semi purified constituents from guaraná seeds [Paullinia cupana var. sorbilis (Mart. lucke] on cognitive performance in Morris water maze in rats

    Directory of Open Access Journals (Sweden)

    Fernanda Jacques Otobone

    2005-09-01

    Full Text Available The effect of crude lyophilized extract (EBPC and the semi-purified constituents (EPA and EPB of Paullinia cupana (guaraná seeds long-term administered in rats by gavage at different doses was studied on cognitive behavior in rats. EBPC (30.0 mg/kg and EPA (2.0 mg/kg, but not EPB (2.0 or 4.0 mg/kg showed a smaller escape latency to find the emerged platform in Morris water maze test (MWMT, showing nootropic-like effect in normal rats, and in scopolamine induced amnesia rats compared to their controls (saline + 0.2% Tween 80 group. These extracts had no significant effect in open field test (OFT. Caffeine did alter escape latency in MWMT only in scopolamine induced amnesia rats and increased the crossings number in OFT, showing significant stimulant effect. Chronic treatment showed the same increase in body weight and average lifespan indicating a low toxicity for the extracts.O efeito do tratamento crônico (gavagem do extrato bruto liofilizado (EBPC das sementes da Paullinia cupana, guaraná, e seus constituintes semi-purificados EPA e EPB, sobre o comportamento cognitivo foi estudado em ratos submetidos ao teste do labirinto aquático de Morris. EBPC (30.0 mg/kg e EPA (2.0 mg/kg, mostraram menor latência para encontrar a plataforma submersa quando comparados ao grupo controle (salina+ tween 80 a 0.2%, em ratos normais ou tratados com escopolamina, o que sugere efeito benéfico sobre a cognição. Estes extratos não alteraram a atividade locomotora no teste do campo aberto. A cafeína, reduziu o tempo de latência para encontrar a plataforma submersa no teste do labirinto aquático de Morris em tratados com escopolamina. Além disso, aumentou o número de cruzamentos no teste do campo aberto, mostrando efeito estimulante. Ratos tratados com EPB não produziram alteração significativa nos testes utilizados. Os animais tratados cronicamente com EBPC, EPA ou EPB tiveram a mesma evolução ponderal e sobrevida o que sugere baixa toxicidade

  5. Behavior at the choice point: decision making in hidden pathway maze learning.

    Science.gov (United States)

    Thomas, Elizabeth; Snyder, Peter J; Pietrzak, Robert H; Maruff, Paul

    2014-12-01

    Hidden pathway maze learning tasks (HPMLTs) have been used in neuropsychological research and practice for more than 80 years. These tasks require the use of visual and auditory task feedback signals to learn the order and direction of a pathway, typically within a grid of stepping-stones, or alleys. Hidden pathway maze learning tasks are purported to assess both visuospatial learning and executive processes. The original motivation for the HPMLT paradigm for humans was to reduce a complex tactual planning task to one in which decisions could be directly measured by discrete actions at choice points guided by visual cues. Hidden maze learning paradigms were used extensively throughout the 20th century, initially to study exploratory, anticipatory, and goal-related behavior within the context of memory research, and later as an experimental tool in neuropsychology. Computerization of HPMLTs have allowed for the measurement of different move categories according to the rule structure and ipso facto, clinically meaningful differences in memory and monitoring functions during spatial search and learning. Hidden pathway maze learning tests have been used to understand the cognitive effects of ageing, neurological disorders, and psychopharmacological challenges. We provide a review of historical antecedents relevant to contemporary applications of HPMLTs in neuropsychology. It is suggested that contemporary applications of HPMLTs could be advanced by analysis of component operations necessary for efficient performance that can inform theoretical interpretations of this class of tests in clinically meaningful terms.

  6. Relationships among gender, cognitive style, academic major, and performance on the Piaget water-level task.

    Science.gov (United States)

    Hammer, R E; Hoffer, N; King, W L

    1995-06-01

    Many researchers have found that more college-age adults than would be expected fail Piaget's water-level task, with women failing more frequently than men. It has been hypothesized that differences in cognitive style may account for performance differences on the water-level task. In the present study, 27 male and 27 female architectural students and 27 male and 27 female liberal-arts students were assessed for their performance on both Piaget's Water-level Task and Witkin's Group Embedded Figures Test. No difference was found in performance of male and female architectural students on either task, but male liberal-arts students scored significantly higher than female liberal-arts students on both measures. A disembedding cognitive style predicted success on the water-level task for the architectural students but not for the liberal arts students.

  7. Incremental Sentence Processing in Japanese: A Maze Investigation into Scrambled and Control Sentences

    Science.gov (United States)

    Witzel, Jeffrey; Witzel, Naoko

    2016-01-01

    This study investigates preverbal structural and semantic processing in Japanese, a head-final language, using the maze task. Two sentence types were tested--simple scrambled sentences (Experiment 1) and control sentences (Experiment 2). Experiment 1 showed that even for simple, mono-clausal Japanese sentences, (1) there are online processing…

  8. The Floor Projection Maze: A novel behavioral apparatus for presenting visual stimuli to rats

    Science.gov (United States)

    Furtak, Sharon C.; Cho, Christine E.; Kerr, Kristin M.; Barredo, Jennifer L.; Alleyne, Janelle E.; Patterson, Yolanda R.; Burwell, Rebecca D.

    2010-01-01

    There is a long tradition of studying visual learning in rats by presenting stimuli vertically on cards or monitors. The procedures are often labor intensive and the rate of acquisition can be prohibitively low. Available evidence suggests that rats process visual information presented in the lower visual hemifield more effectively than information presented in the upper visual hemifield. We capitalized on these findings by developing a novel apparatus, the Floor Projection Maze, for presenting visual information directly to the floor of an exploratory maze. Two-dimensional (2D) visual stimuli were presented on the floor by back-projecting an image from a standard digital projector to the semi-transparent underside of the floor of an open maze. Long-Evans rats rapidly acquired easy 2D visual discriminations (Experiment 1). Rats were also able to learn a more difficult shape discrimination in dramatically fewer trials than previously reported for the same discrimination when presented vertically (Experiment 2). The two choice discrimination task was adapted to determine contrast sensitivity thresholds in a naïve group of rats (Experiment 3). Contrast sensitivity thresholds were uniform across three subjects, demonstrating that the Floor Projection Maze can be used for visual psychophysics in rats. Our findings demonstrate that rats can rapidly acquire visual tasks when stimuli are presented horizontally on the floor, suggesting that this novel behavioral apparatus will provide a powerful behavioral paradigm in the future. PMID:19422855

  9. Guiding brine shrimp through mazes by solving reaction diffusion equations

    Science.gov (United States)

    Singal, Krishma; Fenton, Flavio

    Excitable systems driven by reaction diffusion equations have been shown to not only find solutions to mazes but to also to find the shortest path between the beginning and the end of the maze. In this talk we describe how we can use the Fitzhugh-Nagumo model, a generic model for excitable media, to solve a maze by varying the basin of attraction of its two fixed points. We demonstrate how two dimensional mazes are solved numerically using a Java Applet and then accelerated to run in real time by using graphic processors (GPUs). An application of this work is shown by guiding phototactic brine shrimp through a maze solved by the algorithm. Once the path is obtained, an Arduino directs the shrimp through the maze using lights from LEDs placed at the floor of the Maze. This method running in real time could be eventually used for guiding robots and cars through traffic.

  10. The Scaling of Water Governance Tasks: A Comparative Federal Analysis of the European Union and Australia

    Science.gov (United States)

    Benson, David; Jordan, Andrew

    2010-07-01

    Conflicts over how to “scale” policy-making tasks have characterized environmental governance since time immemorial. They are particularly evident in the area of water policy and raise important questions over the democratic legitimacy, economic efficiency and effectiveness of allocating (or “scaling”) tasks to some administrative levels as opposed to others. This article adopts a comparative federalism perspective to assess the “optimality” of scaling—either upward or downward—in one issue area, namely coastal recreational water quality. It does so by comparing the scaling of recreational water quality tasks in the European Union (EU) and Australia. It reveals that the two systems have adopted rather different approaches to scaling and that this difference can partly be accounted for in federal theoretical terms. However, a much greater awareness of the inescapably political nature of scaling processes is nonetheless required. Finally, some words of caution are offered with regard to transferring policy lessons between these two jurisdictions.

  11. Anomalous neural circuit function in schizophrenia during a virtual Morris water task.

    Science.gov (United States)

    Folley, Bradley S; Astur, Robert; Jagannathan, Kanchana; Calhoun, Vince D; Pearlson, Godfrey D

    2010-02-15

    Previous studies have reported learning and navigation impairments in schizophrenia patients during virtual reality allocentric learning tasks. The neural bases of these deficits have not been explored using functional MRI despite well-explored anatomic characterization of these paradigms in non-human animals. Our objective was to characterize the differential distributed neural circuits involved in virtual Morris water task performance using independent component analysis (ICA) in schizophrenia patients and controls. Additionally, we present behavioral data in order to derive relationships between brain function and performance, and we have included a general linear model-based analysis in order to exemplify the incremental and differential results afforded by ICA. Thirty-four individuals with schizophrenia and twenty-eight healthy controls underwent fMRI scanning during a block design virtual Morris water task using hidden and visible platform conditions. Independent components analysis was used to deconstruct neural contributions to hidden and visible platform conditions for patients and controls. We also examined performance variables, voxel-based morphometry and hippocampal subparcellation, and regional BOLD signal variation. Independent component analysis identified five neural circuits. Mesial temporal lobe regions, including the hippocampus, were consistently task-related across conditions and groups. Frontal, striatal, and parietal circuits were recruited preferentially during the visible condition for patients, while frontal and temporal lobe regions were more saliently recruited by controls during the hidden platform condition. Gray matter concentrations and BOLD signal in hippocampal subregions were associated with task performance in controls but not patients. Patients exhibited impaired performance on the hidden and visible conditions of the task, related to negative symptom severity. While controls showed coupling between neural circuits, regional

  12. Place Learning in the Morris Water Task: Making the Memory Stick

    Science.gov (United States)

    Bolding, Kevin; Rudy, Jerry W.

    2006-01-01

    Although the Morris water task has been used in hundreds of studies of place learning, there have been no systematic studies of retention of the place memory. We report that retention, as measured by selective search behavior on a probe trial, is excellent when the retention interval is short (5-10 min). However, performance rapidly deteriorates,…

  13. Hamsters' (Mesocricetus auratus) memory in a radial maze analog: the role of spatial versus olfactory cues.

    Science.gov (United States)

    Tonneau, François; Cabrera, Felipe; Corujo, Alejandro

    2012-02-01

    The golden hamster's (Mesocricetus auratus) performance on radial maze tasks has not been studied a lot. Here we report the results of a spatial memory task that involved eight food stations equidistant from the center of a circular platform. Each of six male hamsters depleted the food stations along successive choices. After each choice and a 5-s retention delay, the hamster was brought back to the center of the platform for the next choice opportunity. When only one baited station was left, the platform was rotated to evaluate whether olfactory traces guided hamsters' choices. Results showed that despite the retention delay hamsters performed above chance in searching for food. The choice distributions observed during the rotation probes were consistent with spatial memory and could be explained without assuming guidance by olfactory cues. The radial maze analog we devised could be useful in furthering the study of spatial memory in hamsters.

  14. Unilateral robotic hybrid mini-maze: a novel experimental approach.

    Science.gov (United States)

    Moslemi, Mohammad; Rawashdeh, Badi; Meyer, Mark; Nguyen, Duy; Poston, Robert; Gharagozloo, Farid

    2016-03-01

    A complete Cox maze IV procedure is difficult to accomplish using current endoscopic and minimally invasive techniques. These techniques are hampered by inability to adequately dissect the posterior structures of the heart and place all necessary lesions. We present a novel approach, using robotic technology, that achieves placement of all the lesions of the complete maze procedure. In three cadaveric human models, the technical feasibility of using robotic instruments through the right chest to dissect the posterior structures of the heart and place all Cox maze lesions was performed. The entire posterior aspect of the heart was dissected in the cadaveric model facilitating successful placement of all Cox maze IV lesions with robotic assistance through minimally invasive incisions. The robotic Cox maze IV procedure through the novel right thoracic approach is feasible. This obviates the need for sternotomy and avoids the associated morbidity of the conventional Cox-maze procedure. Copyright © 2015 John Wiley & Sons, Ltd.

  15. Comparisons of Online Reading Paradigms: Eye Tracking, Moving-Window, and Maze

    Science.gov (United States)

    Witzel, Naoko; Witzel, Jeffrey; Forster, Kenneth

    2012-01-01

    This study compares four methodologies used to examine online sentence processing during reading. Specifically, self-paced, non-cumulative, moving-window reading (Just et al. in "J Exp Psychol Gen" 111:228-238, 1982), eye tracking (see e.g., Rayner in "Q J Exp Psychol" 62:1457-1506, 2009), and two versions of the maze task (Forster et al. in…

  16. Gazing toward humans: a study on water rescue dogs using the impossible task paradigm.

    Science.gov (United States)

    D'Aniello, Biagio; Scandurra, Anna; Prato-Previde, Emanuela; Valsecchi, Paola

    2015-01-01

    Various studies have assessed the role of life experiences, including learning opportunities, living conditions and the quality of dog-human relationships, in the use of human cues and problem-solving ability. The current study investigates how and to what extent training affects the behaviour of dogs and the communication of dogs with humans by comparing dogs trained for a water rescue service and untrained pet dogs in the impossible task paradigm. Twenty-three certified water rescue dogs (the water rescue group) and 17 dogs with no training experience (the untrained group) were tested using a modified version of the impossible task described by Marshall-Pescini et al. in 2009. The results demonstrated that the water rescue dogs directed their first gaze significantly more often towards the owner and spent more time gazing toward two people compared to the untrained pet dogs. There was no difference between the dogs of the two groups as far as in the amount of time spent gazing at the owner or the stranger; neither in the interaction with the apparatus attempting to obtain food. The specific training regime, aimed at promoting cooperation during the performance of water rescue, could account for the longer gazing behaviour shown toward people by the water rescue dogs and the priority of gazing toward the owner. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Scopolamine during the paradoxical sleep window impairs radial arm maze learning in rats.

    Science.gov (United States)

    Legault, Glenn; Smith, Carlyle T; Beninger, Richard J

    2004-12-01

    It has been proposed that there are paradoxical sleep windows (PSW) during which REM sleep is required for effective learning. Thus, rats deprived of REM sleep during 0-4 (but not 5-8) h after training show impaired learning of a radial maze task. As cholinergic (ACh) systems are active during REM sleep and may be involved in learning, this experiment investigated the effects on learning of pharmacological manipulation of the cholinergic system during the period identified as the PSW. Sprague-Dawley rats were randomly assigned to groups that were physically deprived of REM for 4 h either immediately after training or beginning 4 h after training or treated with the ACh receptor antagonist scopolamine (0-0.4 mg/kg at 0 and 2 h after training or 0.006 mg/kg at 4 and 6 h after training) on each of 9 days of radial maze training. Post-training REM deprivation (0-4 h but not 5-8 h after training) and scopolamine dose-dependently impaired learning. Results suggest that REM sleep and intact ACh neurotransmission are required during the PSW for rats to learn the radial maze task.

  18. Tactile maze solving in congenitally blind individuals

    DEFF Research Database (Denmark)

    Gagnon, Léa; Kupers, Ron; Schneider, Fabien C

    2010-01-01

    Vision is undoubtedly important for navigation although not essential as blind individuals outperform their blindfolded seeing counterparts in a variety of navigational tasks. It is believed that the blind's superior performance is because of their efficient use of proprioceptive signals and envi......Vision is undoubtedly important for navigation although not essential as blind individuals outperform their blindfolded seeing counterparts in a variety of navigational tasks. It is believed that the blind's superior performance is because of their efficient use of proprioceptive signals...

  19. Problem-solving in English through business mazes

    CERN Document Server

    Farthing, Joni

    1981-01-01

    We choose our job carefully. What we cannot choose are our colleagues - so it's not surprising that conflict and friction can arise in our working relationships. Business Mazes presents such problems for you to solve. Follow a route through the maze ans see the outcome of each decision you make. You may find that the quickest rout isn't always the best, or the easiest, in the long run. Business Mazes is designed for intermediate and advanced level students of English, working alone or in groups. It includes full teaching plans and exercises. The mazes may also be used effectively as an interesting approach to discussion for young people preparing their first job.

  20. Spatial memory deficits in a virtual reality eight-arm radial maze in schizophrenia.

    Science.gov (United States)

    Spieker, Elena A; Astur, Robert S; West, Jeffrey T; Griego, Jacqueline A; Rowland, Laura M

    2012-03-01

    Learning and memory impairments are present in schizophrenia (SZ) throughout the illness course and predict psychosocial function. Abnormalities in prefrontal and hippocampal function are thought to contribute to SZ deficits. The radial arm maze (RAM) is a test of spatial learning and memory in rodents that relies on intact prefrontal and hippocampal function. The goal of the present study was to investigate spatial learning in SZ using a virtual RAM. Thirty-three subjects with SZ and thirty-nine healthy controls (HC) performed ten trials of a virtual RAM task. Subjects attempted to learn to retrieve four rewards each located in separate arms. As expected, subjects with SZ used more time and traveled more distance to retrieve rewards, made more reference (RM) and working memory (WM) errors, and retrieved fewer rewards than HC. It is important to note that the SZ group did learn but did not reach the level of HC. Whereas RM errors decreased across trials in the SZ group, WM errors did not. There were no significant relationships between psychiatric symptom severity and maze performance. To our knowledge, use of a virtual 8-arm radial maze task in SZ to assess spatial learning is novel. Impaired virtual RAM performance in SZ is consistent with studies that examined RAM performance in animal models of SZ. Results provide further support for compromised prefrontal and hippocampal function underlying WM and RM deficits in SZ. The virtual RAM task could help bridge preclinical and clinical research for testing novel drug treatments of SZ. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Behavior and spatial learning in radial mazes in birds.

    Science.gov (United States)

    Pleskacheva, M G

    2009-10-01

    This review addresses studies of spatial memory and learning in birds performed using the radial maze method. Descriptions of different versions of this test (standard and "giant" tunnel-type mazes, as well as unstructured "analogs") are described and the methodological problems of testing birds are discussed. Behavioral measures from birds and laboratory rats, as the "standard" system for radial maze studies, are compared. The characteristics of spatial learning in birds of different systematic groups (pigeons, tits, corvids, chickens, etc.) are compared. Particular attention is paid to studies addressing spatial memory in closely related bird species with different ecological features, in terms of the ability to hoard food and finding their hoards after prolonged time periods, as well as to the few reports of results from experiments with migrant birds and homing pigeons.

  2. Research and development of a heat-pump water heater. Volume 2. R and D task reports

    Energy Technology Data Exchange (ETDEWEB)

    Dunning, R.L.; Amthor, F.R.; Doyle, E.J.

    1978-08-01

    The heat pump water heater is a device that works much like a window air conditioner except that heat from the home is pumped into a water tank rather than to the outdoors. The objective established for the device is to operate with a Coefficient of Performance (COP) of 3 or, an input of one unit of electric energy would create three units of heat energy in the form of hot water. With such a COP, the device would use only one-third the energy and at one-third the cost of a standard resistance water heater. This Volume 2 contains the final reports of the three major tasks performed in Phase I. In Task 2, a market study identifies the future market and selects an initial target market and channel of distribution, all based on an analysis of the parameters affecting feasibility of the device and the factors that will affect its market acceptance. In the Task 3 report, the results of a design and test program to arrive at final designs of heat pumps for both new water heaters and for retrofitting existing water heaters are presented. In the Task 4 report, a plan for an extensive field demonstration involving use in actual homes is presented. Volume 1 contains a final summary report of the information in Volume 2.

  3. Mazes and Maps: Can Young Children Find Their Way?

    Science.gov (United States)

    Jirout, Jamie J.; Newcombe, Nora S.

    2014-01-01

    Games provide important informal learning activities for young children, and spatial game play (e.g., puzzles and blocks) has been found to relate to the development of spatial skills. This study investigates 4- and 5-year-old children's use of scaled and unscaled maps when solving mazes, asking whether an important aspect of spatial…

  4. What Does the CBM-Maze Test Measure?

    Science.gov (United States)

    Muijselaar, Marloes M. L.; Kendeou, Panayiota; de Jong, Peter F.; van den Broek, Paul W.

    2017-01-01

    In this study, we identified the code-related (decoding, fluency) and language comprehension (vocabulary, listening comprehension) demands of the CBM-Maze test, a formative assessment, and compared them to those of the Gates-MacGinitie test, a standardized summative assessment. The demands of these reading comprehension tests and their…

  5. A Hierarchical Maze Navigation Algorithm with Reinforcement Learning and Mapping

    NARCIS (Netherlands)

    Mannucci, T.; van Kampen, E.; Jin, Y; Kollias, S.

    2016-01-01

    Goal-finding in an unknown maze is a challenging problem for a Reinforcement Learning agent, because the corresponding state space can be large if not intractable, and the agent does not usually have a model of the environment. Hierarchical Reinforcement Learning has been shown in the past to

  6. Control of magnetotactic bacterium in a micro-fabricated maze

    NARCIS (Netherlands)

    Khalil, I.S.M.; Pichel, Marc Philippe; Pichel, M.P.; Reefman, B.A.; Sardan Sukas, Ö.; Abelmann, Leon; Misra, Sarthak

    2013-01-01

    We demonstrate the closed-loop control of a magnetotactic bacterium (MTB), i.e., Magnetospirillum magnetotacticum, within a micro-fabricated maze using a magneticbased manipulation system. The effect of the channel wall on the motion of the MTB is experimentally analyzed. This analysis is done by

  7. Dizocilpine (MK-801) impairs learning in the active place avoidance task but has no effect on the performance during task/context alternation.

    Science.gov (United States)

    Vojtechova, Iveta; Petrasek, Tomas; Hatalova, Hana; Pistikova, Adela; Vales, Karel; Stuchlik, Ales

    2016-05-15

    The prevention of engram interference, pattern separation, flexibility, cognitive coordination and spatial navigation are usually studied separately at the behavioral level. Impairment in executive functions is often observed in patients suffering from schizophrenia. We have designed a protocol for assessing these functions all together as behavioral separation. This protocol is based on alternated or sequential training in two tasks testing different hippocampal functions (the Morris water maze and active place avoidance), and alternated or sequential training in two similar environments of the active place avoidance task. In Experiment 1, we tested, in adult rats, whether the performance in two different spatial tasks was affected by their order in sequential learning, or by their day-to-day alternation. In Experiment 2, rats learned to solve the active place avoidance task in two environments either alternately or sequentially. We found that rats are able to acquire both tasks and to discriminate both similar contexts without obvious problems regardless of the order or the alternation. We used two groups of rats, controls and a rat model of psychosis induced by a subchronic intraperitoneal application of 0.08mg/kg of dizocilpine (MK-801), a non-competitive antagonist of NMDA receptors. Dizocilpine had no selective effect on parallel/sequential learning of tasks/contexts. However, it caused hyperlocomotion and a significant deficit in learning in the active place avoidance task regardless of the task alternation. Cognitive coordination tested by this task is probably more sensitive to dizocilpine than spatial orientation because no hyperactivity or learning impairment was observed in the Morris water maze. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Emotional reactivity and cognitive performance in aversively motivated tasks: a comparison between four rat strains

    Directory of Open Access Journals (Sweden)

    van Reenen Cornelis G

    2009-12-01

    Full Text Available Abstract Background Cognitive function might be affected by the subjects' emotional reactivity. We assessed whether behavior in different tests of emotional reactivity is correlated with performance in aversively motivated learning tasks, using four strains of rats generally considered to have a different emotional reactivity. Methods The performance of male Brown Norway, Lewis, Fischer 344, and Wistar Kyoto rats in open field (OF, elevated plus-maze (EPM, and circular light-dark preference box (cLDB tasks, which are believed to provide measures of emotional reactivity, was evaluated. Spatial working and reference memory were assessed in two aversively motivated learning and memory tasks: the standard and the "repeated acquisition" versions of the Morris water maze escape task, respectively. All rats were also tested in a passive avoidance task. At the end of the study, levels of serotonin (5-HT and 5-hydroxyindoleacetic acid, and 5-HT turnover in the hippocampus and frontal cortex were determined. Results Strain differences showed a complex pattern across behavioral tests and serotonergic measures. Fischer 344 rats had the poorest performance in both versions of the Morris water escape task, whereas Brown Norway rats performed these tasks very well but the passive avoidance task poorly. Neither correlation analysis nor principal component analysis provided convincing support for the notion that OF, EPM, and cLDB tasks measure the same underlying trait. Conclusions Our findings do not support the hypothesis that the level of emotional reactivity modulates cognitive performance in aversively motivated tasks. Concepts such as "emotional reactivity" and "learning and memory" cannot adequately be tapped with only one behavioral test. Our results emphasize the need for multiple testing.

  9. Postoperative metabolic acidosis following the minimally invasive radiofrequency maze procedure

    Directory of Open Access Journals (Sweden)

    Raymond Patrick Hom

    2016-01-01

    Full Text Available Purpose: Atrial fibrillation (AF is the most common arrhythmia treated in the world. While medical treatment with antiarrhythmic drugs remains the primary treatment modality, symptomatic refractory AF often requires treatment with a catheter or surgical ablation. One minimally invasive therapy is the Mini-Maze procedure, which utilizes epicardial radiofrequency ablation via a subxiphoid approach to rid the heart of arrhythmogenic atrial foci without a median sternotomy or cardiopulmonary bypass. The goal of this retrospective cohort study was to identify clinical factors associated with metabolic acidosis following the Mini-Maze procedure. Materials and Methods: After Institutional Review Board approval, we studied patients undergoing the Mini-Maze procedure, off-pump coronary artery bypass grafting or patients conventional Cox-Maze on cardiopulmonary bypass. The first base deficit value obtained in the Intensive Care Unit was used as a measure of metabolic acidosis. Using logistic regression with Akaike information criteria, we analyzed preoperative, intraoperative, and postoperative data to determine the factors associated with changes in base deficit. Results: A multivariable model using stepwise selection demonstrated that diabetes mellitus and weight were associated with a decrease in the base deficit by 2.87 mEq/L (95% CI: −5.55-−0.19 and 0.04 mEq/L (95%CI: −0.08, 0.004, respectively. Furthermore, creatinine was associated with a 1.57 mEq/L (95% CI: 0.14, 2.99 increase in the base deficit. Conclusion: The Mini-Maze procedure was not associated with postoperative metabolic acidosis. Instead, nondiabetic patients and patients with higher creatinine were associated with greater base deficits after undergoing cardiac surgery.

  10. Postoperative metabolic acidosis following the minimally invasive radiofrequency maze procedure.

    Science.gov (United States)

    Hom, Raymond Patrick; Dubovoy, Anna; Jewell, Elizabeth; Engoren, Milo

    2016-01-01

    Atrial fibrillation (AF) is the most common arrhythmia treated in the world. While medical treatment with antiarrhythmic drugs remains the primary treatment modality, symptomatic refractory AF often requires treatment with a catheter or surgical ablation. One minimally invasive therapy is the Mini-Maze procedure, which utilizes epicardial radiofrequency ablation via a subxiphoid approach to rid the heart of arrhythmogenic atrial foci without a median sternotomy or cardiopulmonary bypass. The goal of this retrospective cohort study was to identify clinical factors associated with metabolic acidosis following the Mini-Maze procedure. After Institutional Review Board approval, we studied patients undergoing the Mini-Maze procedure, off-pump coronary artery bypass grafting or patients conventional Cox-Maze on cardiopulmonary bypass. The first base deficit value obtained in the Intensive Care Unit was used as a measure of metabolic acidosis. Using logistic regression with Akaike information criteria, we analyzed preoperative, intraoperative, and postoperative data to determine the factors associated with changes in base deficit. A multivariable model using stepwise selection demonstrated that diabetes mellitus and weight were associated with a decrease in the base deficit by 2.87 mEq/L (95% CI: -5.55--0.19) and 0.04 mEq/L (95%CI: -0.08, 0.004), respectively. Furthermore, creatinine was associated with a 1.57 mEq/L (95% CI: 0.14, 2.99) increase in the base deficit. The Mini-Maze procedure was not associated with postoperative metabolic acidosis. Instead, nondiabetic patients and patients with higher creatinine were associated with greater base deficits after undergoing cardiac surgery.

  11. Mini-maze suffices as adjunct to mitral valve surgery in patients with preoperative atrial fibrillation

    NARCIS (Netherlands)

    Tuinenburg, AE; Van Gelder, IC; Tieleman, RG; Grandjean, JG; Huet, RCG; Van der Maaten, JMAA; Pieper, EG; De Kam, PJ; Ebels, MSCT; Crijns, HJGM

    Mini-Maze and Mitral Valve Surgery. Introduction: After mitral valve (MV) surgery, preoperative atrial fibrillation (AF) often recurs while cardioversion therapy generally fails. Additional Cox maze surgery improves postoperative arrhythmia outcome, but the extensive nature of such an approach

  12. Dorsal periaqueductal gray stimulation facilitates anxiety-, but not panic-related, defensive responses in rats tested in the elevated T-maze

    Energy Technology Data Exchange (ETDEWEB)

    Camplesi, M. Jr. [Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, GO (Brazil); Bortoli, V.C. de [Departamento de Ciências da Saúde, Centro Universitário Norte do Espírito Santo, Universidade Federal do Espírito Santo, São Mateus, ES (Brazil); Paula Soares, V. de [Departamento de Biofísica e Farmacologia, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, RN (Brazil); Nogueira, R.L. [Laboratório de Psicologia Comparada, Universidade Estácio de Sá, Rio de Janeiro, RJ (Brazil); Zangrossi, H. Jr. [Departamento de Farmacologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

    2012-08-03

    The escape response to electrical or chemical stimulation of the dorsal periaqueductal gray matter (DPAG) has been associated with panic attacks. In order to explore the validity of the DPAG stimulation model for the study of panic disorder, we determined if the aversive consequences of the electrical or chemical stimulation of this midbrain area can be detected subsequently in the elevated T-maze. This animal model, derived from the elevated plus-maze, permits the measurement in the same rat of a generalized anxiety- and a panic-related defensive response, i.e., inhibitory avoidance and escape, respectively. Facilitation of inhibitory avoidance, suggesting an anxiogenic effect, was detected in male Wistar rats (200-220 g) tested in the elevated T-maze 30 min after DPAG electrical stimulation (current generated by a sine-wave stimulator, frequency at 60 Hz) or after local microinjection of the GABA{sub A} receptor antagonist bicuculline (5 pmol). Previous electrical (5, 15, 30 min, or 24 h before testing) or chemical stimulation of this midbrain area did not affect escape performance in the elevated T-maze or locomotion in an open-field. No change in the two behavioral tasks measured by the elevated T-maze was observed after repetitive (3 trials) electrical stimulation of the DPAG. The results indicate that activation of the DPAG caused a short-lived, but selective, increase in defensive behaviors associated with generalized anxiety.

  13. Elective Thoracoscopic Maze with Venoarterial Extracorporeal Life Support.

    Science.gov (United States)

    Stein, Erica J; Elsenraat, Abram; Sirak, John H; Mast, David; Gerhardt, Mark

    2015-09-01

    This case report describes the intraoperative use of extracorporeal life support (ECLS) for an elective thoracoscopic maze procedure in which the patient could not tolerate one-lung ventilation because of hypoxia. Potential pitfalls associated with the anesthetic management of elective intraoperative ECLS include managing native cardiac ejection and ECLS flows to provide optimal oxygenation and cardiac output. Particular attention must be paid to cardiac and respiratory physiology when ECLS is used in a patient with normal cardiac function.

  14. Dizocilpine (MK-801) impairs learning in the active place avoidance task but has no effect on the performance during task/context alternation

    Czech Academy of Sciences Publication Activity Database

    Vojtěchová, Iveta; Petrásek, Tomáš; Hatalová, Hana; Pištíková, Adéla; Valeš, Karel; Stuchlík, Aleš

    2016-01-01

    Roč. 305, May 15 (2016), s. 247-257 ISSN 0166-4328 R&D Projects: GA ČR(CZ) GA14-03627S Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M200111204 Institutional support: RVO:67985823 Keywords : task alternation * context alternation * active place avoidance * Morris water maze * Dizocilpine * schizophrenia Subject RIV: FH - Neurology Impact factor: 3.002, year: 2016

  15. Optimal Navigation of Self-Propelled Colloids in Microstructured Mazes

    Science.gov (United States)

    Yang, Yuguang; Bevan, Michael

    Controlling navigation of self-propelled microscopic `robots' subject to random Brownian motion in complex microstructured environments (e.g., porous media, tumor vasculature) is important to many emerging applications (e.g., enhanced oil recovery, drug delivery). In this work, we design an optimal feedback policy to navigate an active self-propelled colloidal rod in complex mazes with various obstacle types. Actuation of the rods is modelled based on a light-controlled osmotic flow mechanism, which produces different propulsion velocities along the rod's long axis. Actuator-parameterized Langevin equations, with soft rod-obstacle repulsive interactions, are developed to describe the system dynamics. A Markov decision process (MDP) framework is used for optimal policy calculations with design goals of colloidal rods reaching target end points in minimum time. Simulations show that optimal MDP-based policies are able to control rod trajectories to reach target regions order-of-magnitudes faster than uncontrolled rods, which diverges as maze complexity increases. An efficient multi-graph based implementation for MDP is also presented, which scales linearly with the maze dimension.

  16. The transfer from survey (map-like) to route representations into Virtual Reality Mazes: effect of age and cerebral lesion.

    Science.gov (United States)

    Carelli, Laura; Rusconi, Maria Luisa; Scarabelli, Chiara; Stampatori, Chiara; Mattioli, Flavia; Riva, Giuseppe

    2011-01-31

    To go from one place to another, we routinely generate internal representations of surrounding spaces, which can include egocentric (body-centred) and allocentric (world-centred) coordinates, combined into route and survey representations.Recent studies have shown how both egocentric and allocentric representations exist in parallel and are joined to support behaviour according to the task.Our study investigated the transfer from survey (map-like) to route representations in healthy and brain-damaged subjects. The aim was two-fold: first, to understand how this ability could change with age in a sample of healthy participants, aged from 40 to 71 years old; second, to investigate how it is affected after a brain lesion in a 8 patients' sample, with reference to specific neuropsychological frames. Participants were first required to perform the paper and pencil version of eight mazes, then to translate the map-like paths into egocentric routes, in order to find the right way into equivalent Virtual Reality (VR) mazes.Patients also underwent a comprehensive neuropsychological evaluation, including a specific investigation of some topographical orientation components. As regards the healthy sample, we found age-related deterioration in VR task performance. While education level and gender were not found to be related to performance, global cognitive level (Mini Mental State Examination), previous experience with computer and fluidity of navigation into the VR appeared to influence VR task results.Considering the clinical sample, there was a difficulty in performing the VR Maze task; executive functions and visuo-spatial abilities deficits appeared to be more relevant for predicting patients' results. Our study suggests the importance of developing tools aimed at investigating the survey to route transfer ability in both healthy elderly and clinical samples, since this skill seems high cognitive demanding and sensitive to cognitive decline.Human-computer interaction

  17. The transfer from survey (map-like to route representations into Virtual Reality Mazes: effect of age and cerebral lesion

    Directory of Open Access Journals (Sweden)

    Stampatori Chiara

    2011-01-01

    Full Text Available Abstract Background To go from one place to another, we routinely generate internal representations of surrounding spaces, which can include egocentric (body-centred and allocentric (world-centred coordinates, combined into route and survey representations. Recent studies have shown how both egocentric and allocentric representations exist in parallel and are joined to support behaviour according to the task. Our study investigated the transfer from survey (map-like to route representations in healthy and brain-damaged subjects. The aim was two-fold: first, to understand how this ability could change with age in a sample of healthy participants, aged from 40 to 71 years old; second, to investigate how it is affected after a brain lesion in a 8 patients' sample, with reference to specific neuropsychological frames. Methods Participants were first required to perform the paper and pencil version of eight mazes, then to translate the map-like paths into egocentric routes, in order to find the right way into equivalent Virtual Reality (VR mazes. Patients also underwent a comprehensive neuropsychological evaluation, including a specific investigation of some topographical orientation components. Results As regards the healthy sample, we found age-related deterioration in VR task performance. While education level and gender were not found to be related to performance, global cognitive level (Mini Mental State Examination, previous experience with computer and fluidity of navigation into the VR appeared to influence VR task results. Considering the clinical sample, there was a difficulty in performing the VR Maze task; executive functions and visuo-spatial abilities deficits appeared to be more relevant for predicting patients' results. Conclusions Our study suggests the importance of developing tools aimed at investigating the survey to route transfer ability in both healthy elderly and clinical samples, since this skill seems high cognitive

  18. Predictors of virtual radial arm maze performance in adolescent Italian children.

    Science.gov (United States)

    Braun, Joe M; Lucchini, Roberto; Bellinger, David C; Hoffman, Elaine; Nazzaro, Marco; Smith, Donald R; Wright, Robert O

    2012-10-01

    Comparisons between animal and human neurotoxicology studies are a foundation of risk assessment, but are hindered by differences in measured behaviors. The radial arm maze (RAM), a rodent visuospatial learning and memory task, has a computerized version for use in children, which may help improve comparisons between animal and human studies. To describe the characteristics and correlates of the virtual radial arm maze (VRAM) in 255 children age 10-15 years from Italy. We administered the VRAM using a laptop computer and measured children's performance using the latency, distance, and working/reference memory errors during eight trials. Using generalized linear mixed models, we described VRAM performance in relation to demographic factors, child activities, and several standard neuropsychologic tests (Italian translations), including the Conners Parent Rating Scales-Short Version (CPRS), California Verbal Learning Test (CVLT), Wechsler Intelligence Scales for Children, finger tapping speed, reaction time, and motor skills. Children's VRAM performance tended to improve between trials 1 and 6 and then plateaued between trials 6 and 8. Males finished the task 14 s faster (95% confidence interval [CI]: -20, -9) than females. Children who played 2+h of video games per day finished 16 s faster (CI: -26, -6) and with 34% (CI: 5, 54%) fewer working memory errors than children who reported not playing video games. Higher IQ and better CVLT scores were associated with better VRAM performance. Higher cognitive/inattention CPRS scores were associated with more working (11%; CI: 1, 22) and reference memory errors (7%; CI: 1, 12). Consistent with animal studies, VRAM performance improved over the course of test trials and males performed better than females. Better VRAM performance was related to higher IQ, fewer inattentive behaviors, and better verbal memory. The VRAM may help to improve the integration and comparison between animal and epidemiological studies of environmental

  19. Penerapan Algoritma Bactracking Pada Perancangan Line Maze Solver Robotic Berbasis Mikrokontroler Atmega32

    OpenAIRE

    Sembiring, Helmiwati

    2015-01-01

    Backtracking algorithm is usually used to find a way out on a maze. Maze is a tour puzzle in the form of a complex branching passage through which the solver must find a route. Line maze is a maze which made formed line. If line colored white, then the backgroud colored black and the otherwise. The problem is how to get the shortest-path of line maze by using Backtracking algorithm. Backtracking algorithm is consists of two modes namely search mode and return mode. In search mode, the robot...

  20. Un cas particulier du scénario dans l'apprentissage des langues : le labyrinthe (action maze Action Mazes: a special case of the scenario for language learning

    Directory of Open Access Journals (Sweden)

    Joseph Rézeau

    2008-03-01

    Full Text Available En didactique des langues l'approche actionnelle et les scénarios sont d'actualité, en lien avec les Tice (Technologies de l'Information et de la Communication pour l'Enseignement. Cependant, des activités de type labyrinthe (action mazes, courantes dans les années 1980 et souvent portées sur les micro-ordinateurs de l'époque, semblent quelque peu tombées dans l'oubli. Cet article entend montrer qu'il est relativement aisé de concevoir et de réaliser de telles activités sur une plateforme d'enseignement à distance telle que Moodle. Nous analyserons également l'impact d'une activité de type labyrinthe sur une population d'étudiants dans le cadre d'un enseignement d'anglais de type Lansad (langues pour spécialistes d'autres disciplines.The development of ICT in language teaching concurs with an interest in task-based approaches and scenarios. Surprisingly, however, such activities as "adventure games" and "action mazes" which were quite popular in CALL (Computer Assisted Language Learning in the 1980s seem to have fallen into oblivion. This article aims at demonstrating that it is relatively easy to design and implement "action mazes" on an LMS (Learning Management System such as Moodle. We shall then analyse the impact of an "action maze" learning activity on a population of students of ESP (English for Specific Purposes.

  1. The effect of Resveratrol flavonoid on learning and memory in passive avoidance and Y maze in diabetic rat

    Directory of Open Access Journals (Sweden)

    Sima Nasri

    2014-04-01

    Full Text Available Background: Diabetes type I is accompanied with disturbances in cognitive skills, memory and learning. In this research, we evaluated the effect of resveratrol chronic treatment on learning and memory in diabetic male rats. Material and Methods: Rats were divided into 4 groups: control, resveratrol-treated control, diabetic and resveratrol-treated diabetic groups. We used streptozotosin for inducing diabetes. Resveratrol (10mg/kg I.p. was administered for 8 weeks. For evaluation of learning and memory, passive avoidance test and Y-maze task were used. For Statistical analysis, SPSS software and paired T-test and one-way ANOVA were used. Results: Resveratrol decreased serum glucose in diabetic rats (P<0.01. In passive avoidance learning, there wasn’t any significant difference in initial latency between diabetic and treated- diabetic group. Also, a significant decrease of step latency was observed in diabetic and treated diabetic rats (P<0.01. In Y maze, Resveratrol improved alternation percentage in diabetic rats. Conclusion: Probably due to different mechanism of long term and short term memory, long term resveratrol treatment didn’t improve memory and learning in passive avoidance learning. In Y maze, method for determining the spatial memory, resveratrol improved spatial memory in diabetic rats. Resveratrol not only regulates glucose in diabetic rats but also it improves short term memory.

  2. Modeling, control and optimization of water systems systems engineering methods for control and decision making tasks

    CERN Document Server

    2016-01-01

    This book provides essential background knowledge on the development of model-based real-world solutions in the field of control and decision making for water systems. It presents system engineering methods for modelling surface water and groundwater resources as well as water transportation systems (rivers, channels and pipelines). The models in turn provide information on both the water quantity (flow rates, water levels) of surface water and groundwater and on water quality. In addition, methods for modelling and predicting water demand are described. Sample applications of the models are presented, such as a water allocation decision support system for semi-arid regions, a multiple-criteria control model for run-of-river hydropower plants, and a supply network simulation for public services.

  3. Task related doses in Spanish pressurized water reactors over the period 1988-1992

    Energy Technology Data Exchange (ETDEWEB)

    O`Donnell, P.; Labarta, T.; Amor, I. [Subdireccion de Proteccion Radiologica, Madrid (Spain)

    1995-03-01

    In order to evaluate in depth the collective dose trend and its correlation with the effectiveness of the practical application of the ALARA principle in Spanish nuclear facilities, and base the different policy lines to promote this criteria, the CSN has fullfilled an analysis of the task related doses data over the period 1988-1992. Previously, the CSN had required to the utilities the compilation of their refuelling outage collective dose from 1988 according with a predeterminate number of tasks, in order to have available a representative and retrospective set of data in an homogeneous way and coherent with the international data banks on occupational exposure in NPP, as the CEC and the NEA ones. The scope of this analysis was the following: first, the collective dose summaries for outage tasks and departments for PWR and for BWR, including the minimum, maximum and average dose (and statistics data) for 18 different refuelling outage tasks and 12 personal departments for each generation of each type of rector, the task and department related collective dose trends in each plant and in each generation, and second, the dose reduction techniques having been used during that period in each plant and the relative level of adoption. In this presentation the main results and conclusions of the first part of the study are reviewed for PWR.

  4. [Maze operation for chronic atrial fibrillation with valvular heart diseases].

    Science.gov (United States)

    Abe, T; Kukawi, K; Mawatari, T; Sakata, J; Komatsu, K; Urita, R; Komatsu, S

    1996-08-01

    Between July 1994 and August 1995, 14 patients underwent combined modified maze procedure and valvular surgery including 5 patients having reoperation. Associated procedures were performed with mitral valve operation (n = 13), tricuspid annuloplasty or valve replacement (n = 9) and aortic valve replacement (n = 4). Duration of atrial fibrillation (AF) varied from 1 to 18 years (mean 8.0 +/- 5.8 year), the f-wave voltage ranged from 0.05 to 0.5 mV (0.21 +/- 0.13 mV), left atrial dimension (LAD) ranged from 35.6 to 66.3 mm (49.0 +/- 9.3). One patient died 2 months after undergoing combined maze procedure and MVR + TAP due to pulmonary infection and sepsis, but the other 13 patients survived. Nine patients (69%) regained atrial rhythm, two patients (15%) had junctional rhythm and another two (15%) remained in AF at follow-up periods between 1 to 11.5 months (6.3 +/- 3.1). The nine patients who recovered to normal sinus rhythm had preoperative f-wave for a significant higher voltage than the patients with AF and JR (0.27 +/- 0.12 vs 0.13 +/- 0.05 mV, p < 0.05) and a smaller left atrial dimension (44.5 +/- 0.7 vs 54.8 +/- 6.9 mm, p < 0.05). These data suggest that the maze operation is effective and should be considered for patients with chronic AF indicated for surgical valvular diseases.

  5. Cows in the Maze And other mathematical explorations

    CERN Document Server

    Stewart, Ian

    2010-01-01

    From the mathematics of mazes, to cones with a twist, and the amazing sphericon - and how to make one - Ian Stewart is back with more mathematical stories and puzzles that are as quirky as they are fascinating, and each from the cutting edge of the world of mathematics. We find out about the mathematics of time travel, explore the shape of teardrops (which are not tear-drop shaped, but something much, much more strange!), dance with dodecahedra, and play the game of Hex, amongst many more strange and delightful mathematical diversions.

  6. Deuterium-depleted water has stimulating effects on long-term memory in rats.

    Science.gov (United States)

    Mladin, Cristian; Ciobica, Alin; Lefter, Radu; Popescu, Alexandru; Bild, Walther

    2014-11-07

    Deuterium-depleted water (DDW) is a water which has a 6-7-fold less concentration of the naturally occurring deuterium (20-25ppm vs. 150ppm). While administrated for a longer period, it may reduce the concentration of deuterium throughout the body, thus activating cellular mechanisms which are depending on protons (channels, pumps, enzyme proteins). The aim of the present work was to study, for the first time in our knowledge, the possible influence of deuterium-depleted water (DDW) chronic administration in normal Wistar rats, as compared to a control group which received distilled water, on spatial working memory and the locomotor activity (as studied through Y-maze) or both short-term and long-term spatial memory (assed in radial 8 arms-maze task). Our results presented here showed no significant modifications in terms of spatial working memory (assessed through spontaneous alternation percentage) and locomotor activity (expressed through the number of arm entries) in Y-maze, as a result of DDW ingestion. Also, no significant differences between the DDW and control group were found in terms of the number of working memory errors in the eight-arm radial maze, as a parameter of short-term memory. Still, we observed a significant decrease for the number of reference memory errors in the DDW rats. In this way, we could speculate that the administration of DDW may generate an improvement of the reference memory, as an index of long-term memory. Thus, we can reach the conclusion that the change between the deuterium/hydrogen balance may have important consequences for the mechanisms that govern long-term memory, as showed here especially in the behavioral parameters from the eight-arm radial maze task. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  7. LMFBR large valve development. Task II. IHTS isolation valve internals water test. Interim report

    Energy Technology Data Exchange (ETDEWEB)

    DeWall, L.; Perschler, J.

    1975-01-01

    The purpose of this program was to perform proof-of-principle (POP) testing in water of a reduced bore rotating offset ball valve as required by AEC Contract No. AT(04-3)-1035. The water POP test article is shown on AMCO Drawing 16-E-4020, Sheets 1 through 4, dated 3-18-74. This report presents the water flow test results and the leakage results for one of the three seal designs.

  8. Onpost/Offpost Ground/Surface Water Monitoring Program, Task 44

    Science.gov (United States)

    1988-03-01

    ROUPS - 3 QUARTERS SUAME ROUNDSS2 QUARTERSAPPROX. Wv20ELLS 20 .... .. .3 OFFOS W ELINTLLATO N DATA INPUT TASK 44 NETWORK ON - AND OFFPOST LONG TERM...marks the Denver-Arapahou contact III the RMA area. Several regional RMA geologic .ssessments indicate thai the geology and hydrology of RMA is quite...efforts in the areas of geology and hydrology to aid them in achieving specific goals. Comparisons to historical results and applicable standards will

  9. The Allocation of Tasks and Competencies in Dutch Water Management : Discussions, developments and present state

    NARCIS (Netherlands)

    Mostert, E.

    This report discusses subsidiarity in Dutch water management and forms the Dutch contribution to the Water 21 Phase II report on subsidiarity. Rather than discussing the Dutch interpretations of the concept (the concept is used almost exclusively in relation to the European Union), this report

  10. Kinematic and kinetic evidence for functional lateralization in a symmetrical motor task: the water polo eggbeater kick.

    Science.gov (United States)

    Oliveira, Nuno; Sanders, Ross H

    2015-03-01

    Bilaterality and motor lateralization have been associated with neural lateralization, suggesting that the dominant and non-dominant systems might have different specializations. The study of symmetrical motor tasks can provide evidence relating to this hypothesis. The water polo eggbeater kick is a skill comprising anti-phase and directionally opposite rotations of the right and left lower limbs to provide upward thrust to elevate the body. Effectiveness of the skill depends on moving the feet in predominantly horizontal directions with an orientation that produces lift throughout as much of the cycle as possible. The purpose of this study was to investigate the motor lateralization of the dominant (D) and non-dominant (ND) lower limbs during the execution of the water polo eggbeater kick technique. Twelve right-handed and right-footed water polo players performed eggbeater kicks in the vertical position to maintain maximum height. Three-dimensional kinematics and the pattern of vertical forces were quantified for nine cycles for each player. The pattern of vertical force produced showed asymmetries between the equivalent phases of the cycles of the dominant and non-dominant limbs (D, 222.8 N; ND, 201.0 N; p hip. Differences in the technique of the dominant and non-dominant side, particularly during the phase of knee flexion, supported the 'dynamic dominance theory' where each hemisphere/limb might be tuned to control different parameters of task performance.

  11. Improving Students’ English Pronunciation Ability Through Go Fish Game and Maze Game

    Directory of Open Access Journals (Sweden)

    Dwi Astuti Wahyu Nurhayati

    2015-12-01

    Full Text Available The problem highlighted in this research is the low pronunciation ability of Kindergarten students in Al-Irsyad  Madiun  that is caused by (1 the uninteresting activities in learning English; (2 the students' difficulties in pronunciating English words; (3 the students' low motivation in learning. The theoretical review includes the young learners characteristics, games in language, games for young learners. The procedure of the research consists of identifying the problem, planning the action, implementing the action, observing the action, and reflecting the result of the research. In this research, the researcher acts as the teacher who conducts the action research in the classroom and she is helped by the classsroom teacher. In collecting the data, the researcher uses observational technique supported with tests. In analyzing the data, the researcher uses the field notes, teacher's diaries, students ‘work supported with the cassette recording and photograph,then also compares the result of the students' pre-test and post-test to answer the research questions. There is significant improvement in the result of pre-test and post-test of cycle 1 and 2. In cycle 1, t0 (2.55734 is higher than tt (1.73 and in cycle 2, t0 (6.765738 is also higher than tt (1.73. From these two results, therefore, h0 is rejected and the alternative hypothesis (ha is accepted. They practice their pronunciation through taking turn and asking each other for cards to match those they have in their hands, arranging a word and sticking on alphabet, pronunciating the word, giving the meaning, hen making a sentence such as Go Fish Game and Maze Game. By conducting these games, using interesting media, creating various interesting tasks and activities can increase the students' motivation in learning English and pronunciation ability.Keywords: Improving, pronunciation, ability,  go fish and Maze games

  12. Cognitive enrichment for bottlenose dolphins (Tursiops truncatus): evaluation of a novel underwater maze device.

    Science.gov (United States)

    Clark, Fay E; Davies, Samuel L; Madigan, Andrew W; Warner, Abby J; Kuczaj, Stan A

    2013-01-01

    Cognitive enrichment is gaining popularity as a tool to enhance captive animal well-being, but research on captive cetaceans is lacking. Dolphin cognition has been studied intensively since the 1950s, and several hundred bottlenose dolphins are housed in major zoos and aquaria worldwide, but most dolphin enrichment consists of simple floating objects. The aim of this study was to investigate whether a novel, underwater maze device (UMD) was cognitively enriching for one group of male and one group of female dolphins at Six Flags Discovery Kingdom, CA. The dolphin's task was to navigate a rubber ball through a maze of pipes, towards an exit pipe. We also tested a modification where an edible gelatine ball fell into the pool once the UMD was solved. The UMD was provided to each group between 8 and 11 times over a 4-week period. Male dolphins used the UMD without prior training, whereas females did not use the UMD at all. Two male dolphins solved the UMD 17 times, using a variety of problem-solving strategies. The UMD had no significant effect on circular (repetitive) swimming patterns, but males spent significantly more time underwater when the UMD was present. Males used the UMD significantly more when it contained the rubber ball, but the gelatine ball stimulated social play. The UMD is a safe and practical device for captive dolphins. It now requires further testing on other dolphins, particularly females, to in order to examine whether the sex differences we observed are a general phenomenon. © 2013 Wiley Periodicals, Inc.

  13. A Facilitative Role for Corticosterone in the Acquisition of a Spatial Task Under Moderate Stress

    Science.gov (United States)

    Akirav, Irit; Kozenicky, Maya; Tal, Dadi; Sandi, Carmen; Venero, Cesar; Richter-Levin, Gal

    2004-01-01

    Emotionally charged experiences alter memory storage via the activation of hormonal systems. Previously, we have shown that compared with rats trained for a massed spatial learning task in the water maze in warm water (25°C), animals that were trained in cold water (19°C) performed better and showed higher levels of the stress hormone corticosterone. Here, we examined whether manipulating the levels of corticosterone can determine the strength of spatial information acquisition and retention. Rats were injected with metyrapone (25, 50, and 75 mg/kg, i.p.) or with corticosterone (10 and 25 mg/kg, i.p.) and trained in a massed spatial task in either cold (19°C) or warm (25°C) water. We found that whereas animals injected with vehicle performed well in the spatial task in cold water (moderate stress), rats injected with the intermediate metyrapone dose showed impairment in performance. Moreover, whereas animals injected with vehicle on average did not perform well in warm water (mild stress), rats injected with the lower corticosterone dose showed improvement in performance in warm water. These two mirror experiments of corticosterone blockade and enhancement strongly suggest that corticosterone is instrumental in the acquisition and retention of the spatial learning task. PMID:15054134

  14. Penentuan Nilai Motorik Halus Anak Dengan Game Magic Maze Menggunakan Metode Mamdani

    OpenAIRE

    Fadly, Muhammad

    2015-01-01

    Motor development is a very important factor in the development of the whole child. fine motor skills are very important because it affects the other terms of learning in early childhood. Therefore, it made the game Magic Maze to assess motor skills early childhood. Game Magic Maze in this study using Mamdani method in determining the values to a child's fine motor skills. Maze game will be made on the PC. 081402045

  15. The evaluation of the neutron dose equivalent in the two-bend maze.

    Science.gov (United States)

    Tóth, Á Á; Petrović, B; Jovančević, N; Krmar, M; Rutonjski, L; Čudić, O

    2017-04-01

    The purpose of this study was to explore the effect of the second bend of the maze, on the neutron dose equivalent, in the 15MV linear accelerator vault, with two bend maze. These two bends of the maze were covered by 32 points where the neutron dose equivalent was measured. There is one available method for estimation of the neutron dose equivalent at the entrance door of the two bend maze which was tested using the results of the measurements. The results of this study show that the neutron equivalent dose at the door of the two bend maze was reduced almost three orders of magnitude. The measured TVD in the first bend (closer to the inner maze entrance) is about 5m. The measured TVD result is close to the TVD values usually used in the proposed models for estimation of neutron dose equivalent at the entrance door of the single bend maze. The results also determined that the TVD in the second bend (next to the maze entrance door) is significantly lower than the TVD values found in the first maze bend. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  16. Research and development of a high efficiency gas-fired water heater. Volume 2. Task reports

    Energy Technology Data Exchange (ETDEWEB)

    Vasilakis, A.D.; Pearson, J.F.; Gerstmann, J.

    1980-01-01

    Design and development of a cost-effective high efficiency gas-fired water heater to attain a service efficiency of 70% (including the effect of exfiltration) and a service efficiency of 78% (excluding exfiltration) for a 75 GPD draw at a 90/sup 0/F temperature rise, with a stored water to conditioned air temperature difference of 80/sup 0/F, are described in detail. Based on concept evaluation, a non-powered natural draft water heater was chosen as the most cost-effective design to develop. The projected installed cost is $374 compared to $200 for a conventional unit. When the project water heater is compared to a conventional unit, it has a payback of 3.7 years and life cycle savings of $350 to the consumer. A prototype water heater was designed, constructed, and tested. When operated with sealed combustion, the unit has a service efficiency of 66.4% (including the effect of exfiltration) below a burner input of 32,000 Btu/h. In the open combustion configuration, the unit operated at a measured efficiency of 66.4% Btu/h (excluding exfiltration). This compares with a service efficiency of 51.3% for a conventional water heater and 61% for a conventional high efficiency unit capable of meeting ASHRAE 90-75. Operational tests showed the unit performed well with no evidence of stacking or hot spots. It met or exceeded all capacity or usage tests specified in the program test plan and met all emission goals. Future work will concentrate on designing, building, and testing pre-production units. It is anticipated that both sealed combustion and open draft models will be pursued.

  17. Effect of block of α-1-adrenoceptors on overall motor activity but not on spatial cognition in the object-position recognition task.

    Science.gov (United States)

    Levčík, D; Stuchlík, A; Klement, D

    2013-01-01

    Prazosin, an alpha(1)-adrenoceptor antagonist, is well known for its depressant effect on motivation and motor activity, while it has no effect on retention of spatial behavior in several tasks, e.g. in the Morris water maze and radial arm maze. The role of alpha(1)-adrenoceptors in operant tasks with stimulus-controlled behavior has not yet been tested. The present study investigated the effect of prazosin on the modulation of overall motor activity and on cognitive performance in a spatial operant task called object-position recognition task, where operant behavior (lever pressing) was controlled by spatial stimuli displayed on a computer screen. This task has been previously showed to be hippocampal-dependent. Pre-test injection of prazosin at the dose of 3 mg/kg decreased the responding rate, while it did not affect the recognition of object's position. In conclusion, we validated the new cognitive test with a drug with known pharmacological effects on behavior and confirmed the depressant effect of prazosin on motor activity and no effect on retrieval of spatial memory in the hippocampal-dependent operant task.

  18. Task 27 -- Alaskan low-rank coal-water fuel demonstration project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

    Development of coal-water-fuel (CWF) technology has to-date been predicated on the use of high-rank bituminous coal only, and until now the high inherent moisture content of low-rank coal has precluded its use for CWF production. The unique feature of the Alaskan project is the integration of hot-water-drying (HWD) into CWF technology as a beneficiation process. Hot-water-drying is an EERC developed technology unavailable to the competition that allows the range of CWF feedstock to be extended to low-rank coals. The primary objective of the Alaskan Project, is to promote interest in the CWF marketplace by demonstrating the commercial viability of low-rank coal-water-fuel (LRCWF). While commercialization plans cannot be finalized until the implementation and results of the Alaskan LRCWF Project are known and evaluated, this report has been prepared to specifically address issues concerning business objectives for the project, and outline a market development plan for meeting those objectives.

  19. A Virtual Radial Arm Maze for the Study of Multiple Memory Systems in a Functional Magnetic Resonance Imaging Environment.

    Science.gov (United States)

    Xu, Dongrong; Hao, Xuejun; Wang, Zhishun; Duan, Yunsuo; Liu, Feng; Marsh, Rachel; Yu, Shan; Peterson, Bradley S

    2012-06-01

    An increasing number of functional brain imaging studies are employing computer-based virtual reality (VR) to study changes in brain activity during the performance of high-level psychological and cognitive tasks. We report the development of a VR radial arm maze that adapts for human use in a scanning environment with the same general experimental design of behavioral tasks as that has been used with remarkable effectiveness for the study of multiple memory systems in rodents. The software platform is independent of specific computer hardware and operating systems, as we aim to provide shared access to this technology by the research community. We hope that doing so will provide greater standardization of software platform and study paradigm that will reduce variability and improve the comparability of findings across studies. We report the details of the design and implementation of this platform and provide information for downloading of the system for demonstration and research applications.

  20. Characterization of Maze Performance in Adrenalectomized Sleep Disrupted Rats: A Comparison of Radial Arm Maze Performance between Adrenalectomized and Sham Adrenalectomized Sleep Disrupted Rats

    National Research Council Canada - National Science Library

    Mery, Laura

    2007-01-01

    .... Animals adrenalectomized and sham adrenalectomized were trained to criterion in the eight arm radial maze, and sleep disrupted for 12 hours during the light phase using a modified flowerpot in a cage...

  1. Characterization of Maze Performance in Adrenalectomized Sleep Disrupted Rats: A Comparison of Radial Arm Maze Performance Between Adrenalectromized and Sham Adrenalectomized Sleep Disrupted Rats

    National Research Council Canada - National Science Library

    Mery, Laura

    2007-01-01

    .... Animals adrenalcetomized and sham adrenalectomized were trained to criterion in the eight arm radial maze, and sleep disrupted for 12 hours during the light phase using a modified flowerpot in a cage...

  2. Nanotechnology applications to desalination : a report for the joint water reuse & desalination task force.

    Energy Technology Data Exchange (ETDEWEB)

    Brady, Patrick Vane; Mayer, Tom; Cygan, Randall Timothy

    2011-01-01

    Nanomaterials and nanotechnology methods have been an integral part of international research over the past decade. Because many traditional water treatment technologies (e.g. membrane filtration, biofouling, scale inhibition, etc.) depend on nanoscale processes, it is reasonable to expect one outcome of nanotechnology research to be better, nano-engineered water treatment approaches. The most immediate, and possibly greatest, impact of nanotechnology on desalination methods will likely be the development of membranes engineered at the near-molecular level. Aquaporin proteins that channel water across cell membranes with very low energy inputs point to the potential for dramatically improved performance. Aquaporin-laced polymer membranes and aquaporin-mimicking carbon nanotubes and metal oxide membranes developed in the lab support this. A critical limitation to widespread use of nanoengineered desalination membranes will be their scalability to industrial fabrication processes. Subsequent, long-term improvements in nanoengineered membranes may result in self-healing membranes that ideally are (1) more resistant to biofouling, (2) have biocidal properties, and/or (3) selectively target trace contaminants.

  3. Learning about cognition risk with the radial-arm maze in the developmental neurotoxicology battery.

    Science.gov (United States)

    Levin, Edward D

    2015-01-01

    Cognitive dysfunction has been found in epidemiological studies to be among the most sensitive impairments associated with developmental exposure to a variety of environmental contaminants from heavy metals to polyhalogenated hydrocarbons and pesticides. These chemicals have been also shown to impair cognitive function after developmental exposure in experimental animal models. The radial-arm maze (RAM) has proven to be a sensitive and reliable way to assess both learning and memory in a variety of species, most often in rats and mice. The RAM is a very adaptable test method that takes advantage of rodents' instinct to explore new places in the environment to forage. That is, rodents do not need to be trained to run through the maze; they will normally do this from the initial session of testing. Training with differential reinforcement for arm choices provides a more rigorous test of learning and memory. The RAM is quite adaptable for assessing various aspects of cognition. Although the RAM has been mostly used to assess spatial learning and memory, it can be configured to assess non-spatial memory as well. Both working and reference memory can be easily distinguished. The RAM can be run with both appetitive (food reinforced) and aversive (water escape) motivators. The RAM has been found to be sensitive to a wide variety of developmental toxicants including heavy metals such as mercury and pesticides such as chlorpyrifos. There is an extremely rich literature especially with rats showing the effects of many types of brain lesions and drug effects so that the participation of a wide variety of neural systems in RAM performance is known. These systems, notably the hippocampus and frontal cortex, and acetylcholine and glutamate neurotransmitter systems, are the same neural systems that have been shown in humans to be critical for learning and memory. This considerably aids the interpretation of neurobehavioral toxicity studies. Copyright © 2015 Elsevier Inc. All

  4. Effects of Amphetamine and β-Endorphin Fragments on Maze Performance in Rats

    NARCIS (Netherlands)

    Boer, S. de; Bohus, B.

    1990-01-01

    Fragments of β-endorphin and amphetamine cause similar effects in some tests of maze behavior in rats. The present study served to compare the influence of amphetamine and two β-endorphin fragments [β-endorphin (βE)-(2-9) and βE-(2-16)] on maze behavior in more detail. In Experiment I no significant

  5. Effects of amphetamine and beta-endorphin fragments on maze performance in rats

    NARCIS (Netherlands)

    Bohus, B; de Boer, S.F.

    Fragments of beta-endorphin and amphetamine cause similar effects in some tests of maze behavior in rats. The present study served to compare the influence of amphetamine and two beta-endorphin fragments [beta-endorphin (beta E)-(2-9) and beta E-(2-16)] on maze behavior in more detail. In Experiment

  6. The Use of the Arabic CBM Maze among Three Levels of Achievers in Jordan

    Science.gov (United States)

    Abu-Hamour, Bashir

    2013-01-01

    This study examined the applicability of the Arabic version of the Curriculum Based Measurement Maze (CBM Maze) for Jordanian students. A sample of 150 students was recruited from two public primary schools in Jordan. The students were ranked into high, moderate, and low achievers in terms of their performance in the Arabic course. Then all of…

  7. The optomotor maze: a population assay for visual perception in Drosophila.

    Science.gov (United States)

    van Swinderen, Bruno

    2011-11-01

    Vision is a major sensory modality in Drosophila behavior, with more than one-half of the Drosophila brain devoted to visual processing. The mechanisms of vision in Drosophila can now be studied in individuals and in populations of flies by using various paradigms. The optomotor maze, described here, is a novel and efficient approach for querying visual perception in Drosophila populations. The optomotor maze setup is very simple: An eight-choice maze consisting of 3-mm paths grooved into a transparent Plexiglas or acrylic slab is placed over an upturned cathode ray tube (CRT) monitor on which visuals are displayed. The placement or movement of the visuals on the CRT, which the flies can see through the flat bottom of the maze, influences their turning behavior at each choice point. This paradigm can be adapted for visual learning by simply rerunning flies in the maze (habituation) or as a more sophisticated version of the aversive phototaxic suppression (APS) paradigm.

  8. Ocean thermal energy conversion cold water pipe preliminary design project. Task 2. Analysis for concept selection

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-04-01

    The successful performance of the CWP is of crucial importance to the overall OTEC system; the pipe itself is considered the most critical part of the entire operation. Because of the importance the CWP, a project for the analysis and design of CWP's was begun in the fall of 1978. The goals of this project were to study a variety of concepts for delivering cold water to an OTEC plant, to analyze and rank these concepts based on their relative cost and risk, and to develop preliminary design for those concepts which seemed most promising. Two representative platforms and sites were chosen: a spar buoy of a Gibbs and Cox design to be moored at a site off Punta Tuna, Puerto Rico, and a barge designed by APL/Johns Hopkins University, grazing about a site approximately 200 miles east of the coast of Brazil. The approach was to concentrate on the most promising concepts and on those which were either of general interest or espoused by others (e.g., steel and concrete concepts). Much of the overall attention, therefore, focused on analyzing rigid and compliant wall design, while stockade (except for the special case of the FRP stockade) and bottom-mounted concepts received less attention. A total of 67 CWP concepts were initially generated and subjected to a screening process. Of these, 16 were carried through design analysis, costing, and ranking. Study results are presented in detail. (WHK)

  9. Serotonin in anxiety and panic: contributions of the elevated T-maze.

    Science.gov (United States)

    Zangrossi, Hélio; Graeff, Frederico G

    2014-10-01

    The elevated T-maze (ETM) was developed to test the hypothesis that serotonin (5-HT) plays an opposing role in the regulation of defensive behaviors associated with anxiety and panic. This test allows the measurement in the same rat of inhibitory avoidance acquisition, related to generalized anxiety disorder, and of one-way escape, associated with panic disorder. The evidence so far reported with the ETM supports the above hypothesis and indicates that: (1) whereas 5-HT neurons located at the dorsal raphe nucleus are involved in the regulation of both inhibitory avoidance and escape, those of the median raphe nucleus are primarily implicated in the former task; (2) facilitation of 5-HT1A- and 5-HT2A-mediated neurotransmission in the dorsal periaqueductal gray (dPAG) is likely to mediate the panicolytic drug action; (3) stimulation of 5-HT2C receptors in the basolateral amygdala increases anxiety and is implicated in the anxiogenesis caused by short-term administration of antidepressant drugs, and (4) 5-HT1A and the μ-opioid receptors work together in the dPAG to modulate escape or panic attacks. These last results point to the possible benefits of adjunctive opioid therapy for panic patients resistant to antidepressants that act on 5-HT neurotransmission. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Spatial Representation of Hippocampal Place Cells in a T-Maze with an Aversive Stimulation

    Directory of Open Access Journals (Sweden)

    Sakura Okada

    2017-12-01

    Full Text Available The hippocampus contains place cells representing spaces in an environment, and these place cells have been suggested to play a fundamental role in the formation of a cognitive map for spatial processing. However, how alterations in the firing patterns of place cells in response to aversive events encode the locations tied to these aversive events is unknown. Here, we analyzed spiking patterns of place cell ensembles in the dorsal hippocampal CA1 region of rats performing a T-maze alternation task with an aversive air-puff stimulation applied at a specific location on one side of a trajectory. The intensity of the air puff was adjusted so that the rats decreased their running speed before passing the aversive location. The addition of the aversive stimulus induced reorganization of place cell ensembles on both left and right trajectories with and without the aversive stimulus, respectively. Specifically, the animals showed a more abundant spatial representation in the vicinity of the aversive location. Removing the aversive stimulus induced new spatial firing patterns on both of the trajectories that differed from those both before and during application of the aversive stimulus. These results demonstrate that hippocampal spatial maps are flexibly reorganized to represent particular aversive events.

  11. Spatial Representation of Hippocampal Place Cells in a T-Maze with an Aversive Stimulation.

    Science.gov (United States)

    Okada, Sakura; Igata, Hideyoshi; Sasaki, Takuya; Ikegaya, Yuji

    2017-01-01

    The hippocampus contains place cells representing spaces in an environment, and these place cells have been suggested to play a fundamental role in the formation of a cognitive map for spatial processing. However, how alterations in the firing patterns of place cells in response to aversive events encode the locations tied to these aversive events is unknown. Here, we analyzed spiking patterns of place cell ensembles in the dorsal hippocampal CA1 region of rats performing a T-maze alternation task with an aversive air-puff stimulation applied at a specific location on one side of a trajectory. The intensity of the air puff was adjusted so that the rats decreased their running speed before passing the aversive location. The addition of the aversive stimulus induced reorganization of place cell ensembles on both left and right trajectories with and without the aversive stimulus, respectively. Specifically, the animals showed a more abundant spatial representation in the vicinity of the aversive location. Removing the aversive stimulus induced new spatial firing patterns on both of the trajectories that differed from those both before and during application of the aversive stimulus. These results demonstrate that hippocampal spatial maps are flexibly reorganized to represent particular aversive events.

  12. Easy rider: monkeys learn to drive a wheelchair to navigate through a complex maze.

    Science.gov (United States)

    Etienne, Stephanie; Guthrie, Martin; Goillandeau, Michel; Nguyen, Tho Hai; Orignac, Hugues; Gross, Christian; Boraud, Thomas

    2014-01-01

    The neurological bases of spatial navigation are mainly investigated in rodents and seldom in primates. The few studies led on spatial navigation in both human and non-human primates are performed in virtual, not in real environments. This is mostly because of methodological difficulties inherent in conducting research on freely-moving monkeys in real world environments. There is some incertitude, however, regarding the extrapolation of rodent spatial navigation strategies to primates. Here we present an entirely new platform for investigating real spatial navigation in rhesus monkeys. We showed that monkeys can learn a pathway by using different strategies. In these experiments three monkeys learned to drive the wheelchair and to follow a specified route through a real maze. After learning the route, probe tests revealed that animals successively use three distinct navigation strategies based on i) the place of the reward, ii) the direction taken to obtain reward or iii) a cue indicating reward location. The strategy used depended of the options proposed and the duration of learning. This study reveals that monkeys, like rodents and humans, switch between different spatial navigation strategies with extended practice, implying well-conserved brain learning systems across different species. This new task with freely driving monkeys provides a good support for the electrophysiological and pharmacological investigation of spatial navigation in the real world by making possible electrophysiological and pharmacological investigations.

  13. Easy rider: monkeys learn to drive a wheelchair to navigate through a complex maze.

    Directory of Open Access Journals (Sweden)

    Stephanie Etienne

    Full Text Available The neurological bases of spatial navigation are mainly investigated in rodents and seldom in primates. The few studies led on spatial navigation in both human and non-human primates are performed in virtual, not in real environments. This is mostly because of methodological difficulties inherent in conducting research on freely-moving monkeys in real world environments. There is some incertitude, however, regarding the extrapolation of rodent spatial navigation strategies to primates. Here we present an entirely new platform for investigating real spatial navigation in rhesus monkeys. We showed that monkeys can learn a pathway by using different strategies. In these experiments three monkeys learned to drive the wheelchair and to follow a specified route through a real maze. After learning the route, probe tests revealed that animals successively use three distinct navigation strategies based on i the place of the reward, ii the direction taken to obtain reward or iii a cue indicating reward location. The strategy used depended of the options proposed and the duration of learning. This study reveals that monkeys, like rodents and humans, switch between different spatial navigation strategies with extended practice, implying well-conserved brain learning systems across different species. This new task with freely driving monkeys provides a good support for the electrophysiological and pharmacological investigation of spatial navigation in the real world by making possible electrophysiological and pharmacological investigations.

  14. Radial maze performance in three strains of mice - Role of the fimbria/fornix

    Science.gov (United States)

    Reinstein, D. K.; Deboissiere, T.; Robinson, N.; Wurtman, R. J.

    1983-01-01

    Three strains of mice were tested on an 8-arm radial maze, an index of hippocampus-dependent spatial memory. Levels of performance differed betweens strains with C57Br/cdj greater than Balb/cj greater than C57B1/6j. Lesions of the fimbria/fornix disrupted performance in the C57Br and Balb strains: the C57Bl mice never performed better than chance before or after surgery. Choline acetyltransferase activity in hippocampus was not correlated with radial maze performance. These findings suggest a possible genetic contribution towards radial maze behavior.

  15. Inflorescence development in petunia: through the maze of botanical terminology.

    Science.gov (United States)

    Castel, Rob; Kusters, Elske; Koes, Ronald

    2010-05-01

    Flowering plants have developed many ways to arrange their flowers. A flower-bearing branch or system of branches is called an inflorescence. The number of flowers that an inflorescence contains ranges from a single flower to endless flower-clusters. Over the past centuries, botanists have classified inflorescences based on their morphology, which has led to an unfortunate maze of complex botanical terminology. With the rise of molecular developmental biology, research has become increasingly focused on how inflorescences develop, rather than on their morphology. It is the decisions taken by groups of stem cells at the growing tips of shoots, called meristems, on when and where to produce a flower or a shoot that specify the course of inflorescence development. Modelling is a helpful aid to follow the consequences of these decisions for inflorescence development. The so-called transient model can produce the broad inflorescence types: cyme, raceme, and panicle, into which most inflorescences found in nature can be classified. The analysis of several inflorescence branching mutants has led to a solid understanding of cymose inflorescence development in petunia (Petunia hybrida). The cyme of petunia is a distinct body plan compared with the well-studied racemes of Arabidopsis and Antirrhinum, which provides an excellent opportunity to study evolutionary developmental biology (evo-devo) related questions. However, thus far, limited use has been made of this opportunity, which may, at least in part, be due to researchers getting lost in the terminology. Some general issues are discussed here, while focusing on inflorescence development in petunia.

  16. The elevated plus-maze is not sensitive to the effect of stressor controllability in rats.

    Science.gov (United States)

    Grahn, R E; Kalman, B A; Brennan, F X; Watkins, L R; Maier, S F

    1995-11-01

    The present experiments examined the sensitivity of the elevated plus-maze to the effects of stressor controllability. Previous work had established that inescapable but not an equal amount of escapable electric tail shock reduced social interaction. The present experiments demonstrate that prior exposure to shock alters elevated plus-maze behavior, but that this effect is not sensitive to the escapability of the shock. These experiments include a replication of the usual pharmacologic effects of benzodiazepine ligands (2 mg/kg diazepam; 0.4 mg/kg methyl 6,7-dimethoxy-4-ethyl-beta-carboline-3-carboxylate) to demonstrate the sensitivity of the elevated plus-maze procedures used. The results provide additional support for the idea that the social interaction and elevated plus-maze measures of "anxiety" are sensitive to different processes.

  17. Modified radial v/s biatrial maze for atrial fibrillation in rheumatic valvular heart surgery

    Directory of Open Access Journals (Sweden)

    Sajid A. Sayed

    2014-09-01

    Discussion: In patients with AF undergoing rheumatic valvular surgery, radiofrequency radial approach is as effective as modified Cox's maze III for conversion to NSR with better atrial transport function.

  18. Chronic stress leaves novelty-seeking behavior intact while impairing spatial recognition memory in the Y-maze.

    Science.gov (United States)

    Wright, Ryan L; Conrad, Cheryl D

    2005-06-01

    This experiment examined whether chronic stress disrupts novelty-seeking behavior under conditions that impair spatial memory. Rats were restrained for 6 h per day for 21 days, then tested in either a traditional spatial recognition Y-maze that requires extra-maze spatial cues to navigate or a version with salient intra-maze cues in addition to the extra-maze spatial cues. As previously shown, chronic restraint stress impaired performance on the spatial version of the Y-maze. However, chronically stressed rats performed well in the intra-maze cue version. The results indicate that the deficits in Y-maze performance following chronic stress are not attributed to neophobia, but likely reflect neurochemical and/or neurobiological changes underlying spatial memory ability.

  19. Active Brownian particles and run-and-tumble particles separate inside a maze

    Science.gov (United States)

    Khatami, Maryam; Wolff, Katrin; Pohl, Oliver; Ejtehadi, Mohammad Reza; Stark, Holger

    2016-11-01

    A diverse range of natural and artificial self-propelled particles are known and are used nowadays. Among them, active Brownian particles (ABPs) and run-and-tumble particles (RTPs) are two important classes. We numerically study non-interacting ABPs and RTPs strongly confined to different maze geometries in two dimensions. We demonstrate that by means of geometrical confinement alone, ABPs are separable from RTPs. By investigating Matryoshka-like mazes with nested shells, we show that a circular maze has the best filtration efficiency. Results on the mean first-passage time reveal that ABPs escape faster from the center of the maze, while RTPs reach the center from the rim more easily. According to our simulations and a rate theory, which we developed, ABPs in steady state accumulate in the outermost region of the Matryoshka-like mazes, while RTPs occupy all locations within the maze with nearly equal probability. These results suggest a novel technique for separating different types of self-propelled particles by designing appropriate confining geometries without using chemical or biological agents.

  20. Cox-maze IV cryoablation and postoperative heart failure in mitral valve surgery patients.

    Science.gov (United States)

    Boano, Gabriella; Åström Aneq, Meriam; Kemppi, Jennie; Vánky, Farkas

    2017-02-01

    The indications for and the risk and benefit of concomitant surgical ablation for atrial fibrillation (AF) have not been fully delineated. Our aim was to survey whether the Cox-maze IV procedure is associated with postoperative heart failure (PHF) or other adverse short-term outcomes after mitral valve surgery (MVS). Consecutive patients with AF undergoing MVS with (n = 50) or without (n = 66) concomitant Cox-maze IV cryoablation were analysed regarding perioperative data and one-year mortality. The patients in the Maze group were younger, were in lower NYHA classes, had better right ventricular function and had lower pulmonary artery pressure. The Maze group had 30 min longer median cross-clamp time (CCT) and 50% had PHF compared with 33% in the No-maze group, p = 0.09. Two patients in the No-maze group died within one year of surgery. Congestive heart failure (OR 4.3 [CI 95%: 1.8-10], p < 0.0001) and CCT (OR 1.03 [CI 95%: 1.01-1.04], p = 0.001) were associated with PHF. The current data cannot exclude that concomitant cryoablation increases the risk for PHF, possibly by increasing the cross clamp time.

  1. Impaired tunnel-maze behavior in rats with sensory lesions: vestibular and auditory systems.

    Science.gov (United States)

    Schaeppi, U; Krinke, G; FitzGerald, R E; Classen, W

    1991-01-01

    Maze behavior of rodents provides insight into processes of learning and memory and also serves to assess cognitive functions in neurotoxicity tests. Neurotoxic agents may impair maze behavior by acting upon different parts of the nervous system. To assess the dependence of maze learning upon vestibular and/or auditory input, the two systems were lesioned. Daily treatment of rat pups with streptomycin (400 mg/kg sc) on postnatal day 11 to 22 caused irreversible impairment of vestibular and auditory functions, whereas, 20 injections of neomycin in adult rats (100 mg/kg sc, postnatal weeks 8 to 11) led to hearing loss only. Hearing loss was assessed by absence of Preyer's reflex and impaired vestibular function by loss or shortened duration of postrotatory nystagmus. Learning in the unbaited 6-arm radial maze was tested at the age of 2 to 3 mon using a maze configuration that allowed to assess order of arm entries ("working memory") and left-right discrimination within each arm ("reference memory"). Treatment with streptomycin but not with neomycin led to impaired order of arm entries. Since treatment with streptomycin failed to induce any signs of brain lesions, impaired maze learning is considered to result from destruction of vestibular hair cell receptors with subsequent vestibular impairment and not from hearing loss or cognitive impairment.

  2. Cox-Maze III procedure with valvular surgery in an autopneumonectomized patient

    Directory of Open Access Journals (Sweden)

    Wi Jin

    2012-11-01

    Full Text Available Abstract Destructive pulmonary inflammation can leave patients with only a single functional lung, resulting in anatomical and physiological changes that may interfere with subsequent cardiac surgeries. Such patients are vulnerable to perioperative cardiopulmonary complications. Herein, we report the first case, to our knowledge, of an autopneumonectomized patient who successfully underwent a modified Cox-Maze III procedure combined with valvular repairs. The three major findings in this case can be summarized as follows: (1 a median sternotomy with peripheral cannulations, such as femoral cannulations, can provide an optimal exposure and prevent the obstruction of vision that may occur as a result of multiple cannulations through a median sternotomy; (2 a modified septal incision combined with biatrial incisions facilitate adequate exposure of the mitral valve; and (3 the aggressive use of intraoperative ultrafiltration may be helpful for the perioperative managements as decreasing pulmonary water contents, thereby avoiding the pulmonary edema associated with secretion of inflammatory cytokines during a cardiopulmonary bypass. We also provide several suggestions for achieving similar satisfactory surgical outcomes in patients with a comparable condition.

  3. Groundwater Quality Changes in a Karst Aquifer of Northeastern Wisconsin, USA: Reduction of Brown Water Incidence and Bacterial Contamination Resulting from Implementation of Regional Task Force Recommendations

    Directory of Open Access Journals (Sweden)

    Kevin Erb

    2015-08-01

    Full Text Available In the Silurian Dolostone region of eastern Wisconsin, the combination of thin soils and waste application (animal manure, organic waste has led to significant groundwater contamination, including Brown Water Incidents (BWIs—contamination resulting in a color or odor change in well water and detections of pathogen indicator bacteria such as E. coli and others. In response, a Karst Task Force (KTF was convened to identify risks and recommend solutions. This article looks at the impact eight years after the 2007 Karst Task Force report—both the actions taken by local resource managers and the changes to water quality. We present the first regional analysis of the 2007 Karst Task Force report and subsequent regulatory changes to determine if these regulations impacted the prevalence of wells contaminated with animal waste and the frequency of BWIs. While all of the counties in the KTF area promoted increased awareness, landowner/manager and waste applicator education alone did not result in a drop in BWIs or other water quality improvements. The two counties in the study that adopted winter manure spreading restrictions on frozen or snow-covered ground showed statistically significant reductions in the instances of BWIs and other well water quality problems.

  4. [Environmental investigation of ground water contamination at Wright- Patterson Air Force Base, Ohio]. Volume 4, Health and Safety Plan (HSP); Phase 1, Task 4 Field Investigation report: Draft

    Energy Technology Data Exchange (ETDEWEB)

    1991-10-01

    This Health and Safety Plan (HSP) was developed for the Environmental Investigation of Ground-water Contamination Investigation at Wright-Patterson Air Force Base near Dayton, Ohio, based on the projected scope of work for the Phase 1, Task 4 Field Investigation. The HSP describes hazards that may be encountered during the investigation, assesses the hazards, and indicates what type of personal protective equipment is to be used for each task performed. The HSP also addresses the medical monitoring program, decontamination procedures, air monitoring, training, site control, accident prevention, and emergency response.

  5. Water management. A core task of the Wismut remediation programme; Kernaufgaben des langfristigen Wassermanagements an den saechsisch-thueringischen Wismut-Standorten

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Michael; Meyer, Juergen; Jenk, Ulf; Kassahun, Andrea; Schramm, Andrea; Baacke, Delf; Forbrig, Norbert; Metschies, Thomas [Wismut GmbH, Chemnitz (Germany). Bereich Ingenieurwesen/Strahlenschutz

    2015-07-01

    Water management and conventional technical water treatment are by far the most cost-intensive long-term tasks of the Wismut remediation programme. Over the medium term, there is no viable alternative to the operation of active systems to catch and treat contaminated mine waters at the Ronneburg, Schlema, Koenigstein, Poehla, Seelingstaedt and Heimsdorf sites. Based on the status quo this paper outlines the key issues of the Wismut GmbH water management strategy over the medium and long term. lt is focused primarily on achieving protection goals for potentially impacted water bodies in the surroundings of Wismut sites and on optimising associated remediation expenditure as well as on creating the prerequisites for achieving low post-remedial care and maintenance or walk-away system status over the long term. The topic of this paper is the presentation of priority tasks related to future water management at Wismut sites in Saxony and Thuringia. The reflections are based on experiences and lessons learned and take into account current statutory management requirements referring to ground and surface water bodies affected by Wismut. The paper is based on a presentation made at the International Mining Symposium WISSYM 2015 on 2nd September 2015 in Bad Schlema, Germany.

  6. Effects of an electrolytic lesion of the prelimbic area on anxiety-related and cognitive tasks in the rat

    NARCIS (Netherlands)

    Gispen, W.H.; Maaswinkel, H.; Spruijt, B.M.

    1996-01-01

    The aim of this paper was to study the role of the prelimbic area of rats in response selection. A bilateral electrolytic lesion was made in the prelimbic area. The rats were tested in the Morris water-maze, the conditioned shock-prod burying test, the elevated plus-maze, a modified open field test,

  7. Postnatal MK-801 treatment of female rats impairs acquisition of working memory, but not reference memory in an eight-arm radial maze; no beneficial effects of enriched environment.

    Science.gov (United States)

    Nozari, Masoumeh; Mansouri, Farshad Alizadeh; Shabani, Mohammad; Nozari, Hojat; Atapour, Nafiseh

    2015-07-01

    Memory impairment has been documented in MK-801 (NMDA receptor antagonist) model of schizophrenia, but less is known on the rescue and/or differential effects of MK-801 on short- and long-term memories. We determined the effects of MK-801 treatment and/or enriched environment (EE) on acquisition of reference and working memory in developing rats. Female Wistar rats were injected with MK-801 (1 mg/kg) from postnatal days (P) 6-10. Task acquisition, working memory error (WME), and reference memory error (RME) were assessed in an eight-arm radial maze task. Behavioral performance of rats was also tested in an open field test before (P35-P40) and after (P65-P70) radial maze training to assess anxiety and locomotion. EE was applied from birth up to the end of experiments. MK-801 treatment did not influence task acquisition in the radial maze; however, by the end of training, MK-801-treated rats made significantly more WME, but not RME, compared to control rats. Ratio of WME to total error was also significantly higher in MK-801 group. EE prevented MK-801-associated behaviors in the open field but did not exert beneficial effects on working memory deficit in the radial maze task. EE per se affected behavioral performance of rats only in the open field test. Our results suggest that postnatal MK-801 treatment differentially affects working and reference memory in a young brain. Anxiety and hyperactivity associated with MK-801 are observed more severely in adulthood. Dissociation of the positive effects of EE may suggest selective modification of distinct pathways.

  8. Effects of an early experience involving training in a T-maze under either denial or receipt of expected reward through maternal contact.

    Directory of Open Access Journals (Sweden)

    Antonios eStamatakis

    2013-11-01

    Full Text Available The mother is the most salient stimulus for the developing pups and a number of early experience models employ manipulation of the mother-infant interaction. We have developed a new model which in addition to changes in maternal behavior includes a learning component on the part of the pups. More specifically, pups were trained in a T-maze and either received (RER rats or were denied (DER the reward of maternal contact, during postnatal days 10—13.Pups of both experimental groups learn the T-maze, but the RER do so more efficiently utilizing a procedural-type of learning and memory with activation of the dorsal basal ganglia. On the other hand, the DER experience leads to activation of the hippocampus, prefrontal cortex and amygdala in the pups.In adulthood, male DER animals exhibit better mnemonic abilities in the Morris water maze and higher activation of the hippocampus, while they have decreased brain serotonergic activity, exhibit a depressive-like phenotype and proactive aggressive behavior in the resident-intruder test. On the other hand, male RER animals assume a reactive coping style in this test, showed increased emotionality as well as freezing in the memory test following both contextual and cued fear conditioning.

  9. Effect of acute pesticide exposure on bee spatial working memory using an analogue of the radial-arm maze

    Science.gov (United States)

    Samuelson, Elizabeth E. W.; Chen-Wishart, Zachary P.; Gill, Richard J.; Leadbeater, Ellouise

    2016-12-01

    Pesticides, including neonicotinoids, typically target pest insects by being neurotoxic. Inadvertent exposure to foraging insect pollinators is usually sub-lethal, but may affect cognition. One cognitive trait, spatial working memory, may be important in avoiding previously-visited flowers and other spatial tasks such as navigation. To test this, we investigated the effect of acute thiamethoxam exposure on spatial working memory in the bumblebee Bombus terrestris, using an adaptation of the radial-arm maze (RAM). We first demonstrated that bumblebees use spatial working memory to solve the RAM by showing that untreated bees performed significantly better than would be expected if choices were random or governed by stereotyped visitation rules. We then exposed bees to either a high sub-lethal positive control thiamethoxam dose (2.5 ng-1 bee), or one of two low doses (0.377 or 0.091 ng-1) based on estimated field-realistic exposure. The high dose caused bees to make more and earlier spatial memory errors and take longer to complete the task than unexposed bees. For the low doses, the negative effects were smaller but statistically significant, and dependent on bee size. The spatial working memory impairment shown here has the potential to harm bees exposed to thiamethoxam, through possible impacts on foraging efficiency or homing.

  10. Long-term enhancement of maze learning in mice via a generalized Mozart effect.

    Science.gov (United States)

    Aoun, Peter; Jones, Timothy; Shaw, Gordon L; Bodner, Mark

    2005-12-01

    An animal model of the 'generalized Mozart effect' (GME) - enhanced/normalized higher brain function in response to music exposure - has been established. We extend those results in two studies using another species (mice). Study 1: (1) maze testing after music exposure was extended to a minimum of 6 hours; (2) no exposure to music in utero. Study 2: (1) music exposure time further reduced; (2) maze testing extended to 24 hours. Study 1: two mouse groups were exposed to music continuously for 10 hours per day for 10 weeks (Group I: Mozart's Sonata K.448, Group II: Beethoven's Fur Elise). After 10 weeks, the ability to negotiate a T-maze was assessed (recording working time in maze, number of errors). Maze ability was tested 6 hours following the last music exposure. Study 2: two mouse groups were exposed periodically to music (58% silence) 10 hours per day for 10 weeks. Experiments after 10 weeks examined the groups' abilities to run the maze (recording working time/errors). Experiments were conducted 24 hours following the last music exposure. The Mozart group exhibited significant enhancements compared with the control mice in both studies, i.e. significantly lower working time (p<0.05) and committed fewer errors. Observation of GME in another species supports its generality for the mammalian cortex. The absence of a GME in fMRI studies for the control music also indicates a neurophysiological basis. With extended exposure, GME is a long-term effect, indicating potential clinical importance. It has been demonstrated that GME reduces neuropathological spiking significantly in epileptics. We discuss the relevance of this study for epilepsy treatment.

  11. Repeated unpredictable threats without harm impair spatial working memory in the Barnes maze.

    Science.gov (United States)

    Kim, Diane J; St Louis, Nathan; Molaro, Ralph A; Hudson, Glenn T; Chorley, Robert C; Anderson, Brenda J

    2017-01-01

    Psychological stressors elicit the anticipation of homeostatic challenge, whereas physical stressors are direct threats to homeostasis. Many rodent models of stress include both types of stressors, yet deficits, like those reported for working memory, are often attributed to psychological stress. To empirically test whether intermittent psychological stressors, such as repeated threats, are solely sufficient to impair spatial working memory, we developed a novel rodent model of stress that is restricted to the anticipation of threat, and free of direct physical challenge. Adolescent male Sprague-Dawley rats were randomly assigned to control (CT) or stress (ST) housing conditions consisting of two tub cages, one with food and another with water, separated by a tunnel. Over three weeks (P31-P52), the ST group received random (probability of 0.25), simultaneous presentations of ferret odor, and abrupt lights, and sound at the center of the tunnel. Relative to the CT group, the ST group had consistently fewer tunnel crossings, consistent with avoidance of a psychological stressor. Both groups had similar body weights and crossed the tunnel more in the dark than light period. Three days after removal from the treatment conditions, spatial working memory was tested on the Barnes maze. The ST group displayed deficits in spatial working memory, including longer latencies to enter the goal box position, and a greater number of returns to incorrect holes, but no significant differences in speed. Memory can be affected by sleep disruption, and sleep can be affected by stress. Circadian activity patterns in the tunnels were similar across groups. Therefore, the data suggest that intermittent threats without physical stress are sufficient to impair spatial working memory in adolescence. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Influence of lactation on motor activity and elevated plus maze behavior

    Directory of Open Access Journals (Sweden)

    M.R.P. Silva

    1997-02-01

    Full Text Available Lactating rats show less noise-induced freezing and fewer inhibitory responses on the 6th day post-delivery when submitted to water and food deprivation in a classical conflict paradigm. Lactating mice go more often to the illuminated chamber in a light-dark cage and stay longer in it than virgin females. The present study was designed to assess the influence of this physiological state, i.e. lactation, on the elevated plus maze (EPM and open-field behavior in adult female rats. Total (TL and central (CL locomotion and rearing (RF frequencies were measured in an open-field. Number of entries into the open and closed arms as well as the time spent in each of these arms were measured in the EPM. Percent time spent and number of entries into the open arms were calculated and compared. In the open-field, TL was significantly decreased (115 ± 10.6 vs 150 ± 11.6 while CL and RF did not differ from those presented by virgin rats. In the EPM, lactating rats displayed a significant reduction in percent time spent (10.9 ± 1.5 vs 17.4 ± 2.3 in the open arms as well as a tendency to a reduction in percent entries into the open arms (35.7 ± 4.7 vs 45.7 ± 4.3. These results show that the physiological state of lactation modulates the open-field and EPM behaviors in rats

  13. A Boundedness Theoretical Analysis for GrADPDesign: A Case Study on Maze Navigation

    Science.gov (United States)

    2015-08-17

    derived above. The sigmoid function is adopted for the output neurons in the goal network, thus the internal goal signal s is constraint between −1...number of state in the maze. In this case study, we set the maze size as 15 ∗ 15 and the goal locates at [15, 15]. The learning curves (sum of squared...errors) are presented in Fig.2, where the x axis refers to the number of the steps and the y axis refers the sum of squared errors. All the curves

  14. Spatial memory impairments in amnestic mild cognitive impairment in a virtual radial arm maze

    Directory of Open Access Journals (Sweden)

    Lee JY

    2014-04-01

    Full Text Available Jun-Young Lee,1,2 Sooyeon Kho,1,2 Hye Bin Yoo,1,2 Soowon Park,1,2 Jung-Seok Choi,1,2 Jun Soo Kwon,3 Kyung Ryeol Cha,4 Hee-Yeon Jung1,21Department of Psychiatry, Seoul National University, 2Seoul Metropolitan Government – Seoul National University Boramae Medical Center, 3Department of Psychiatry, Seoul National University College of Medicine, Seoul, South Korea; 4Department of Psychiatry, Osan Mental Hospital, Gyeonggi, South KoreaObjective: This study aims to apply the virtual radial arm maze (VRAM task to find spatial working memory and reference memory impairments in patients of amnestic mild cognitive impairment (aMCI and Alzheimer's disease (AD. Spatial memory functions between aMCI converters and nonconverters are also compared using VRAM results.Methods: We assessed the spatial memory in 20 normal controls, 20 aMCI, and 20 mild AD subjects using VRAM. The Mini-Mental State Examination, Clinical Dementia Rating scale, and other neuropsychological tests were given to the subjects in conjunction with the VRAM test. Scores in working memory errors and reference memory errors were compared among the three groups using repeated measures analysis of variance. In addition, aMCI patients were followed-up after 5 years and surveyed for AD conversion rate.Results: In AD patients, both spatial working and reference memory were impaired. However, in aMCI subjects, only spatial reference memory was impaired. Significant spatial reference memory impairment was found in the aMCI converter group when compared to the nonconverter group.Conclusion: Spatial working memory is less impaired in aMCI while reference memory is similarly damaged in AD. In aMCI patients, more severe spatial reference memory deficit is a neuropsychological marker for AD conversion. VRAM may be well utilized in humans to assess spatial memory in normal aging, in aMCI, and in AD.Keywords: spatial behavior, Alzheimer's disease, user computer interface, cognition

  15. A randomized study of combining maze surgery for atrial fibrillation with mitral valve surgery

    NARCIS (Netherlands)

    Jessurun, ER; Van Hemel, NM; Defauw, JJ; De La Riviere, AB; Stofmeel, MAM; Kingma, JH; Ernst, JMPG

    Aim Mitral valve surgery seldom suppresses atrial fibrillation (AF), present prior to surgery. Maze III surgery eliminates AF in >80% of cases, the reason why combining this procedure with mitral valve surgery in patients with AF seems worthwhile. We prospectively studied the outcome of combining

  16. Surgical Radiofrequency MAZE III Ablation for Treatment of Atrial Fibrillation During Open Heart Surgery

    Directory of Open Access Journals (Sweden)

    Fariborz Akbarzadeh

    2006-05-01

    Full Text Available Background: Atrial fibrillation is a common arrhythmia in patients with rheumatic mitral and other valve diseases who are candidates for valve repair surgeries. Conversion of rhythm to sinus has positive effects on quality of life and lower use of medications. The aim of this clinical study was to evaluate the effectiveness of the radiofrequency ablation Maze III procedure in the treatment of atrial fibrillation associated with rheumatic heart valve disease. Methods: We applied a modified Cox III Maze procedure using radiofrequency ablation in the treatment of atrial fibrillation associated with rheumatic heart valve disease and evaluated the outcome of 20 patients of atrial fibrillation associated rheumatic valve disease who underwent radiofrequency ablation Maze III procedure plus heart valve surgery. Demographic, echocardiographic, Electrocardiographic and Doppler study data were calculated before surgery, six month and one year after surgery.. Results: No perioperative deaths occurred in the study group. Duration of additional time for doing radiofrequency ablation was about 22 minutes. Freedom from atrial fibrillation was 85% and 75% at six months and one year follow-up respectively... Conclusions: The addition of the radiofrequency ablation Maze procedure to heart valve surgery is safe and effective in the treatment of atrial fibrillation associated with rheumatic heart valve disease.

  17. Brain functional network changes following Prelimbic area inactivation in a spatial memory extinction task.

    Science.gov (United States)

    Méndez-Couz, Marta; Conejo, Nélida M; Vallejo, Guillermo; Arias, Jorge L

    2015-01-01

    Several studies suggest a prefrontal cortex involvement during the acquisition and consolidation of spatial memory, suggesting an active modulating role at late stages of acquisition processes. Recently, we have reported that the prelimbic and infralimbic areas of the prefrontal cortex, among other structures, are also specifically involved in the late phases of spatial memory extinction. This study aimed to evaluate whether the inactivation of the prelimbic area of the prefrontal cortex impaired spatial memory extinction. For this purpose, male Wistar rats were implanted bilaterally with cannulae into the prelimbic region of the prefrontal cortex. Animals were trained during 5 consecutive days in a hidden platform task and tested for reference spatial memory immediately after the last training session. One day after completing the training task, bilateral infusion of the GABAA receptor agonist Muscimol was performed before the extinction protocol was carried out. Additionally, cytochrome c oxidase histochemistry was applied to map the metabolic brain activity related to the spatial memory extinction under prelimbic cortex inactivation. Results show that animals acquired the reference memory task in the water maze, and the extinction task was successfully completed without significant impairment. However, analysis of the functional brain networks involved by cytochrome oxidase activity interregional correlations showed changes in brain networks between the group treated with Muscimol as compared to the saline-treated group, supporting the involvement of the mammillary bodies at a the late stage in the memory extinction process. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Variance in Broad Reading Accounted for by Measures of Reading Speed Embedded within Maze and Comprehension Rate Measures

    Science.gov (United States)

    Hale, Andrea D.; Skinner, Christopher H.; Wilhoit, Brian; Ciancio, Dennis; Morrow, Jennifer A.

    2012-01-01

    Maze and reading comprehension rate measures are calculated by using measures of reading speed and measures of accuracy (i.e., correctly selected words or answers). In sixth- and seventh-grade samples, we found that the measures of reading speed embedded within our Maze measures accounted for 50% and 39% of broad reading score (BRS) variance,…

  19. Walkable self-overlapping virtual reality maze and map visualization demo: public virtual reality setup for asymmetric collaboration

    DEFF Research Database (Denmark)

    Serubugo, Sule; Skantarova, Denisa; Evers, Nicolaj

    2017-01-01

    This paper describes our demonstration of a walkable self-overlapping maze and its corresponding map to facilitate asymmetric collaboration for room-scale virtual reality setups in public places.......This paper describes our demonstration of a walkable self-overlapping maze and its corresponding map to facilitate asymmetric collaboration for room-scale virtual reality setups in public places....

  20. Regional Systems Development for Geothermal Energy Resources Pacific Region (California and Hawaii). Task 3: water resources evaluation. Topical report

    Energy Technology Data Exchange (ETDEWEB)

    Sakaguchi, J.L.

    1979-03-19

    The fundamental objective of the water resources analysis was to assess the availability of surface and ground water for potential use as power plant make-up water in the major geothermal areas of California. The analysis was concentrated on identifying the major sources of surface and ground water, potential limitations on the usage of this water, and the resulting constraints on potentially developable electrical power in each geothermal resource area. Analyses were completed for 11 major geothermal areas in California: four in the Imperial Valley, Coso, Mono-Long Valley, Geysers-Calistoga, Surprise Valley, Glass Mountain, Wendel Amedee, and Lassen. One area in Hawaii, the Puna district, was also included in the analysis. The water requirements for representative types of energy conversion processes were developed using a case study approach. Cooling water requirements for each type of energy conversion process were estimated based upon a specific existing or proposed type of geothermal power plant. The make-up water requirements for each type of conversion process at each resource location were then estimated as a basis for analyzing any constraints on the megawatts which potentially could be developed.

  1. [Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio]. Volume 3, Sampling and analysis plan (SAP): Phase 1, Task 4, Field Investigation: Draft

    Energy Technology Data Exchange (ETDEWEB)

    1991-10-01

    In April 1990, Wright-Patterson Air Force Base (WPAFB), initiated an investigation to evaluate a potential Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) removal action to prevent, to the extent practicable, the offsite migration of contaminated ground water from WPAFB. WPAFB retained the services of the Environmental Management Operations (EMO) and its principle subcontractor, International Technology Corporation (IT) to complete Phase 1 of the environmental investigation of ground-water contamination at WPAFB. Phase 1 of the investigation involves the short-term evaluation and potential design for a program to remove ground-water contamination that appears to be migrating across the western boundary of Area C, and across the northern boundary of Area B along Springfield Pike. Primarily, Task 4 of Phase 1 focuses on collection of information at the Area C and Springfield Pike boundaries of WPAFB. This Sampling and Analysis Plan (SAP) has been prepared to assist in completion of the Task 4 field investigation and is comprised of the Quality Assurance Project Plan (QAPP) and the Field Sampling Plan (FSP).

  2. Behavioral and functional strategies during tool use tasks in bonobos.

    Science.gov (United States)

    Bardo, Ameline; Borel, Antony; Meunier, Hélène; Guéry, Jean-Pascal; Pouydebat, Emmanuelle

    2016-09-01

    Different primate species have developed extensive capacities for grasping and manipulating objects. However, the manual abilities of primates remain poorly known from a dynamic point of view. The aim of the present study was to quantify the functional and behavioral strategies used by captive bonobos (Pan paniscus) during tool use tasks. The study was conducted on eight captive bonobos which we observed during two tool use tasks: food extraction from a large piece of wood and food recovery from a maze. We focused on grasping postures, in-hand movements, the sequences of grasp postures used that have not been studied in bonobos, and the kind of tools selected. Bonobos used a great variety of grasping postures during both tool use tasks. They were capable of in-hand movement, demonstrated complex sequences of contacts, and showed more dynamic manipulation during the maze task than during the extraction task. They arrived on the location of the task with the tool already modified and used different kinds of tools according to the task. We also observed individual manual strategies. Bonobos were thus able to develop in-hand movements similar to humans and chimpanzees, demonstrated dynamic manipulation, and they responded to task constraints by selecting and modifying tools appropriately, usually before they started the tasks. These results show the necessity to quantify object manipulation in different species to better understand their real manual specificities, which is essential to reconstruct the evolution of primate manual abilities. © 2016 Wiley Periodicals, Inc.

  3. The effect of a paraffin screen on the neutron dose at the maze door of a 15 MV linear accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Krmar, M.; Kuzmanović, A. [Physics Department, Faculty of Science, University of Novi Sad, Novi Sad 21000 (Serbia); Nikolić, D. [National Institute for Nanotechnology, Edmonton, Alberta T6G 2M9 (Canada); Kuzmanović, Z. [International Medical Centers, Banja Luka 78000, Republika Srpska, Bosnia and Herzegovina (Bosnia and Herzegowina); Ganezer, K. [Physics Department, California State University Dominguez Hills, Carson, California 90747 (United States)

    2013-08-15

    Purpose: The purpose of this study was to explore the effects of a paraffin screen located at various positions in the maze on the neutron dose equivalent at the maze door.Methods: The neutron dose equivalent was measured at the maze door of a room containing a 15 MV linear accelerator for x-ray therapy. Measurements were performed for several positions of the paraffin screen covering only 27.5% of the cross-sectional area of the maze. The neutron dose equivalent was also measured at all screen positions. Two simple models of the neutron source were considered in which the first assumed that the source was the cross-sectional area at the inner entrance of the maze, radiating neutrons in an isotropic manner. In the second model the reduction in the neutron dose equivalent at the maze door due to the paraffin screen was considered to be a function of the mean values of the neutron fluence and energy at the screen.Results: The results of this study indicate that the equivalent dose at the maze door was reduced by a factor of 3 through the use of a paraffin screen that was placed inside the maze. It was also determined that the contributions to the dosage from areas that were not covered by the paraffin screen as viewed from the dosimeter, were 2.5 times higher than the contributions from the covered areas. This study also concluded that the contributions of the maze walls, ceiling, and floor to the total neutron dose equivalent were an order of magnitude lower than those from the surface at the far end of the maze.Conclusions: This study demonstrated that a paraffin screen could be used to reduce the neutron dose equivalent at the maze door by a factor of 3. This paper also found that the reduction of the neutron dose equivalent was a linear function of the area covered by the maze screen and that the decrease in the dose at the maze door could be modeled as an exponential function of the product φ·E at the screen.

  4. ALGORITMA FLOODFILL UNTUK MENENTUKAN TITIK KOORDINAT MAZE MAPPING PADA ROBOT LINEFOLLOWER

    OpenAIRE

    Ary Sulistyo Utomo

    2016-01-01

    Robot line follower (RLF) adalah robot yang dapat berjalan mengikuti suatu maze yang berupa garis secara otomatis. RLF dapat digunakan untuk aplikasi pengiriman barang dari suatu tempat awal ke tempat tujuan dengan cepat, tepat dan akurat. Untuk menyelesaikan permasalahan tersebut dibutuhkan suatu algoritma yang digunakan untuk mengetahui posisi koordinat robot sehingga robot dapat diketahui pergerakannya. Pergerakan robot berawal dari start dan mecapai titik finish yang telah di tentukan. Pa...

  5. Memory-impairing effects of local anesthetics in an elevated plus-maze test in mice

    Directory of Open Access Journals (Sweden)

    S.L. Blatt

    1998-04-01

    Full Text Available Post-training intracerebroventricular administration of procaine (20 µg/µl and dimethocaine (10 or 20 µg/µl, local anesthetics of the ester class, prolonged the latency (s in the retention test of male and female 3-month-old Swiss albino mice (25-35 g body weight; N = 140 in the elevated plus-maze (mean ± SEM for 10 male mice: control = 41.2 ± 8.1; procaine = 78.5 ± 10.3; 10 µg/µl dimethocaine = 58.7 ± 12.3; 20 µg/µl dimethocaine = 109.6 ± 5.73; for 10 female mice: control = 34.8 ± 5.8; procaine = 55.3 ± 13.4; 10 µg/µl dimethocaine = 59.9 ± 12.3 and 20 µg/µl dimethocaine = 61.3 ± 11.1. However, lidocaine (10 or 20 µg/µl, an amide class type of local anesthetic, failed to influence this parameter. Local anesthetics at the dose range used did not affect the motor coordination of mice exposed to the rota-rod test. These results suggest that procaine and dimethocaine impair some memory process(es in the plus-maze test. These findings are interpreted in terms of non-anesthetic mechanisms of action of these drugs on memory impairment and also confirm the validity of the elevated plus-maze for the evaluation of drugs affecting learning and memory in mice

  6. ALGORITMA FLOODFILL UNTUK MENENTUKAN TITIK KOORDINAT MAZE MAPPING PADA ROBOT LINEFOLLOWER

    Directory of Open Access Journals (Sweden)

    Ary Sulistyo Utomo

    2016-04-01

    Full Text Available Robot line follower (RLF adalah robot yang dapat berjalan mengikuti suatu maze yang berupa garis secara otomatis. RLF dapat digunakan untuk aplikasi pengiriman barang dari suatu tempat awal ke tempat tujuan dengan cepat, tepat dan akurat. Untuk menyelesaikan permasalahan tersebut dibutuhkan suatu algoritma yang digunakan untuk mengetahui posisi koordinat robot sehingga robot dapat diketahui pergerakannya. Pergerakan robot berawal dari start dan mecapai titik finish yang telah di tentukan. Pada penelitian ini menggunakan algoritma floodfill untuk mengetahui posisi koordinat RLF. Pengujian dilakukan dengan cara menjalankan RLF dari titik start menuju ke titik finish. Area yang digunakan berukuran 200 x 200 cm mempunyai tebal garis lintasan 2 cm dengan jarak terdekat pada setiap simpangnya adalah 40 cm Warna garis adalah putih dan background berwarna hitam. Hasil penelitian menunjukkan bahwa kestabilan RLF menyusuri garis lintasan dicapai pada nilai pengaturan PID Kp=30, Ki=8 dan KD=100. Hasil dari koordinat pada saat robot bergerak di simpan pada memori eeprom dari mikrokontroller dan di tampilkan pada LCD 2x16. Koordinat start dimulai dengan (0,0 dengan finish (2,2 pada maze yang telah ditentukan. Kata kunci: Robot line follower, floodfill, maze mapping, PID.

  7. Improved posttraumatic acquisition of a place learning task after repeated administration of a serotonergic agonist 8-OH-DPA

    DEFF Research Database (Denmark)

    Mala, Hana; Mogensen, Jesper

    2008-01-01

    of the water maze based place learning task started on the 8th day after surgery and continued daily for the next 25 days.   Results: The results show that within the lesioned groups, the group that was subjected to repeated administration of 8-OH-DPAT (REPEAT TREATM) showed a significantly improved......Introduction/Objectives Studies have indicated that serotonergic agonists may act neuroprotectively against neurochemical and mechanical injury to the brain, and diminish the negative consequences of secondary tissue response to the initial insult. Little is known about the mechanisms...... of such effects. Likewise, it is presently uncertain to what extent serotonergic agonists can reduce the functional consequences of focal brain injury. In this study, we have addressed the neuroprotective potential of 8-hydroxy-2-di-n-propylamino-tetralin (8-OH-DPAT), which is a serotonin agonist binding...

  8. Subjects' skill and biphasic effects of met-enkephalin upon the acquisition and retention of a perceptual motor task.

    Science.gov (United States)

    Woosley, E A; Chara, P J

    1988-06-01

    The effects of met-enkephalin on the acquisition and retention over 10 days of a perceptual motor skill were investigated. Mice were randomly assigned to either one of two experimental groups (1-mg or 3-mg injections per 1-kg of body weight of met-enkephalin) or one of two control groups (dH2O injections). During the acquisition phase of the study, they were separated into "slow" and "fast" learners on the basis of their skill in negotiating a water maze. The results indicated an inhibitory effect of met-enkephalin in the 3-mg condition in the retention phase of the experiment. Subjects' skill was not implicated as a critical factor in retention of this simple task.

  9. Maze Surgery

    Science.gov (United States)

    ... called chronic atrial fibrillation (AF). AF is a fast, irregular heart rhythm where the upper chambers of the heart contract in an uncoordinated fashion. AF is dangerous because it may cause blood ...

  10. Corticosterone infused into the dorsal striatum selectively enhances memory consolidation of cued water-maze training

    NARCIS (Netherlands)

    Quirarte, Gina L.; Sofia Ledesma de la Teja, I.; Casillas, Miriam; Serafin, Norma; Prado-Alcala, Roberto A.; Roozendaal, Benno

    2009-01-01

    Glucocorticoid hormones enhance memory consolidation of hippocampus-dependent spatial/contextual learning, but little is known about their possible influence on the consolidation of procedural/implicit memory. Therefore, in this study we examined the effect of corticosterone (2, 5, or 10 ng) infused

  11. Modafinil and Memory: Effects of Modafinil on Morris Water Maze Learning and Pavlovian Fear Conditioning

    OpenAIRE

    Shuman, Tristan; Wood, Suzanne C.; Anagnostaras, Stephan G.

    2009-01-01

    Modafinil has been shown to promote wakefulness and some studies suggest the drug can improve cognitive function. Because of many similarities, the mechanism of action may be comparable to classical psychostimulants, although the exact mechanisms of modafinil’s actions in wakefulness and cognitive enhancement are unknown. The current study aims to further examine the effects of modafinil as a cognitive enhancer on hippocampus-dependent memory in mice. A high dose of modafinil (75 mg/kg, i.p.)...

  12. Mouse hippocampal GABAB1 but not GABAB2 subunit-containing receptor complex levels are paralleling retrieval in the multiple-T-maze

    Directory of Open Access Journals (Sweden)

    Soheil eKeihan Falsafi

    2015-10-01

    Full Text Available GABAB receptors are heterodimeric G-protein coupled receptors known to be involved in learning and memory. Although a role for GABAB receptors in cognitive processes is evident, there is no information on hippocampal GABAB receptor complexes in a multiple T maze (MTM task, a robust paradigm for evaluation of spatial learning.Trained or untrained (yoked control C57BL/6J male mice (n=10/group were subjected to the MTM task and sacrificed 6 hours following their performance. Hippocampi were taken, membrane proteins extracted and run on blue native PAGE followed by immunoblotting with specific antibodies against GABAB1, GABAB1a and GABAB2. Immunoprecipitation with subsequent mass spectrometric identification of co-precipitates was carried out to show if GABAB1 and GABAB2 as well as other interacting proteins co-precipitate. An antibody shift assay (ASA and a proximity ligation assay (PLA were also used to see if the two GABAB subunits are present in the receptor complex.Single bands were observed on Western blots, each representing GABAB1, GABAB1a or GABAB2 at an apparent molecular weight of approximately 100 kDa. Subsequently, densitometric analysis revealed that levels of GABAB1 and GABAB1a but not GABAB2- containing receptor complexes were significantly higher in trained than untrained groups. Immunoprecipitation followed by mass spectrometric studies confirmed the presence of GABAB1, GABAB2, calcium calmodulin kinases I and II, GluA1 and GluA2 as constituents of the complex. ASA and PLA also showed the presence of the two subunits of GABAB receptor within the complex. It is shown that increased levels of GABAB1 subunit-containing complexes are paralleling performance in a land maze.

  13. Study of Pu consumption in advanced light water reactors: Evaluation of GE advanced boiling water reactor plants - compilation of Phase 1B task reports

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-09-15

    This report contains an extensive evaluation of GE advanced boiling water reactor plants prepared for United State Department of Energy. The general areas covered in this report are: core and system performance; fuel cycle; infrastructure and deployment; and safety and environmental approval.

  14. Isolating the entire posterior left atrium improves surgical outcomes after the Cox maze procedure.

    Science.gov (United States)

    Voeller, Rochus K; Bailey, Marci S; Zierer, Andreas; Lall, Shelly C; Sakamoto, Shun-ichiro; Aubuchon, Kristen; Lawton, Jennifer S; Moazami, Nader; Huddleston, Charles B; Munfakh, Nabil A; Moon, Marc R; Schuessler, Richard B; Damiano, Ralph J

    2008-04-01

    The importance of each ablation line in the Cox maze procedure for treatment of atrial fibrillation remains poorly defined. This study evaluated differences in surgical outcomes of the procedure performed either with a single connecting lesion between the right and left pulmonary vein isolations versus 2 connecting lesions (the box lesion), which isolated the entire posterior left atrium. Data were collected prospectively on 137 patients who underwent the Cox maze procedure from April 2002 through September 2006. Before May 2004, the pulmonary veins were connected with a single bipolar radiofrequency ablation lesion (n = 56), whereas after this time, a box lesion was routinely performed (n = 81). The mean follow-up was 11.8 +/- 9.6 months. The incidence of early atrial tachyarrhythmia was significantly higher in the single connecting lesion group compared with that in the box lesion group (71% vs 37%, P box lesion group at 1 (87% vs 69%, P = .015) and 3 (96% vs 85%, P = .028) months. The use of antiarrhythmic drugs was significantly lower in the box lesion group at 3 (35% vs 58%, P = .018) and 6 (15% vs 44%, P = .002) months. Isolating the entire posterior left atrium by creating a box lesion instead of a single connecting lesion between the pulmonary veins showed a significantly lower incidence of early atrial tachyarrhythmias, higher freedom from atrial fibrillation recurrence at 1 and 3 months, and lower use of antiarrhythmic drugs at 3 and 6 months. A complete box lesion should be included in all patients undergoing the Cox maze procedure.

  15. Robotic excision of aortic valve papillary fibroelastoma and concomitant maze procedure.

    Science.gov (United States)

    Murphy, Edward T

    2012-01-01

    Cardiothoracic surgeons have utilized the surgical robot to provide a minimally invasive approach to a number of intracardiac operations, including tumor resection, valve repair, and ablation of atrial arrhythmia. We report the case of a 58 year-old woman who was found to have a mobile mass on her aortic valve during evaluation of atrial fibrillation. Both of these conditions were addressed when she underwent a combined robotic biatrial Maze procedure and excision of the mass, which proved to be a papillary fibroelastoma of the aortic valve.

  16. Robotic excision of aortic valve papillary fibroelastoma and concomitant Maze procedure

    Directory of Open Access Journals (Sweden)

    Edward T Murphy

    2012-12-01

    Full Text Available Cardiothoracic surgeons have utilized the surgical robot to provide a minimally invasive approach to a number of intracardiac operations, including tumor resection, valve repair, and ablation of atrial arrhythmia. We report the case of a 58 year-old woman who was found to have a mobile mass on her aortic valve during evaluation of atrial fibrillation. Both of these conditions were addressed when she underwent a combined robotic biatrial Maze procedure and excision of the mass, which proved to be a papillary fibroelastoma of the aortic valve.

  17. Learning, memory and search strategies of inbred mouse strains with different visual abilities in the Barnes maze.

    Science.gov (United States)

    O'Leary, Timothy P; Savoie, Vicki; Brown, Richard E

    2011-01-20

    Visuo-spatial learning and memory were assessed in male and female mice of 13 inbred strains on a small diameter mouse version of the Barnes maze surrounded by a wall and intra-maze visual cues. Mice completed acquisition and reversal training to assess learning, followed by a probe test to assess memory for the spatial location of the escape hole. The C57BL/6J and CAST/EiJ strains showed better learning performance than the other strains. A/J and 129/SvImJ strains showed poor learning performance, which may be due to their low rates of exploration. No differences in memory were found between strains in the probe test. Males showed better learning performance than females in the DBA/2J and C3H/HeJ strains, but there were no sex differences in the other strains. However, mice may not have used visuo-spatial cues to locate the escape hole in this maze, as (1) all strains primarily used the non-spatial serial/thigmotaxic search strategy, (2) no strains showed a reversal effect when the escape hole location was moved, and (3) learning and memory performance were not correlated with measures of visual ability. Multivariate and univariate analyses of variance indicated that mice with good visual ability performed better than mice with poor visual ability, but the effect sizes were small. The small diameter of the maze and the presence of a wall around the edge of the maze may promote thigmotaxis in mice, increasing the use of a non-visual search strategy, thereby reducing the influence of vision on performance and decreasing the sensitivity of this maze design to detect strain differences in visuo-spatial learning and memory. These results indicate that the design of the Barnes maze has a significant effect on learning and memory processes. Copyright © 2010 Elsevier B.V. All rights reserved.

  18. Dynamic trajectory of multiple single-unit activity during working memory task in rats

    OpenAIRE

    Zhang, Xiaofan; Yi, Hu; Bai, Wenwen; Tian, Xin

    2015-01-01

    Working memory plays an important role in complex cognitive tasks. A popular theoretical view is that transient properties of neuronal dynamics underlie cognitive processing. The question raised here as to how the transient dynamics evolve in working memory. To address this issue, we investigated the multiple single-unit activity dynamics in rat medial prefrontal cortex (mPFC) during a Y-maze working memory task. The approach worked by reconstructing state space from delays of the original si...

  19. Heading which way? Y-maze chemical assays: not all crustaceans are alike

    Science.gov (United States)

    Kenning, Matthes; Lehmann, Philipp; Lindström, Magnus; Harzsch, Steffen

    2015-09-01

    In a world full of chemicals, many crustaceans rely on elaborate olfactory systems to guide behaviors related to finding food or to assess the presence of conspecifics and predators. We analyzed the responses of the isopod Saduria entomon to a range of stimuli by which the animal is likely to encounter in its natural habitat using a Y-maze bioassay. In order to document the efficiency of the experimental design, the same bioassay was used to test the behavior of the crayfish Procambarus fallax whose ability to track odors is well documented. The crayfish performed well in the Y-maze and were able to locate the source of a food-related odor with high fidelity. The isopod S. entomon reacted indifferently or with aversion to most of the stimuli applied. In 1800 trials, only four out of 15 different stimuli yielded statistically significant results, and only one odorant was found to be significantly attractive. The findings raise several questions whether the stimuli presented and/or the experimental setup used represents an ecologically relevant situation for S. entomon. In each instance, our experiments illustrate that established methods cannot be readily transferred from one species to another.

  20. Assessment of anxiety in open field and elevated plus maze using infrared thermography.

    Science.gov (United States)

    Lecorps, Benjamin; Rödel, Heiko G; Féron, Christophe

    2016-04-01

    Due to their direct inaccessibility, affective states are classically assessed by gathering concomitant physiological and behavioral measures. Although such a dual approach to assess emotional states is frequently used in different species including humans, the invasiveness of procedures for physiological recordings particularly in smaller-sized animals strongly restricts their application. We used infrared thermography, a non-invasive method, to assess physiological arousal during open field and elevated plus maze tests in mice. By measuring changes in surface temperature indicative of the animals' emotional response, we aimed to improve the inherently limited and still controversial information provided by behavioral parameters commonly used in these tests. Our results showed significant and consistent thermal responses during both tests, in accordance with classical physiological responses occurring in stressful situations. Besides, we found correlations between these thermal responses and the occurrence of anxiety-related behaviors. Furthermore, initial temperatures measured at the start of each procedure (open field, elevated plus maze), which can be interpreted as a measure of the animals' initial physiological arousal, predicted the levels of activity and of anxiety-related behaviors displayed during the tests. Our results stress the strong link between physiological correlates of emotions and behaviors expressed during unconditioned fear tests. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Navigating to new frontiers in behavioral neuroscience: Traditional neuropsychological tests predict human performance on a rodent-inspired radial-arm maze

    Directory of Open Access Journals (Sweden)

    Sarah E. Mennenga

    2014-09-01

    Full Text Available We constructed an 11-arm, walk-through, human radial-arm maze (HRAM as a translational instrument to compare existing methodology in the areas of rodent and human learning and memory research. The HRAM, utilized here, serves as an intermediary test between the classic rat radial-arm maze (RAM and standard human neuropsychological and cognitive tests. We show that the HRAM is a useful instrument to examine working memory ability, explore the relationships between rodent and human memory and cognition models, and evaluate factors that contribute to human navigational ability. One-hundred-and-fifty-seven participants were tested on the HRAM, and scores were compared to performance on a standard cognitive battery focused on episodic memory, working memory capacity, and visuospatial ability. We found that errors on the HRAM increased as working memory demand became elevated, similar to the pattern typically seen in rodents, and that for this task, performance appears similar to Miller’s classic description of human working memory capacity of 7±2 items. Regression analysis revealed that measures of working memory capacity and visuospatial ability accounted for a large proportion of variance in HRAM scores, while measures of episodic memory and general intelligence did not serve as significant predictors of HRAM performance. We present the HRAM as a novel instrument for measuring navigational behavior in humans, as is traditionally done in basic science studies evaluating rodent learning and memory, thus providing a useful tool to help connect and translate between human and rodent models of cognitive functioning.

  2. Spatial learning and neurogenesis: Effects of cessation of wheel running and survival of novel neurons by engagement in cognitive tasks.

    Science.gov (United States)

    Motta-Teixeira, Lívia Clemente; Takada, Silvia Honda; Machado-Nils, Aline Vilar; Nogueira, Maria Inês; Xavier, Gilberto Fernando

    2016-06-01

    Physical exercise stimulates cell proliferation in the adult dentate gyrus and facilitates acquisition and/or retention of hippocampal-dependent tasks. It is established that regular physical exercise improves cognitive performance. However, it is unclear for how long these benefits last after its interruption. Independent groups of rats received both free access to either unlocked (EXE Treatment) or locked (No-EXE Treatment) running wheels for 7 days, and daily injections of bromodeoxyuridine (BrdU) in the last 3 days. After a time delay period of either 1, 3, or 6 weeks without training, the animals were tested in the Morris water maze (MWM) either in a working memory task dependent on hippocampal function (MWM-HD) or in a visible platform searching task, independent on hippocampal function (MWM-NH). Data confirmed that exposure of rats to 7 days of spontaneous wheel running increases cell proliferation and neurogenesis. In contrast, neurogenesis was not accompanied by significant improvements of performance in the working memory version of the MWM. Longer time delays between the end of exercise and the beginning of cognitive training in the MWM resulted in lower cell survival; that is, the number of novel surviving mature neurons was decreased when this delay was 6 weeks as compared with when it was 1 week. In addition, data showed that while exposure to the MWM-HD working memory task substantially increased survival of novel neurons, exposure to the MWM-NH task did not, thus indicating that survival of novel dentate gyrus neurons depends on the engagement of this brain region in performance of cognitive tasks. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  3. Long-term effects of chronic intermittent ethanol exposure in adolescent and adult rats: radial-arm maze performance and operant food reinforced responding.

    Directory of Open Access Journals (Sweden)

    Mary-Louise Risher

    Full Text Available Adolescence is not only a critical period of late-stage neurological development in humans, but is also a period in which ethanol consumption is often at its highest. Given the prevalence of ethanol use during this vulnerable developmental period we assessed the long-term effects of chronic intermittent ethanol (CIE exposure during adolescence, compared to adulthood, on performance in the radial-arm maze (RAM and operant food-reinforced responding in male rats.Male Sprague Dawley rats were exposed to CIE (or saline and then allowed to recover. Animals were then trained in either the RAM task or an operant task using fixed- and progressive- ratio schedules. After baseline testing was completed all animals received an acute ethanol challenge while blood ethanol levels (BECs were monitored in a subset of animals. CIE exposure during adolescence, but not adulthood decreased the amount of time that animals spent in the open portions of the RAM arms (reminiscent of deficits in risk-reward integration and rendered animals more susceptible to the acute effects of an ethanol challenge on working memory tasks. The operant food reinforced task showed that these effects were not due to altered food motivation or to differential sensitivity to the nonspecific performance-disrupting effects of ethanol. However, CIE pre-treated animals had lower BEC levels than controls during the acute ethanol challenges indicating persistent pharmacokinetic tolerance to ethanol after the CIE treatment. There was little evidence of enduring effects of CIE alone on traditional measures of spatial and working memory.These effects indicate that adolescence is a time of selective vulnerability to the long-term effects of repeated ethanol exposure on neurobehavioral function and acute ethanol sensitivity. The positive and negative findings reported here help to further define the nature and extent of the impairments observed after adolescent CIE and provide direction for future

  4. Comparison of the stand-alone Cox-Maze IV procedure to the concomitant Cox-Maze IV and mitral valve procedure for atrial fibrillation.

    Science.gov (United States)

    Lawrance, Christopher P; Henn, Matthew C; Miller, Jacob R; Sinn, Laurie A; Schuessler, Richard B; Damiano, Ralph J

    2014-01-01

    The majority of patients undergoing surgical ablation for atrial fibrillation (AF) worldwide receive a concomitant mitral valve (MV) procedure. This study compared outcomes of the Cox-Maze IV (CMIV) in patients with lone AF to those with AF and MV disease. A retrospective review of 335 patients receiving either a stand-alone CMIV for AF (n=151) or a CMIV with a MV procedure (n=184) was performed from January 2002 through December of 2012. Data were obtained at 3, 6, 12, 24, and 48 months and patients were evaluated for recurrence of AF. Twenty-four preoperative and perioperative variables were evaluated to identify predictors of AF recurrence at one year. The two groups differed in that stand-alone CMIV patients were younger, had AF of longer duration and had more failed catheter ablations, while patients with AF and MV disease had larger left atria and worse New York Heart Association class (P≤0.001). Operative mortality was higher in the concomitant MV group (1% vs. 5%, P=0.015). Freedom from AF and antiarrhythmic drugs at 12 and 24 months were similar between the two groups (73% and 76% at 12 months; 77% vs. 78% at 24 months). Predictors of recurrence included failure to use a box-lesion to isolate the pulmonary veins and posterior left atria, early recurrence of atrial tachyarrhythmias (ATAs) and the presence of a preoperative pacemaker (P=0.001). The efficacy of the CMIV procedure was similar in patients with and without co-existent MV pathology. Patients receiving a concomitant CMIV and MV procedure represented an older and sicker patient population and had higher mortality rates than those receiving a stand-alone CMIV procedure.

  5. Greater efficacy of preweaning than postweaning environmental enrichment on maze learning in adult rats.

    Science.gov (United States)

    Venable, N; Pinto-Hamuy, T; Arraztoa, J A; Contador, M T; Chellew, A; Perán, C; Valenzuela, X

    1988-11-01

    In order to assess the behavioural effects of environmental stimulation at different stages of development, two groups of rats were exposed to multisensory enrichment on days 10-24 (preweaning) or 25-39 (postweaning). Both groups had four 25-min sessions per day in a large cage with a variety of stimuli, in addition to 3 min of handling before each session. The mother of the preweaning group remained in the home cage during the stimulation sessions. A third group was maintained in a social condition. Testing in a Hebb-Williams maze started when the rats of the 3 groups were 100 days old. Error, latency and running time scores were lowest in the preweaning group.

  6. Effects of emotional reactivity on inhibitory avoidance in the elevated T-maze

    Directory of Open Access Journals (Sweden)

    C. Conde

    2000-02-01

    Full Text Available The possibility of the presence of inter-individual emotional differences and the memory performance of rats was examined in the elevated T-maze. Two kinds of aversively motivated behaviors, inhibitory avoidance and escape learning, were measured. Based on the number of trials to achieve a learning criterion, rats were divided into two subgroups with either low or high avoidance reactivity (LAR or HAR, respectively. Retention test avoidance latencies showed that HAR animals had better avoidance memory (Mann-Whitney rank sum test, P = 0.0035. No such differences were found for the escape component of this test. These data suggest that individual emotional differences affect inhibitory avoidance performance, which may help to explain the dispersion of the data observed in other studies using this paradigm.

  7. Simulation of behavioral profiles in the plus-maze: a Classification and Regression tree approach.

    Science.gov (United States)

    Molina-Delgado, Mauricio; Padilla-Mora, Michael; Fonaguera, Jaime

    2013-10-01

    This article introduces a simulation model of rat behavior in the elevated plus-maze, designed through a Decision trees approach using Classification and Regression algorithms. Starting from the analysis of the behavior performed by a sample of 18 Sprague-Dawley male rats, probabilistic rules describing behavioral patterns of the animals were extracted, and were used as the basis of the model computations. The model adequacy was tested by contrasting a simulated sample against an independent sample of real animals. Statistical tests showed that the simulated sample exhibits similar behaviors to those displayed by the real animals, both in terms of the number of entries to open and close arms as well as in terms of the time spent by the animals in those arms. However, the performance of the model in parameters related to the behavioral patterns was partially satisfactory. Given that previous attempts in the literature have neither include this kind of patterns nor the time as a crucial model parameter, the present model offers a suitable alternative for the computational simulation of this paradigm. Compared with antecedent models, the present simulation produced similar or better results in all the considered parameters. Beyond the goal of establish an appropriate simulational model, extracted rules also reveal important regularities associated to the rat behavior previously ignored by other models, i.e. that specific rat behaviors in the elevated plus-maze are time dependent. These and other important considerations to improve the model performance are discussed. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  8. Use of maze in cyclotron hoppers; Utilizacao de labirinto em bunker de ciclotron

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Fernando A.; Alves, Juliano S.; Fochesatto, Cintia; Cerioli, Luciane; Borges, Joao Alfredo; Gonzalez, Delfin; Silva, Daniel C., E-mail: fernandofernandes@biofarmaco.com.br [Delfin Farmacos e Derivados (Biofarmaco Marcadores Moleculares), Lauro de Freitas, BA (Brazil)

    2013-07-01

    Introduction: the increasing number of cyclotrons in Brazil due to constitutional amendment 49 /06 that enabled the production of radiopharmaceuticals with a short half - life by private companies. The radionuclides used for PET - CT require production centers near or within the diagnostic centers. In order to minimize maintenance and operating risks, gaining efficiency, our facility was the first in Brazil to use the access to a cyclotron bunker via maze, rather than armored door stopper type. Materials: the design calculations were based on the Monte Carlo method (MCNP5 - Monte Carlo N-Particletransportcode version 5). At the ends of the labyrinth are installed a door of polyethylene, for thermalization of neutrons, and other of wood for limiting access. Both legs of the maze have wall thickness of 100cm. In inspection Brazilian CNEN realize measures of dose rate for neutrons and gamma 9 points: 7 around the bunker, 1 over the bunker and 1 in the exhaust with the cyclotron operating with maximum load, double beam of 50uA for 2 hours. After commissioning were carried out around the bunker, the following measures: cumulative dose in three months with dosimeters for neutron rate dose with a gas proportional detector type filled with {sup 3}He and polyethylene neutron moderator and dose rate with a Geiger - Mueller detector for gamma radiation. Readings with neutron detectors were classified as background radiation and dose rates were always below the limits established in standard EN 3.01, and the calculation of the predicted regardless of the intensity of irradiation inside the bunker. Conclusion: the use of labyrinths as a way to access the bunkers cyclotron has been shown to be effective as the radiation shielding and efficient by allowing quick and easy access, virtually eliminating the maintenance.

  9. Inference Based on Transitive Relation in Tree Shrews ("Tupaia belangeri") and Rats ("Rattus norvegicus") on a Spatial Discrimination Task

    Science.gov (United States)

    Takahashi, Makoto; Ushitani, Tomokazu; Fujita, Kazuo

    2008-01-01

    Six tree shrews and 8 rats were tested for their ability to infer transitively in a spatial discrimination task. The apparatus was a semicircular radial-arm maze with 8 arms labeled A through H. In Experiment 1, the animals were first trained in sequence on 4 discriminations to enter 1 of the paired adjacent arms, AB, BC, CD, and DE, with right…

  10. Long-term effects of immunotoxic cholinergic lesions in the septum on acquisition of the cone-field task and noncognitive measures in rats.

    Science.gov (United States)

    van der Staay, F Josef; Bouger, Pascale; Lehmann, Olivia; Lazarus, Christine; Cosquer, Brigitte; Koenig, Julie; Stump, Veronika; Cassel, Jean-Christophe

    2006-01-01

    In rats, nonspecific mechanical or neurotoxic lesions of the septum impair spatial memory in, e.g., Morris water- and radial-maze tasks. Unfortunately, the lack of specificity of such lesions limits inferences about the role of the cholinergic hippocampal projections in spatial cognition. We therefore tested the effects of septal lesions produced by 192 IgG-saporin in rats, which is highly selective for basal forebrain cholinergic neurons, on home cage activity, noncognitive tests (modified Irwin test, open field and forced swimming tests, and various sensorimotor tasks), and the cone-field spatial learning task. The immunotoxic lesion reduced acetylcholine (ACh) levels in the septum (-61%) and hippocampus (>-75%). Rats with lesions showed mild home-cage hyperactivity at 4 weeks postlesion, but no noncognitive deficits at 13 weeks postsurgery. In the cone-field task, rats with septal lesions made more working- and reference-memory errors than the controls, but acquisition curves were parallel in both groups. The speed of visiting cones was faster in the rats with lesions, indicative of disturbed attention or increased motivation. These data support the growing evidence that involvement of the septohippocampal cholinergic system in spatial learning and memory may have been overestimated in studies that used lesions with poor selectivity. (c) 2006 Wiley-Liss, Inc.

  11. Water

    Science.gov (United States)

    ... www.girlshealth.gov/ Home Nutrition Nutrition basics Water Water Did you know that water makes up more ... to drink more water Other drinks How much water do you need? top Water is very important, ...

  12. The Canine Sand Maze: An Appetitive Spatial Memory Paradigm Sensitive to Age-Related Change in Dogs

    Science.gov (United States)

    Salvin, Hannah E.; McGreevy, Paul D.; Sachdev, Perminder S.; Valenzuela, Michael J.

    2011-01-01

    Aged dogs exhibit a spectrum of cognitive abilities including a syndrome similar to Alzheimer's disease. A major impediment to research so far has been the lack of a quick and accurate test of visuospatial memory appropriate for community-based animals. We therefore report on the development and validation of the Canine Sand Maze. A 4.5-m-diameter…

  13. Fear-potentiation in the elevated plus-maze test depends on stressor controllability and fear conditioning

    NARCIS (Netherlands)

    Korte, S M; Bohus, B; de Boer, Sietse

    The purpose of the study was to determine which stressor qualities (escapable vs. inescapable stress and unconditioned vs. conditioned stress) can potentiate fear in the elevated plus-maze. While inescapable stress potentiated fear, escapable stress did not, but escapable stress increased the

  14. Egocentric virtual maze learning in adult survivors of childhood abuse with dissociative disorders: evidence from functional magnetic resonance imaging.

    Science.gov (United States)

    Weniger, Godehard; Siemerkus, Jakob; Barke, Antonia; Lange, Claudia; Ruhleder, Mirjana; Sachsse, Ulrich; Schmidt-Samoa, Carsten; Dechent, Peter; Irle, Eva

    2013-05-30

    Present neuroimaging findings suggest two subtypes of trauma response, one characterized predominantly by hyperarousal and intrusions, and the other primarily by dissociative symptoms. The neural underpinnings of these two subtypes need to be better defined. Fourteen women with childhood abuse and the current diagnosis of dissociative amnesia or dissociative identity disorder but without posttraumatic stress disorder (PTSD) and 14 matched healthy comparison subjects underwent functional magnetic resonance imaging (fMRI) while finding their way in a virtual maze. The virtual maze presented a first-person view (egocentric), lacked any topographical landmarks and could be learned only by using egocentric navigation strategies. Participants with dissociative disorders (DD) were not impaired in learning the virtual maze when compared with controls, and showed a similar, although weaker, pattern of activity changes during egocentric learning when compared with controls. Stronger dissociative disorder severity of participants with DD was related to better virtual maze performance, and to stronger activity increase within the cingulate gyrus and the precuneus. Our results add to the present knowledge of preserved attentional and visuospatial mnemonic functioning in individuals with DD. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  15. Environmental enrichment decreases avoidance responses in the elevated T-maze and delta FosB immunoreactivity in anxiety-related brain regions.

    Science.gov (United States)

    Lopes, Danielle A; Souza, Thaissa M O; de Andrade, José S; Silva, Mariana F S; Antunes, Hanna K M; Sueur-Maluf, Luciana Le; Céspedes, Isabel C; Viana, Milena B

    2018-02-12

    Environmental enrichment (EE) is an animal management technique, which seems to improve adaptation to the experimental conditions of housing in laboratory animals. Previous studies have pointed to different beneficial effects of the procedure in the treatment of several disorders, including psychiatric conditions such as depression. The anxiolytic effects induced by EE, on the other hand, are not as clear. In fact, it has been proposed that EE acts as a mild stressor agent. To better understand the relationship of EE with anxiety-related responses, the present study exposed rats to one week of EE and subsequently tested these animals in the inhibitory avoidance and escape tasks of the elevated T-maze (ETM). In clinical terms, these responses have been respectively related to generalized anxiety and panic disorder. All animals were tested in an open field, immediately after the ETM, for locomotor activity assessment. Additionally, analysis of delta FosB protein immunoreactivity (FosB-ir) was used to map areas activated by EE exposure and plasma corticosterone measurements were performed. The results obtained demonstrate that exposure to EE for one week impaired avoidance responses, an anxiolytic-like effect, without altering escape reactions. Also, in animals submitted to the avoidance task EE exposure decreased FosB-ir in the cingulate cortex, dorsolateral and intermediate lateral septum, hippocampus (cornus of Ammon), anterior and dorsomedial hypothalamus, medial and basolateral amygdala and ventral region of the dorsal raphe nucleus. Although no behavioral differences were observed in animals submitted to the escape task, EE exposure also decreased FosB-ir in the cingulate cortex, hippocampus (dentate gyrus), lateral amygdala, paraventricular, anterior and ventromedial hypothalamus, dorsomedial periaqueductal gray and ventral and dorsal region of the dorsal raphe. No changes in corticosterone levels, however, were observed. These results contribute to a better

  16. Optimization of Apparatus Design and Behavioral Measures for the Assessment of Visuo-Spatial Learning and Memory of Mice on the Barnes Maze

    Science.gov (United States)

    O'Leary, Timothy P.; Brown, Richard E.

    2013-01-01

    We have previously shown that apparatus design can affect visual-spatial cue use and memory performance of mice on the Barnes maze. The present experiment extends these findings by determining the optimal behavioral measures and test procedure for analyzing visuo-spatial learning and memory in three different Barnes maze designs. Male and female…

  17. Induction of habits in rats by a forced-choice procedure in T-maze and the effect of pre-test free exploration

    DEFF Research Database (Denmark)

    Moustgaard, Anette; Hau, Jann

    2009-01-01

    A forced-choice procedure in T-maze designed for the induction of habits was used to induce strong habits in rats. The response choices of rats in 20 free-choice trials were compared after the rats had been subjected to 1 or 200 forced-choice trials to one side of the T-maze. After 200 forced-cho...

  18. Multivariate temporal pattern analysis applied to the study of rat behavior in the elevated plus maze: methodological and conceptual highlights.

    Science.gov (United States)

    Casarrubea, M; Magnusson, M S; Roy, V; Arabo, A; Sorbera, F; Santangelo, A; Faulisi, F; Crescimanno, G

    2014-08-30

    Aim of this article is to illustrate the application of a multivariate approach known as t-pattern analysis in the study of rat behavior in elevated plus maze. By means of this multivariate approach, significant relationships among behavioral events in the course of time can be described. Both quantitative and t-pattern analyses were utilized to analyze data obtained from fifteen male Wistar rats following a trial 1-trial 2 protocol. In trial 2, in comparison with the initial exposure, mean occurrences of behavioral elements performed in protected zones of the maze showed a significant increase counterbalanced by a significant decrease of mean occurrences of behavioral elements in unprotected zones. Multivariate t-pattern analysis, in trial 1, revealed the presence of 134 t-patterns of different composition. In trial 2, the temporal structure of behavior become more simple, being present only 32 different t-patterns. Behavioral strings and stripes (i.e. graphical representation of each t-pattern onset) of all t-patterns were presented both for trial 1 and trial 2 as well. Finally, percent distributions in the three zones of the maze show a clear-cut increase of t-patterns in closed arm and a significant reduction in the remaining zones. Results show that previous experience deeply modifies the temporal structure of rat behavior in the elevated plus maze. In addition, this article, by highlighting several conceptual, methodological and illustrative aspects on the utilization of t-pattern analysis, could represent a useful background to employ such a refined approach in the study of rat behavior in elevated plus maze. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Spatial Working Memory Deficits in Male Rats Following Neonatal Hypoxic Ischemic Brain Injury Can Be Attenuated by Task Modifications

    Directory of Open Access Journals (Sweden)

    Amanda L. Smith

    2014-04-01

    Full Text Available Hypoxia-ischemia (HI; reduction in blood/oxygen supply is common in infants with serious birth complications, such as prolonged labor and cord prolapse, as well as in infants born prematurely (<37 weeks gestational age; GA. Most often, HI can lead to brain injury in the form of cortical and subcortical damage, as well as later cognitive/behavioral deficits. A common domain of impairment is working memory, which can be associated with heightened incidence of developmental disorders. To further characterize these clinical issues, the current investigation describes data from a rodent model of HI induced on postnatal (P7, an age comparable to a term (GA 36–38 human. Specifically, we sought to assess working memory using an eight-arm radial water maze paradigm. Study 1 used a modified version of the paradigm, which requires a step-wise change in spatial memory via progressively more difficult tasks, as well as multiple daily trials for extra learning opportunity. Results were surprising and revealed a small HI deficit only for the final and most difficult condition, when a delay before test trial was introduced. Study 2 again used the modified radial arm maze, but presented the most difficult condition from the start, and only one daily test trial. Here, results were expected and revealed a robust and consistent HI deficit across all weeks. Combined results indicate that male HI rats can learn a difficult spatial working memory task if it is presented in a graded multi-trial format, but performance is poor and does not appear to remediate if the task is presented with high initial memory demand. Male HI rats in both studies displayed impulsive characteristics throughout testing evidenced as reduced choice latencies despite more errors. This aspect of behavioral results is consistent with impulsiveness as a core symptom of ADHD—a diagnosis common in children with HI insult. Overall findings suggest that task specific behavioral modifications are

  20. Dose reduction of scattered photons from concrete walls lined with lead: Implications for improvement in design of megavoltage radiation therapy facility mazes.

    Science.gov (United States)

    Al-Affan, I A M; Hugtenburg, R P; Bari, D S; Al-Saleh, W M; Piliero, M; Evans, S; Al-Hasan, M; Al-Zughul, B; Al-Kharouf, S; Ghaith, A

    2015-02-01

    This study explores the possibility of using lead to cover part of the radiation therapy facility maze walls in order to absorb low energy photons and reduce the total dose at the maze entrance of radiation therapy rooms. Experiments and Monte Carlo simulations were utilized to establish the possibility of using high-Z materials to cover the concrete walls of the maze in order to reduce the dose of the scattered photons at the maze entrance. The dose of the backscattered photons from a concrete wall was measured for various scattering angles. The dose was also calculated by the FLUKA and EGSnrc Monte Carlo codes. The FLUKA code was also used to simulate an existing radiotherapy room to study the effect of multiple scattering when adding lead to cover the concrete walls of the maze. Monoenergetic photons were used to represent the main components of the x ray spectrum up to 10 MV. It was observed that when the concrete wall was covered with just 2 mm of lead, the measured dose rate at all backscattering angles was reduced by 20% for photons of energy comparable to Co-60 emissions and 70% for Cs-137 emissions. The simulations with FLUKA and EGS showed that the reduction in the dose was potentially even higher when lead was added. One explanation for the reduction is the increased absorption of backscattered photons due to the photoelectric interaction in lead. The results also showed that adding 2 mm lead to the concrete walls and floor of the maze reduced the dose at the maze entrance by up to 90%. This novel proposal of covering part or the entire maze walls with a few millimeters of lead would have a direct implication for the design of radiation therapy facilities and would assist in upgrading the design of some mazes, especially those in facilities with limited space where the maze length cannot be extended to sufficiently reduce the dose. © 2015 American Association of Physicists in Medicine.

  1. Dose reduction of scattered photons from concrete walls lined with lead: Implications for improvement in design of megavoltage radiation therapy facility mazes

    Energy Technology Data Exchange (ETDEWEB)

    Al-Affan, I. A. M., E-mail: info@medphys-environment.co.uk; Hugtenburg, R. P.; Piliero, M. [Swansea University, Swansea SA2 8PP (United Kingdom); Bari, D. S. [Swansea University, Swansea SA2 8PP, United Kingdom and University of Zakho, Duhok (Iraq); Al-Saleh, W. M. [Swansea University, Swansea SA2 8PP, United Kingdom and King Saud Bin Abdulaziz University for Health Science, Hofuf (Saudi Arabia); Evans, S. [Department of Medical Physics and Clinical Engineering, Singleton Hospital, Swansea SA2 8QA (United Kingdom); Al-Hasan, M.; Al-Zughul, B. [College of Sciences, Zarqa University, Zarqa (Jordan); Al-Kharouf, S. [The Royal Scientific Society, Amman (Jordan); Ghaith, A. [Association of Arab Universities, Amman (Jordan)

    2015-02-15

    Purpose: This study explores the possibility of using lead to cover part of the radiation therapy facility maze walls in order to absorb low energy photons and reduce the total dose at the maze entrance of radiation therapy rooms. Methods: Experiments and Monte Carlo simulations were utilized to establish the possibility of using high-Z materials to cover the concrete walls of the maze in order to reduce the dose of the scattered photons at the maze entrance. The dose of the backscattered photons from a concrete wall was measured for various scattering angles. The dose was also calculated by the FLUKA and EGSnrc Monte Carlo codes. The FLUKA code was also used to simulate an existing radiotherapy room to study the effect of multiple scattering when adding lead to cover the concrete walls of the maze. Monoenergetic photons were used to represent the main components of the x ray spectrum up to 10 MV. Results: It was observed that when the concrete wall was covered with just 2 mm of lead, the measured dose rate at all backscattering angles was reduced by 20% for photons of energy comparable to Co-60 emissions and 70% for Cs-137 emissions. The simulations with FLUKA and EGS showed that the reduction in the dose was potentially even higher when lead was added. One explanation for the reduction is the increased absorption of backscattered photons due to the photoelectric interaction in lead. The results also showed that adding 2 mm lead to the concrete walls and floor of the maze reduced the dose at the maze entrance by up to 90%. Conclusions: This novel proposal of covering part or the entire maze walls with a few millimeters of lead would have a direct implication for the design of radiation therapy facilities and would assist in upgrading the design of some mazes, especially those in facilities with limited space where the maze length cannot be extended to sufficiently reduce the dose.

  2. A novel elevated plus-maze procedure to avoid the one-trial tolerance problem

    Directory of Open Access Journals (Sweden)

    Peggy eSchneider

    2011-07-01

    Full Text Available The elevated plus-maze (EPM test is one of the most commonly used behavioural assays to evaluate anxiety-related behaviour in rodents. It is a rather economic test which usually uses a short (5 min protocol and does not require conditioning of the animals. The critical measure for anxiety is the time spent in the open arms of the maze. A confounding problem of the EPM is the so called one-trial tolerance (OTT, characterised by a marked decrease of open arm exploration in spite of treatment with anxiolytic acting benzodiazepines upon re-exposure to the EPM. This consistent finding is often raised as an evidence for the inappropriateness to re-test rodents in the EPM. However, a reliable re-test paradigm would broaden the usability and effectiveness of this test.Therefore, we tested how a prolongation of the inter-trial interval to 28 days (instead of the usual 24 hours, and an additional change of the testing room would affect the open arm time and other behaviours on the EPM. In two experiments, drug naive Wistar rats were exposed to the EPM on trial 1, and treated intraperitoneally with either vehicle or midazolam (0.25 mg/kg 30 min before trial 2. Then, trial 2 (28 days after trial 1 was carried out in either the same testing room (Exp. 1 or a second unfamiliar room (Exp. 2.Twenty-eight days after trial 1 the open arm time of the rats in the vehicle treated control rats of both experimental groups was comparable to that of the first trial, independent of the testing room. Most importantly, we found that the treatment with the benzodiazepine midazolam had a significantly anxiolytic-like (i.e. increase of open arm time effect in trial 2 only when conducted in the previously unfamiliar testing room (Exp. 2. We suggest that in order to reliably re-test the EPM and to prevent confounding effects due to the OTT, an inter-trial interval of 28 days and a change in testing rooms reinstates anxiolytic-like actions of benzodiazepines

  3. Chunking versus foraging search patterns by rats in the hierarchically baited radial maze.

    Science.gov (United States)

    Cohen, Jerome; Pardy, Sandra; Solway, Heidi; Graham, Harold

    2003-06-01

    Rats were exposed to a radial maze containing six black smooth arms and six wire-grid-covered arms and a striped 'exit arm' in experiment 1. The probability of a black or grid arm being baited (5/6 vs 1/6) with sunflower seeds was associated with its proximal cue for some rats (the Relevant Arm Cue group) but not for others (the Irrelevant Arm Cue group). All rats could terminate a trial and receive a highly preferred morsel of apple by entering the exit arm only after having sampled all six seed-baited arms. Relevant Arm Cue rats usually chose some arms from the more densely baited set before choosing an arm from the less densely baited set and made fewer reentries than Irrelevant Arm Cue rats. Although such clustered, higher choice accuracy in the Relevant Arm Cue group corresponds to human clustered, better recall of verbal items from lists hierarchically organized by categories, these rats did not similarly exhaustively retrieve items (arm locations). That is, when required to terminate a trial by entering the 'exit' arm for an apple morsel after having sampled all seed-baited arms, both groups were equally unable to withhold making nonrewarded premature exits. This nonexhaustive foraging search pattern was maintained in the next two experiments in which the radial maze was reduced to three black and three grid arms along with the striped 'exit' arm and in which black and grid arm cues were paired with number of seeds (eight or one) in an arm for Relevant Arm Cue rats. Although Relevant Arm Cue rats displayed perfect clustering by entering all eight-seeded arms before a one-seeded arm, they made more premature exits and reentries into eight-seeded arms in experiment 2 or when forced to enter all eight-seeded arms in experiment 3 than did Irrelevant Arm Cue rats. These foraging tendencies prevent accurate estimations of the amount of information (i.e., arm locations) rats can 'chunk'.

  4. 18 CFR 701.58 - Task forces.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Task forces. 701.58... Headquarters Organization § 701.58 Task forces. The Director with Council concurrence or the Council may establish task forces from time to time to aid in the preparation of issues for presentation to the Council...

  5. Myristic Acid Produces Anxiolytic-Like Effects in Wistar Rats in the Elevated Plus Maze

    Directory of Open Access Journals (Sweden)

    Carlos M. Contreras

    2014-01-01

    Full Text Available A mixture of eight fatty acids (linoleic, palmitic, stearic, myristic, elaidic, lauric, oleic, and palmitoleic acids at similar concentrations identified in human amniotic fluid produces anxiolytic-like effects comparable to diazepam in Wistar rats. However, individual effects of each fatty acid remain unexplored. In Wistar rats, we evaluated the separate action of each fatty acid at the corresponding concentrations previously found in human amniotic fluid on anxiety-like behaviour. Individual effects were compared with vehicle, an artificial mixture of the same eight fatty acids, and a reference anxiolytic drug (diazepam, 2 mg/kg. Myristic acid, the fatty acid mixture, and diazepam increased the time spent in the open arms of the elevated plus maze and reduced the anxiety index compared with vehicle, without altering general locomotor activity. The other fatty acids had no effect on anxiety-like behaviour, but oleic acid reduced locomotor activity. Additionally, myristic acid produced anxiolytic-like effects only when the concentration corresponded to the one identified in human amniotic fluid (30 g/mL but did not alter locomotor activity. We conclude that of the eight fatty acids contained in the fatty acid mixture, only myristic acid produces anxiolytic-like effects when administered individually at a similar concentration detected in human amniotic fluid.

  6. The scientific learning approach using multimedia-based maze game to improve learning outcomes

    Science.gov (United States)

    Setiawan, Wawan; Hafitriani, Sarah; Prabawa, Harsa Wara

    2016-02-01

    The objective of curriculum 2013 is to improve the quality of education in Indonesia, which leads to improving the quality of learning. The scientific approach and supported empowerment media is one approach as massaged of curriculum 2013. This research aims to design a labyrinth game based multimedia and apply in the scientific learning approach. This study was conducted in one of the Vocational School in Subjects of Computer Network on 2 (two) classes of experimental and control. The method used Mix Method Research (MMR) which combines qualitative in multimedia design, and quantitative in the study of learning impact. The results of a survey showed that the general of vocational students like of network topology material (68%), like multimedia (74%), and in particular, like interactive multimedia games and flash (84%). Multimediabased maze game developed good eligibility based on media and material aspects of each value 840% and 82%. Student learning outcomes as a result of using a scientific approach to learning with a multimediabased labyrinth game increase with an average of gain index about (58%) and higher than conventional multimedia with index average gain of 0.41 (41%). Based on these results the scientific approach to learning by using multimediabased labyrinth game can improve the quality of learning and increase understanding of students. Multimedia of learning based labyrinth game, which developed, got a positive response from the students with a good qualification level (75%).

  7. Insular muscarinic signaling regulates anxiety-like behaviors in rats on the elevated plus-maze.

    Science.gov (United States)

    Li, Hui; Chen, Lei; Li, Peng; Wang, Xiaohong; Zhai, Haifeng

    2014-08-15

    Anxiety is one of the most prevalent neuropsychiatric disorders, and little is known about its pathogenesis. In order to investigate the neural mechanisms of this mental disorder, we used rat behavior in the elevated plus-maze as an animal model of anxiety and the insular cortex (insula) as a brain target. The microinjection of non-selective and selective M1 and M4 muscarinic acetylcholine receptor (mAChR) agonists or antagonists was used to explore whether the insular muscarinic receptor and its subtypes regulate levels of anxiety. The results showed that both non-selective and selective M1 and M4 mAChR agonists increased the time spent on exploring in the open arms, whereas antagonists decreased exploration. Our results indicate that activation of insular mAChRs could produce anxiolytic effects, whereas inhibition of insular mAChRs could increase anxiety. We concluded that the insular muscarinic system plays a role in the modulation of anxiety, and dysfunction of mAChR signaling may be involved in the mechanism of anxiogenesis. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. An elevated plus-maze in mixed reality for studying human anxiety-related behavior.

    Science.gov (United States)

    Biedermann, Sarah V; Biedermann, Daniel G; Wenzlaff, Frederike; Kurjak, Tim; Nouri, Sawis; Auer, Matthias K; Wiedemann, Klaus; Briken, Peer; Haaker, Jan; Lonsdorf, Tina B; Fuss, Johannes

    2017-12-21

    A dearth of laboratory tests to study actual human approach-avoidance behavior has complicated translational research on anxiety. The elevated plus-maze (EPM) is the gold standard to assess approach-avoidance behavior in rodents. Here, we translated the EPM to humans using mixed reality through a combination of virtual and real-world elements. In two validation studies, we observed participants' anxiety on a behavioral, physiological, and subjective level. Participants reported higher anxiety on open arms, avoided open arms, and showed an activation of endogenous stress systems. Participants' with high anxiety exhibited higher avoidance. Moreover, open arm avoidance was moderately predicted by participants' acrophobia and sensation seeking, with opposing influences. In a randomized, double blind, placebo controlled experiment, GABAergic stimulation decreased avoidance of open arms while alpha-2-adrenergic antagonism increased avoidance. These findings demonstrate cross-species validity of open arm avoidance as a translational measure of anxiety. We thus introduce the first ecologically valid assay to track actual human approach-avoidance behavior under laboratory conditions.

  9. [Task 1.] Biodenitrification of low nitrate solar pond waters using sequencing batch reactors. [Task 2.] Solidification/stabilization of high strength and biodenitrified heavy metal sludges with a Portland cement/flyash system

    Energy Technology Data Exchange (ETDEWEB)

    Figueroa, L.; Cook, N.E.; Siegrist, R.L.; Mosher, J.; Terry, S.; Canonico, S.

    1995-09-22

    Process wastewater and sludges were accumulated on site in solar evaporation ponds during operations at the Department of Energy's Rocky Flats Plant (DOE/RF). Because of the extensive use of nitric acid in the processing of actinide metals, the process wastewater has high concentrations of nitrate. Solar pond waters at DOE/RF contain 300-60,000 mg NO{sub 3}{sup {minus}}/L. Additionally, the pond waters contain varying concentrations of many other aqueous constituents, including heavy metals, alkali salts, carbonates, and low level radioactivity. Solids, both from chemical precipitation and soil material deposition, are also present. Options for ultimate disposal of the pond waters are currently being evaluated and include stabilization and solidification (S/S) by cementation. Removal of nitrates can enhance a wastes amenability to S/S, or can be a unit operation in another treatment scheme. Nitrate removal is also a concern for other sources of pollution at DOE/RF, including contaminated groundwater collected by interceptor trench systems. Finally, nitrate pollution is a problem at many other DOE facilities where actinide metals were processed. The primary objective of this investigation was to optimize biological denitrification of solar pond waters with nitrate concentrations of 300--2,100 mg NO{sub 3}{sup {minus}}/L to below the drinking water standard of 45 mg NO{sub 3}{sup {minus}}/L (10 mg N/L). The effect of pH upon process stability and denitrification rate was determined. In addition, the effect Cr(VI) on denitrification and fate of Cr(VI) in the presence of denitrifying bacteria was evaluated.

  10. Spatial Working Memory in Male Rats: Pre-Experience and Task Dependent Roles of Dopamine D1- and D2-Like Receptors

    Directory of Open Access Journals (Sweden)

    Mekite Bezu

    2017-10-01

    Full Text Available The dopaminergic system is known to be involved in working memory processed by several brain regions like prefrontal cortex (PFC, hippocampus, striatum. In an earlier study we could show that Levodopa but not Modafinil enhanced working memory in a T-maze only during the early phase of training (day 3, whereas the later phase remained unaffected. Rats treated with a higher dose performed better than low dose treated rats. Here we could more specifically segregate the contributions of dopamine type 1- and 2- like receptors (D1R; D2R to the training state dependent modulation of spatial working memory by intracerebroventricular (ICV application of a D1R-like (SKF81297 and D2R-like agonist (Sumanirole and antagonist (SCH23390, Remoxipride at a low and high dose through 3 days of training. The D1R-like-agonist at both doses enhanced working memory at day 1 but only in the low dose treated rats enhancement persists over training compared to control rats. Rats treated with a high dose of a D1R-like-antagonist show persistent enhancement of working memory over training, whereas in low dose treated rats no statistical difference at any time point could be determined compared to controls. The D2R-like-agonist at both doses does not show an effect at any time point when compared to control animals, whereas the D2R-like antagonist at a low dose enhanced working memory at day 2. For the most effective D1R-like agonist, we repeated the experiments in a water maze working memory task, to test for task dependent differences in working memory modulations. Treated rats at both doses did not differ as compared to controls, but the temporal behavioral performance of all groups was different compared to T-maze trained rats. The results are in line with the view that spatial working memory is optimized within a limited range of dopaminergic transmission, however suggest that these ranges vary during spatial training.

  11. Training on motor and visual spatial learning tasks in early adulthood produces large changes in dendritic organization of prefrontal cortex and nucleus accumbens in rats given nicotine prenatally.

    Science.gov (United States)

    Muhammad, A; Mychasiuk, R; Hosain, S; Nakahashi, A; Carroll, C; Gibb, R; Kolb, B

    2013-11-12

    Experience-dependent plasticity is an ongoing process that can be observed and measured at multiple levels. The first goal of this study was to examine the effects of prenatal nicotine on the performance of rats in three behavioral tasks (elevated plus maze (EPM), Morris water task (MWT), and Whishaw tray reaching). The second goal of this experiment sought to examine changes in dendritic organization following exposure to the behavioral training paradigm and/or low doses of prenatal nicotine. Female Long-Evans rats were administered daily injections of nicotine for the duration of pregnancy and their pups underwent a regimen of behavioral training in early adulthood (EPM, MWT, and Whishaw tray reaching). All offspring exposed to nicotine prenatally exhibited substantial increases in anxiety. Male offspring also showed increased efficiency in the Whishaw tray-reaching task and performed differently than the other groups in the probe trial of the MWT. Using Golgi-Cox staining we examined the dendritic organization of the medial and orbital prefrontal cortex as well as the nucleus accumbens. Participation in the behavioral training paradigm was associated with dramatic reorganization of dendritic morphology and spine density in all brain regions examined. Although both treatments (behavior training and prenatal nicotine exposure) markedly altered dendritic organization, the effects of the behavioral experience were much larger than those of the prenatal drug exposure, and in some cases interacted with the drug effects. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  12. Effects of Ginsenoside Rg1 on Learning and Memory in a Reward-directed Instrumental Conditioning Task in Chronic Restraint Stressed Rats.

    Science.gov (United States)

    Kezhu, Wang; Pan, Xu; Cong, Lu; Liming, Dong; Beiyue, Zhang; Jingwei, Lu; Yanyan, Yang; Xinmin, Liu

    2017-01-01

    Ginsenoside Rg1 is one of the major active ingredients of Panax ginseng and has showed notable improving learning and memory effects in several behavioral tasks, such as water maze, shuttle-box, and step-through, based on avoidance. However, there was no report about the role of Rg1 on the performance of reward-directed instrumental conditioning, which could reflect the adaptive capacity to ever-changing environments. Thus, in this study, the reward devaluation test and conditional visual discrimination task were conducted to study the ameliorating effects of Rg1 on cognitive deficits, especially the loss of adaptation capacity in chronic restraint stress (CRS) rat model. Our results showed that rat subjected to CRS became insensitive to the changes in outcome value, and it significantly harmed the rat's performance in conditional visual discrimination task. Moreover, the levels of BDNF, TrkB, and Erk phosphorylation were decreased in the prefrontal cortex of CRS rats. However, these changes were effectively reversed by Rg1 (5 and 10 mg/kg, i.p.). Therefore, it demonstrated that Rg1 has a good ability to improve learning and memory and also ameliorate impaired adaptive capacity induced by CRS. This amelioration effect of Rg1 might be mediated partially by BDNF/TrkB/Erk pathway in prefrontal cortex. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  13. Analysis of movement kinematics on analogous spatial learning tasks demonstrates conservation of direction and distance estimation across humans (Homo sapiens) and rats (Rattus norvegicus).

    Science.gov (United States)

    Köppen, Jenny R; Winter, Shawn S; Loda, Eileah L; Apger, Brianne P; Grimelli, Danielle; Hamilton, Derek A; Wallace, Douglas G

    2013-05-01

    This series of experiments evaluates the nature of the representation that mediates human (Homo sapiens) and rat (Rattus norvegicus) movement characteristics on analogous spatial learning tasks. The results of Experiment 1 demonstrated that self-movement cues were sufficient to guide the performance of human participants during place training and matching-to-place testing tasks adapted to tabletop or manipulatory scale. Experiment 2 investigated the effect of manipulating access to environmental cues during place training on the nature of the representation used to guide performance. Blindfolded human participants appeared to encode the absolute location of the goal, whereas participants with access to environmental cues appeared to encode the relative location of the goal. The results of Experiment 3 demonstrated that human participants with access to environmental cues exhibited a similar response tendency (as observed in Experiment 2) after half as many trials of place training. During Experiment 4, rats exhibited movement characteristics in the water maze that were similar to movement characteristics observed in human participants who were provided access to environmental cues. These observations provide evidence that direction and distance estimation processes mediate performance on spatial tasks that are conserved across humans and rats.

  14. Altered performance characteristics in cognitive tasks: comparison of the albino ICR and CD1 mouse strains.

    Science.gov (United States)

    Adams, Benjamin; Fitch, Thomas; Chaney, Stephen; Gerlai, Robert

    2002-07-18

    With the advent of recombinant DNA technology the mouse has become a favored model organism in brain research. Numerous mouse strains are available to use as a host for carrying genetic alteration induced by targeted or random mutagenesis. Most strains differ in their genetic makeup and phenotypical characteristics. The choice of the host strain thus can be crucial for the analysis of functional effects of the induced mutation. In the present paper we analyze the behavior of two related outbred albino strains of mice, ICR and CD1, that are often used in transgenic research. Using two frequently employed learning tasks, the Morris water maze (MWM) and the context-dependent fear conditioning (CFC) as well as other behavioral tests, we demonstrate significant performance differences between the strains. ICR suffers from a severe visual impairment making this strain difficult to use in several behavioral paradigms that require good visual perception, e.g. the MWM. CD1 does not suffer from grossly impaired vision but, similarly to the ICR strain, CD1 mice exhibit decreased freezing in all phases of CFC. Although the strains are able to learn, such deficits can render them significantly impaired dependent on the performance demands of the cognitive test employed. Our findings underscore the need for careful examination of the characteristics of the host strain, the choice of which must be made in accordance with the expected functional alterations induced by the mutation.

  15. Behavioral effects of "vehicle" microinjected into the dorsal periaqueductal grey of rats tested in the elevated plus maze

    Directory of Open Access Journals (Sweden)

    Matheus M.G.

    1997-01-01

    Full Text Available To investigate the behavioral effects of different vehicles microinjected into the dorsal periaqueductal grey (DPAG of male Wistar rats, weighing 200-250 g, tested in the elevated plus maze, animals were implanted with cannulas aimed at this structure. One week after surgery the animals received microinjections into the DPAG of 0.9% (w/v saline, 10% (v/v dimethyl sulfoxide (DMSO, 2% (v/v Tween-80, 10% (v/v propylene glycol, or synthetic cerebrospinal fluid (CSF. Ten min after the injection (0.5 µl the animals (N = 8-13/group were submitted to the elevated plus maze test. DMSO significantly increased the number of entries into both the open and enclosed arms when compared to 0.9% saline (2.7 ± 0.8 and 8.7 ± 1.3 vs 0.8 ± 0.3 and 5.1 ± 0.9, respectively, Duncan test, P<0.05, and tended to increase enclosed arm entries as compared to 2% Tween-80 (8.7 ± 1.3 vs 5.7 ± 0.9, Duncan test, P<0.10. In a second experiment no difference in plus maze exploration was found between 0.9% saline- or sham-injected animals (N = 11-13/group. These results indicate that intra-DPAG injection of some commonly used vehicles such as DMSO, saline or Tween-80 affects the exploratory activity of rats exposed to the elevated plus maze in statistically different manners

  16. Successful performance of Cox-Maze procedure on beating heart using bipolar radiofrequency ablation: a feasibility study in animals.

    Science.gov (United States)

    Gaynor, Sydney L; Ishii, Yosuke; Diodato, Michael D; Prasad, Sunil M; Barnett, Kara M; Damiano, Nicholas R; Byrd, Gregory D; Wickline, Samuel A; Schuessler, Richard B; Damiano, Ralph J

    2004-11-01

    The Cox-Maze procedure is the gold standard for the surgical treatment of atrial fibrillation with proven long-term efficacy. However, its application has been limited by its complexity and significant morbidity. The purpose of this study was to test the feasibility and safety of performing the Cox-Maze procedure using bipolar radiofrequency ablation on the beating heart without cardiopulmonary bypass. After median sternotomy, 6 Hanford mini-pigs underwent a modified Cox-Maze procedure using bipolar radiofrequency energy. The animals survived for 30 days. Atrial function, coronary artery, pulmonary vein anatomy, and valve function were assessed by magnetic resonance imaging. At reoperation, pacing documented electrical isolation of the pulmonary veins. Induction of atrial fibrillation was attempted by burst pacing with cholinergic stimulation. Histologic assessment was performed after sacrifice. There were no perioperative mortalities or neurologic events. At 30 days, atrial fibrillation was unable to be induced, and pulmonary vein isolation was confirmed by pacing. Magnetic resonance imaging assessment revealed no coronary artery or pulmonary vein stenoses. Although atrial ejection fraction decreased slightly from 0.344 +/- 0.0114 to 0.300 +/- 0.055 (p = 0.18), atrial contractility was preserved in every animal. Histologic assessment showed all lesions to be transmural, and there were no significant stenoses of the coronary vessels or injuries to the valves. Virtually all of the lesions of the Cox-Maze procedure can be performed without cardiopulmonary bypass using bipolar radiofrequency energy. There were no late stenoses of the pulmonary veins. Clinical trials of this new technology on the beating heart are warranted.

  17. A Minimally Invasive Stand-alone Cox-Maze Procedure Is as Effective as Median Sternotomy Approach.

    Science.gov (United States)

    Schill, Matthew R; Sinn, Laurie A; Greenberg, Jason W; Henn, Matthew C; Lancaster, Timothy S; Schuessler, Richard B; Maniar, Hersh S; Damiano, Ralph J

    The Cox-Maze IV procedure has been shown to be an effective treatment for atrial fibrillation when performed concomitantly with other operations either via median sternotomy or right minithoracotomy. Few studies have compared these approaches in patients with lone atrial fibrillation. This study examined outcomes with sternotomy versus minithoracotomy in stand-alone Cox-Maze IV procedures at our institution. Between 2002 and 2015, 195 patients underwent stand-alone biatrial Cox-Maze IV. Minithoracotomy was used in 75 patients, sternotomy in 120. Freedom from atrial tachyarrhythmias was ascertained using electrocardiography, Holter, or pacemaker interrogation at 3 to 60 months. Predictors of recurrence were determined using logistic regression. Of 23 preoperative variables, the only differences between groups were that minithoracotomy patients had a higher rate of New York Heart Association 3/4 symptoms and a lower rate of previous stroke. Minithoracotomy and sternotomy patients had similar atrial fibrillation duration and type. Minithoracotomy patients had a smaller left atrial diameter (4.5 vs 4.8 cm, P = 0.03). More minithoracotomy patients received a box lesion (73/75 vs 100/120, P = 0.002). Minithoracotomy patients had a shorter hospital stay (7 vs 8 days, P = 0.009) and a similar rate of major complications (3/75 (4%) vs 7/120 (6%), P = 0.74). There were no differences in mortality or freedom from atrial tachyarrhythmias. Predictors of atrial fibrillation recurrence included a preoperative pacemaker, omission of the left atrial roof line, and New York Heart Association 3/4 symptoms. Stand-alone Cox-Maze IV via minithoracotomy was as effective as via sternotomy with a shorter hospital stay. A minimally invasive approach is our procedure of choice.

  18. Kv4.2 knockout mice display learning and memory deficits in the Lashley maze [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Gregory D. Smith

    2016-10-01

    Full Text Available Background: Potassium channels have been shown to be involved in neural plasticity and learning. Kv4.2 is a subunit of the A-type potassium channel. Kv4.2 channels modulate excitability in the dendrites of pyramidal neurons in the cortex and hippocampus. Deletion of Kv4.2 results in spatial learning and conditioned fear deficits; however, previous studies have only examined deletion of Kv4.2 in aversive learning tests. Methods: For the current study, we used the Lashley maze as an appetitive learning test. We examined Kv4.2 wildtype (WT and knockout (KO mice in the Lashley maze over 4 days during adulthood. The first day consisted of habituating the mice to the maze. The mice then received five trials per day for the next 3 days. The number of errors and the time to the goal box was recorded for each trial. The goal box contained a weigh boat with an appetitive reward (gelatin with sugar. There was an intertrial interval of 15 minutes. Results: We found that Kv4.2 KO mice committed more errors across the trials compared to the WT mice p<0.001. There was no difference in the latency to find the goal box over the period. Discussion: Our finding that deletion of Kv4.2 resulted in more errors in the Lashley maze across 15 trials contribute to a growing body of evidence that Kv4.2 channels are significantly involved in learning and memory.

  19. Kv4.2 knockout mice display learning and memory deficits in the Lashley maze [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Gregory D. Smith

    2017-02-01

    Full Text Available Background: Potassium channels have been shown to be involved in neural plasticity and learning. Kv4.2 is a subunit of the A-type potassium channel. Kv4.2 channels modulate excitability in the dendrites of pyramidal neurons in the cortex and hippocampus. Deletion of Kv4.2 results in spatial learning and conditioned fear deficits; however, previous studies have only examined deletion of Kv4.2 in aversive learning tests. Methods: For the current study, we used the Lashley maze as an appetitive learning test. We examined Kv4.2 wildtype (WT and knockout (KO mice in the Lashley maze over 4 days during adulthood. The first day consisted of habituating the mice to the maze. The mice then received five trials per day for the next 3 days. The number of errors and the time to the goal box was recorded for each trial. The goal box contained a weigh boat with an appetitive reward (gelatin with sugar. There was an intertrial interval of 15 minutes. Results: We found that Kv4.2 KO mice committed more errors across the trials compared to the WT mice p<0.001. There was no difference in the latency to find the goal box over the period. Discussion: Our finding that deletion of Kv4.2 resulted in more errors in the Lashley maze across 15 trials contribute to a growing body of evidence that Kv4.2 channels are significantly involved in learning and memory.

  20. Effect of phencyclidine derivatives on anxiety-like behavior using an elevated-plus maze test in mice.

    Science.gov (United States)

    Hajikhani, Ramin; Ahmadi, Abbas; Naderi, Nima; Yaghoobi, Kayvan; Shirazizand, Zahra; Rezaee, Nazereh M; Niknafs, Babak N

    2012-01-01

    The study attempted to investigate the anti-anxiety activities of Phencyclidine (1-(1-phenylcyclohexyl) piperidine, PCP, I) and some of its derivatives (M, F, L, B, S, P) with the elevated-plus maze (EPM) Test. Phencyclidine and its derivatives (M, F, L, B, S, P) were administrated intraperitoneally (i.p.) at a dose of 10 mg/kg to male mice. Anxiety-like behaviors were assessed using the elevated-plus maze test. EPM results revealed an increase in open arms time spent after applying PCP and M, L, P, and B compounds at the administered dosage. Moreover, an increase in the number of open arm entries was observed with M, P, and B compounds. The P, B and S compounds increased the locomotion of animals, too, which might be considered as the side effect to the compounds. Considering the elevated-plus maze results, it was concluded that M and L compounds could be considered as a potential anxiolytic with less side effects due to a probable high electron donation of the methoxy group, as well as the hydrophilic properties of hydroxyl groups on these compounds.

  1. New neurons generated from running are broadly recruited into neuronal activation associated with three different hippocampus-involved tasks

    Science.gov (United States)

    Clark, Peter J.; Bhattacharya, Tushar K.; Miller, Daniel S.; Kohman, Rachel A.; DeYoung, Erin K.; Rhodes, Justin S.

    2012-01-01

    Running increases the formation of new neurons in the adult rodent hippocampus. However, the function of new neurons generated from running is currently unknown. One hypothesis is that new neurons from running contribute to enhanced cognitive function by increasing plasticity in the adult hippocampus. An alternative hypothesis is that new neurons generated from running incorporate into experience-specific hippocampal networks that only become active during running. The purpose of this experiment was to determine if new neurons generated from running are selectively activated by running, or can become recruited into granule cell activity occurring during performance on other behavioral tasks that engage the hippocampus. Therefore, the activation of new 5–6 week neurons was detected using BrdU, NeuN, and Zif268 triple-label immunohistochemistry in cohorts of female running and sedentary adult C57BL/6J mice following participation in one of three different tasks: the Morris water maze, novel environment exploration, or wheel running. Results showed that running and sedentary mice displayed a nearly equivalent proportion of new neurons that expressed Zif268 following each task. Since running approximately doubled the number of new neurons, the results demonstrated that running mice had a greater number of new neurons recruited into the Zif268 induction in the granule cell layer following each task than sedentary mice. The results suggest that new neurons incorporated into hippocampal circuitry from running are not just activated by wheel running itself, but rather become broadly recruited into granule cell layer activity during distinct behavioral experiences. PMID:22467337

  2. A virtual reality task based on animal research - spatial learning and memory in patients after the first episode of schizophrenia.

    Science.gov (United States)

    Fajnerová, Iveta; Rodriguez, Mabel; Levčík, David; Konrádová, Lucie; Mikoláš, Pavol; Brom, Cyril; Stuchlík, Aleš; Vlček, Kamil; Horáček, Jiří

    2014-01-01

    Cognitive deficit is considered to be a characteristic feature of schizophrenia disorder. A similar cognitive dysfunction was demonstrated in animal models of schizophrenia. However, the poor comparability of methods used to assess cognition in animals and humans could be responsible for low predictive validity of current animal models. In order to assess spatial abilities in schizophrenia and compare our results with the data obtained in animal models, we designed a virtual analog of the Morris water maze (MWM), the virtual Four Goals Navigation (vFGN) task. Twenty-nine patients after the first psychotic episode with schizophrenia symptoms and a matched group of healthy volunteers performed the vFGN task. They were required to find and remember four hidden goal positions in an enclosed virtual arena. The task consisted of two parts. The Reference memory (RM) session with a stable goal position was designed to test spatial learning. The Delayed-matching-to-place (DMP) session presented a modified working memory protocol designed to test the ability to remember a sequence of three hidden goal positions. Data obtained in the RM session show impaired spatial learning in schizophrenia patients compared to the healthy controls in pointing and navigation accuracy. The DMP session showed impaired spatial memory in schizophrenia during the recall of spatial sequence and a similar deficit in spatial bias in the probe trials. The pointing accuracy and the quadrant preference showed higher sensitivity toward the cognitive deficit than the navigation accuracy. Direct navigation to the goal was affected by sex and age of the tested subjects. The age affected spatial performance only in healthy controls. Despite some limitations of the study, our results correspond well with the previous studies in animal models of schizophrenia and support the decline of spatial cognition in schizophrenia, indicating the usefulness of the vFGN task in comparative research.

  3. A Virtual Reality Task Based on Animal Research - Spatial Learning and Memory in Patients after the First Episode of Schizophrenia

    Directory of Open Access Journals (Sweden)

    Iveta eFajnerova

    2014-05-01

    Full Text Available Objective: Cognitive deficit is considered to be a characteristic feature of schizophrenia disorder. A similar cognitive dysfunction was demonstrated in animal models of schizophrenia. However, the poor comparability of methods used to assess cognition in animals and humans could be responsible for low predictive validity of current animal models. In order to assess spatial abilities in schizophrenia and compare our results with the data obtained in animal models we designed a virtual analogue of the Morris water maze (MWM, the virtual Four Goals Navigation (vFGN task.Method: Twenty-nine patients after the first psychotic episode with schizophrenia symptoms and a matched group of healthy volunteers performed the vFGN task. They were required to find and remember four hidden goal positions in an enclosed virtual arena. The task consisted of two parts. The Reference memory (RM session with a stable goal position was designed to test spatial learning. The Delayed-matching-to-place (DMP session presented a modified working memory protocol designed to test the ability to remember a sequence of three hidden goal positions.Results: Data obtained in the RM session show impaired spatial learning in schizophrenia patients compared to healthy controls in pointing and navigation accuracy. The DMP session showed impaired spatial memory in schizophrenia during the recall of spatial sequence and similar deficit in spatial bias in probe trials. The pointing accuracy and the quadrant preference showed higher sensitivity toward the cognitive deficit than the navigation accuracy. Direct navigation to the goal was affected by sex and age of the tested subjects. Age affected spatial performance only in healthy controls. Conclusions: Despite some limitations of the study, our results correspond well to previous studies in animal models of schizophrenia and support the decline of spatial cognition in schizophrenia, indicating the usefulness of the vFGN task in

  4. New neurons generated from running are broadly recruited into neuronal activation associated with three different hippocampus-involved tasks.

    Science.gov (United States)

    Clark, Peter J; Bhattacharya, Tushar K; Miller, Daniel S; Kohman, Rachel A; DeYoung, Erin K; Rhodes, Justin S

    2012-09-01

    Running increases the formation of new neurons in the adult rodent hippocampus. However, the function of new neurons generated from running is currently unknown. One hypothesis is that new neurons from running contribute to enhanced cognitive function by increasing plasticity in the adult hippocampus. An alternative hypothesis is that new neurons generated from running incorporate into experience-specific hippocampal networks that only become active during running. The purpose of this experiment was to determine if new neurons generated from running are selectively activated by running, or can become recruited into granule cell activity occurring during performance on other behavioral tasks that engage the hippocampus. Therefore, the activation of new 5-6 week neurons was detected using BrdU, NeuN, and Zif268 triple-label immunohistochemistry in cohorts of female running and sedentary adult C57BL/6J mice following participation in one of three different tasks: the Morris water maze, novel environment exploration, or wheel running. Results showed that running and sedentary mice displayed a nearly equivalent proportion of new neurons that expressed Zif268 following each task. Since running approximately doubled the number of new neurons, the results demonstrated that running mice had a greater number of new neurons recruited into the Zif268 induction in the granule cell layer following each task than sedentary mice. The results suggest that new neurons incorporated into hippocampal circuitry from running are not just activated by wheel running itself, but rather become broadly recruited into granule cell layer activity during distinct behavioral experiences. Copyright © 2012 Wiley Periodicals, Inc.

  5. Progesterone withdrawal effects in the open field test can be predicted by elevated plus maze performance.

    Science.gov (United States)

    Löfgren, Magnus; Johansson, Inga-Maj; Meyerson, Bengt; Lundgren, Per; Bäckström, Torbjörn

    2006-08-01

    Allopregnanolone (3alpha-hydroxy-5alpha-pregnane-20-one) is a ring-A-reduced metabolite of progesterone, which is naturally produced during the luteal phase of the menstrual cycle, during pregnancy and by stressful events. The steroid hormone inhibits neural functions through increased chloride ion flux through the GABA(A) receptor. The effects and subsequent withdrawal symptoms are similar to those caused by alcohol, benzodiazepines and barbiturates. This study examined the withdrawal effects of progesterone with regards to the influence of individual baseline exploration and risk taking. Rats were tested on the elevated plus maze (EPM) before hormonal treatment, in order to evaluate differences in risk taking and exploration of open and elevated areas. Treatment consisted of ten consecutive once a day progesterone or vehicle s.c. injections. On the last day of treatment, estradiol was injected in addition to progesterone, followed by a 24-h withdrawal before testing in the open field test (OF). Progesterone-treated rats showed a withdrawal effect of open area avoidance in the OF. The vehicle-treated control rats showed strong correlations between the EPM and OF parameters. This relationship was not found for the progesterone group at withdrawal. Rats with greater numbers of open arm entrance in the EPM pretest showed an increased sensitivity to progesterone withdrawal (PWD) compared to rats with low exploration and risk taking. The results indicate that the effects of PWD relate to individual exploration and risk taking. Furthermore, the possible analogy of PWD and PMS/PMDD in relation to individual traits is discussed.

  6. Water

    Science.gov (United States)

    ... environment and your health: Green living Sun Water Health effects of water pollution How to protect yourself from water pollution Air Chemicals Noise Quizzes Links to more information girlshealth glossary girlshealth. ...

  7. Chunking in task sequences modulates task inhibition.

    Science.gov (United States)

    Koch, Iring; Philipp, Andrea M; Gade, Miriam

    2006-04-01

    In a study of the formation of representations of task sequences and its influence on task inhibition, participants first performed tasks in a predictable sequence (e.g., ABACBC) and then performed the tasks in a random sequence. Half of the participants were explicitly instructed about the predictable sequence, whereas the other participants did not receive these instructions. Task-sequence learning was inferred from shorter reaction times (RTs) in predictable relative to random sequences. Persisting inhibition of competing tasks was indicated by increased RTs in n- 2 task repetitions (e.g., ABA) compared with n- 2 nonrepetitions (e.g., CBA). The results show task-sequence learning for both groups. However, task inhibition was reduced in predictable relative to random sequences among instructed-learning participants who formed an explicit representation of the task sequence, whereas sequence learning and task inhibition were independent in the noninstructed group. We hypothesize that the explicit instructions led to chunking of the task sequence, and that n- 2 repetitions served as chunk points (ABA-CBC), so that within-chunk facilitation modulated the inhibition effect.

  8. Mars surface based factory. Phase 2, task 1C: Computer control of a water treatment system to support a space colony on Mars

    Science.gov (United States)

    Fuller, John; Ali, Warsame; Willis, Danette

    1989-01-01

    In a continued effort to design a surface based factory on Mars for the production of oxygen and water, a preliminary study was made of the surface and atmospheric composition on Mars and determined the mass densities of the various gases in the Martian atmosphere. Based on the initial studies, oxygen and water were determined to be the two products that could be produced economically under the Martian conditions. Studies were also made on present production techniques to obtain water and oxygen. Analyses were made to evaluate the current methods of production that were adaptable to the Martian conditions. Even though the initial effort was the production of oxygen and water, it was found necessary to produce some diluted gases that can be mixed with the oxygen produced to constitute 'breathable' air. The conceptual design of a breathable air manufacturing system, a means of drilling for underground water, and storage of water for future use were completed. The design objective was the conceptual design of an integrated system for the supply of quality water for biological consumption, farming, residential and industrial use.

  9. Effects of periadolescent fluoxetine and paroxetine on elevated plus-maze, acoustic startle, and swimming immobility in rats while on and off-drug

    Directory of Open Access Journals (Sweden)

    Williams Michael T

    2011-10-01

    Full Text Available Abstract Rationale Whether selective serotonin reuptake inhibitors (SSRIs exposure during adolescent brain development causes lasting effects remains unresolved. Objective Assess the effects of fluoxetine and paroxetine 60 days after adolescent exposure compared with when on-drug. Methods Male Sprague-Dawley littermates (41 litters were gavaged on postnatal days 33-53 with fluoxetine (3 or 10 mg/kg/day, paroxetine (3, 10 or, 17 mg/kg/day, or water; half were tested while on-drug (21 litters and half after 60 days off-drug (20 litters. Results The highest dose of the drugs reduced body weight gain during treatment that rebounded 1 week post-treatment. On-drug, no significant group differences were found on elevated plus maze time-in-open, zone entries, or latency to first open entry; however, the high dose of paroxetine significantly reduced head-dips (N = 20/group. No significant effects were found on-drug for acoustic startle response/prepulse inhibition (ASR/PPI although a trend (p Conclusions The data provide no evidence that fluoxetine or paroxetine have long-term adverse effects on the behaviors measured here after adolescent to young adult exposure.

  10. Un cas particulier du scénario dans l'apprentissage des langues : le labyrinthe (action maze) Action Mazes: a special case of the scenario for language learning

    OpenAIRE

    Joseph Rézeau

    2008-01-01

    En didactique des langues l'approche actionnelle et les scénarios sont d'actualité, en lien avec les Tice (Technologies de l'Information et de la Communication pour l'Enseignement). Cependant, des activités de type labyrinthe (action mazes), courantes dans les années 1980 et souvent portées sur les micro-ordinateurs de l'époque, semblent quelque peu tombées dans l'oubli. Cet article entend montrer qu'il est relativement aisé de concevoir et de réaliser de telles activités sur une plateforme d...

  11. Water

    Science.gov (United States)

    Leopold, Luna Bergere; Baldwin, Helene L.

    1962-01-01

    What do you use water for?If someone asked you this question you would probably think right away of water for drinking. Then you would think of water for bathing, brushing teeth, flushing the toilet. Your list would get longer as you thought of water for cooking, washing the dishes, running the garbage grinder. Water for lawn watering, for play pools, for swimming pools, for washing the car and the dog. Water for washing machines and for air conditioning. You can hardly do without water for fun and pleasure—water for swimming, boating, fishing, water-skiing, and skin diving. In school or the public library, you need water to wash your hands, or to have a drink. If your home or school bursts into flames, quantities of water are needed to put it out.In fact, life to Americans is unthinkable without large supplies of fresh, clean water. If you give the matter a little thought, you will realize that people in many countries, even in our own, may suffer from disease and dirt simply because their homes are not equipped with running water. Imagine your own town if for some reason - an explosion, perhaps - water service were cut off for a week or several weeks. You would have to drive or walk to a neighboring town and bring water back in pails. Certainly if people had to carry water themselves they might not be inclined to bathe very often; washing clothes would be a real chore.Nothing can live without water. The earth is covered by water over three-fourths of its surface - water as a liquid in rivers, lakes and oceans, and water as ice and snow on the tops of high mountains and in the polar regions. Only one-quarter of our bodies is bone and muscle; the other three-fourths is made of water. We need water to live, and so do plants and animals. People and animals can live a long time without food, but without water they die in a few days. Without water, everything would die, and the world would turn into a huge desert.

  12. Echocardiographic evaluation of mitral durability following valve repair in rheumatic mitral valve disease: impact of Maze procedure.

    Science.gov (United States)

    Kim, Gwan Sic; Lee, Chee Hoon; Kim, Joon Bum; Jung, Sung-Ho; Choo, Suk Jung; Chung, Cheol Hyun; Lee, Jae Won

    2014-01-01

    The data on echocardiographic evaluation of mitral durability after rheumatic mitral repair is scarce. A total of 193 patients (mean age, 39.4 ± 12.8 years; 154 females) who underwent mitral valve repair for rheumatic valve disease from 1997 to 2010 were included in the study. A Maze operation was performed in 90.3% (n = 102) of the patients with atrial fibrillation (n = 113). Survival, valve-related complications, and echocardiographic data were evaluated. Mitral regurgitation was the predominant disease in 75.6% of patients (n = 146). There was one early death (0.5%) . During the mean follow-up period of 76.7 ± 45.6 months, there were 9 late deaths and 5 mitral reoperations. Valve-related, event-free survival at 10 years was 85.5% ± 3.3%. In serial postoperative echocardiographic evaluations (mean follow-up duration, 53.7 ± 43.5 months), 40 patients showed either mitral regurgitation (>mild; n = 31) or mitral stenosis (mitral valve area ≤1.5 cm(2); n = 9). At 10 years, 66.4% ± 5.4% of the patients did not have moderate to severe mitral dysfunction. By multivariate analysis, no Maze operation for atrial fibrillation was an independent predictor of mitral dysfunctions (hazard ratio, 3.72; 95% confidence interval, 1.47-9.42; P = .005), whereas the presence of hypertension had borderline significance (hazard ratio, 3.15; 95% confidence interval, 0.96-10.38; P = .059). Although rheumatic mitral repair showed excellent long-term clinical outcomes, a significant proportion of patients experienced moderate to severe mitral dysfunctions postoperatively. Atrial fibrillation without a Maze procedure increased significantly the risks of mitral dysfunctions and adverse outcomes. Therefore, routine performance of a Maze procedure is warranted in the presence of atrial fibrillation whenever possible. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

  13. Un cas particulier du scénario dans l'apprentissage des langues : le labyrinthe (action maze)

    OpenAIRE

    Rézeau, Joseph

    2008-01-01

    En didactique des langues l'approche actionnelle et les scénarios sont d'actualité, en lien avec les Tice (Technologies de l'Information et de la Communication pour l'Enseignement). Cependant, des activités de type labyrinthe (action mazes), courantes dans les années 1980 et souvent portées sur les micro-ordinateurs de l'époque, semblent quelque peu tombées dans l'oubli. Cet article entend montrer qu'il est relativement aisé de concevoir et de réaliser de telles activités sur une plateforme d...

  14. Transgenic Mice Lacking NMDAR-Dependent LTD Exhibit Deficits in Behavioral Flexibility

    National Research Council Canada - National Science Library

    Nicholls, Russell E; Alarcon, Juan Marcos; Malleret, Gaël; Carroll, Reed C; Grody, Michael; Vronskaya, Svetlana; Kandel, Eric R

    2008-01-01

    .... This physiological phenotype was associated with deficits in behavioral flexibility in both the Morris water maze and a delayed nonmatch to place T-maze task, suggesting that NMDAR-dependent LTD...

  15. Water

    Science.gov (United States)

    ... the tap as described). 3. In all situations, drink or cook only with water that comes out of the tap cold. Water that comes out of the tap warm or hot can contain much higher levels of lead. Boiling ...

  16. Effect of Ellagic Acid on Animal Behavior in Elevated Plus Maze and Open Field Tests

    Directory of Open Access Journals (Sweden)

    Farbood

    2015-12-01

    Full Text Available Background Anxiety is one the most common psychiatric disorders. Recently, anti-oxidants have been shown to possess anxiolytic properties. Objectives The present study aimed to investigate anxiolytic effect of ellagic acid (EA in mice and its interaction with GABAA receptor. Materials and Methods 184 male albino mice (25 - 30 g were randomly assigned into two subgroups (12 groups in each. In the first set of experiments, to evaluate acute administration of EA (single dose on anxiety, experimental groups (10 groups, 8 mice per group were control (received vehicle, EA-treated groups (received ellagic acid, 3, 10, 30 and 100 mg/kg, i.p., diazepam (DZP-treated groups (received DZP, 1, 3 and 5 mg/kg, i.p., Flumazenil (FLZ + diazepam-treated group (received FLZ, 3 mg/kg and + DPZ, 5 mg/kg, i.p. and FLZ+EA-treated group (received FLZ, 3 mg/kg and ellagic acid, 30 mg/kg, i.p.. Moreover, in the first set of experiments, to evaluate the effect of chronic administration of EA on anxiety, experimental groups (2 groups, 8 mice per group were control (received vehicle once a day for 10 days and EA-treated group (received ellagic acid at the dose of 30 mg/kg, i.p. once a day for 10 days. In the second set of experiments, to evaluate acute (single dose and chronic (for 10 days administration of EA on motor activity, animal groupings were similar to the first set of experiment. Elevated plus maze (EPM and open field tests used to study anxiolytic and motor activity effect of EA, respectively. Statistical analysis was performed by one-way ANOVA and post hoc Tukey’s test. P values less than 0.05 were considered as significant. Results Acute and chronic application of EA significantly enhanced the number of open arm entries and percentage of time spent in open arm compared with the control (P < 0.05. Pretreatment with flumazenil (FLZ + EA-treated group significantly decreased the number of open arm entries and percentage of time spent in open arm compared with EA

  17. The baby or the bath water? Lessons learned from the National Action Alliance for Suicide Prevention Research Prioritization Task Force literature review.

    Science.gov (United States)

    Davis Molock, Sherry; Heekin, Janet M; Matlin, Samantha G; Barksdale, Crystal L; Gray, Ekwenzi; Booth, Chelsea L

    2014-09-01

    The Research Prioritization Task Force of the National Action Alliance for Suicide Prevention conducted a comprehensive literature review of suicide prevention/intervention trials to assess the quality of the scientific evidence. A literature "review of reviews" was conducted by searching the most widely used databases for mental health and public health research. The quality of the reviews was evaluated using the Revised Assessment of Multiple Systematic Reviews system; the quality of the scientific evidence for the suicide preventions/interventions was assessed using U.S. Preventive Services Task Force criteria. The reviews were limited to peer-reviewed publications with human subjects published in English. Ninety-eight systematic reviews and 45 primary sources on suicide prevention/interventions published between January 2000 and September 2012 were evaluated. The results suggest that the quality of both the systematic reviews and the scientific evidence for suicide preventions/interventions were mixed. The majority of the systematic reviews and prevention/interventions were evaluated as fair to poor in quality. There are many promising suicide prevention/intervention trials, but research findings are often inconclusive because of methodologic problems. Methodologic problems across systematic reviews include not conducting hand searches, not surveying gray literature, and being unable to aggregate data across studies. Methodologic problems with the scientific quality of the prevention/intervention trials include paucity of information on sample demographic characteristics, poorly defined outcomes, and excluding actively suicidal participants. Suggestions for ways to improve the quality of the systematic reviews and suicide preventions/interventions are provided. Copyright © 2014 American Journal of Preventive Medicine. All rights reserved.

  18. Sertindole, in contrast to clozapine and olanzapine, does not disrupt water maze performance after acute or chronic treatment

    DEFF Research Database (Denmark)

    Didriksen, Michael; Kreilgaard, Mads; Arnt, Jørn

    2006-01-01

    antipsychotics tested differentially affected rodent cognition, whereby sertindole appeared to have a lower potential than either clozapine or olanzapine to induce cognitive impairment. The hypothesis that the low potency of sertindole in inducing dopamine D2 receptor blockade, combined with lack...

  19. Anxiogenic-like effect of acute and chronic fluoxetine on rats tested on the elevated plus-maze

    Directory of Open Access Journals (Sweden)

    M.T.A. Silva

    1999-03-01

    Full Text Available The selective serotonin reuptake inhibitor fluoxetine (FLX is widely prescribed for depression and anxiety-related disorders. On the other hand, enhanced serotonergic transmission is known to be classically related to anxiety. In this study, the effects of acute (5.0 mg/kg and chronic (5.0 mg/kg, 22 days FLX were investigated in both food-deprived and non-deprived rats tested in the elevated plus-maze. Significant main effects of the three factors (drug, food condition and administration regimen were observed, but no interaction between them. The administration of either acute or chronic FLX resulted in an anxiogenic effect, as detected by a significant reduction in the percentage of time spent in the open arms and in the percentage of open arm entries. Food deprivation yielded an anxiolytic-like profile, probably related to changes in locomotor activity. The administration regimen resulted in an anxiolytic profile in chronically treated rats, as would be expected after 22 days of regular handling. The anxiogenic action of acute FLX is consistent with both its neurochemical and clinical profile. The discrepancy between the anxiogenic profile of chronic FLX and its therapeutic uses is discussed in terms of possible differences between the type of anxiety that is measured in the plus-maze and the types of human anxiety that are alleviated by fluoxetine.

  20. A low noise remotely controllable wireless telemetry system for single-unit recording in rats navigating in a vertical maze.

    Science.gov (United States)

    Chen, Hsin-Yung; Wu, Jin-Shang; Hyland, Brian; Lu, Xiao-Dong; Chen, Jia Jin Jason

    2008-08-01

    The use of cables for recording neural activity limits the scope of behavioral tests used in conscious free-moving animals. Particularly, cable attachments make it impossible to record in three-dimensional (3D) mazes where levels are vertically stacked or in enclosed spaces. Such environments are of particular interest in investigations of hippocampal place cells, in which neural activity is correlated with spatial position in the environment. We developed a flexible miniaturized Bluetooth-based wireless data acquisition system. The wireless module included an 8-channel analogue front end, digital controller, and Bluetooth transceiver mounted on a backpack. Our bidirectional wireless design allowed all data channels to be previewed at 1 kHz sample rate, and one channel, selected by remote control, to be sampled at 10 kHz. Extracellular recordings of neuronal activity are highly susceptible to ambient electrical noise due to the high electrode impedance. Through careful design of appropriate shielding and hardware configuration to avoid ground loops, mains power and Bluetooth hopping frequency noise were reduced sufficiently to yield signal quality comparable to those recorded by wired systems. With this system we were able to obtain single-unit recordings of hippocampal place cells in rats running an enclosed vertical maze, over a range of 5 m.

  1. Late Results of Cox Maze III Procedure in Patients with Atrial Fibrillation Associated with Structural Heart Disease.

    Science.gov (United States)

    Gomes, Gustavo Gir; Gali, Wagner Luis; Sarabanda, Alvaro Valentim Lima; Cunha, Claudio Ribeiro da; Kessler, Iruena Moraes; Atik, Fernando Antibas

    2017-07-01

    Cox-Maze III procedure is one of the surgical techniques used in the surgical treatment of atrial fibrillation (AF). To determine late results of Cox-Maze III in terms of maintenance of sinus rhythm, and mortality and stroke rates. Between January 2006 and January 2013, 93 patients were submitted to the cut-and-sew Cox-Maze III procedure in combination with structural heart disease repair. Heart rhythm was determined by 24-hour Holter monitoring. Procedural success rates were determined by longitudinal methods and recurrence predictors by multivariate Cox regression models. Thirteen patients that obtained hospital discharge alive were excluded due to lost follow-up. The remaining 80 patients were aged 49.9 ± 12 years and 47 (58.7%) of them were female. Involvement of mitral valve and rheumatic heart disease were found in 67 (83.7%) and 63 (78.7%) patients, respectively. Seventy patients (87.5%) had persistent or long-standing persistent AF. Mean follow-up with Holter monitoring was 27.5 months. There were no hospital deaths. Sinus rhythm maintenance rates were 88%, 85.1% and 80.6% at 6 months, 24 months and 36 months, respectively. Predictors of late recurrence of AF were female gender (HR 3.52; 95% CI 1.21-10.25; p = 0.02), coronary artery disease (HR 4.73 95% CI 1.37-16.36; p = 0.01) and greater left atrium diameter (HR 1.05; 95% CI 1.01-1.09; p = 0.02). Actuarial survival was 98.5% at 12, 24 and 48 months and actuarial freedom from stroke was 100%, 100% and 97.5% in the same time frames. The Cox-Maze III procedure, in our experience, is efficacious for sinus rhythm maintenance, with very low late mortality and stroke rates. A operação de Cox-Maze III é uma das variantes técnicas no tratamento cirúrgico da fibrilação atrial (FA). Estudar os resultados tardios da operação de Cox-Maze III, quanto à eficácia na manutenção de ritmo sinusal e taxas de mortalidade e acidente vascular cerebral (AVC). Entre janeiro de 2006 a janeiro de 2013, 93 pacientes

  2. The chronology of age-related spatial learning impairment in two rat strains, as tested by the Barnes maze.

    Science.gov (United States)

    Barrett, Graham L; Bennie, Antoinette; Trieu, Jennifer; Ping, Sophie; Tsafoulis, Christine

    2009-06-01

    The Barnes maze offers advantages for cognitive aging studies, because of its relatively unstressful design and its modest physical demands. The authors therefore undertook a detailed chronological investigation of performance against age, for female Sprague-Dawley and male and female Dark Agouti rats. The trial duration was 10 days. Rats were tested at 6, 11, 14, 17, 20, and 26 months of age, but individual rats were tested at one age only. At 6 months of age, all rats reached the criterion. Sprague-Dawley rats performed best at this age. Impairment began at 14 months in Dark Agouti rats and continued to increase up to 26 months of age. Impairment was greater in Dark Agouti than Sprague-Dawley rats and was greater in females than males. At 26 months, 70% of Sprague-Dawley females reached criterion; of the Dark Agoutis, only 33% of females and 57% of males reached criterion. This study confirms the utility of the Barnes maze as a robust vehicle in aged rats. It also highlights major performance differences between strains and genders in aging rats. Copyright (c) 2009 APA, all rights reserved.

  3. Mandatory requirements in relation to air, soil, or water protection. Analysis of need and feasibility. Final Report (Tasks 3 and 4)

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Chavez, R.; Kunen, E.; Walden, D.; Fingerman, K.; Arya, L; Chalmers, J. [Winrock International, Little Rock (United States); Kretschmer, B.; Polakova, J.; Farmer, A.; Bowyer, C.; Menadue, H. [Institute for European Environmental Policy IEEP, London (United Kingdom); Alberici, S.; Toop, G. [Ecofys, Utrecht (Netherlands)

    2013-02-15

    This study focusses on the environmental impacts, both within and outside Europe, associated with the agricultural management of biofuel feedstocks consumed within the European Union (EU). This study has focussed on an examination of the environmental effects associated with crops that: Represent the prevailing cropping type in a country/region and are already produced in intensive agricultural systems and in zones with vulnerable soil/water conditions; and have become the prevailing feedstocks to supply the EU biofuel markets. The report starts with an overview of key biofuel crops and focus countries within and outside the EU (Section 2). Section 3 provides an overview of soils risks from biofuels consumed in the EU. It sets out the type of risks arising from the cultivation of biofuel feedstocks within Europe and in non-EU countries, provides information from case studies on actual risks arising in the selected countries, as well as considering the scope and effectiveness of existing provisions for soil protection. A synthesis of the estimated risks per region for different types of risks concludes the section. Section 4 sets out water risks associated with the identified biofuel crops in the selected EU and non-EU focus areas. Similarly to the soil section, the assessment of existing provisions for water protection addresses their scope and effectiveness in containing the pressures from biofuel feedstock production and concludes with a synthesis estimating the actual risks. Section 5 provides a corresponding analysis of air quality risks. Section 6 discussed the feasibility of introducing additional sustainability criteria in the RED to mitigate identified risks to soil, water and air and overall concludes the study.

  4. A Robotic Approach to Understanding the Role and the Mechanism of Vicarious Trial-And-Error in a T-Maze Task

    Science.gov (United States)

    Matsuda, Eiko; Hubert, Julien; Ikegami, Takashi

    2014-01-01

    Vicarious trial-and-error (VTE) is a behavior observed in rat experiments that seems to suggest self-conflict. This behavior is seen mainly when the rats are uncertain about making a decision. The presence of VTE is regarded as an indicator of a deliberative decision-making process, that is, searching, predicting, and evaluating outcomes. This process is slower than automated decision-making processes, such as reflex or habituation, but it allows for flexible and ongoing control of behavior. In this study, we propose for the first time a robotic model of VTE to see if VTE can emerge just from a body-environment interaction and to show the underlying mechanism responsible for the observation of VTE and the advantages provided by it. We tried several robots with different parameters, and we have found that they showed three different types of VTE: high numbers of VTE at the beginning of learning, decreasing numbers afterward (similar VTE pattern to experiments with rats), low during the whole learning period, and high numbers all the time. Therefore, we were able to reproduce the phenomenon of VTE in a model robot using only a simple dynamical neural network with Hebbian learning, which suggests that VTE is an emergent property of a plastic and embodied neural network. From a comparison of the three types of VTE, we demonstrated that 1) VTE is associated with chaotic activity of neurons in our model and 2) VTE-showing robots were robust to environmental perturbations. We suggest that the instability of neuronal activity found in VTE allows ongoing learning to rebuild its strategy continuously, which creates robust behavior. Based on these results, we suggest that VTE is caused by a similar mechanism in biology and leads to robust decision making in an analogous way. PMID:25050548

  5. A robotic approach to understanding the role and the mechanism of vicarious trial-and-error in a T-maze task.

    Science.gov (United States)

    Matsuda, Eiko; Hubert, Julien; Ikegami, Takashi

    2014-01-01

    Vicarious trial-and-error (VTE) is a behavior observed in rat experiments that seems to suggest self-conflict. This behavior is seen mainly when the rats are uncertain about making a decision. The presence of VTE is regarded as an indicator of a deliberative decision-making process, that is, searching, predicting, and evaluating outcomes. This process is slower than automated decision-making processes, such as reflex or habituation, but it allows for flexible and ongoing control of behavior. In this study, we propose for the first time a robotic model of VTE to see if VTE can emerge just from a body-environment interaction and to show the underlying mechanism responsible for the observation of VTE and the advantages provided by it. We tried several robots with different parameters, and we have found that they showed three different types of VTE: high numbers of VTE at the beginning of learning, decreasing numbers afterward (similar VTE pattern to experiments with rats), low during the whole learning period, and high numbers all the time. Therefore, we were able to reproduce the phenomenon of VTE in a model robot using only a simple dynamical neural network with Hebbian learning, which suggests that VTE is an emergent property of a plastic and embodied neural network. From a comparison of the three types of VTE, we demonstrated that 1) VTE is associated with chaotic activity of neurons in our model and 2) VTE-showing robots were robust to environmental perturbations. We suggest that the instability of neuronal activity found in VTE allows ongoing learning to rebuild its strategy continuously, which creates robust behavior. Based on these results, we suggest that VTE is caused by a similar mechanism in biology and leads to robust decision making in an analogous way.

  6. A robotic approach to understanding the role and the mechanism of vicarious trial-and-error in a T-maze task.

    Directory of Open Access Journals (Sweden)

    Eiko Matsuda

    Full Text Available Vicarious trial-and-error (VTE is a behavior observed in rat experiments that seems to suggest self-conflict. This behavior is seen mainly when the rats are uncertain about making a decision. The presence of VTE is regarded as an indicator of a deliberative decision-making process, that is, searching, predicting, and evaluating outcomes. This process is slower than automated decision-making processes, such as reflex or habituation, but it allows for flexible and ongoing control of behavior. In this study, we propose for the first time a robotic model of VTE to see if VTE can emerge just from a body-environment interaction and to show the underlying mechanism responsible for the observation of VTE and the advantages provided by it. We tried several robots with different parameters, and we have found that they showed three different types of VTE: high numbers of VTE at the beginning of learning, decreasing numbers afterward (similar VTE pattern to experiments with rats, low during the whole learning period, and high numbers all the time. Therefore, we were able to reproduce the phenomenon of VTE in a model robot using only a simple dynamical neural network with Hebbian learning, which suggests that VTE is an emergent property of a plastic and embodied neural network. From a comparison of the three types of VTE, we demonstrated that 1 VTE is associated with chaotic activity of neurons in our model and 2 VTE-showing robots were robust to environmental perturbations. We suggest that the instability of neuronal activity found in VTE allows ongoing learning to rebuild its strategy continuously, which creates robust behavior. Based on these results, we suggest that VTE is caused by a similar mechanism in biology and leads to robust decision making in an analogous way.

  7. A virtual reality task based on animal research – spatial learning and memory in patients after the first episode of schizophrenia

    Science.gov (United States)

    Fajnerová, Iveta; Rodriguez, Mabel; Levčík, David; Konrádová, Lucie; Mikoláš, Pavol; Brom, Cyril; Stuchlík, Aleš; Vlček, Kamil; Horáček, Jiří

    2014-01-01

    Objectives: Cognitive deficit is considered to be a characteristic feature of schizophrenia disorder. A similar cognitive dysfunction was demonstrated in animal models of schizophrenia. However, the poor comparability of methods used to assess cognition in animals and humans could be responsible for low predictive validity of current animal models. In order to assess spatial abilities in schizophrenia and compare our results with the data obtained in animal models, we designed a virtual analog of the Morris water maze (MWM), the virtual Four Goals Navigation (vFGN) task. Methods: Twenty-nine patients after the first psychotic episode with schizophrenia symptoms and a matched group of healthy volunteers performed the vFGN task. They were required to find and remember four hidden goal positions in an enclosed virtual arena. The task consisted of two parts. The Reference memory (RM) session with a stable goal position was designed to test spatial learning. The Delayed-matching-to-place (DMP) session presented a modified working memory protocol designed to test the ability to remember a sequence of three hidden goal positions. Results: Data obtained in the RM session show impaired spatial learning in schizophrenia patients compared to the healthy controls in pointing and navigation accuracy. The DMP session showed impaired spatial memory in schizophrenia during the recall of spatial sequence and a similar deficit in spatial bias in the probe trials. The pointing accuracy and the quadrant preference showed higher sensitivity toward the cognitive deficit than the navigation accuracy. Direct navigation to the goal was affected by sex and age of the tested subjects. The age affected spatial performance only in healthy controls. Conclusions: Despite some limitations of the study, our results correspond well with the previous studies in animal models of schizophrenia and support the decline of spatial cognition in schizophrenia, indicating the usefulness of the vFGN task in

  8. A New Electrochemical Sensor Based on Task-Specific Ionic Liquids-Modified Palm Shell Activated Carbon for the Determination of Mercury in Water Samples

    Science.gov (United States)

    Ismaiel, Ahmed Abu; Aroua, Mohamed Kheireddine; Yusoff, Rozita

    2014-01-01

    In this study, a potentiometric sensor composed of palm shell activated carbon modified with trioctylmethylammonium thiosalicylate (TOMATS) was used for the potentiometric determination of mercury ions in water samples. The proposed potentiometric sensor has good operating characteristics towards Hg (II), including a relatively high selectivity; a Nernstian response to Hg (II) ions in a concentration range of 1.0 × 10−9 to 1.0 × 10−2 M, with a detection limit of 1 × 10−10 M and a slope of 44.08 ± 1.0 mV/decade; and a fast response time (∼5 s). No significant changes in electrode potential were observed when the pH was varied over the range of 3–9. Additionally, the proposed electrode was characterized by good selectivity towards Hg (II) and no significant interferences from other cationic or anionic species. PMID:25051034

  9. Project Tasks in Robotics

    DEFF Research Database (Denmark)

    Sørensen, Torben; Hansen, Poul Erik

    1998-01-01

    Description of the compulsary project tasks to be carried out as a part of DTU course 72238 Robotics......Description of the compulsary project tasks to be carried out as a part of DTU course 72238 Robotics...

  10. Management: tasks, responsibilities, practices

    National Research Council Canada - National Science Library

    Drucker, Peter Ferdinand

    1974-01-01

    Drucker looks at management from a task orientated point of view. In Part I he looks at management first from the outside and studies the dimensions of the tasks and the requirements to each of them...

  11. Task assignment and coaching

    OpenAIRE

    Dominguez-Martinez, S.

    2009-01-01

    An important task of a manager is to motivate her subordinates. One way in which a manager can give incentives to junior employees is through the assignment of tasks. How a manager allocates tasks in an organization, provides information to the junior employees about his ability. Without coaching from a manager, the junior employee only has information about his past performance. Based on his past performance, a talented junior who has performed a difficult task sometimes decides to leave the...

  12. Water

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2010-08-01

    Full Text Available , and of the remaining 2,5 percent, some 70 percent is frozen in the polar caps and around 30 percent is present as soil moisture or in underground aquifers. Less than 1 percent is thus accessible for direct use by humans, animals and plants. Consequently... be serviced with harvested water and/or grey water. Conserve and reuse cooling tower water by using efficient systems and strategies. Avoid ?once-through systems? commonly used for evaporation coolers, ice makers, hydraulic equipment, and air compressors...

  13. Task assignment and coaching

    NARCIS (Netherlands)

    Dominguez-Martinez, S.

    2009-01-01

    An important task of a manager is to motivate her subordinates. One way in which a manager can give incentives to junior employees is through the assignment of tasks. How a manager allocates tasks in an organization, provides information to the junior employees about his ability. Without coaching

  14. Flight deck task management

    Science.gov (United States)

    2016-12-21

    This report documents the work undertaken in support of Volpe Task Order No. T0026, Flight Deck Task Management. The objectives of this work effort were to: : 1) Develop a specific and standard definition of task management (TM) : 2) Conduct a ...

  15. Water

    Directory of Open Access Journals (Sweden)

    E. Sanmuga Priya

    2017-05-01

    Full Text Available Phytoremediation through aquatic macrophytes treatment system (AMATS for the removal of pollutants and contaminants from various natural sources is a well established environmental protection technique. Water hyacinth (Eichhornia crassipes, a worst invasive aquatic weed has been utilised for various research activities over the last few decades. The biosorption capacity of the water hyacinth in minimising various contaminants present in the industrial wastewater is well studied. The present review quotes the literatures related to the biosorption capacity of the water hyacinth in reducing the concentration of dyestuffs, heavy metals and minimising certain other physiochemical parameters like TSS (total suspended solids, TDS (total dissolved solids, COD (chemical oxygen demand and BOD (biological oxygen demand in textile wastewater. Sorption kinetics through various models, factors influencing the biosorption capacity, and role of physical and chemical modifications in the water hyacinth are also discussed.

  16. [Maze procedure in a case of dextrocardia with atrial septal defect and persistent left superior vena cava].

    Science.gov (United States)

    Muraoka, Arata; Kawada, Masaaki; Misawa, Yoshio

    2014-08-01

    A 52-year-old man was diagnosed with dextrocardia at the age of 1 year and was asymptomatic until 1 year before admission. He was transferred to our hospital for management of atrial fibrillation. A transthoracic echocardiogram showed dextrocardia with atrial septal defect;moderate tricuspid valve regurgitation; and a large, persistent left superior vena cava. A cardiac catheterization study revealed that pulmonary flow/systemic flow (Qp/Qs) was 3.6 and that pulmonary vascular resistance was 2.5 Wood U·m². Intracardiac repair with tricuspid annuloplasty and a maze procedure was scheduled. When establishing cardiopulmonary bypass, venous drainage was initially obtained from the inferior vena cava and the left superior vena cava, and the small superior vena cava was then directly cannulated after opening the right atrium. The patient's postoperative course was uneventful, and serial electrocardiograms have demonstrated maintenance of normal sinus rhythm for 3.5 years after the operation.

  17. Improvements in motor tasks through the use of smartphone technology for individuals with Duchenne muscular dystrophy

    Directory of Open Access Journals (Sweden)

    Capelini CM

    2017-08-01

    Full Text Available Camila Miliani Capelini,1 Talita Dias da Silva,2 James Tonks,3–5 Suzanna Watson,6 Mayra Priscila Boscolo Alvarez,1 Lilian Del Ciello de Menezes,1 Francis Meire Favero,2 Fátima Aparecida Caromano,1 Thais Massetti,1 Carlos Bandeira de Mello Monteiro1 1Graduate Program in Rehabilitation Sciences, Faculty of Medicine, University of São Paulo, 2Department of Medicine, Paulista School of Medicine, Federal University of São Paulo, São Paulo, SP, Brazil; 3University of Exeter Medical School, Exeter, 4University of Lincoln, Lincoln, 5Haven Clinical Psychology Practice, Cornwall, 6The Cambridge Centre for Paediatric Neuropsychologicial Rehabilitation, Cambridge, UK Background: In individuals severely affected with Duchenne muscular dystrophy (DMD, virtual reality has recently been used as a tool to enhance community interaction. Smartphones offer the exciting potential to improve communication, access, and participation, and present the unique opportunity to directly deliver functionality to people with disabilities.Objective: To verify whether individuals with DMD improve their motor performance when undertaking a visual motor task using a smartphone game.Patients and methods: Fifty individuals with DMD and 50 healthy, typically developing (TD controls, aged 10–34 years participated in the study. The functional characterization of the sample was determined through Vignos, Egen Klassifikation, and the Motor Function Measure scales. To complete the task, individuals moved a virtual ball around a virtual maze and the time in seconds was measured after every attempt in order to analyze improvement of performance after the practice trials. Motor performance (time to finish each maze was measured in phases of acquisition, short-term retention, and transfer.Results: Use of the smartphone maze game promoted improvement in performance during acquisition in both groups, which remained in the retention phase. At the transfer phases, with alternative maze

  18. Tests of the Aversive Summation Hypothesis in Rats: Effects of Restraint Stress on Consummatory Successive Negative Contrast and Extinction in the Barnes Maze

    Science.gov (United States)

    Ortega, Leonardo A.; Prado-Rivera, Mayerli A.; Cardenas-Poveda, D. Carolina; McLinden, Kristina A.; Glueck, Amanda C.; Gutierrez, German; Lamprea, Marisol R.; Papini, Mauricio R.

    2013-01-01

    The present research explored the effects of restraint stress on two situations involving incentive downshift: consummatory successive negative contrast (cSNC) and extinction of escape behavior in the Barnes maze. First, Experiment 1 confirmed that the restraint stress procedure used in these experiments increased levels of circulating…

  19. The Prognostic Scoring System Establishment and Validation for Chronic Atrial Fibrillation Patients Receiving Modified Cox-Maze IV and Concomitant Cardiac Surgery.

    Directory of Open Access Journals (Sweden)

    Feng-Chun Tsai

    Full Text Available Traditional Cox maze III is the gold standard for treatment of atrial fibrillation (AF. Because of its invasiveness, it has been replaced by a simplified procedure involving radiofrequency ablation of modified Cox maze IV. Although the modified Cox maze IV has the advantages of simplicity and less morbidity, a lower rate of sinus rhythm conversion has been reported. We try to establish a scoring system to predict the outcome of this procedure.The derivation group consisted of 287 patients with structural heart disease and chronic AF who underwent cardiac surgery and modified Cox-maze IV procedure between August 2005 and March 2013. Demographics, clinical and laboratory variables were retrospectively collected as sinus conversional predictors. Overall sinus conversion rate was 75.8%. The parameters of the Soft Markers Scoring system included AF duration, preoperative left atrial (LA size, rheumatic pathology and postoperative LA remodeling. We compared 80 patients from another hospital between January 2004 and December 2011 as a validation group to evaluate the power of the scoring system. Soft Markers Score indicated a good discriminative power by using the areas under the receiver operating characteristic curve (AUROC: 0.759 ± 0.032. The score was further divided into three groups: low (0-2, intermediate (3-5, and high (6-10, with predicted sinus conversion rates of 92.4%, 74.2%, and 47.8%, respectively.In patients with chronic AF receiving modified Cox-maze IV procedure, the Soft Markers Score demonstrated good discriminative power of predicting sinus recovery in our patients and applied well to the other validation populations.

  20. Real-time changes in hippocampal energy demands during a spatial working memory task.

    Science.gov (United States)

    Kealy, John; Bennett, Rachel; Woods, Barbara; Lowry, John P

    2017-05-30

    Activity-dependent changes in hippocampal energy consumption have largely been determined using microdialysis. However, real-time recordings of brain energy consumption can be more accurately achieved using amperometric sensors, allowing for sensitive real-time monitoring of concentration changes. Here, we test the theory that systemic pre-treatment with glucose in rats prevents activity-dependent decreases in hippocampal glucose levels and thus enhances their performance in a spontaneous alternation task. Male Sprague Dawley rats were implanted into the hippocampus with either: 1) microdialysis probe; or 2) an oxygen sensor and glucose biosensor co-implanted together. Animals were pre-treated with either saline or glucose (250mg/kg) 30min prior to performing a single 20-min spontaneous alternation task in a +-maze. There were no significant differences found between either treatment group in terms of spontaneous alternation performance. Additionally, there was a significant difference found between treatment groups on hippocampal glucose levels measured using microdialysis (a decrease associated with glucose pre-treatment in control animals) but not amperometry. There were significant increases in hippocampal oxygen during +-maze exploration. Combining the findings from both methods, it appears that hippocampal activity in the spontaneous alternation task does not cause an increase in glucose consumption, despite an increase in regional cerebral blood flow (using oxygen supply as an index of blood flow) and, as such, pre-treatment with glucose does not enhance spontaneous alternation performance. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Resposta cronotrópica ao exercício após isolamento das veias pulmonares ou cirurgia de Cox-maze Chronotropic response to exercise after pulmonary veins isolation or Cox-maze operation

    Directory of Open Access Journals (Sweden)

    Daniela Marchiori Flores

    2008-12-01

    Full Text Available OBJETIVO: Avaliar a resposta cronotrópica ao exercício nos períodos pós-operatório imediato e tardio, após tratamento cirúrgico de fibrilação atrial e valva mitral por técnicas distintas. MÉTODOS: Estudo clínico prospectivo controlado, com amostra de 42 pacientes, portadores de fibrilação atrial crônica associada à valvulopatia mitral, submetidos a cirurgia pela técnica de isolamento de veias pulmonares (n=16, pela técnica do labirinto (Cox-maze modificado, sem uso de crioblação (n=13, ambas com correção de valvulopatia mitral, ou para correção de valvulopatia isolada (n=13. As características clínicas pré-operatórias, indicações para cirurgia tipo e etiologia da lesão valvar foram semelhantes entre os três grupos. Os pacientes foram acompanhados em ambulatório e submetidos a testes ergométricos seriados. RESULTADOS: A resposta cronotrópica no pós-operatório imediato foi semelhante nos grupos analisados, em média 73,6% ± 12,3% da freqüência cardíaca máxima prevista. No grupo de isolamento das veias pulmonares, houve aumento de 64,4% ± 12,4% da freqüência cardíaca máxima, no pós-operatório imediato, para 78,9% ± 10,5% no 12º mês de pós-operatório (P=0,012. No grupo Cox-maze, a freqüência cardíaca máxima variou de 73,9% ± 11,14% para 78.8% ± 15,2% (P=1,000 e no grupo controle (apenas correção da valva mitral, de 67,2% ± 14,3% para 71,9% ± 12,9% (P=0,889. CONCLUSÃO: A atenuação pós-operatória imediata da resposta cronotrópica ao exercício foi semelhante no pós-operatório das três diferentes técnicas cirúrgicas. Houve melhora significativa da mesma, na evolução pós-operatória, no grupo de isolamento das veias pulmonares. Estes resultados sugerem que o procedimento de simples isolamento cirúrgico das veias pulmonares pode estar relacionado à melhor preservação do cronotropismo atrial.OBJECTIVE: To evaluate the chronotropic response to exercise during immediate and

  2. India's Unfinished Telecom Tasks

    Indian Academy of Sciences (India)

    India's Unfinished Telecom Tasks · India's Telecom Story is now well known · Indian Operators become an enviable force · At the same time · India Amongst the Leaders · Unfinished Tasks as Operators · LightGSM ON: Innovation for Rural Area from Midas ... The Consortium Approach … What more will it take to obtain Tech ...

  3. Shifting tasks in telecare

    DEFF Research Database (Denmark)

    Nickelsen, Niels Christian Mossfeldt

    2017-01-01

    with focus on shifting tasks was undertaken. Furthermore, the method of ‘Interview to double’ was used the analytical ambition being to explore the becoming of tasks and relations. Analytically the study draws predominantly on Stars notion of ‘infrastructure’. Infrastructure is seen as human and non...

  4. Energy Efficient Task Light

    DEFF Research Database (Denmark)

    Logadottir, Asta; Ardkapan, Siamak Rahimi; Johnsen, Kjeld

    2014-01-01

    the light source as far from the bottom edge as possible. The main results of the project show opportunities for energy savings in an office environment by reducing the installed power for the general lighting by applying a task light with a wide light distribution across the desk area , providing high...... illuminance uniformity . There is still work to be done on the prototype to optimize the energy consumption of the task light and measures need to be taken to minimize glare from the task light as well as reflected glare . The lamp head adjustment possibilities regarding tilting and turning result in problems...... to all objects on the desk than the two traditional reference task lights with LED retrofit light bulbs . By utilising this new type of task light, the energy consumption by general lighting can be reduced by approximately 40 % by fully exploiting the lower illuminance levels required by lighting...

  5. Supporting complex search tasks

    DEFF Research Database (Denmark)

    Gäde, Maria; Hall, Mark; Huurdeman, Hugo

    2015-01-01

    There is broad consensus in the field of IR that search is complex in many use cases and applications, both on the Web and in domain specific collections, and both professionally and in our daily life. Yet our understanding of complex search tasks, in comparison to simple look up tasks......, is fragmented at best. The workshop addressed the many open research questions: What are the obvious use cases and applications of complex search? What are essential features of work tasks and search tasks to take into account? And how do these evolve over time? With a multitude of information, varying from...... introductory to specialized, and from authoritative to speculative or opinionated, when to show what sources of information? How does the information seeking process evolve and what are relevant differences between different stages? With complex task and search process management, blending searching, browsing...

  6. Task Description Language

    Science.gov (United States)

    Simmons, Reid; Apfelbaum, David

    2005-01-01

    Task Description Language (TDL) is an extension of the C++ programming language that enables programmers to quickly and easily write complex, concurrent computer programs for controlling real-time autonomous systems, including robots and spacecraft. TDL is based on earlier work (circa 1984 through 1989) on the Task Control Architecture (TCA). TDL provides syntactic support for hierarchical task-level control functions, including task decomposition, synchronization, execution monitoring, and exception handling. A Java-language-based compiler transforms TDL programs into pure C++ code that includes calls to a platform-independent task-control-management (TCM) library. TDL has been used to control and coordinate multiple heterogeneous robots in projects sponsored by NASA and the Defense Advanced Research Projects Agency (DARPA). It has also been used in Brazil to control an autonomous airship and in Canada to control a robotic manipulator.

  7. Application of a thiourea-containing task-specific ionic liquid for the solid-phase extraction cleanup of lead ions from red lipstick, pine leaves, and water samples.

    Science.gov (United States)

    Saljooqi, Asma; Shamspur, Tayebeh; Mohamadi, Maryam; Mostafavi, Ali

    2014-07-01

    Here, task-specific ionic liquid solid-phase extraction is proposed for the first time. In this approach, a thiourea-functionalized ionic liquid is immobilized on the solid sorbent, multiwalled carbon nanotubes. These modified nanotubes packed into a solid-phase extraction column are used for the selective extraction and preconcentration of ultra-trace amounts of lead(II) from aqueous samples prior to electrothermal atomic absorption spectroscopy determination. The thiourea functional groups act as chelating agents for lead ions retaining them and so, give the selectivity to the sorbent. Elution of the retained ions can be performed using an acidic thiourea solution. The effects of experimental parameters including pH of the aqueous solution, type and amount of eluent, and the flow rates of sample and eluent solutions on the separation efficiency are investigated. The linear dependence of absorbance of lead on its concentration in the initial solution is in the range of 0.5-40.0 ng/mL with the detection limit of 0.13 ng/mL (3(Sb)/m, n = 10). The proposed method is applicable to the analysis of red lipstick, pine leaves, and water samples for their lead contents. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Vacuum Die Casting Process and Simulation for Manufacturing 0.8 mm-Thick Aluminum Plate with Four Maze Shapes

    Directory of Open Access Journals (Sweden)

    Chul Kyu Jin

    2015-02-01

    Full Text Available Using vacuum die casting, 0.8 mm-thick plates in complicated shapes are manufactured with the highly castable aluminum alloy Silafont-36 (AlSi9MgMn. The sizes and shapes of the cavities, made of thin plates, feature four different mazes. To investigate formability and mechanical properties by shot condition, a total of six parameters (melt temperatures of 730 °C and 710 °C; plunger speeds of 3.0 m/s and 2.5 m/s; vacuum pressure of 250 mbar and no vacuum are varied in experiments, and corresponding simulations are performed. Simulation results obtained through MAGMA software show similar tendencies to those of the experiments. When the melt pouring temperature is set to 730 °C rather than 710 °C, formability and mechanical properties are superior, and when the plunger speed is set to 3.0 m/s rather than to 2.5 m/s, a fine, even structure is obtained with better mechanical properties. The non-vacuumed sample is half unfilled. The tensile strength and elongation of the sample fabricated under a melt temperature of 730 °C, plunger speed of 3.0 m/s, and vacuum pressure of 250 mbar are 265 MPa and 8.5%, respectively.

  9. Anxiety levels and wild running susceptibility in rats: assessment with elevated plus maze test and predator odor exposure.

    Science.gov (United States)

    de Paula, Hugo Medeiros Garrido; Gouveia, Amauri; de Almeida, Marcos Vinícius; Hoshino, Katsumasa

    2005-02-28

    It is reported in the literature that nearly 20% of rats are susceptible to displays of wild running (WR) behavior when submitted to high intensity acoustic stimulation. Some characteristics of WR suggest that it can be viewed as a panic-like reaction. This work aimed to test whether WR-sensitive rats show higher levels of anxiety in elevated-plus-maze (EPM) and predator-odor exposure paradigms in comparison with WR-resistant ones. Male adult Wistar rats were submitted to two trials of acoustic stimulation (104 dB, 60 s) in order to assess WR susceptibility. Seven WR-sensitive and 15 WR-resistant rats were evaluated by the EPM test. Other 13 WR-sensitive and 18 WR-resistant animals were submitted to the predator-odor exposure test which consisted of a 10 min-session of free exploration in a specific apparatus containing two odoriferous stimuli: cotton swab imbedded with snake cloacal gland secretion or with iguana feces (control). WR-sensitive rats presented a significantly higher closed-to open-arm-entry ratio in the EPM test. All rats responded with anxiety-like behaviors to the predator odor exposure, although the WR-sensitive ones showed a marked behavioral inhibition regardless of the odor condition. We conclude that WR-sensitive rats present elevated levels of anxiety manifested by means of passive behavioral strategies. (c) 2004 Elsevier B.V. All rights reserved.

  10. Anxiolytic effects of Dolichandrone falcata Seem., Bignoniaceae, stem-bark in elevated plus maze and marble burying test on mice

    Directory of Open Access Journals (Sweden)

    Vishal B Badgujar

    2010-10-01

    Full Text Available Dolichandrone falcata Seem., Bignoniaceae, is a deciduous tree commonly known as Medshingi in local areas of Toranmal region of Maharashtra, India. Its bark paste is applied on fractured or dislocated bones, used as a fish poison; bark juice is used in cases of menorragia and leucorrhoea. The leaves of the plant have afforded chrysin-7-rutinoside. The present study was carried out to investigate the anxiolytic effects of methanol extract (DFBM, ethyl acetate extract (DFBEA and isolated compound DFB (V+VI of D. falcata stem-bark using animal models. Anxiolytic effects were studied by elevated plus maze (EPM and marble burying test (MBT assay. The crude dried DFBM and DFBEA extract was prepared in doses of 100, 200 and 400 mg/kg whereas DFB (V+VI compound was prepared in doses of 50, 100 and 200 mg/kg and were administered orally to mice for evaluation of anxiolytic activity. DFBEA 400 and DFB (V+VI 200 mg/kg produced highly significant (p <0.01 anxiolytic effects in dose dependent manner by increasing the time spent on and the number of entries into the open arms of the EPM and by decreasing the number of marbles buried by mice in MBT test. This study showed that the DFBM, DFBEA extracts and DFB (V+VI isolated compound possesses potential pharmacological active constituents flavonoids (like chrysin which may be responsible for the anxiolytic activity.

  11. Be aware of neutrons outside short mazes from 10-MV linear accelerators X-rays in radiotherapy facilities.

    Science.gov (United States)

    Brockstedt, S; Holstein, H; Jakobsson, L; Tomaszewicz, A; Knöös, T

    2015-07-01

    During the radiation survey of a reinstalled 10-MV linear accelerator in an old radiation treatment facility, high dose rates of neutrons were observed. The area outside the maze entrance is used as a waiting room where patients, their relatives and staff other than those involved in the actual treatment can freely pass. High fluence rates of neutrons would cause an unnecessary high effective dose to the staff working in the vicinity of such a system, and it can be several orders higher than the doses received due to X-rays at the same location. However, the common knowledge appears to have been that the effect of neutrons at 10-MV X-ray linear accelerator facilities is negligible and shielding calculations models seldom mention neutrons for this operating energy level. Although data are scarce, reports regarding this phenomenon are now emerging. For the future, it is advocated that contributions from neutrons are considered already during the planning stage of new or modified facilities aimed for 10 MV and that estimated dose levels are verified. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Investigation of Dose-Related Effects of Carnosine on Anxiety with Sympathetic Skin Response and T-maze

    Directory of Open Access Journals (Sweden)

    Nazan Dolu

    2014-01-01

    Full Text Available Carnosine is a dipeptide formed of the amino acids β-alanine and histidine. Only a limited number of studies have examined the effects of carnosine on sympathetic nerve activation and anxiety. The present study was undertaken to determine the dose-related effects of carnosine on anxiety in the elevated T-maze test (ETM with electrodermal activity (EDA. Carnosine was injected in three groups of rats with doses of 10 (low dose, 100 (medium dose and 1000 (high dose mg/kg i.p. Physiological saline was injected in the sham group. The anxiety scores of the rats were measured with ETM 20 minutes after injection. Then, SCL was measured. The decreased number of entries into the open arm (NEOA, the percentage of time spent in the open arm (% TSOA and higher EDA [shown by skin conductance level (SCL] indicate higher anxiety. The NEOA and % TSOA were lower in the high-dose group than in the other groups. SCL was lower in the medium-dose carnosine group than in the high-dose carnosine and sham groups. SCL was higher in the high-dose group than in the medium-dose and sham groups. Our results suggest that high-dose carnosine produced anxiety-like effects as assessed in the SCL and ETM. Medium-dose carnosine acted as an anxiolytic. The anxiety-related responses of carnosine depend on its dose-related effect.

  13. Treatment of Atrial Fibrillation in Elderly Patients with the Cox Maze Procedure Concurrently with Other Cardiac Operations

    Directory of Open Access Journals (Sweden)

    Ja Hong Kuh

    2017-06-01

    Full Text Available Background: In elderly patients who have atrial fibrillation (AF, surgical ablation of the arrhythmia during cardiac surgery may be challenging. Despite the reported advantages of ablating AF with the Cox maze procedure (CMP, the addition of the CMP may complicate other cardiac operations. We evaluated the effect of the CMP in elderly patients concurrent with other cardiac operations. Methods: From October 2007 to December 2015, we enrolled 27 patients aged >70 years who had AF and who underwent the CMP concurrently with other cardiac operations. The mean preoperative additive European System for Cardiac Operative Risk Evaluation score was 8±11 (high risk. Results: Only 1 hospital death occurred (4%. The Kaplan-Meier method showed a high 5‐year cumulative survival rate (92%. At mean follow‐up of 51 months, 23 patients (89% had sinus rhythm conversion. The postoperative left atrial dimensions did not significantly differ between the 8 patients who had reduction plasty for giant left atrium (53.4±7.5 cm and the 19 patients who did not have reduction plasty (48.7±5.7 cm. Conclusion: In patients aged >70 years, concurrent CMP may be associated with a high rate of sinus rhythm conversion without increased surgical risk, despite the added complexity of the main cardiac procedure.

  14. Essential role of the perirhinal cortex in complex tactual discrimination tasks in rats.

    Science.gov (United States)

    Ramos, Juan M J

    2014-08-01

    We designed a battery of tactual discrimination tasks to study whether rats with perirhinal cortex (Prh) lesions had any deficit in resolving complex/ambiguous tactual tasks in the dark. Animals had to discriminate among 3 stimuli simultaneously exposed in 3 arms of a 4-arm plus-shaped maze. Rats with Prh lesions showed a profound impairment in a texture discrimination learning task when the stimuli had a high or intermediate degree of feature ambiguity (experiments 1a and 1b), but not when they had a low degree of feature ambiguity (experiment. 1c). Hippocampal lesions, however, did not cause any impairment in task acquisition even when the stimuli had a high degree of feature ambiguity (experiment 2). Experiments 3a, 3b, and 4 showed that perirhinal and control rats performed the task similarly when the animals had to discriminate on the basis of simple/individual, nonoverlapping features of the stimuli (size) with different levels of difficulty. Finally, to isolate the task's memory functions from its perceptual functions, a reversal learning task revealed a profound deficit in the initial learning phase, but unimpaired learning in the reversal phase with identical stimuli (experiment 5). The findings suggest that the Prh plays an essential role in somatosensory perceptual functions. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  15. Task-Driven Computing

    National Research Council Canada - National Science Library

    Wang, Zhenyu

    2000-01-01

    .... They will want to use the resources to perform computing tasks. Today's computing infrastructure does not support this model of computing very well because computers interact with users in terms of low level abstractions...

  16. Organizing Core Tasks

    DEFF Research Database (Denmark)

    Boll, Karen

    Civil servants conduct the work which makes welfare states functions on an everyday bases: Police men police, school teachers teach, and tax inspectors inspect. Focus in this paper is on the core tasks of tax inspectors. The paper argues that their core task of securing the collection of revenue...... has remained much the same within the last 10 years. However, how the core task has been organized has changed considerable under the influence of various “organizing devices”. The paper focusses on how organizing devices such as risk assessment, output-focus, effect orientation, and treatment...... projects influence the organization of core tasks within the tax administration. The paper shows that the organizational transformations based on the use of these devices have had consequences both for the overall collection of revenue and for the employees’ feeling of “making a difference”. All in all...

  17. Prenatal exposure to alcohol does not affect radial maze learning and hippocampal mossy fiber sizes in three inbred strains of mouse

    Directory of Open Access Journals (Sweden)

    Bertholet Jean-Yves

    2005-04-01

    Full Text Available Abstract Background The aim of this study was to investigate the effects of prenatal alcohol exposure on radial-maze learning and hippocampal neuroanatomy, particularly the sizes of the intra- and infrapyramidal mossy fiber (IIPMF terminal fields, in three inbred strains of mice (C57BL/6J, BALB/cJ, and DBA/2J. Results Although we anticipated a modification of both learning and IIPMF sizes, no such effects were detected. Prenatal alcohol exposure did, however, interfere with reproduction in C57BL/6J animals and decrease body and brain weight (in interaction with the genotype at adult age. Conclusion Prenatal alcohol exposure influenced neither radial maze performance nor the sizes of the IIPMF terminal fields. We believe that future research should be pointed either at different targets when using mouse models for Fetal Alcohol Syndrome (e.g. more complicated behavioral paradigms, different hippocampal substructures, or other brain structures or involve different animal models.

  18. Quantitative physics tasks

    OpenAIRE

    Snětinová, Marie

    2015-01-01

    Title: Quantitative Physics Tasks Author: Mgr. Marie Snětinová Department: Department of Physics Education Supervisor of the doctoral thesis: doc. RNDr. Leoš Dvořák, CSc., Department of Physics Education Abstract: The doctoral thesis concerns with problem solving in physics, especially on students' attitudes to solving of quantitative physics tasks, and various methods how to develop students' problem solving skills in physics. It contains brief overview of the theoretical framework of proble...

  19. Performing Task Integration

    DEFF Research Database (Denmark)

    Elkjaer, Bente; Nickelsen, Niels Christian Mossfeldt

    . Here cross-professional coordination of work was done by scheduled communication twice a day. When we proposed a way for further integration of tasks through an all-inclusive team organization, we were met with resistance. We use the study to discuss whether relational coordination theory is able to do...... away with differences regarding task definitions and working conditions as well as professional knowledge hierarchies and responsibilities for parts and wholes....

  20. Does serotonin-modulating anticonsolidation protein (SMAP) influence the choice of turning direction in carps, Cyprinus carpio, in a T-maze?

    Science.gov (United States)

    Garina, D V; Nepomnyashchikh, V A; Mekhtiev, A A

    2016-08-01

    Serotonin-modulating anticonsolidation protein (SMAP) can impair the formation of memory traces in mammals and fish. We have studied the influence of SMAP on behavioral lateralization of juvenile carps Cyprinus carpio in a T-maze without food reinforcement in three experimental groups (n = 8 each): (1) negative control (intact animals); (2) experimental group (fish injected ICV with SMAP; 2 μl, 1.2 mg ml(-1)) and (3) active control group (fish injected ICV with inactivated SMAP). The behavioral lateralization of carps was observed on the 1st, 2nd, 3rd and 6th days after the injections. In each observation session, a fish was placed five times in a start chamber of the T-maze. The direction of the turn upon leaving the start chamber, as well as the latency from the opening of start chamber flap to the fish's turn was registered. The number of right turns (of all five turns observed during the session) was a criterion of lateralization. It was found that carps have no inherent preference for turning left or right. The SMAP injection did not influence the choice of turning direction, but increases latency values insignificantly. The results are important for the correct interpretation and clarification of data reporting the role of SMAP in training and formation of spatial memory of fish in a maze.

  1. Evaluation of neurotransmitters involved in the anxiolytic and panicolytic effect of the aqueous fraction of Paullinia cupana (guaraná in elevated T maze

    Directory of Open Access Journals (Sweden)

    Marcel P. Rangel

    2013-04-01

    Full Text Available This study investigated the effects of repeatedly administration of an aqueous fraction of Paullinia cupana Kunth, Sapindaceae (guaraná seeds (8 mg/kg on rats submitted to the elevated T-maze, model of generalized anxiety and panic disorders. The selective serotonin reuptake inhibitor paroxetine (3 mg/kg, was used as a positive control. To evaluate possible neurotransmissions involvement, ineffective doses of metergoline (3 mg/kg - non-selective serotonin receptor antagonist, sulpiride (20 mg/kg - non-selective dopaminergic receptor antagonist or ketamine (0.125 mg/kg - non-selective glutamate receptor antagonist were acutely administered in association with the aqueous fraction of P. cupana. Both aqueous fraction and paroxetine decrease the inhibitory avoidance latencies of the elevated T-maze, indicating anxiolytic effect and increased one-way escape latencies from the open arm of the elevated T-maze, indicating a panicolytic effect. The pre-treatment with metergoline, sulpiride and ketamine blocked the anxiolytic effect of aqueous fraction. The panicolytic effect of aqueous fraction was blocked by both metergoline and sulpiride. These results show that the serotonergic, dopaminergic and glutamatergic neurotransmission systems are involved in anxiolytic effect promoted by aqueous fraction, whereas only the serotonergic and the dopaminergic neurotransmission systems are involved in the panicolytic effect promoted by aqueous fraction of P. cupana. The effects produced by paroxetine, were blocked only by metergoline, validating this experimental procedure.

  2. Postischemic fish oil treatment confers task-dependent memory recovery.

    Science.gov (United States)

    de Oliveira, Janaína Nicolau; Reis, Luane Oliveira; Ferreira, Emilene Dias Fiuza; Godinho, Jacqueline; Bacarin, Cristiano Correia; Soares, Ligia Mendes; de Oliveira, Rúbia Maria Weffort; Milani, Humberto

    2017-08-01

    A series of our previous studies demonstrated that fish oil (FO), equivalent to 300mg/kg docosahexahenoic acid (DHA), facilitates memory recovery after transient, global cerebral ischemia (TGCI) in the aversive radial maze (AvRM). The present study sought to address two main issues: (i) whether the memory-protective effect of FO that has been observed in the AvRM can be replicated in the passive avoidance test (PAT) and object location test (OLT) and (ii) whether FO at doses that are lower than those used previously can also prevent TGCI-induced memory loss. In Experiment 1, naive rats were trained in the PAT, subjected to TGCI (4-vessel occlusion model), and tested for retrograde memory performance 8 and 15days after ischemia. Fish oil (300mg/kg/day DHA) was given orally for 8days. The first dose was delivered 4h postischemia. In Experiment 2, the rats were subjected to TGCI, treated with the same FO regimen, and then trained and tested in the OLT. In Experiment 3, the rats were trained in the AvRM, subjected to TGCI, administered FO (100, 200, and 300mg/kg DHA), and tested for memory performance up to 3weeks after TGCI. At the end of the behavioral tests, the brains were examined for neurodegeneration and neuroblast proliferation. All of the behavioral tests (PAT, OLT, and AvRM) were sensitive to ischemia, but only the AvRM was able to detect the memory-protective effect of FO. Ischemia-induced neurodegeneration and neuroblast proliferation were unaffected by FO treatment. These results suggest that (i) the beneficial effect of FO on memory recovery after TGCI is task-dependent, (ii) doses of FOmemory function in the radial maze, and (iii) cognitive recovery occurs in the absence of neuronal rescue and/or hippocampal neurogenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Baclofen prevents the elevated plus maze behavior and BDNF expression during naloxone precipitated morphine withdrawal in male and female mice.

    Science.gov (United States)

    Pedrón, Valeria T; Varani, André P; Balerio, Graciela N

    2016-05-01

    In previous studies we have shown that baclofen, a selective GABAB receptor agonist, prevents the somatic expression and reestablishes the dopamine and μ-opioid receptors levels, modified during naloxone-precipitated morphine withdrawal syndrome in male and female mice. There are no previous reports regarding sex differences in the elevated plus maze (EPM) and the expression of BDNF in morphine-withdrawn mice. The present study analyses the behavioral and biochemical variations during morphine withdrawal in mice of both sexes, and whether these variations are prevented with baclofen. Swiss-Webster albino prepubertal mice received morphine (2 mg/kg, i.p.) twice daily, for 9 consecutive days. On the 10th day, one group of morphine-treated mice received naloxone (opioid receptor antagonist; 6 mg/kg, i.p.) 1 h after the last dose of morphine to precipitate withdrawal. A second group received baclofen (2 mg/kg, i.p.) before naloxone administration. The EPM behavior was measured during 15 min after naloxone injection. The expression of BDNF-positive cells was determined by immunohistochemistry. Withdrawn male mice showed a higher percentage of time spent and number of entries to the open arms compared to withdrawn female mice. Baclofen prevented this behavior in both sexes. BDNF expression decreased in the AcbC, BNST, CeC, and CA3 of the hippocampus while increased in the BLA of morphine withdrawn male. Baclofen pretreatment prevented the BDNF expression observed in morphine withdrawn male mice in all the brain areas studied except in the CeC. Baclofen prevention of the EPM behavior associated to morphine withdrawal could be partially related to changes in BDNF expression. © 2016 Wiley Periodicals, Inc.

  4. Can Anxiety Tested in the Elevated Plus-maze Be Related to Nociception Sensitivity in Adult Male Rats?

    Science.gov (United States)

    Pometlová, Marie; Yamamotová, Anna; Nohejlová, Kateryna; Šlamberová, Romana

    Methamphetamine (MA) is one of the most addictive psychostimulant drugs with a high potential for abuse. Our previous studies demonstrated that MA administered to pregnant rats increases pain sensitivity and anxiety in their adult offspring and makes them more sensitive to acute administration of the same drug in adulthood. Because individuals can differ considerably in terms of behaviour and physiology, such as rats that do not belong in some characteristics (e.g. anxiety) to average, can be described as low-responders or high-responders, are then more or less sensitive to pain. Therefore, prenatally MA-exposed adult male rats treated in adulthood with a single dose of MA (1 mg/ml/kg) or saline (1 ml/kg) were tested in the present study. We examined the effect of acute MA treatment on: (1) the anxiety in the Elevated plus-maze (EPM) test and memory in EPM re-test; (2) nociception sensitivity in the Plantar test; (3) the correlation between the anxiety, memory and the nociception. Our results demonstrate that: (1) MA has an anxiogenic effect on animals prenatally exposed to the same drug in the EPM; (2) all the differences induced by acute MA treatment disappeared within the time of 48 hours; (3) there was no effect of MA on nociception per se, but MA induced higher anxiety in individuals less sensitive to pain than in animals more sensitive to pain. In conclusion, the present study demonstrates unique data showing association between anxiety and nociceptive sensitivity of prenatally MA-exposed rats that is induced by acute drug administration.

  5. Board Task Performance

    DEFF Research Database (Denmark)

    Minichilli, Alessandro; Zattoni, Alessandro; Nielsen, Sabina

    2012-01-01

    This paper addresses recent calls to narrow the micro–macro gap in management research (Bamberger, 2008), by incorporating a macro-level context variable (country) in exploring micro-level determinants of board effectiveness. Following the integrated model proposed by Forbes and Milliken (1999), we...... identify three board processes as micro-level determinants of board effectiveness. Specifically, we focus on effort norms, cognitive conflicts and the use of knowledge and skills as determinants of board control and advisory task performance. Further, we consider how two different institutional settings...... influence board tasks, and how the context moderates the relationship between processes and tasks. Our hypotheses are tested on a survey-based dataset of 535 medium-sized and large industrial firms in Italy and Norway, which are considered to substantially differ along legal and cultural dimensions...

  6. Effects of post-training modafinil administration in a discriminative avoidance task in mice.

    Science.gov (United States)

    Fernandes, Helaine Arrais; Zanin, Karina Agustini; Patti, Camilla de Lima; Lopes-Silva, Leonardo Brito; Bizerra, Carolina Souza; Bittencourt, Lia Rita Azeredo; Tufik, Sergio; Frussa-Filho, Roberto

    2015-08-01

    Although the cognitive-enhancing abilities after modafinil have been demonstrated, its effects on memory consolidation remain overlooked. We investigated the effects of repeated modafinil administration on consolidation of a discriminative avoidance task. Mice were trained in the plus-maze discriminative avoidance task. After training, mice received intraperitonial modafinil (doses of 32, 64 or 128 mg/kg). Animals were treated for more 9 consecutive days; 30 min after the last injection, testing was performed. In addition, the effects of 32 mg/kg modafinil on consolidation at different time points were examined. The smaller dose of modafinil (32 mg/kg) impaired memory consolidation, without modifying anxiety or locomotion. Still, modafinil post-training administration at 1 or 2 h impaired memory persistence. Modafinil impaired memory consolidation in a dose- and time-dependent fashion.

  7. Algebra task & drill sheets

    CERN Document Server

    Reed, Nat

    2011-01-01

    For grades 6-8, our State Standards-based combined resource meets the algebraic concepts addressed by the NCTM standards and encourages the students to review the concepts in unique ways. The task sheets introduce the mathematical concepts to the students around a central problem taken from real-life experiences, while the drill sheets provide warm-up and timed practice questions for the students to strengthen their procedural proficiency skills. Included are opportunities for problem-solving, patterning, algebraic graphing, equations and determining averages. The combined task & drill sheets

  8. Task Specific Tremors.

    Science.gov (United States)

    Friedman, Joseph H

    2015-07-01

    A patient reported bilateral hand tremors when writing but not with other tasks. These "task specific" tremors are considered subcategories of essential tremor. Primary writing tremor, in which the tremor occurs only with writing, is probably the most common. The important teaching point is that the "standard" tremor assessment, watching the patient holding a sustained posture and touching his finger to the examiner's and then back to the nose is not adequate. Patients should be tested doing the activity that causes them the most difficulty.

  9. Impact of task difficulty on gaze behavior in a sequential object manipulation task.

    Science.gov (United States)

    Kurz, Johannes; Hegele, Mathias; Reiser, Mathias; Munzert, Jörn

    2017-11-01

    Task difficulty affects both gaze behavior and hand movements. Therefore, the present study aimed to investigate how task difficulty modulates gaze behaviour with respect to the balance between visually monitoring the ongoing action and prospectively collecting visual information about the future course of the ongoing action. For this, we examined sequences of reach and transport movements of water glasses that differed in task difficulty using glasses filled to different levels. Participants had to grasp water glasses with different filling levels (100, 94, 88, 82, and 76%) and transport them to a target. Subsequently, they had to grasp the next water glass and transport it to a target on the opposite side. Results showed significant differences in both gaze and movement kinematics for higher filling levels. However, there were no relevant differences between the 88, 82, and 76% filling levels. Results revealed a significant influence of task difficulty on the interaction between gaze and kinematics during transport and a strong influence of task difficulty on gaze during the release phase between different grasp-to-place movements. In summary, we found a movement and gaze pattern revealing an influence of task difficulty that was especially evident for the later phases of transport and release.

  10. Paradoxical increase of exploratory behavior in the elevated plus-maze by rats exposed to two kinds of aversive stimuli

    Directory of Open Access Journals (Sweden)

    Morato S.

    1997-01-01

    Full Text Available Albino rats were submitted to a 24-h period of social isolation (individual housing combined with 0, 1, 2 or 3 twenty-four-hour periods of exposure to different vivaria (novelty and tested in the elevated plus-maze. Results, reported as mean ± SEM for N = 12, show that the time (in seconds spent in the open arms by rats exposed to novelty for 0, 1, 2 and 3 days was 28.3 ± 4.4, 31.6 ± 3.2, 29.1 ± 3.5 and 25.0 ± 3.3, respectively, when grouped in the same vivarium; 29.6 ± 2.7, 7.6 ± 2.1, 9.6 ± 4.4 and 28.5 ± 3.7 when grouped in different vivaria; 2.9 ± 1.1, 1.8 ± 1.0, 2.7 ± 1.1 and 0 ± 0 when isolated in the same vivarium, and 2.6 ± 1.1, 31.5 ± 8.2, 24.8 ± 4.2 and 0 ± 0 when isolated in different vivaria. The number of entries into the open and closed arms followed a similar trend. This indicates that, separately, both exposure to novelty and isolation are aversive manipulations. Paradoxically, when novelty was combined with a concomitant 24-h period of social isolation prior to testing, the decrease in exploratory behavior caused by either of the two aversive manipulations alone was reverted. These results are indicative that less intense anxiety triggers mechanisms mediating less energetic behavior such as freezing, while higher levels trigger mechanisms mediating more vigorous action, such as flight/fight behavior, since the combination of two aversive situations resulted in more exploratory behavior than with either alone. They are also suggestive of habituation to the effects of novelty, since exposure to it for 3 days produced exploratory behavior similar to that of controls

  11. Restoration of sinus rhythm and atrial transport function after the maze procedure: U lesion set versus box lesion set.

    Science.gov (United States)

    Nitta, Takashi; Ishii, Yosuke; Fujii, Masahiro; Miyagi, Yasuo; Sakamoto, Shun-Ichiro; Hiromoto, Atsushi; Imura, Hajime

    2016-04-01

    In a U lesion set, the left atrium (LA) roof between the right and left superior pulmonary veins is not ablated, to allow activation to propagate across the posterior LA and to recruit this segment as a contractile atrial component. In contrast, the box lesion set isolates the entire posterior LA. To compare the two lesion sets, postoperative freedom from atrial fibrillation (AF) and LA transport function were examined in 402 patients who underwent surgery for AF with a U lesion (n = 329) or box lesion (n = 73) set. Patients who underwent pulmonary vein isolation alone or other simplified procedures were excluded from the study. LA transport function was quantified at 20 ± 33 months postoperatively by the ratio of peak velocity of the A wave to the E wave (peak A/E) of the transmitral Doppler flow. In patients with long-standing persistent AF, freedom from AF was 85% with the U lesion set and 77% with the box lesion set at 5 years after the maze procedure, and 82% and 77%, respectively, at 10 years after the procedure. There was no significant difference between the U lesion set and box lesion set in patients with long-standing persistent AF (P = .30) and those with paroxysmal or persistent AF (P = .90). Proportional hazards analysis identified increased LA diameter (P = .003) and long-standing persistent AF (P = .03), but not the type of lesion set (P = .51), as predictive of postoperative AF recurrence. The postoperative peak A/E was significantly greater after the U lesion set than after the box lesion set (0.42 ± 0.22 vs 0.23 ± 0.17), and multiple regression analysis demonstrated that the type of lesion set and preoperative LA diameter significantly affected postoperative A/E. The U lesion set restores sinus rhythm frequently as the box lesion set and provides better LA transport function. A dilated LA is a risk factor for postoperative recurrence of AF and poor postoperative LA transport function. Copyright © 2016 The American Association for Thoracic

  12. Task 1 quarternary tectonics

    Energy Technology Data Exchange (ETDEWEB)

    Bell, J.W.

    1994-12-31

    Activities on the task of quarternary tectonics for the Yucca Mountain Site investigations are described. Technical topics include: A preliminary reveiw of Bare Mountain Trench; A preliminary detailed lineament map of the Southwestern part of the proposed repository; A discussion on the 1994 Double Spring Flat, Nevada earthquake; and evidence for temporal clustering.

  13. Use of high and low responders to novelty in rat studies on the role of the ventral striatum in radial maze performance: effects of intra-accumbens injections of sulpiride.

    Science.gov (United States)

    Cools, A R; Ellenbroek, B; Heeren, D; Lubbers, L

    1993-01-01

    High and low responders to novelty (Wistar rats) were selected with the help of an open-field test and then equipped with intra-accumbens cannulae. They were then tested in a simple four-arm radial maze during 5 successive days, three trials per day, following intra-accumbens injections of distilled water or the dopaminergic D2 antagonist (+/-)-sulpiride. The injections were given 15 min before the first trial on each day. Both types of drug-naive rats reached the same level of performance on day 5. However, high responders made more visits, more revisits, and needed less time to make the first visit than low responders. Moreover, high responders showed their greatest increase in learning 2 days earlier than low responders. It is discussed that these differences between high and low responders are not due simply to differences in locomotor activity, but are due to a subtle, but important, difference in the mode of learning between both types. Sulpiride significantly attenuated the learning in both rat types; however, its effect in high responders was much less than that in low responders. It is suggested that the effects of sulpiride are not due to changes in locomotor activity, motivation, or perception, but are due to a learning deficit. The data are discussed in view of the genetic variation in the neurochemical and neurobiological makeup of the nucleus accumbens in both types.

  14. Computational modelling and analysis of hippocampal-prefrontal information coding during a spatial decision-making task

    Directory of Open Access Journals (Sweden)

    Thomas eJahans-Price

    2014-03-01

    Full Text Available We introduce a computational model describing rat behaviour and the interactions of neural populations processing spatial and mnemonic information during a maze-based, decision-making task. The model integrates sensory input and implements a working memory to inform decisions at a choice point, reproducing rat behavioural data and predicting the occurrence of turn- and memory-dependent activity in neuronal networks supporting task performance. We tested these model predictions using a new software toolbox (Maze Query Language, MQL to analyse activity of medial prefrontal cortical (mPFC and dorsal hippocampal (dCA1 neurons recorded from 6 adult rats during task performance. The firing rates of dCA1 neurons discriminated context (i.e. the direction of the previous turn, whilst a subset of mPFC neurons was selective for current turn direction or context, with some conjunctively encoding both. mPFC turn-selective neurons displayed a ramping of activity on approach to the decision turn and turn-selectivity in mPFC was significantly reduced during error trials. These analyses complement data from neurophysiological recordings in non-human primates indicating that firing rates of cortical neurons correlate with integration of sensory evidence used to inform decision-making.

  15. A reversal learning task detects cognitive deficits in a Dachshund model of late-infantile neuronal ceroid lipofuscinosis

    Science.gov (United States)

    Sanders, Douglas N.; Kanazono, Shinichi; Wininger, Fred A.; Whiting, Rebecca E.H.; Flournoy, Camille A.; Coates, Joan R.; Castaner, Lani J.; O’Brien, Dennis P.; Katz, Martin L.

    2011-01-01

    The neuronal ceroid lipofuscinoses (NCLs) are autosomal recessive lysosomal storage diseases characterized by progressive neurodegeneration and by accumulation of autofluorescent storage material in the central nervous system and other tissues. One of the most prominent clinical signs of NCL is progressive decline in cognitive function. We previously described a frame shift mutation of TPP1 in miniature long-haired Dachshunds which causes an early-onset form of NCL analogous to classical late-infantile onset NCL (CLN2) in children. Dogs homozygous for the TPP1 mutation exhibit progressive neurological signs similar to those exhibited by human patients. In order to establish biomarkers for evaluating the efficacy of ongoing therapeutic studies in this canine model, we characterized phenotypic changes in 13 dogs through 9 months of age. Cognitive function was assessed using a T-maze reversal learning task. Cognitive dysfunction was detected in affected dogs as early as 6 months of age and worsened as the disease progressed. Physical and neurological examination, funduscopy, and electroretinography (ERG) were performed at regular intervals. Only changes in ERG responses revealed signs of disease progression earlier than the reversal learning task. In the later stages of the disease clinical signs of visual and motor deficits became evident. The visual and motor deficits were not severe enough to affect the performance of dogs in the T-maze. Declining performance on the reversal learning task is a sensitive measure of higher order cognitive dysfunction which can serve as a useful biomarker of disease progression. PMID:21745338

  16. Task Engagement and Attentional Resources.

    Science.gov (United States)

    Matthews, Gerald; Warm, Joel S; Smith, Andrew P

    2017-02-01

    Two studies tested multivariate models of relationships between subjective task engagement and vigilance. The second study included a stress factor (cold infection). Modeling tested relationships between latent factors for task engagement and vigilance, and the role of engagement in mediating effects of cold infection. Raja Parasuraman's research on vigilance identified several key issues, including the roles of task factors, arousal processes, and individual differences, within the framework of resource theory. Task engagement is positively correlated with performance on various attentional tasks and may serve as a marker for resource availability. In the first study, 229 participants performed simultaneous and successive vigilance tasks. In the second study, 204 participants performed a vigilance task and a variable-foreperiod simple reaction-time task on two separate days. On the second day, 96 participants performed while infected with a naturally occurring common cold. Task engagement was assessed in both studies. In both studies, vigilance decrement in hit rate was observed, and task performance led to loss of task engagement. Cold infection also depressed both vigilance and engagement. Fitting structural equation models indicated that simultaneous and successive tasks should be represented by separate latent factors (Study 1), and task engagement fully mediated the impact of cold infection on vigilance but not reaction time (Study 2). Modeling individual differences in task engagement elucidates the role of resources in vigilance and underscores the relevance of Parasuraman's vision of the field. Assessment of task engagement may support diagnostic monitoring of operators performing tasks requiring vigilance.

  17. Effects of caloric restriction on learning and recovery of a spatial task in rats exposed to acute stress

    Directory of Open Access Journals (Sweden)

    Lamprea Rodríguez, Marisol

    2009-06-01

    Full Text Available The purpose of the present study was to describe the effects of caloric restriction on spatial learning and recovery in the Barnes maze in animals experimentally stressed before recovery of the spatial task. Male Wistar rats were exposed for two months to one of two conditions: ad libitum (AL or intermittent fasting (IF. Both groups were exposed then to an experimental form of acute stress, induced by movement restriction for 4 hours. IF subjects had better performance in learning tasks during the acquisition trials but required more time to complete the task after the stressor was applied. These results are discussed in light of previous data reported in the literature emphasizing differences in the instruments used to evaluate spatial learning and its interaction with experimentally induced stress.

  18. Differential requirements of hippocampal de novo protein and mRNA synthesis in two long-term spatial memory tests: Spontaneous place recognition and delay-interposed radial maze performance in rats.

    Science.gov (United States)

    Ozawa, Takaaki; Yamada, Kazuo; Ichitani, Yukio

    2017-01-01

    Hippocampal de novo mRNA and protein synthesis has been suggested to be critical for long-term spatial memory. However, its requirement in each memory process (i.e. encoding, consolidation and retrieval) and the differences in the roles of de novo mRNA and protein synthesis in different situations where spatial memory is tested have not been thoroughly investigated. To address these questions, we examined the effects of hippocampal administration of the protein synthesis inhibitors, anisomycin (ANI) and emetine (EME), as well as that of an mRNA synthesis inhibitor, 5,6-dichlorobenzimidazole 1-β-D-ribofuranoside (DRB), on rat performance in two long-term spatial memory tests. In a spontaneous place recognition test with a 6 h delay, ANI, administered either before or immediately after the sample phase, but not before the test phase, eliminated the exploratory preference for the object in a novel place. This amnesic effect was replicated by both EME and DRB. In a 6 h delay-interposed radial maze task, however, administering ANI before the first-half and before the second-half, but not immediately or 2 h after the first-half, impaired performance in the second-half. This disruptive effect of ANI was successfully replicated by EME. However, DRB administered before the first-half performance did not impair the second-half performance, while it did impair it if injected before the second-half. None of these drugs caused amnesic effects during the short (5 min)/non-delayed conditions in either tests. These results suggest that 1) hippocampal protein synthesis is required for the consolidation of spatial memory, while mRNA synthesis is not necessarily required, and 2) hippocampal mRNA and protein synthesis requirement for spatial memory retrieval depends on the types of memory tested, probably because their demands are different.

  19. An automated Y-maze based on a reduced instruction set computer (RISC) microcontroller for the assessment of continuous spontaneous alternation in rats.

    Science.gov (United States)

    Heredia-López, Francisco J; Álvarez-Cervera, Fernando J; Collí-Alfaro, José G; Bata-García, José L; Arankowsky-Sandoval, Gloria; Góngora-Alfaro, José L

    2016-12-01

    Continuous spontaneous alternation behavior (SAB) in a Y-maze is used for evaluating working memory in rodents. Here, the design of an automated Y-maze equipped with three infrared optocouplers per arm, and commanded by a reduced instruction set computer (RISC) microcontroller is described. The software was devised for recording only true entries and exits to the arms. Experimental settings are programmed via a keyboard with three buttons and a display. The sequence of arm entries and the time spent in each arm and the neutral zone (NZ) are saved as a text file in a non-volatile memory for later transfer to a USB flash memory. Data files are analyzed with a program developed under LabVIEW® environment, and the results are exported to an Excel® spreadsheet file. Variables measured are: latency to exit the starting arm, sequence and number of arm entries, number of alternations, alternation percentage, and cumulative times spent in each arm and NZ. The automated Y-maze accurately detected the SAB decrease produced in rats by the muscarinic antagonist trihexyphenidyl, and its reversal by caffeine, having 100 % concordance with the alternation percentages calculated by two trained observers who independently watched videos of the same experiments. Although the values of time spent in the arms and NZ measured by the automated system had small discrepancies with those calculated by the observers, Bland-Altman analysis showed 95 % concordance in three pairs of comparisons, while in one it was 90 %, indicating that this system is a reliable and inexpensive alternative for the study of continuous SAB in rodents.

  20. Features or tasks?

    DEFF Research Database (Denmark)

    Heilesen, Simon

    In this paper for the Workshop on Human-computer interaction and e-learning, NordiCHI 2002, the author argues that in developing innovative E-learning systems, especially if constructivist pedagogy is to be applied, it will be useful to model the user interface on the often complex tasks that the...... that the user has to perform rather than just focusing on technical features (and adapting system use to them).......In this paper for the Workshop on Human-computer interaction and e-learning, NordiCHI 2002, the author argues that in developing innovative E-learning systems, especially if constructivist pedagogy is to be applied, it will be useful to model the user interface on the often complex tasks...

  1. Behavioral Task Analysis

    Science.gov (United States)

    2010-01-01

    methods included task analysis as a critical phase in developing instruction and training. Mon- temerlo and Tennyson (1976) noted that from 1951 to 1976...designed. The trend in the U.S . Department of Defense toward extensive procedural documentation noted by Montemerlo and Tennyson (1976) has not...M. Gagne’ (Ed.), Psychological principles in system development (pp. 187-228). New York: Holt. Montemerlo, M. D., & Tennyson , M. E. (1975

  2. Task Inventory Construction

    Science.gov (United States)

    1976-06-01

    Orientation , Training and Team Performance Research Area 7, Peace Time Task Analysis and Its Relation to War Time Conditions Research Area 8. Worker...January jar jaw jay jelly jellyfish jerk jig job jockey join joke joking jolly journey joy(ful) joyous judge jug juice juicy July...straight swept soil squash strange(r) swift sold squeak strap swim soldier squeeze straw swimming sole squirrel strawberry swing some stable

  3. Operationally Responsive Tasking

    Science.gov (United States)

    2011-09-01

    RESPONSIVE TASKING by Aaron C. Bass September 2011 Thesis Advisor: Alan D. Scott Second Reader: Mark Rhoades THIS PAGE INTENTIONALLY LEFT...September 2011 Author: Aaron C. Bass Approved by: Alan D. Scott Thesis Advisor Mark M. Rhoades Second Reader Rudy...web.cs.gc.cuny.edu/~mjohnson/pubs/algosensors.pdf. [34] D. Pizzocaro, M. Johnson, H. Rowaihy, S. Chalmers , A. Preece, A. Bar- Noy, and T. La Porta, “A Knapsack

  4. IMAGE INTERPRETATION TASK.

    Science.gov (United States)

    In response to a research requirement of the Department of the Army, an extensive exploratory survey of human factors problems in image in...imagery. (2) How can the Army best utilize its available human resources to cope with ever increasing variety of image types and at the same time...experiments conduct ed to date within each of four subtask areas encompassed by the research program of the Image Interpretation Task.

  5. Dose- and time-dependent expression of anxiety-like behavior in the elevated plus-maze during withdrawal from acute and repeated intermittent ethanol intoxication in rats.

    Science.gov (United States)

    Zhang, Zhongqi; Morse, Andrew C; Koob, George F; Schulteis, Gery

    2007-11-01

    Withdrawal from acute bolus intraperitoneal (IP) injection of high doses of ethanol elicits anxiety-like behavior (e.g. Doremus et al., 2003; Gauvin et al., 1989, 1992) and conditioned place aversion (Morse et al., 2000). More recently we demonstrated that withdrawal from a single moderate dose of ethanol (2.0 g/kg) is accompanied by elevations in brain reward thresholds, and that repeated intermittent treatment with this dose results in a significant potentiation of reward deficit (Schulteis and Liu, 2006). In the current study, the time- and dose-dependent emergence of anxiety-like behavior was measured in the elevated plus-maze at various times (3 to 24 hours) after acute or 3 daily IP injections of ethanol (1.0, 2.0, or 3.0 g/kg). Rats receiving daily handling for 2 days, and a single anxiety opportunity to explore the maze on a third day were divided into 1 of several treatment protocols: (1) NAIVE conditions: vehicle IP on all 3 days; (2) ACUTE conditions: vehicle on the first 2 days, ethanol on the third day; or (3) REPEAT conditions: ethanol on all 3 days. ACUTE ethanol elicited reduced exploration of the open arms of the elevated plus-maze in a dose- and time-dependent fashion: 1.0 g/kg failed to elicit any significant effects, whereas 2.0 and 3.0 g/kg ethanol elicited a significant anxiety-like response at 6 hours and 9 to 12 hours postinjection, respectively. REPEAT treatment was still without effect at any time point tested following 1.0 g/kg ethanol, but extended the time course of anxiety-like behavior after treatment with either 2.0 or 3.0 g/kg doses. REPEAT treatment with 2.0 and 3.0 g/kg ethanol also produced significant hypoactivity in the maze at some time points postinjection. Withdrawal from a single exposure to ethanol produces transient but significant anxiety-like behavior, and repeated intermittent bouts of intoxication result in a significant extension of the duration of effect. The rapid emergence and progression of negative emotional

  6. Mobile Thread Task Manager

    Science.gov (United States)

    Clement, Bradley J.; Estlin, Tara A.; Bornstein, Benjamin J.

    2013-01-01

    The Mobile Thread Task Manager (MTTM) is being applied to parallelizing existing flight software to understand the benefits and to develop new techniques and architectural concepts for adapting software to multicore architectures. It allocates and load-balances tasks for a group of threads that migrate across processors to improve cache performance. In order to balance-load across threads, the MTTM augments a basic map-reduce strategy to draw jobs from a global queue. In a multicore processor, memory may be "homed" to the cache of a specific processor and must be accessed from that processor. The MTTB architecture wraps access to data with thread management to move threads to the home processor for that data so that the computation follows the data in an attempt to avoid L2 cache misses. Cache homing is also handled by a memory manager that translates identifiers to processor IDs where the data will be homed (according to rules defined by the user). The user can also specify the number of threads and processors separately, which is important for tuning performance for different patterns of computation and memory access. MTTM efficiently processes tasks in parallel on a multiprocessor computer. It also provides an interface to make it easier to adapt existing software to a multiprocessor environment.

  7. Gap Task Force

    CERN Multimedia

    Lissuaer, D

    One of the more congested areas in the ATLAS detector is the GAP region (the area between the Barrel Calorimeter and the End Cap calorimeter) where Inner Detector services, LAr Services and some Tile services all must co-habitat in a very limited area. It has been clear for some time that the space in the GAP region is not sufficient to accommodate all that is needed. In the last few month additional problems of routing all the services to Z=0 have been encountered due to the very limited space between the Tile Calorimeter and the first layer of Muon chambers. The Technical Management Board (TMB) and the Executive Board (EB) decided in the middle of March to establish a Task Force to look at this problem and come up with a solution within well-specified guidelines. The task force consisted of experts from the ID, Muon, Liquid Argon and Tile systems in addition to experts from the Technical Coordination team and the Physics coordinator. The task force held many meetings and in general there were some very l...

  8. Task Dominance Determines Backward Inhibition in Task Switching

    Directory of Open Access Journals (Sweden)

    Kerstin Jost

    2017-05-01

    Full Text Available Switching between tasks is assumed to be accompanied by inhibiting currently irrelevant, but competing tasks. A dominant task that strongly interferes with performing a weaker task may receive especially strong inhibition. We tested this prediction by letting participants switch among three tasks that differ in dominance: a location discrimination task with strong stimulus–response bindings (responding with left-hand and right-hand button presses to stimuli presented left or right to the fixation cross was combined with a color/pattern and a shape discrimination task, for which stimulus–response mappings were arbitrary (e.g., left-hand button press mapped to a red stimulus. Across three experiments, the dominance of the location task was documented by faster and more accurate responses than in the other tasks. This even held for incompatible stimulus–response mappings (i.e., right-hand response to a left-presented stimulus and vice versa, indicating that set-level compatibility (i.e., “dimension overlap” was sufficient for making this location task dominant. As a behavioral marker for backward inhibition, we utilized n-2 repetition costs that are defined by higher reaction times for a switch back to a just abandoned and thus just inhibited task (ABA sequence than for a switch to a less recently inhibited task (CBA, n-2 non-repetition. Reliable n-2 task repetition costs were obtained for all three tasks. Importantly, these costs were largest for the location task, suggesting that inhibition indeed was stronger for the dominant task. This finding adds to other evidence that the amount of inhibition is adjusted in a context-sensitive way.

  9. Functional connectivity changes during a Working memory task in rat via NMF analysis

    Directory of Open Access Journals (Sweden)

    Jing eWei

    2015-01-01

    Full Text Available Working memory (WM is necessary in higher cognition. The brain as a complex network is formed by interconnections among neurons. Connectivity results in neural dynamics to support cognition. The first aim is to investigate connectivity dynamics in medial prefrontal cortex (mPFC networks during WM. As brain neural activity is sparse, the second aim is to find the intrinsic connectivity property in a feature space. Using multi-channel electrode recording techniques, spikes were simultaneously obtained from mPFC of rats that performed a Y-maze WM task. Continuous time series converted from spikes were embedded in a low-dimensional space by non-negative matrix factorization (NMF. mPFC network in original space was constructed by measuring connections among neurons. And the same network in NMF space was constructed by computing connectivity values between the extracted NMF components. Causal density (Cd and global efficiency (E were estimated to present the network property. The results showed that Cd and E significantly peaked in the interval right before the maze choice point in correct trials. However, the increase did not emerge in error trials. Additionally, Cd and E in two spaces displayed similar trends in correct trials. The difference was that the measures in NMF space were significantly greater than those in original space. Our findings indicated that the anticipatory changes in mPFC networks may have an effect on future WM behavioral choices. Moreover, the NMF analysis achieves a better characterization for a brain network.

  10. Noradrenaline microinjected into the dorsal periaqueductal gray matter causes anxiolytic-like effects in rats tested in the elevated T-maze.

    Science.gov (United States)

    Estrada, Viviane Batista; Matsubara, Natália Kimie; Gomes, Marcus Vinicius; Corrêa, Fernando Morgan Aguiar; Pelosi, Gislaine Garcia

    2016-05-01

    The dorsal periaqueductal gray matter (dPAG) is involved in the integration of behavioral and cardiovascular responses caused by fear and anxiety situations. Some studies suggest an involvement of noradrenergic neurotransmission in the dPAG in anxiety modulation, however, there is no evidence about its role in panic attacks. The goal of this work was to study the effect of NA microinjection in dPAG in rats submitted to the elevated T-maze (ETM). Male Wistar had a cannula implanted in the PAG where it was injected NA in the doses of 1, 3, 15, 45nmol/50nl or artificial cerebrospinal fluid previous the ETM test. NA intra-dPAG decreased inhibitory avoidance behavior in the ETM without changing escape, indicating only an anxiolytic-like effect. Furthermore, the microinjection of NA did not change the general exploratory activity of the animals submitted to the open field test, suggesting that the anxiolytic-like effect is not due to an increase in exploratory activity. The results indicate an involvement of noradrenergic neurotransmission in the dPAG in defensive reactions associated with generalized anxiety, but not as main mechanisms for the panic, in rats submitted to the elevated T-maze providing support for other research aimed at improving the treatment of generalized anxiety. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. [Effects of nootropic drugs on behavior of BALB/c and C57BL/6 mice in the exploratory cross-maze test].

    Science.gov (United States)

    Vasil'eva, E V; Salimov, R M; Kovalev, G I

    2012-01-01

    Exploratory behavior, locomotor activity, and anxiety in inbred mice of C57BL/6 and BALB/c strains subchronically treated with placebo or various types of nootropic (cognition enhancing) drugs (piracetam, phenotropil, noopept, semax, pantogam, nooglutil) have been evaluated using the exploratory cross-maze test. It was found that BALB/c mice in comparison to C57BL/6 mice are characterized by greater anxiety and lower efficiency of exploratory behavior in the previously unfamiliar environment. All tested drugs clearly improved the exploratory behavior in BALB/c mice only. In BALB/c mice, piracetam, phenotropil, noopept, and semax also reduced anxiety, while phenotropil additionally increased locomotor activity. Thus, the nootropic drugs displayed clear positive modulation of spontaneous orientation in the mice strain with initially low exploratory efficiency (BALB/c) in the cross-maze test. Some drugs (pantogam, nooglutil) exhibited only nootropic properties, while the other drugs exhibited both nootropic effects on the exploratory activity and produced modulation of the anxiety level (piracetam, fenotropil, noopept, semax) and locomotor activity (fenotropil).

  12. Temporary inhibition of dorsal or ventral hippocampus by muscimol: distinct effects on measures of innate anxiety on the elevated plus maze, but similar disruption of contextual fear conditioning.

    Science.gov (United States)

    Zhang, Wei-Ning; Bast, Tobias; Xu, Yan; Feldon, Joram

    2014-04-01

    Studies in rats, involving hippocampal lesions and hippocampal drug infusions, have implicated the hippocampus in the modulation of anxiety-related behaviors and conditioned fear. The ventral hippocampus is considered to be more important for anxiety- and fear-related behaviors than the dorsal hippocampus. In the present study, we compared the role of dorsal and ventral hippocampus in innate anxiety and classical fear conditioning in Wistar rats, examining the effects of temporary pharmacological inhibition by the GABA-A agonist muscimol (0.5 ug/0.5 ul/side) in the elevated plus maze and on fear conditioning to a tone and the conditioning context. In the elevated plus maze, dorsal and ventral hippocampal muscimol caused distinct behavioral changes. The effects of ventral hippocampal muscimol were consistent with suppression of locomotion, possibly accompanied by anxiolytic effects, whereas the pattern of changes caused by dorsal hippocampal muscimol was consistent with anxiogenic effects. In contrast, dorsal and ventral hippocampal muscimol caused similar effects in the fear conditioning experiments, disrupting contextual, but not tone, fear conditioning. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Effects of atomoxetine, desipramine, d-amphetamine and methylphenidate on impulsivity in juvenile rats, measured in a T-maze procedure.

    Science.gov (United States)

    Bizot, Jean-Charles; David, Sabrina; Trovero, Fabrice

    2011-02-01

    Impulsivity is a core symptom of Attention Deficit/Hyperactivity Disorder (ADHD). In the present study, we assessed the effects of two stimulants, methylphenidate and d-amphetamine and of two non stimulant noradrenaline reuptake inhibitors, atomoxetine and desipramine, on the tolerance to delay of reward, taken as an index of impulsivity, in juvenile Wistar rats. Animals were trained in a T-maze to choose between a small-and-immediate reward and a large-but-30s-delayed reward. The effects of drugs were studied on the performance of animals at 30-40 day of age. Methylphenidate (3mg/kg), atomoxetine (1mg/kg), d-amphetamine (1 and 2mg/kg) and desipramine (8 and 16mg/kg) increased the number of choices of the large-but-delayed reward, i.e. decreased impulsivity. Given that these drugs are commonly prescribed in ADHD, these data indicate that the T-maze procedure in juvenile animals may be suitable for testing the therapeutic potential of drugs intended to the treatment of ADHD in children. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  14. Quarternary tectonics, Task 1

    Energy Technology Data Exchange (ETDEWEB)

    Bell, J.W.

    1993-09-30

    Activities conducted for the evaluation of the geology and seismotectonics stability of Yucca Mountain as a potential site for the underground disposal of high-level radioactive wastes continued. Tasks concerned with quaternary tectonics include: scheduling of photography of Little Skull Mountain area; the collection and dating of rock varnish samples from the 1932 Cedar Mountain earthquake area for carbon 14 AMS and cation-ratio analysis; collection of samples for thermoluminescence dating from the 1932 Cedar Mountain earthquake area; mapping of the northern area of Crater Flat; and surveying of the May 17, 1993 Eureka the Valley earthquake area.

  15. A statistical approach for segregating cognitive task stages from multivariate fMRI BOLD time series.

    Science.gov (United States)

    Demanuele, Charmaine; Bähner, Florian; Plichta, Michael M; Kirsch, Peter; Tost, Heike; Meyer-Lindenberg, Andreas; Durstewitz, Daniel

    2015-01-01

    Multivariate pattern analysis can reveal new information from neuroimaging data to illuminate human cognition and its disturbances. Here, we develop a methodological approach, based on multivariate statistical/machine learning and time series analysis, to discern cognitive processing stages from functional magnetic resonance imaging (fMRI) blood oxygenation level dependent (BOLD) time series. We apply this method to data recorded from a group of healthy adults whilst performing a virtual reality version of the delayed win-shift radial arm maze (RAM) task. This task has been frequently used to study working memory and decision making in rodents. Using linear classifiers and multivariate test statistics in conjunction with time series bootstraps, we show that different cognitive stages of the task, as defined by the experimenter, namely, the encoding/retrieval, choice, reward and delay stages, can be statistically discriminated from the BOLD time series in brain areas relevant for decision making and working memory. Discrimination of these task stages was significantly reduced during poor behavioral performance in dorsolateral prefrontal cortex (DLPFC), but not in the primary visual cortex (V1). Experimenter-defined dissection of time series into class labels based on task structure was confirmed by an unsupervised, bottom-up approach based on Hidden Markov Models. Furthermore, we show that different groupings of recorded time points into cognitive event classes can be used to test hypotheses about the specific cognitive role of a given brain region during task execution. We found that whilst the DLPFC strongly differentiated between task stages associated with different memory loads, but not between different visual-spatial aspects, the reverse was true for V1. Our methodology illustrates how different aspects of cognitive information processing during one and the same task can be separated and attributed to specific brain regions based on information contained in

  16. Perirhinal cortex supports tactual discrimination tasks with increasing levels of complexity: Retrograde effect.

    Science.gov (United States)

    Ramos, Juan M J

    2016-05-01

    Recent studies have suggested that the perirhinal cortex (Prh) supports representations of feature conjunctions in the visual modality during the acquisition/encoding of complex discriminations. To extend this idea to other sensory modalities and to another stage of the discrimination process, we studied the effect of Prh lesions on the expression of a series of tactual discrimination tasks learned preoperatively. These tasks differed from one another in the degree of feature overlap of the stimuli and in the difficulty of the task. During pre- and post-operative testing phases, rats had to discriminate among 3 stimuli simultaneously exposed in 3 arms of a 4-arm plus-shaped maze. Prh-damaged rats showed a profound impairment in the expression of tactual discrimination tasks when the stimuli had a high or intermediate degree of feature ambiguity, but not when they had a low degree of ambiguity (experiments 1a-1c). In order to experimentally dissociate between subregions within the medial temporal lobe, experiment 2 was conducted to show that hippocampal lesions did not cause any impairment in task expression even when the stimuli had a high degree of feature ambiguity. When the tactual discrimination tasks used simple/individual nonoverlapping features of the stimuli (size), Prh lesions did not affect the expression of these discriminations despite the high level of difficulty of these tasks (experiments 3a and 3b). These findings suggest that, in the somatosensory modality, the Prh plays an essential role in the processing of complex stimuli with overlapping features but not in simple tactual discriminations. Furthermore, the Prh is necessary not just during acquisition but also during expression/performance of the discrimination task. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. A statistical approach for segregating cognitive task stages from multivariate fMRI BOLD time series

    Directory of Open Access Journals (Sweden)

    Charmaine eDemanuele

    2015-10-01

    Full Text Available Multivariate pattern analysis can reveal new information from neuroimaging data to illuminate human cognition and its disturbances. Here, we develop a methodological approach, based on multivariate statistical/machine learning and time series analysis, to discern cognitive processing stages from fMRI blood oxygenation level dependent (BOLD time series. We apply this method to data recorded from a group of healthy adults whilst performing a virtual reality version of the delayed win-shift radial arm maze task. This task has been frequently used to study working memory and decision making in rodents. Using linear classifiers and multivariate test statistics in conjunction with time series bootstraps, we show that different cognitive stages of the task, as defined by the experimenter, namely, the encoding/retrieval, choice, reward and delay stages, can be statistically discriminated from the BOLD time series in brain areas relevant for decision making and working memory. Discrimination of these task stages was significantly reduced during poor behavioral performance in dorsolateral prefrontal cortex (DLPFC, but not in the primary visual cortex (V1. Experimenter-defined dissection of time series into class labels based on task structure was confirmed by an unsupervised, bottom-up approach based on Hidden Markov Models. Furthermore, we show that different groupings of recorded time points into cognitive event classes can be used to test hypotheses about the specific cognitive role of a given brain region during task execution. We found that whilst the DLPFC strongly differentiated between task stages associated with different memory loads, but not between different visual-spatial aspects, the reverse was true for V1. Our methodology illustrates how different aspects of cognitive information processing during one and the same task can be separated and attributed to specific brain regions based on information contained in multivariate patterns of voxel

  18. Measuring Multi-tasking Ability

    Science.gov (United States)

    2003-07-01

    Bunting, 2001), antisaccade tasks (Kane, Bleckley, Conway, & Engle, 2001), and Stroop tasks (Kane & Engle, 2003). These attention-control tasks...departments of hospitals care for individuals who have cancer or who have other medical problems requiring surgery, respectively. Patients may be very...competition, and task set to Stroop interference. Journal of Experimental Psychology: General, 132, 47-70. Lansman, M., Poltrock, S., & Hunt, E. (1983

  19. Principles of Communicative Task Design.

    Science.gov (United States)

    Nunan, David

    The use of the learning task as a basic planning and instructional tool for communicative second language instruction is discussed, and considerations and procedures for designing such tasks are outlined. A task is defined as a piece of classroom work that involves learners in comprehending, manipulating, producing, or interacting in the target…

  20. Task-oriented rehabilitation robotics.

    Science.gov (United States)

    Schweighofer, Nicolas; Choi, Younggeun; Winstein, Carolee; Gordon, James

    2012-11-01

    Task-oriented training is emerging as the dominant and most effective approach to motor rehabilitation of upper extremity function after stroke. Here, the authors propose that the task-oriented training framework provides an evidence-based blueprint for the design of task-oriented robots for the rehabilitation of upper extremity function in the form of three design principles: skill acquisition of functional tasks, active participation training, and individualized adaptive training. The previous robotic systems that incorporate elements of task-oriented trainings are then reviewed. Finally, the authors critically analyze their own attempt to design and test the feasibility of a TOR robot, ADAPT (Adaptive and Automatic Presentation of Tasks), which incorporates the three design principles. Because of its task-oriented training-based design, ADAPT departs from most other current rehabilitation robotic systems: it presents realistic functional tasks in which the task goal is constantly adapted, so that the individual actively performs doable but challenging tasks without physical assistance. To maximize efficacy for a large clinical population, the authors propose that future task-oriented robots need to incorporate yet-to-be developed adaptive task presentation algorithms that emphasize acquisition of fine motor coordination skills while minimizing compensatory movements.

  1. TASK: Let's Have a Party!

    Science.gov (United States)

    Rees, James

    2012-01-01

    In this article, the author describes a creative way to demystify contemporary art for students. TASK is artist Oliver Herring's creation, where participants actively interpret instructions found on little pieces of paper--what he calls "tasks." An art classroom has all the key ingredients for a TASK event: (1) people; (2) materials; (3) space;…

  2. Vestibular loss promotes procedural response during a spatial task in rats.

    Science.gov (United States)

    Machado, Marie-Laure; Lelong-Boulouard, Véronique; Philoxene, Bruno; Davis, Audrey; Denise, Pierre; Besnard, Stéphane

    2014-05-01

    Declarative memory refers to a spatial strategy using numerous sources of sensory input information in which visual and vestibular inputs are assimilated in the hippocampus. In contrast, procedural memory refers to a response strategy based on motor skills and familiar gestures and involves the striatum. Even if vestibular loss impairs hippocampal activity and spatial memory, vestibular-lesioned rats remain able to find food rewards during complex spatial memory task. Since hippocampal lesions induce a switch from declarative memory to procedural memory, we hypothesize that vestibular-lesioned rats use a strategy other than that of hippocampal spatial response to complete the task and to counterbalance the loss of vestibular information. We test, in a reverse T-maze paradigm, the types of strategy vestibular-lesioned rats preferentially uses in a spatial task. We clearly demonstrate that all vestibular-lesioned rats shift to a response strategy to solve the spatial task, while control rats use spatial and response strategies equally. We conclude that the loss of vestibular informations leading to spatial learning impairments is not offset at the hippocampus level by integration process of other sense mainly visual informations; but favors a response strategy through procedural memory most likely involving the striatum, cerebellum, and motor learning. Copyright © 2014 Wiley Periodicals, Inc.

  3. Advantages of Task-Specific Multi-Objective Optimisation in Evolutionary Robotics.

    Directory of Open Access Journals (Sweden)

    Vito Trianni

    Full Text Available The application of multi-objective optimisation to evolutionary robotics is receiving increasing attention. A survey of the literature reveals the different possibilities it offers to improve the automatic design of efficient and adaptive robotic systems, and points to the successful demonstrations available for both task-specific and task-agnostic approaches (i.e., with or without reference to the specific design problem to be tackled. However, the advantages of multi-objective approaches over single-objective ones have not been clearly spelled out and experimentally demonstrated. This paper fills this gap for task-specific approaches: starting from well-known results in multi-objective optimisation, we discuss how to tackle commonly recognised problems in evolutionary robotics. In particular, we show that multi-objective optimisation (i allows evolving a more varied set of behaviours by exploring multiple trade-offs of the objectives to optimise, (ii supports the evolution of the desired behaviour through the introduction of objectives as proxies, (iii avoids the premature convergence to local optima possibly introduced by multi-component fitness functions, and (iv solves the bootstrap problem exploiting ancillary objectives to guide evolution in the early phases. We present an experimental demonstration of these benefits in three different case studies: maze navigation in a single robot domain, flocking in a swarm robotics context, and a strictly collaborative task in collective robotics.

  4. Advantages of Task-Specific Multi-Objective Optimisation in Evolutionary Robotics.

    Science.gov (United States)

    Trianni, Vito; López-Ibáñez, Manuel

    2015-01-01

    The application of multi-objective optimisation to evolutionary robotics is receiving increasing attention. A survey of the literature reveals the different possibilities it offers to improve the automatic design of efficient and adaptive robotic systems, and points to the successful demonstrations available for both task-specific and task-agnostic approaches (i.e., with or without reference to the specific design problem to be tackled). However, the advantages of multi-objective approaches over single-objective ones have not been clearly spelled out and experimentally demonstrated. This paper fills this gap for task-specific approaches: starting from well-known results in multi-objective optimisation, we discuss how to tackle commonly recognised problems in evolutionary robotics. In particular, we show that multi-objective optimisation (i) allows evolving a more varied set of behaviours by exploring multiple trade-offs of the objectives to optimise, (ii) supports the evolution of the desired behaviour through the introduction of objectives as proxies, (iii) avoids the premature convergence to local optima possibly introduced by multi-component fitness functions, and (iv) solves the bootstrap problem exploiting ancillary objectives to guide evolution in the early phases. We present an experimental demonstration of these benefits in three different case studies: maze navigation in a single robot domain, flocking in a swarm robotics context, and a strictly collaborative task in collective robotics.

  5. Recuperación de la contracción auricular luego de la cirugía de MAZE III izquierdo

    Directory of Open Access Journals (Sweden)

    Antonio Piazza

    2009-01-01

    Full Text Available IntroducciónLa cirugía de MAZE III izquierdo demostró una efectividad elevada en la restauración a ritmo sinusal. Sin embargo, la efectividad en la restauración de la sístole auricular en poblaciones con cardiopatía estructural y el predominio de enfermedad reumática resultan áreas de incertidumbre.ObjetivoEvaluar la efectividad de la cirugía de MAZE en la restauración de la sístole auricular en pacientes con cardiopatía estructural.Material y métodosEstudio prospectivo, consecutivo de 27 pacientes portadores de fibrilación auricular crónica persistente con indicación de cirugía cardiovascular y en los que se realizó la técnica de MAZE como tratamiento de la arritmia. La presencia de sístole auricular se evaluó mediante Doppler tisular del anillo mitral lateral.ResultadosEn una población caracterizada por predominancia de cardiopatía reumática (41% y tiempo prolongado de evolución de la arritmia (61 meses promedio, al final del seguimiento el 87% se encontraba en ritmo sinusal en el 80% de los casos con actividad mecánica. El antecedente de cardiopatía reumática, una duración de la arritmia mayor de 5,5 años, el sexo femenino y el reemplazo de válvula mitral fueron variables estadísticamente significativas en cuanto a la ausencia de sístole auricular. No tuvieron significación la edad, la fracción de eyección del ventrículo izquierdo y el tamaño de la aurícula izquierda.ConclusionesEn esta población es significativa la falta de correspondencia entre ritmo sinusal y sístole auricular. El Doppler tisular es un método útil para identificar a aquellos pacientes sin contracción auricular. El impacto clínico de este hallazgo está vinculado con la decisión en la continuidad del tratamiento anticoagulante.REV ARGENT CARDIOL 2009;77:7-13.

  6. TASK 2: QUENCH ZONE SIMULATION

    Energy Technology Data Exchange (ETDEWEB)

    Fusselman, Steve

    2015-09-30

    Aerojet Rocketdyne (AR) has developed an innovative gasifier concept incorporating advanced technologies in ultra-dense phase dry feed system, rapid mix injector, and advanced component cooling to significantly improve gasifier performance, life, and cost compared to commercially available state-of-the-art systems. A key feature of the AR gasifier design is the transition from the gasifier outlet into the quench zone, where the raw syngas is cooled to ~ 400°C by injection and vaporization of atomized water. Earlier pilot plant testing revealed a propensity for the original gasifier outlet design to accumulate slag in the outlet, leading to erratic syngas flow from the outlet. Subsequent design modifications successfully resolved this issue in the pilot plant gasifier. In order to gain greater insight into the physical phenomena occurring within this zone, AR developed a cold flow simulation apparatus with Coanda Research & Development with a high degree of similitude to hot fire conditions with the pilot scale gasifier design, and capable of accommodating a scaled-down quench zone for a demonstration-scale gasifier. The objective of this task was to validate similitude of the cold flow simulation model by comparison of pilot-scale outlet design performance, and to assess demonstration scale gasifier design feasibility from testing of a scaled-down outlet design. Test results did exhibit a strong correspondence with the two pilot scale outlet designs, indicating credible similitude for the cold flow simulation device. Testing of the scaled-down outlet revealed important considerations in the design and operation of the demonstration scale gasifier, in particular pertaining to the relative momentum between the downcoming raw syngas and the sprayed quench water and associated impacts on flow patterns within the quench zone. This report describes key findings from the test program, including assessment of pilot plant configuration simulations relative to actual

  7. "Wagging the dog": How service delivery can lose its way in the procurement maze -- and could find it again

    CSIR Research Space (South Africa)

    Wall, K

    2012-09-01

    Full Text Available of contractors, leading to delays in the delivery of services. The SCM "tail" would appear on those occasions to be “wagging the dog", namely service delivery. The paper does not suggest the watering down of SCM regulations. On the contrary, it argues...

  8. Long-lasting effects of prenatal MAM treatment on water maze performance in rats : Associations with altered brain development and neurotrophin levels

    NARCIS (Netherlands)

    Fiore, M; Korf, J; Antonelli, A; Talamini, L; Aloe, L

    2002-01-01

    We previously reported that prenatal methylazoxymethanol (MAM) administered on days I I and 12 of rat pregnancy induces structural changes in the cytoarchitecture of the hippocampal-entorhinal axis. We also showed that young and middle-aged prenatally treated MAM animals displayed changes in brain

  9. Egocentric spatial orientation in a water maze by rats subjected to transection of the fimbria-fornix and/or ablation of the prefrontal cortex

    DEFF Research Database (Denmark)

    Mogensen, Jesper; Moustgaard, Anette; Khan, Usman

    2005-01-01

    prefrontal cortex, hippocampus, fimbria-fornix, egocentrisk spatial orientering, vandlabyrint, adfærdsstrategier, kognitive strategier, funktionel genopretning, rehabilitering, problemløsning, rotter......prefrontal cortex, hippocampus, fimbria-fornix, egocentrisk spatial orientering, vandlabyrint, adfærdsstrategier, kognitive strategier, funktionel genopretning, rehabilitering, problemløsning, rotter...

  10. Evidence for a virtual human analog of a rodent relational memory task: a study of aging and fMRI in young adults.

    Science.gov (United States)

    Etchamendy, Nicole; Konishi, Kyoko; Pike, G Bruce; Marighetto, Aline; Bohbot, Véronique D

    2012-04-01

    A radial maze concurrent spatial discrimination learning paradigm consisting of two stages was previously designed to assess the flexibility property of relational memory in mice, as a model of human declarative memory. Aged mice and young adult mice with damage to the hippocampus, learned accurately Stage 1 of the task which required them to learn a constant reward location in a specific set of arms (i.e., learning phase). In contrast, they were impaired relative to healthy young adult mice in a second stage when faced with rearrangements of the same arms (i.e., flexibility probes). This mnemonic inflexibility in Stage 2 is thought to derive from insufficient relational processing by the hippocampus during initial learning (Stage 1) which favors stimulus-response learning, a form of procedural learning. This was proposed as a model of the selective declarative and relational memory decline classically described in elderly people. As a first step to examine the validity of this model, we adapted this protocol to humans using a virtual radial-maze. (1) We showed that performance in the flexibility probes in young and older adults positively correlated with performance in a wayfinding task, suggesting that our paradigm assesses relational memory. (2) We demonstrated that older healthy participants displayed a deficit in the performance of the flexibility probes (Stage 2), similar to the one previously seen in aged mice. This was associated with a decline in the wayfinding task. (3) Our fMRI data in young adults confirmed that hippocampal activation during early discrimination learning in Stage 1 correlated with memory flexibility in Stage 2, whereas caudate nucleus activation in Stage 1 negatively correlated with subsequent flexibility. By enabling relational memory assessment in mice and humans, our radial-maze paradigm provides a valuable tool for translational research. Copyright © 2011 Wiley Periodicals, Inc.

  11. Decision time and perseveration of adolescent rats in the T-maze are affected differentially by buspirone and independent of 5-HT-1A expression.

    Science.gov (United States)

    Rhoads, Dennis E; Grimes, Nicole; Kaushal, Sunaina; Mallari, Janine; Orlando, Krystal

    2012-07-01

    Disruption of spontaneous alternation behavior (SAB) by the serotonin 1A (5-HT-1A) receptor agonist, 8-hydroxy-dipropylaminotetraline (8-OH-DPAT), results in repetitive behaviors that have been used to model the perseveration and indecisiveness of human obsessive-compulsive disorder (OCD). In the present study, we compared the effects of buspirone to those of 8-OH-DPAT in two strains of adolescent rats and analyzed repetitive choices of arms of the maze and prolonged apparent decision time due to induction of vicarious trial and error (VTE) behavior. In adolescent Sprague-Dawley (SD) rats, 8-OH-DPAT induced repetitive choices of arms of the maze (perseveration) and increased the apparent decision time. Buspirone induced VTE behavior and increased apparent decision time without perseveration. This distinct effect of buspirone was seen in SD adolescents but not in Long-Evans (LE) adolescents which appeared to be insensitive to buspirone. Lack of responsiveness to buspirone was dependent on the developmental stage because buspirone induced VTE behavior and prolonged decision time in LE adults. Western blotting of brain 5-HT-1A receptors showed expression of receptor protein in adolescent LE brain was comparable to that of adolescent SD and adult LE. The 5-HT-1A antagonist WAY 100365 blocked the effect 8-OH-DPAT on repetitive choice of arms but not the effect of buspirone on VTE behavior. We conclude that the adolescent LE rat has normal levels of 5-HT-1A receptor and that the effect of buspirone on VTE behavior is not mediated by the 5-HT-1A receptor. The LE strain may provide a useful system for further study of the adolescent brain and potential genetic differences in induction of repetitive behaviors. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Microinjection of naltrexone into the central, but not the basolateral, amygdala blocks the anxiolytic effects of diazepam in the plus maze

    Science.gov (United States)

    Burghardt, Paul R.; Wilson, Marlene A.

    2009-01-01

    The amygdala is involved in behavioral and physiological responses to fear, and the anxiolytic properties of several drugs are localized to this region. Activation of endogenous opioid systems is known to occur in response to stress and a growing body of literature suggests that opioid systems regulate the properties of anxiolytic drugs. These experiments sought to elucidate the role of opioid receptors in the central (CeA) and basolateral (BLA) nuclei of the amygdala in regulating the anxiolytic properties of ethanol and diazepam. Male rats fitted with cannula received bilateral microinjections of the non-selective opioid receptor antagonist naltrexone (NAL) immediately followed by systemic delivery of either ethanol (1 g/kg) or diazepam (2 mg/kg) in the elevated plus maze. Both diazepam and ethanol decreased anxiety-like behavior. Delivery of NAL into the CeA blocked the anxiolytic properties of diazepam. Delivery of NAL into the BLA slightly increased open arm avoidance, but had no effect on the anxiolytic properties of diazepam. Microinjection of NAL into either nucleus failed to block the effects of ethanol. These results were specific to the anxiolytic properties of diazepam, since baseline behaviors were unaffected by microinjection of naltrexone. Microinjection of lidocaine produced results distinct from NAL and failed to block the anxiolytic actions of diazepam. These studies indicate distinct roles for opioid receptor systems in the CeA and BLA in regulating the anxiolytic properties of diazepam in the elevated plus maze. Further, opioid receptor systems in the CeA and BLA do not regulate the anxiolytic properties of ethanol in this test. PMID:16123750

  13. Task 3: PNNL Visit by JAEA Researchers to Participate in TODAM Code Applications to Fukushima Rivers and to Evaluate the Feasibility of Adaptation of FLESCOT Code to Simulate Radionuclide Transport in the Pacific Ocean Coastal Water Around Fukushima

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, Yasuo

    2013-03-29

    Four JAEA researchers visited PNNL for two weeks in February, 2013 to learn the PNNL-developed, unsteady, one-dimensional, river model, TODAM and the PNNL-developed, time-dependent, three dimensional, coastal water model, FLESCOT. These codes predict sediment and contaminant concentrations by accounting sediment-radionuclide interactions, e.g., adsorption/desorption and transport-deposition-resuspension of sediment-sorbed radionuclides. The objective of the river and coastal water modeling is to simulate • 134Cs and 137Cs migration in Fukushima rivers and the coastal water, and • their accumulation in the river and ocean bed along the Fukushima coast. Forecasting the future cesium behavior in the river and coastal water under various scenarios would enable JAEA to assess the effectiveness of various on-land remediation activities and if required, possible river and coastal water clean-up operations to reduce the contamination of the river and coastal water, agricultural products, fish and other aquatic biota. PNNL presented the following during the JAEA visit to PNNL: • TODAM and FLESCOT’s theories and mathematical formulations • TODAM and FLESCOT model structures • Past TODAM and FLESCOT applications • Demonstrating these two codes' capabilities by applying them to simple hypothetical river and coastal water cases. • Initial application of TODAM to the Ukedo River in Fukushima and JAEA researchers' participation in its modeling. PNNL also presented the relevant topics relevant to Fukushima environmental assessment and remediation, including • PNNL molecular modeling and EMSL computer facilities • Cesium adsorption/desorption characteristics • Experiences of connecting molecular science research results to macro model applications to the environment • EMSL tour • Hanford Site road tour. PNNL and JAEA also developed future course of actions for joint research projects on the Fukushima environmental and remediation assessments.

  14. High-sucrose diets in male rats disrupt aspects of decision making tasks, motivation and spatial memory, but not impulsivity measured by operant delay-discounting.

    Science.gov (United States)

    Wong, Alanna; Dogra, Vimi R; Reichelt, Amy C

    2017-06-01

    Excessive consumption of sugar sweetened drinks is proposed to produce functional changes in the hippocampus and prefrontal cortex, leading to perturbations in behavioural control. Impairments in behavioural control have been observed in obese people on tasks that involve making choices, including delay-discounting, indicative of increased impulsivity. In this study we examined the impact of 2h daily access to 10% sucrose (or no sucrose in controls) in young male rats on behavioural tasks reliant on hippocampal function including delay-discounting, T-maze forced choice alternation and place recognition memory, as well as progressive ratio to measure motivation. We observed deficits in place recognition memory and T-maze forced choice alternation, indicative of hippocampal deficits in rats with a history of sucrose consumption. Moreover, rats with a history of sucrose consumption were less motivated to lever press for rewards on a progressive ratio schedule. However, rats with a history of sucrose consumption performed equally to control animals during the delay-discounting task, suggesting that they discounted for reward size over a delay in a manner comparable to control animals. These findings indicate that high-sucrose diets impact on spatial and working memory processes, but do not induce impulsive-like choice behaviours in rats, suggesting that unhealthy diet choices may not influence this aspect of decision-making behaviour. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Sleep deprivation and time-on-task performance decrement in the rat psychomotor vigilance task.

    Science.gov (United States)

    Oonk, Marcella; Davis, Christopher J; Krueger, James M; Wisor, Jonathan P; Van Dongen, Hans P A

    2015-03-01

    The rat psychomotor vigilance task (rPVT) was developed as a rodent analog of the human psychomotor vigilance task (hPVT). We examined whether rPVT performance displays time-on-task effects similar to those observed on the hPVT. The rPVT requires rats to respond to a randomly presented light stimulus to obtain a water reward. Rats were water deprived for 22 h prior to each 30-min rPVT session to motivate performance. We analyzed rPVT performance over time on task and as a function of the response-stimulus interval, at baseline and after sleep deprivation. The study was conducted in an academic research vivarium. Male Long-Evans rats were trained to respond to a 0.5 sec stimulus light within 3 sec of stimulus onset. Complete data were available for n = 20 rats. Rats performed the rPVT for 30 min at baseline and after 24 h total sleep deprivation by gentle handling. Compared to baseline, sleep deprived rats displayed increased performance lapses and premature responses, similar to hPVT lapses of attention and false starts. However, in contrast to hPVT performance, the time-on-task performance decrement was not significantly enhanced by sleep deprivation. Moreover, following sleep deprivation, rPVT response times were not consistently increased after short response-stimulus intervals. The rPVT manifests similarities to the hPVT in global performance outcomes, but not in post-sleep deprivation effects of time on task and response-stimulus interval. © 2015 Associated Professional Sleep Societies, LLC.

  16. Illinois task force on global climate change

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, B.S. [Illinois Dept. of Natural Resources, Springfield, IL (United States)

    1996-12-31

    The purpose of this report is to document progress in the areas of national policy development, emissions reduction, research and education, and adaptation, and to identify specific actions that will be undertaken to implement the Illinois state action plan. The task force has been tracking national and international climate change policy, and helping shape national policy agenda. Identification and implementation of cost-effective mitigation measures has been performed for emissions reduction. In the area of research and education, the task force is developing the capacity to measure climate change indicators, maintaining and enhancing Illinois relevant research, and strengthening climate change education. Activities relevant to adaptation to new policy include strengthening water laws and planning for adaptation. 6 figs., 4 tabs.

  17. Correlates of academic procrastination: discomfort, task aversiveness, and task capability.

    Science.gov (United States)

    Milgram, N; Marshevsky, S; Sadeh, C

    1995-03-01

    The relationships among five aspects of academic procrastination--behavioral delay, personal upset about the delay, task aversiveness, task capability, and the desire to reduce behavioral delay--were investigated in 10th-grade Israeli students (N = 195). Upset about delay was weakly related to delay itself, and--unlike delay--was strongly related to perceived capability to perform academic tasks and to the desire to change delaying behavior. Students delayed more on academic tasks labeled unpleasant than pleasant, were neutral in between, and were correspondingly more upset about the former than the latter. They more frequently acknowledged reasons for academic procrastination that were less threatening to their self-image (e.g., problems in time management) than reasons that were more threatening (e.g., lack of ability). Interest in reducing delay is related more to self-perceived ability to handle tasks than to time spent procrastinating or reasons given for procrastinating.

  18. Does Student Proficiency on Local Reading Assessment Measures Align with State Mandated Reading Proficiency Standards? An Investigation of the Relationship between the Developmental Reading Assessment, Reading Curriculum Based Measurement, and Maze, with the New York State English Language Arts Exam

    Science.gov (United States)

    Weschler, Michael J.

    2016-01-01

    Data from three reading assessment tools--the Developmental Reading Assessment (DRA), Reading Curriculum Based Measurement (R-CBM), and Maze--were compiled from 61 fourth grade and 59 fifth grade students across Fall and Spring administrations in order to determine how proficiency on these measures was associated with proficiency on the New York…

  19. THE USE OF THE ELEVATED PLUS MAZE IN THE TOXICOLOGY LABORAOTRY: PILOT STUDIES AND ASSESSMENT OF ANXIETY IN RATS EXPOSED TO LEAD ACETATE OR SUB-CHRONIC LEVELS OF TOLUENE.

    Science.gov (United States)

    A common complaint of individuals exposed to neurotoxic agents is increased anxiety. Rat models of the effects of long-term exposure to environmental chemicals on anxiety are lacking. The elevated plus-maze (EPM) is a widely used tool in the search for new

  20. Cosmetology Series. Duty Task List.

    Science.gov (United States)

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains the occupational duty/task lists for three occupations in the cosmetology series. Each occupation is divided into a number of duties. A separate page for each duty in the occupation lists the tasks in that duty along with its code number and columns to indicate whether that particular duty has been taught and to provide…

  1. The task of landscape ecology

    NARCIS (Netherlands)

    Barendregt, A.; Jongman, R.H.G.; Smidt, de J.; Wassen, M.

    2007-01-01

    This final chapter is a personal reflection of the authors on this book. To find an answer to the question what the task is of landscape ecology, we split the question in two parts. The first past of the question is about science for society: what is the task of landscape ecology in a changing

  2. Human-System task integration

    NARCIS (Netherlands)

    Schraagen, J.M.C.

    2005-01-01

    The Dutch Ministry of Defence research programme Human-System Task Integration aims at acquiring knowledge for the optimal cooperation between human and computer, under the following constraints: freedom of choice in decisions to automate and multiple, dynamic task distributions. This paper

  3. Science 102: This Month's Task

    Science.gov (United States)

    Robertson, Bill

    2015-01-01

    This task asks readers to figure out why when you stir a cup of hot liquid and tap on the side of the cup with a spoon, the pitch of sound starts low and ends up high. The solution to last month's tasks relating to the circumference of the Earth and how many stars are in the (visible) sky is also presented.

  4. Caffeine improves anticipatory processes in task switching

    NARCIS (Netherlands)

    Tieges, Zoe; Snel, Jan; Kok, Albert; Wijnen, Jasper G.; Lorist, Monicque M.; Ridderinkhof, K. Richard

    We studied the effects of moderate amounts of caffeine on task switching and task maintenance using mixed-task (AABB) blocks, in which participants alternated predictably between two tasks, and single-task (AAAA, BBBB) blocks. Switch costs refer to longer reaction times (RT) on task switch trials

  5. Functional connectivity among spike trains in neural assemblies during rat working memory task.

    Science.gov (United States)

    Xie, Jiacun; Bai, Wenwen; Liu, Tiaotiao; Tian, Xin

    2014-11-01

    Working memory refers to a brain system that provides temporary storage to manipulate information for complex cognitive tasks. As the brain is a more complex, dynamic and interwoven network of connections and interactions, the questions raised here: how to investigate the mechanism of working memory from the view of functional connectivity in brain network? How to present most characteristic features of functional connectivity in a low-dimensional network? To address these questions, we recorded the spike trains in prefrontal cortex with multi-electrodes when rats performed a working memory task in Y-maze. The functional connectivity matrix among spike trains was calculated via maximum likelihood estimation (MLE). The average connectivity value Cc, mean of the matrix, was calculated and used to describe connectivity strength quantitatively. The spike network was constructed by the functional connectivity matrix. The information transfer efficiency Eglob was calculated and used to present the features of the network. In order to establish a low-dimensional spike network, the active neurons with higher firing rates than average rate were selected based on sparse coding. The results show that the connectivity Cc and the network transfer efficiency Eglob vaired with time during the task. The maximum values of Cc and Eglob were prior to the working memory behavior reference point. Comparing with the results in the original network, the feature network could present more characteristic features of functional connectivity. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Configuration space as a means for augmenting human performance in teleoperation tasks.

    Science.gov (United States)

    Ivanisevic, I; Lumelsky, V J

    2000-01-01

    This paper considers an approach to operator-guided real time motion control of robot arm manipulators that's based on the use of configuration space (C-space). The goal is to improve operator performance in a complex environment with obstacles, In such tasks, traditional teleoperation techniques, which are all based on control in work space (W-space), suffer from human errors tied to deficiencies in human spatial reasoning. The C-space approach transforms the problem into one humans are much better equipped to handle-moving a point in a maze-and results in a significant improvement in performance: shorter path, less time to complete the task, and virtually no arm-obstacle collisions. Versions of the approach are described for two-dimensional (2-D) and three-dimensional (3-D) tasks, and tools are developed to efficiently interface the human and machine intelligence. Effectiveness of the C-space approach is demonstrated by a series of experiments, showing an improvement in performance on the order of magnitude in the 2-D case and a factor of two to four in the 3-D case, compared to usual work space control.

  7. Effects of developmental exposure to manganese and/or low iron diet: Changes to metal transporters, sucrose preference, elevated zero-maze, open-field, and locomotion in response to fenfluramine, amphetamine, and MK-801

    Directory of Open Access Journals (Sweden)

    Robyn M. Amos-Kroohs

    2015-01-01

    Full Text Available Manganese overexposure (MnOE can be neurotoxic. In humans this can occur through occupational exposure, air or water contamination, well water, soy milk, and some baby formulas. In children MnOE has been associated with cognitive and behavioral deficits. The effects of MnOE may be modified by factors such as iron status. We hypothesized that developmental MnOE would be exacerbated by iron deficiency. A diet with a 90% decrease in iron (FeD was given to gravid female rats starting on embryonic day 15 and continued through postnatal day (P 28. Mn (100 mg/kg or vehicle (VEH was administered by gavage every other day from P4-28. Metal transporters and receptors (divalent metal transporter-1 (DMT1, transferrin (Tf, transferrin receptor (TfR, and Zrt-Irt-like protein 8 (ZIP8 were quantified in brain at P28. These markers were increased but the changes were specific: MnOE increased TfR and decreased Tf in hippocampus, whereas FeD increased TfR in neostriatum and increased TfR and DMT1 in the hippocampus, and the combination increased TfR in neostriatum (ZIP8 was unaffected. Identically treated animals were tested behaviorally at P29 or P60. The combination of FeD + MnOE increased head dips in an elevated zero-maze, reversed deficits in sucrose preference induced by MnOE alone, and increased spontaneous locomotion in an open-field. Rats were also evaluated for changes in locomotor activity after challenge with (±-fenfluramine (FEN, a 5-HT agonist: 5 mg/kg, MK-801 (MK801, an NMDA antagonist: 0.2 mg/kg, or (+-amphetamine (AMPH, a dopamine agonist: 1 mg/kg. Compared with VEH animals, MnOE animals were more hyperactive after amphetamine or MK-801, and were less inhibited after fenfluramine, regardless of FeD exposure. The results indicate persistent effects of developmental MnOE on brain and behavior but few interactions with dietary iron deficiency.

  8. EFFORTS Sub-task report on task 4.1: Experimental Techniques

    DEFF Research Database (Denmark)

    Andreasen, Jan Lasson; Bay, Niels

    1998-01-01

    Task 4.1 is a sub-task of task 4: Physical modelling validation. In sub-task 4.1 the existing experimental techniques has been conditioned to the tasks ahead in physical modelling.......Task 4.1 is a sub-task of task 4: Physical modelling validation. In sub-task 4.1 the existing experimental techniques has been conditioned to the tasks ahead in physical modelling....

  9. Engineering and Development Support of General Decon Technology for the U.S. Army’s Installation Restoration Program. Task 1. Literature Review on Ground Water Containment and Diversion Barriers.

    Science.gov (United States)

    1982-04-01

    cutoff walls require no maintenance after installation. Protective coatings or sacrificial anodes can be applied to the finished piling to help resist...viscosity slurry (Xanthakos, 1979). Calcium salts at concentrations greater than 100 mg/l (Xanthakos, 1979) interfere with the hydration by replacing...sodium bentonite with calcium bentonite which does not swell (Hughes, 1976). According to Xanthakos (1979), water mixed with bentonite should be

  10. Computer-Related Task Performance

    DEFF Research Database (Denmark)

    Longstreet, Phil; Xiao, Xiao; Sarker, Saonee

    2016-01-01

    The existing information system (IS) literature has acknowledged computer self-efficacy (CSE) as an important factor contributing to enhancements in computer-related task performance. However, the empirical results of CSE on performance have not always been consistent, and increasing an individual......'s CSE is often a cumbersome process. Thus, we introduce the theoretical concept of self-prophecy (SP) and examine how this social influence strategy can be used to improve computer-related task performance. Two experiments are conducted to examine the influence of SP on task performance. Results show...

  11. Employee involvement, technology and job tasks

    OpenAIRE

    Green, Francis

    2009-01-01

    Using new job requirements data for Britain I show that there has been a rise in various forms of communication tasks: influencing and literacy tasks have grown especially fast, as have self-planning tasks. External communication tasks, and numerical tasks have also become more important, but physical tasks have largely remained unchanged. Although the classification of tasks as programmable or otherwise is found to be problematic, computer use accounts for much of the changed use of generic ...

  12. The effect of rat strain and stress exposure on performance in touchscreen tasks.

    Science.gov (United States)

    Martis, Lena-Sophie; Krog, Simone; Tran, Thao Phuong; Bouzinova, Elena; Christiansen, Sofie L; Møller, Arne; Holmes, Megan C; Wiborg, Ove

    2018-02-01

    Patients suffering from depression-associated cognitive impairments often recover incompletely after remission from the core symptoms of depression (lack of energy, depressed mood and anhedonia). This study aimed to set the basis for clinically relevant testing of cognitive impairments in a preclinical model of depression. Hence, we used the chronic mild stress (CMS) model of depression, which provokes the core symptom of anhedonia in a fraction of the stress exposed animals, while others remain resilient, and assessed the entire CMS groups' cognitive performance on the touchscreen operant platform. Specifically, we applied the pairwise discrimination (PD) and reversal task including a retention phase on Wistar and Long Evans controls and CMS exposed Long Evans rats. We observed differences between the albino Wistar and the pigmented Long Evans strain regarding performance in the PD and reversal task as well as in memory consolidation. CMS exposure did not alter learning and memory in the PD and reversal task, even though it altered affective behaviours in the elevated plus-maze and open field test. This is likely due to the heterogeneity of the CMS group, in which stress exposure elicited the expected range of phenotypes from anhedonic-like to resilient shown with the sucrose consumption test. Thus, our study suggests that pigmented rat strains, such as Long Evans, are superior to albino rats in the vision-based touchscreen studies. Furthermore, we propose investigation of the CMS subgroups in more complex, hippocampus-dependent tasks to refine a translational preclinical model of depression-induced cognitive impairments. Hence, this study increased awareness of strain-specific differences in touchscreen performance and added to the literature regarding the sensitivity of the PD and reversal task to stress-induced cognitive alterations. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Dynamic trajectory of multiple single-unit activity during working memory task in rats.

    Science.gov (United States)

    Zhang, Xiaofan; Yi, Hu; Bai, Wenwen; Tian, Xin

    2015-01-01

    Working memory plays an important role in complex cognitive tasks. A popular theoretical view is that transient properties of neuronal dynamics underlie cognitive processing. The question raised here as to how the transient dynamics evolve in working memory. To address this issue, we investigated the multiple single-unit activity dynamics in rat medial prefrontal cortex (mPFC) during a Y-maze working memory task. The approach worked by reconstructing state space from delays of the original single-unit firing rate variables, which were further analyzed using kernel principal component analysis (KPCA). Then the neural trajectories were obtained to visualize the multiple single-unit activity. Furthermore, the maximal Lyapunov exponent (MLE) was calculated to quantitatively evaluate the neural trajectories during the working memory task. The results showed that the neuronal activity produced stable and reproducible neural trajectories in the correct trials while showed irregular trajectories in the incorrect trials, which may establish a link between the neurocognitive process and behavioral performance in working memory. The MLEs significantly increased during working memory in the correctly performed trials, indicating an increased divergence of the neural trajectories. In the incorrect trials, the MLEs were nearly zero and remained unchanged during the task. Taken together, the trial-specific neural trajectory provides an effective way to track the instantaneous state of the neuronal population during the working memory task and offers valuable insights into working memory function. The MLE describes the changes of neural dynamics in working memory and may reflect different neuronal population states in working memory.

  14. Analysis of proposed eco-design requirements for boilers and water heaters. Paper within the framwork of the ''Material Efficiency and Resource Conservation'' (MaRess) Project - Task 14

    Energy Technology Data Exchange (ETDEWEB)

    Barthel, Klaus; Franke, Moritz [Wuppertal Institute for Climate, Environment and Energy, Wuppertal (Germany)

    2009-12-15

    In 2005, the European Union released the EuP Directive focusing on ecodesign requirements for energy-using products (2005/32/EC: EU Parliament and Council of the EU 2005). This directive, also called Ecodesign Directive, is a framework directive establishing a structure in which so-called implementing measures define specific requirements for placing products on the market and/or putting them into service within the internal European market. These requirements can be environmental performance standards (e.g. minimum energy efficiency or emission standards) and labelling or information requirements. Some existing European directives are already declared as being implementing measures of the Ecodesign Directive. Additionally, new implementing measures have been and will further be developed. Product-specific preparatory studies on behalf of the European Commission provide the basis for this. The preparatory studies for boilers (Lot 1) and water heaters (Lot 2) have been conducted from February 2006 to October 2007 by Van Holsteijn en Kemna (VHK). Based on the preparatory studies, the EU Commission has released several working documents (WD) on possible ecodesign requirements for boilers and water heaters at the beginning of 2008. Following these documents, boilers and water heaters comprise gas-fired, oil-fired and electric central heating (CH) (combi-) boilers / dedicated water heaters in combination with capturing solar thermal energy or ambient heat1. The requirements contain basically energy labelling measures, minimum efficiency performance standards and limits on NOx emissions. An ''Ecoboiler Model'' resp. an ''Eco Hot Water Model'' has been elaborated within the preparatory studies. These models are a crucial part of the requirements and allow for calculation of the efficiencies of boilers and water heaters. Since the models have a high degree of complexity, the Federal Environment Agency (UBA) has asked Wuppertal

  15. Naval Postgraduate School Support Task

    National Research Council Canada - National Science Library

    2000-01-01

    The purpose of this task was to provide lecturing and curriculum development support, as needed, to the Naval Postgraduate School's Physics Department/Weapons Curriculum in the area of High Energy Laser systems...

  16. Vocabulary Maintenance Task Group Report

    OpenAIRE

    Baskauf, Steve

    2016-01-01

    This was a presentation at the TDWG Annual Meeting in Costa Rica, 2016-12-08 in a Task Group report session.  Abstract: The Vocabulary Maintenance Task Group has completed drafts of a Standards Documentation Specification and a Vocabulary Management Specification (https://github.com/tdwg/vocab). This session will outline the important aspects of the specifications and answer questions about their content and implementation.

  17. Annual Progress report - General Task

    Energy Technology Data Exchange (ETDEWEB)

    Wesnousky, S.G.

    1993-09-30

    This report provides a summary of progress for the project {open_quotes}Evaluation of the Geologic Relations and Seismotectonic Stability of the Yucca Mountain Area, Nevada Nuclear Waste Site Investigation (NNWSI).{close_quotes} A similar report was previously provided for the period of 1 October 1991 to 30 September 1992. The report initially covers the activities of the General Task and is followed by sections that describe the progress of the other ongoing tasks.

  18. [Effects of piracetam and meclofenoxate on the brain NMDA and nicotinic receptors in mice with different exploratory efficacy in the cross maze test].

    Science.gov (United States)

    Kovalev, G I; Firstova, Iu Iu; Salimov, R M

    2008-01-01

    A population of outbred mice of the ICR strain was divided into two subpopulations according to their high (EH mice) or low (EL mice) exploratory efficacy in the closed cross maze test. In addition, the EH and EL mice differed in the number of binding sites of (i) [G-3H]-MK-801 with NMDA receptors from hippocampus and (ii) [G-3H]-nicotine with nicotine cholinoreceptors (nACh) from neocortex. A subchronic administration of the cognition enhancer piracetam (200 mg/kg, once per day for 5 days) increased by 70% the number of binding sites of NMDA receptors in the EL mice. At the same time, this treatment decreased the density of neocortical nACh receptors in both EL and EH mice (by 55% and 40%, respectively). A subchronic administration of the cognition enhancer and anti-oxidant meclofenoxate (100 mg/kg, once per day for 5 days) also decreased the density of neocortical nACh receptors in both EL and EH mice (by 48% and 20%, respectively). However, meclofenoxate also increased by 41% the number of binding sites of NMDA receptors in the EH mice.

  19. Redintegration, task difficulty, and immediate serial recall tasks.

    Science.gov (United States)

    Ritchie, Gabrielle; Tolan, Georgina Anne; Tehan, Gerald

    2015-03-01

    While current theoretical models remain somewhat inconclusive in their explanation of short-term memory (STM), many theories suggest at least a contribution of long-term memory (LTM) to the short-term system. A number of researchers refer to this process as redintegration (e.g., Schweickert, 1993). Under short-term recall conditions, the current study investigated the effects of redintegration and task difficulty in order to extend research conducted by Neale and Tehan (2007). Thirty participants in Experiment 1 and 26 participants in Experiment 2 completed a serial recall task in which retention interval, presentation rate, and articulatory suppression were used to modify task difficulty. Redintegration was examined by manipulating the characteristics of the to-be-remembered items; lexicality in Experiment 1 and wordlikeness in Experiment 2. Responses were scored based on correct-in-position recall, item scoring, and order accuracy scoring. In line with the Neale and Tehan results, as the difficulty of the task increased so did the effects of redintegration. This was evident in that the advantage for words in Experiment 1 and wordlikeness in Experiment 2 decreased as task difficulty increased. This relationship was observed for item but not order memory, and findings were discussed in relation to the theory of redintegration. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

  20. China's water scarcity.

    Science.gov (United States)

    Jiang, Yong

    2009-08-01

    China has been facing increasingly severe water scarcity, especially in the northern part of the country. China's water scarcity is characterized by insufficient local water resources as well as reduced water quality due to increasing pollution, both of which have caused serious impacts on society and the environment. Three factors contribute to China's water scarcity: uneven spatial distribution of water resources; rapid economic development and urbanization with a large and growing population; and poor water resource management. While it is nearly impossible to adjust the first two factors, improving water resource management represents a cost-effective option that can alleviate China's vulnerability to the issue. Improving water resource management is a long-term task requiring a holistic approach with constant effort. Water right institutions, market-based approaches, and capacity building should be the government's top priority to address the water scarcity issue.

  1. Decreases in rat extracellular hippocampal glucose concentration associated with cognitive demand during a spatial task

    OpenAIRE

    McNay, Ewan C.; Fries, Thomas M.; Gold, Paul E.

    2000-01-01

    Using in vivo microdialysis, we measured hippocampal extracellular glucose concentrations in rats while they performed spontaneous alternation tests of spatial working memory in one of two mazes. Extracellular glucose levels in the hippocampus decreased by 32% below baseline during the test period on the more complex maze, but by a maximum of 11% on the less complex maze. Comparable decreases were not observed in samples taken from rats tested on the more complex m...

  2. Novice supervisors' tasks and training

    DEFF Research Database (Denmark)

    Nielsen, Jan; Jacobsen, Claus Haugaard; Mathiesen, Birgit Bork

    2012-01-01

    The debut as a clinical supervisor is still rather unknown. The aim of this study is to explore what kind of tasks novice supervisors undertake and how they are prepared for these. During 2009–2010, 350 Danish clinical psychologists have responded to the Development of Psychotherapists Common Core...... Questionnaire covering a wide range of items on professional development, experience, and practice. In this paper we focus on background data (experience, training and practice), specifically the tasks and training of the respondents as novice supervisors. The results show, that a majority of novice supervisors...... were confronted with complicated jobs, e.g., group, internal and interdisciplinary supervision, but were not prepared, i.e. trained, prior to these tasks. These findings imply that more training is needed for novice supervisors. Preferably, this training should be introduced before, or at least...

  3. A Task Taxonomy for Temporal Graph Visualisation.

    Science.gov (United States)

    Kerracher, Natalie; Kennedy, Jessie; Chalmers, Kevin

    2015-10-01

    By extending and instantiating an existing formal task framework, we define a task taxonomy and task design space for temporal graph visualisation. We discuss the process involved in their generation, and describe how the design space can be 'sliced and diced' into multiple overlapping task categories, requiring distinct visual techniques for their support. The approach addresses deficiencies in the task literature, offering domain independence, greater task coverage, and unambiguous task specification. The taxonomy and design space capture tasks for temporal graphs, and also static graphs, multivariate graphs, and graph comparison, and will be of value in the design and evaluation of temporal graph visualisation systems.

  4. Task Content Familiarity, Task Type and Efficacy of Recasts

    Science.gov (United States)

    Revesz, Andrea; Han, ZhaoHong

    2006-01-01

    The role of recasts has been the subject of an increasing number of second language acquisition (SLA) studies in recent years, as has been the role of tasks. Few studies, nevertheless, exist that investigate the interaction between the two. The present study makes a preliminary excursion into this unexplored domain by examining the impact of two…

  5. Canonical correlation between LFP network and spike network during working memory task in rat.

    Science.gov (United States)

    Yi, Hu; Zhang, Xiaofan; Bai, Wenwen; Liu, Tiaotiao; Tian, Xin

    2015-08-01

    Working memory refers to a system to temporary holding and manipulation of information. Previous studies suggested that local field potentials (LFPs) and spikes as well as their coordination provide potential mechanism of working memory. Popular methods for LFP-spike coordination only focus on the two modality signals, isolating each channel from multi-channel data, ignoring the entirety of the networked brain. Therefore, we investigated the coordination between the LFP network and spike network to achieve a better understanding of working memory. Multi-channel LFPs and spikes were simultaneously recorded in rat prefrontal cortex via microelectrode array during a Y-maze working memory task. Functional connectivity in the LFP network and spike network was respectively estimated by the directed transfer function (DTF) and maximum likelihood estimation (MLE). Then the coordination between the two networks was quantified via canonical correlation analysis (CCA). The results show that the canonical correlation (CC) varied during the working memory task. The CC-curve peaked before the choice point, describing the coordination between LFP network and spike network enhanced greatly. The CC value in working memory showed a significant higher level than inter-trial interval. Our results indicate that the enhanced canonical correlation between the LFP network and spike network may provide a potential network integration mechanism for working memory. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. The effect of rat strain and stress exposure on performance in touchscreen tasks

    DEFF Research Database (Denmark)

    Martis, Lena-Sophie; Tran, Thao Phuong; Bouzinova, Elena

    2017-01-01

    Patients suffering from depression-associated cognitive impairments often recover incompletely after remission from the core symptoms of depression (lack of energy, depressed mood and anhedonia). This study aimed to set the basis for clinically relevant testing of cognitive impairments in a precl......Patients suffering from depression-associated cognitive impairments often recover incompletely after remission from the core symptoms of depression (lack of energy, depressed mood and anhedonia). This study aimed to set the basis for clinically relevant testing of cognitive impairments...... in a preclinical model of depression. Hence, we used the chronic mild stress (CMS) model of depression, which provokes the core symptom of anhedonia in a fraction of the stress exposed animals, while others remain resilient, and assessed the entire CMS groups' cognitive performance on the touchscreen operant...... and reversal task as well as in memory consolidation. CMS exposure did not alter learning and memory in the PD and reversal task, even though it altered affective behaviours in the elevated plus-maze and open field test. This is likely due to the heterogeneity of the CMS group, in which stress exposure...

  7. Estrogen enhances the retention of spatial reference memory in the open field tower task, but disrupts the expression of spatial memory following a novel start position.

    Science.gov (United States)

    Lipatova, Olga; Toufexis, Donna J

    2013-01-01

    Estrogen's (E) involvement in cognition has been difficult to characterize; numerous studies show that E can both enhance and impair learning and memory. One difficulty may be that experimental paradigms often examine only a single aspect of E's involvement in cognition, for example, the role E plays in the expression of memory after learning has taken place. In addition, the effect of aversive and/or stressful features inherent to many cognitive tests may contribute to the contradictory findings. The present experiment aims to examine the effect of estradiol (E2) on several elements of cognition in a specific experimental setting. We investigated the within-subject effects of long-term E2 replacement in ovariectomized (OVX) female rats on the acquisition and retention of a hippocampal-mediated spatial reference memory task in a familiar non-threatening environment. Results show that E2-replaced rats and OVX sham-replaced rats acquired the ability to navigate an open-field tower maze in order to obtain a food reward at the same rate. Subsequent to acquisition, both E2-replaced and OVX rats performed the task at comparable levels. However, following a 21-day retention interval, non-replaced rats exhibited a significant impairment in spatial memory when returned to the maze environment, while E2-replaced rats exhibited no change in maze performance. When the OVX group was performing once again at asymptote, test trials were administered during which the rats were placed in a non-experienced start location within the maze. This novel condition significantly reduced correct responses in E2-replaced females whereas OVX controls remained unaffected. These results suggest that while the presence of E2 is not important for acquisition of spatial memory in a safe familiar environment, it improves retention of spatial memory. Data further suggests that E2 disrupts the expression of spatial reference memory following an alteration of the test conditions sustaining a habitual

  8. IEA Wind Task 36 Forecasting

    Science.gov (United States)

    Giebel, Gregor; Cline, Joel; Frank, Helmut; Shaw, Will; Pinson, Pierre; Hodge, Bri-Mathias; Kariniotakis, Georges; Sempreviva, Anna Maria; Draxl, Caroline

    2017-04-01

    Wind power forecasts have been used operatively for over 20 years. Despite this fact, there are still several possibilities to improve the forecasts, both from the weather prediction side and from the usage of the forecasts. The new International Energy Agency (IEA) Task on Wind Power Forecasting tries to organise international collaboration, among national weather centres with an interest and/or large projects on wind forecast improvements (NOAA, DWD, UK MetOffice, …) and operational forecaster and forecast users. The Task is divided in three work packages: Firstly, a collaboration on the improvement of the scientific basis for the wind predictions themselves. This includes numerical weather prediction model physics, but also widely distributed information on accessible datasets for verification. Secondly, we will be aiming at an international pre-standard (an IEA Recommended Practice) on benchmarking and comparing wind power forecasts, including probabilistic forecasts aiming at industry and forecasters alike. This WP will also organise benchmarks, in cooperation with the IEA Task WakeBench. Thirdly, we will be engaging end users aiming at dissemination of the best practice in the usage of wind power predictions, especially probabilistic ones. The Operating Agent is Gregor Giebel of DTU, Co-Operating Agent is Joel Cline of the US Department of Energy. Collaboration in the task is solicited from everyone interested in the forecasting business. We will collaborate with IEA Task 31 Wakebench, which developed the Windbench benchmarking platform, which this task will use for forecasting benchmarks. The task runs for three years, 2016-2018. Main deliverables are an up-to-date list of current projects and main project results, including datasets which can be used by researchers around the world to improve their own models, an IEA Recommended Practice on performance evaluation of probabilistic forecasts, a position paper regarding the use of probabilistic forecasts

  9. Critical neuropsychobiological analysis of panic attack- and anticipatory anxiety-like behaviors in rodents confronted with snakes in polygonal arenas and complex labyrinths: a comparison to the elevated plus- and T-maze behavioral tests.

    Science.gov (United States)

    Coimbra, Norberto C; Paschoalin-Maurin, Tatiana; Bassi, Gabriel S; Kanashiro, Alexandre; Biagioni, Audrey F; Felippotti, Tatiana T; Elias-Filho, Daoud H; Mendes-Gomes, Joyce; Cysne-Coimbra, Jade P; Almada, Rafael C; Lobão-Soares, Bruno

    2017-01-01

    To compare prey and snake paradigms performed in complex environments to the elevated plus-maze (EPM) and T-maze (ETM) tests for the study of panic attack- and anticipatory anxiety-like behaviors in rodents. PubMed was reviewed in search of articles focusing on the plus maze test, EPM, and ETM, as well as on defensive behaviors displayed by threatened rodents. In addition, the authors' research with polygonal arenas and complex labyrinth (designed by the first author for confrontation between snakes and small rodents) was examined. The EPM and ETM tests evoke anxiety/fear-related defensive responses that are pharmacologically validated, whereas the confrontation between rodents and snakes in polygonal arenas with or without shelters or in the complex labyrinth offers ethological conditions for studying more complex defensive behaviors and the effects of anxiolytic and panicolytic drugs. Prey vs. predator paradigms also allow discrimination between non-oriented and oriented escape behavior. Both EPM and ETM simple labyrinths are excellent apparatuses for the study of anxiety- and instinctive fear-related responses, respectively. The confrontation between rodents and snakes in polygonal arenas, however, offers a more ethological environment for addressing both unconditioned and conditioned fear-induced behaviors and the effects of anxiolytic and panicolytic drugs.

  10. Effect of cannabidiol on sleep disruption induced by the repeated combination tests consisting of open field and elevated plus-maze in rats.

    Science.gov (United States)

    Hsiao, Yi-Tse; Yi, Pei-Lu; Li, Chia-Ling; Chang, Fang-Chia

    2012-01-01

    Patients with post-traumatic stress disorder (PTSD) frequently complain of having sleep disturbances, such as insomnia and rapid eye movement (REM) sleep abnormality. Cannabidiol (CBD), a psycho-inactive constituent of marijuana, reduces physiological non-REM (NREM) sleep and REM sleep in normal rats, in addition to generating its anxiolytic effect. However, the effects of CBD on anxiety-induced sleep disturbances remain unclear. Because anxiety progression is caused by persistent stress for a period of time, we employed the repeated combination tests (RCT) consisting of a 50-min open field (OF) and a subsequent 10-min elevated plus-maze (EPM) for four consecutive days to simulate the development of anxiety. Time spent in the centre arena of OF and during open arms of the EPM was substantially decreased in latter days of RCT, suggesting the habituation, which potentially lessens anxiety-mediated behavioural responses, was not observed in current tests. CBD microinjected into the central nucleus of amygdala (CeA) significantly enhanced time spent in centre arena of OF, increased time during the open arms and decreased frequency of entry to the enclosed arms of EPM, further confirming its anxiolytic effect. The decrease of NREM sleep during the first hour and the suppression of REM sleep during hours 4-10 after the RCT represent the similar clinical observations (e.g. insomnia and REM sleep interruption) in PTSD patients. CBD efficiently blocked anxiety-induced REM sleep suppression, but had little effect on the alteration of NREM sleep. Conclusively, CBD may block anxiety-induced REM sleep alteration via its anxiolytic effect, rather than via sleep regulation per se. This article is part of a Special Issue entitled 'Anxiety and Depression'. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Anxiolytic effects of repeated treatment with an essential oil from Lippia alba and (R)-(-)-carvone in the elevated T-maze

    Energy Technology Data Exchange (ETDEWEB)

    Hatano, V.Y.; Torricelli, A.S. [Departamento de Biociências, Universidade Federal de São Paulo, Santos, SP (Brazil); Giassi, A.C.C. [Cellular and Molecular Medicine, University of Ottawa, Ottawa (Canada); Coslope, L.A. [Parque Nacional da Chapada Diamantina, Chapada Diamantina, BA (Brazil); Viana, M.B. [Departamento de Biociências, Universidade Federal de São Paulo, Santos, SP (Brazil)

    2012-02-27

    Lippia alba (Mill.) N.E. Brown (Verbenaceae) is widely used in different regions of Central and South America as a tranquilizer. The plant's anxiolytic properties, however, merit investigation. The present study evaluated the effects of repeated daily (14 days) intraperitoneal (ip) treatment with an essential oil (EO) from a chemotype of L. alba (LA, chemotype II, 12.5 and 25 mg/kg; N = 6-8) and (R)-(-)-carvone (25 mg/kg; N = 8-12), the main constituent of this chemotype, on male Wistar rats (weighing 250 g at the beginning of the experiments) submitted to the elevated T-maze (ETM). The ETM allows the measurement of two defensive responses: inhibitory avoidance and one-way escape. In terms of psychopathology, these responses have been related to generalized anxiety and panic disorder, respectively. Treatment with the EO impaired ETM avoidance latencies, without altering escape, in a way similar to the reference drug diazepam (P < 0.05) (avoidance 2: control = 84.6 ± 35.2; EO 12.5 mg/kg = 11.8 ± 3.8; EO 25 mg/kg = 14.6 ± 2.7; diazepam = 7 ± 2.1). (R)-(-)-carvone also significantly altered this same response (P < 0.05; avoidance 1: control = 91.9 ± 31.5; carvone = 11.6 ± 1.8; diazepam = 8.1 ± 3.3). These results were not due to motor changes since no significant effects were detected in an open field. These observations suggest that LA exerts anxiolytic-like effects on a specific subset of defensive behaviors that have been implicated in generalized anxiety disorder, and suggest that carvone is one of the constituents of LA responsible for its action as a tranquilizer.

  12. H1 but not H2 histamine antagonist receptors mediate anxiety-related behaviors and emotional memory deficit in mice subjected to elevated plus-maze testing

    Directory of Open Access Journals (Sweden)

    K.R. Serafim

    2013-05-01

    Full Text Available This study investigated the role of H1 and H2 receptors in anxiety and the retrieval of emotional memory using a Trial 1/Trial 2 (T1/T2 protocol in an elevated plus-maze (EPM. Tests were performed on 2 consecutive days, designated T1 and T2. Before T1, the mice received intraperitoneal injections of saline (SAL, 20 mg/kg zolantidine (ZOL, an H2 receptor antagonist, or 8.0 or 16 mg/kg chlorpheniramine (CPA, an H1 receptor antagonist. After 40 min, they were subjected to the EPM test. In T2 (24 h later, each group was subdivided into two additional groups, and the animals from each group were re-injected with SAL or one of the drugs. In T1, the Student t-test showed no difference between the SAL and ZOL or 8 mg/kg CPA groups with respect to the percentages of open arm entries (%OAE and open arm time (%OAT. However, administration of CPA at the highest dose of 16 mg/kg decreased %OAE and %OAT, but not locomotor activity, indicating anxiogenic-like behavior. Emotional memory, as revealed by a reduction in open arm exploration between the two trials, was observed in all experimental groups, indicating that ZOL and 8 mg/kg CPA did not affect emotional memory, whereas CPA at the highest dose affected acquisition and consolidation, but not retrieval of memory. Taken together, these results suggest that H1 receptor, but not H2, is implicated in anxiety-like behavior and in emotional memory acquisition and consolidation deficits in mice subjected to EPM testing.

  13. The Cox-Maze IV procedure for atrial fibrillation is equally efficacious in patients with rheumatic and degenerative mitral valve disease.

    Science.gov (United States)

    Labin, Jonathan E; Haque, Nowrin; Sinn, Laurie A; Schuessler, Richard B; Moon, Marc R; Maniar, Hersh S; Melby, Spencer J; Damiano, Ralph J

    2017-09-01

    To determine whether the etiology of mitral valve disease (MVD), due to either rheumatic or degenerative pathology, influences long-term outcomes after the Cox-Maze IV procedure (CMPIV). Between February 2001 and July 2015, 245 patients received a CMIV and concomitant mitral valve procedure. Patients were separated into 2 cohorts based on their etiology of MVD, degenerative (n = 153) and rheumatic (n = 92). Patients were followed prospectively (mean follow-up: 41 ± 37 months) for recurrent atrial tachyarrhythmias (ATAs). Perioperative variables and long-term freedom from ATAs on and off antiarrhythmic drugs (AADs) were analyzed retrospectively. The 2 groups differed in that patients with rheumatic MVD were younger, more likely female, had a larger preoperative left atrial diameter, a longer duration of atrial fibrillation (AF), a greater percentage of longstanding persistent AF, and worse New York Heart Association functional class (P ≤ .001). Although there was no difference in operative mortality or overall major complications between the groups, the median length of stay in the intensive care unit was longer in the rheumatic cohort. Freedom from recurrent ATAs through 5 years was similar between the 2 cohorts. Predictors of recurrence included failure to use a box-lesion (P = .012), the duration of preoperative AF (P = .001), and early occurrence of ATAs (P = .015). The long-term efficacy of the CMPIV in restoring sinus rhythm was similar in patients with either rheumatic or degenerative mitral valve disease. Despite representing a sicker patient population with a longer duration of preoperative AF, patients with rheumatic MVD equally benefit from the CMPIV. Copyright © 2017. Published by Elsevier Inc.

  14. A novel heterocyclic compound CE-104 enhances spatial working memory in the radial arm maze in rats and modulates the dopaminergic system

    Directory of Open Access Journals (Sweden)

    Yogesh D Aher

    2016-02-01

    Full Text Available Various psychostimulants targeting monoamine neurotransmitter transporters (MAT have been shown to rescue cognition in patients with neurological disorders and improve cognitive abilities in healthy subjects at low doses. Here, we examined the effects upon cognition of a chemically synthetized novel MAT inhibiting compound 2-(benzhydrylsulfinylmethyl-4-methylthiazole (named as CE-104. The efficacy of CE-104 in blocking MAT (DAT – dopamine transporter, SERT – serotonin transporter and NET – norepinephrine transporter was determined using in vitro neurotransmitter uptake assay. The effect of the drug at low doses (1 and 10mg/kg on spatial memory was studied in male rats in the radial arm maze (RAM. Furthermore, the dopamine receptor and transporter complex levels of frontal cortex (FC tissue of trained and untrained animals treated either with the drug or vehicle were quantified on blue native PAGE (BN-PAGE. The drug inhibited dopamine (IC50: 27.88µM and norepinephrine uptake (IC50: 160.40µM, but had a negligible effect on SERT. In the RAM, both drug-dose groups improved spatial working memory during the performance phase of RAM as compared to vehicle. BN-PAGE western blot quantification of dopamine receptor and transporter complexes revealed that D1, D2, D3 and DAT complexes were modulated due to training and by drug effects. The drug’s ability to block DAT and its influence on dopamine transporter and receptor complex levels in the FC is proposed as a possible mechanism for the observed learning and memory enhancement in the RAM.

  15. Male rats with same sex preference show high experimental anxiety and lack of anxiogenic-like effect of fluoxetine in the plus maze test.

    Science.gov (United States)

    García-Cárdenas, Nallely; Olvera-Hernández, Sandra; Gómez-Quintanar, Blanca Nelly; Fernández-Guasti, Alonso

    2015-08-01

    Homosexual men show a 2-4 higher risk to suffer anxiety in comparison with heterosexuals. It is unknown if biological factors collaborate to increase such incidence. Fluoxetine produces differential brain activation in homosexuals as compared with heterosexuals, suggesting that it may produce a divergent behavioral effect dependant on sex-preference. The first aim was to evaluate experimental anxiety in male rats that show same-sex preference in the elevated plus maze (EPM). The second goal explored the putative differential effect of fluoxetine (10mg/kg) in male rats with female and same-sex preference in the EPM. To induce same-sex preference males were prenatally treated with letrozole (0.56μg/kg, 10-20 gestation days), while controls were males prenatally treated with letrozole that retain female-preference or which mothers received oil. In both groups we found animals with male preference, but the proportion was higher in males that prenatally received letrozole (10 vs. 27%). Males with same-sex preference spent less time and showed lower number of entries to the open arms of the EPM than males that prefer females, regardless of the prenatal treatment. In males with female preference, fluoxetine reduced the time spent and number of entries to the open arms that was absent in males with same-sex preference. These data suggest that biological factors contribute to the high levels of anxiety in subjects with same-sex preference and that fluoxetine in men may produce a divergent action depending on sexual orientation. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. The interaction of housing condition and acute immobilization stress on the elevated plus-maze behaviors of protein-malnourished rats

    Directory of Open Access Journals (Sweden)

    Françolin-Silva A.L.

    2004-01-01

    Full Text Available Protein malnutrition induces structural, neurochemical and functional alterations in the central nervous system, leading to behavioral alterations. In the present study, we used the elevated plus-maze (EPM as a measure of anxiety to evaluate the interaction between acute immobilization and housing conditions on the behavior of malnourished rats. Pups (6 males and 2 females were fed by Wistar lactating dams receiving a 6% (undernourished or 16% (well-nourished protein diet. After weaning, the animals continued to receive the same diets ad libitum until 49 days of age when they started to receive a regular lab chow diet. From weaning to the end of the tests on day 70, the animals were housed under two different conditions, i.e., individual or in groups of three. On the 69th day, half of the animals were submitted to immobilization for 2 h, while the other half were undisturbed, and both groups were tested 24 h later for 5 min in the EPM. Independent of other factors, protein malnutrition increased, while immobilization and social isolation per se decreased, EPM exploration. Analysis of the interaction of diet vs immobilization vs housing conditions showed that the increased EPM exploration presented by the malnourished group was reversed by acute immobilization in animals reared in groups but not in animals reared individually. The interaction between immobilization and housing conditions suggests that living for a long time in social isolation is sufficiently stressful to reduce the responses to another anxiogenic procedure (immobilization, while living in groups prompts the animals to react to acute stress. Thus, it is suggested that housing condition can modulate the effects of an anxiogenic procedure on behavioral responses of malnourished rats in the EPM.

  17. The effect of modafinil on the rat dopamine transporter and dopamine receptors D1-D3 paralleling cognitive enhancement in the radial arm maze

    Directory of Open Access Journals (Sweden)

    Yasemin eKarabacak

    2015-08-01

    Full Text Available A series of drugs have been reported to increase memory performance modulating the dopaminergic system and herein modafinil was tested for its working memory (WM enhancing properties. Reuptake inhibition of dopamine, serotonin (SERT and norepinephrine (NET by modafinil was tested. 60 male Sprague Dawley rats were divided into six groups (modafinil-treated 1-5-10 mg/kg body weight, trained and untrained and vehicle treated trained and untrained rats; daily injected intraperitoneally for a period of 10 days and tested in a radial arm maze (RAM, a paradigm for testing spatial WM. Hippocampi were taken six hours following the last day of training and complexes containing the unphosphorylated or phosphorylated dopamine transporter (DAT-CC and pDAT-CC and complexes containing the D1-3 dopamine receptor subunits (D1-D3-CC were determined. Modafinil was binding to the DAT but insignificantly to SERT or NET and dopamine reuptake was blocked specifically (IC50=11.11; SERT 1547; NET 182. From day 8 (day 9 for 1 mg/kg body weight modafinil was decreasing WM errors in the RAM significantly and remarkably at all doses tested as compared to the vehicle controls. WMEs were linked to the D2R-CC and the pDAT-CC. pDAT and D1-D3-CC levels were modulated significantly and modafinil was shown to enhance spatial WM in the rat in a well-documented paradigm at all the three doses and dopamine reuptake inhibition with subsequent modulation of D1-3-CC is proposed as a possible mechanism of action.

  18. The effect of modafinil on the rat dopamine transporter and dopamine receptors D1-D3 paralleling cognitive enhancement in the radial arm maze.

    Science.gov (United States)

    Karabacak, Yasemin; Sase, Sunetra; Aher, Yogesh D; Sase, Ajinkya; Saroja, Sivaprakasam R; Cicvaric, Ana; Höger, Harald; Berger, Michael; Bakulev, Vasiliy; Sitte, Harald H; Leban, Johann; Monje, Francisco J; Lubec, Gert

    2015-01-01

    A series of drugs have been reported to increase memory performance modulating the dopaminergic system and herein modafinil was tested for its working memory (WM) enhancing properties. Reuptake inhibition of dopamine, serotonin (SERT) and norepinephrine (NET) by modafinil was tested. Sixty male Sprague-Dawley rats were divided into six groups (modafinil-treated 1-5-10 mg/kg body weight, trained and untrained and vehicle treated trained and untrained rats; daily injected intraperitoneally for a period of 10 days) and tested in a radial arm maze (RAM), a paradigm for testing spatial WM. Hippocampi were taken 6 h following the last day of training and complexes containing the unphosphorylated or phosphorylated dopamine transporter (DAT-CC and pDAT-CC) and complexes containing the D1-3 dopamine receptor subunits (D1-D3-CC) were determined. Modafinil was binding to the DAT but insignificantly to SERT or NET and dopamine reuptake was blocked specifically (IC50 = 11.11 μM; SERT 1547 μM; NET 182 μM). From day 8 (day 9 for 1 mg/kg body weight) modafinil was decreasing WM errors (WMEs) in the RAM significantly and remarkably at all doses tested as compared to the vehicle controls. WMEs were linked to the D2R-CC and the pDAT-CC. pDAT and D1-D3-CC levels were modulated significantly and modafinil was shown to enhance spatial WM in the rat in a well-documented paradigm at all the three doses and dopamine reuptake inhibition with subsequent modulation of D1-3-CC is proposed as a possible mechanism of action.

  19. Do Task Complexity Demands Influence the Learners’ Perception of Task Difficulty?

    Directory of Open Access Journals (Sweden)

    Nasrin Sanajou

    2017-09-01

    Full Text Available This study investigates the effects of cognitive task complexity on EFL learners’ perception of task difficulty. Learners’ perception of task difficulty is measured by a five-item task difficulty questionnaire (as in Robinson, 2001a. The participants were 76 intermediate learners which were divided into two groups. One group performed a simple task (single task and the other group performed a complex task (dual task. Having performed the tasks, the participants completed the task difficulty questionnaire. In order to see how the participants evaluated task difficulty, their ratings for each question of the questionnaire in the simple and complex tasks was compared using Mann-Whitney U. The results indicate that the complex task significantly affected learners’ perception of task difficulty in three items of difficulty, stress and interest. The results of task difficulty studies can help language educators in designing and employing more effective language teaching materials.

  20. Psoriasis & Comorbidities: Unraveling the Maze

    NARCIS (Netherlands)

    E.A. Dowlatshahi (Emmilia)

    2014-01-01

    markdownabstract__Abstract__ In this thesis we used a multifaceted approach to analyzing depression in psoriasis, by investigating Health Related Quality of Life (HRQoL), depressive symptoms, clinical depression and antidepressant use, using various data sources and statistical methods. These

  1. Authentic Assessment through Rich Tasks

    Science.gov (United States)

    Wrigley, Terry

    2017-01-01

    This short article explains the key principles of "rich tasks," a version of authentic assessment developed in Queensland, Australia, as part of a major curriculum development called the "New Basics." In various documents, the project leaders recognised the danger that inappropriate assessment would undermine the proposed…

  2. Survey of Task Analysis Methods

    Science.gov (United States)

    1978-02-14

    Taylor, for example, referred to task analysis in his work on scientific management (65). In the same time frame, the Gilbreths developed the first...ciation, Washington, D. C., 1965. 21. Gilbreth , F. B. Bricklaying System, M. C. Clark, New York, 1909. -42- REFERENCES (Continued) 22. Gilbreth , F

  3. A Population of Assessment Tasks

    Science.gov (United States)

    Daro, Phil; Burkhardt, Hugh

    2012-01-01

    We propose the development of a "population" of high-quality assessment tasks that cover the performance goals set out in the "Common Core State Standards for Mathematics." The population will be published. Tests are drawn from this population as a structured random sample guided by a "balancing algorithm."

  4. Use cases versus task descriptions

    DEFF Research Database (Denmark)

    Lauesen, Søren; Kuhail, Mohammad Amin

    2011-01-01

    to specify require-ments for the same project: Acquire a new system to support a hotline. [Princi-pal ideas/results] Among the 15 replies, eight used traditional use cases that specified a dialog between users and system. Seven used a related technique, task description, which specified the customer's needs...

  5. Task Group 9 Update (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Bosco, N.

    2014-04-01

    This presentation is a brief update of IEC TC82 QA Task Force, Group 9. Presented is an outline of the recently submitted New Work Item Proposal (NWIP) for a Comparative Thermal Cycling Test for CPV Modules to Differentiate Thermal Fatigue Durability.

  6. Capturing Common Knowledge about Tasks

    NARCIS (Netherlands)

    Gil, Y; Ratnakar, V; Chklovski, T; Groth, P.T.; Vrandecic, D

    2012-01-01

    Although to-do lists are a ubiquitous form of personal task management, there has been no work on intelligent assistance to automate, elaborate, or coordinate a users to-dos. Our research focuses on three aspects of intelligent assistance for to-dos. We investigated the use of intelligent agents to

  7. Scientists and the Selection Task.

    Science.gov (United States)

    Griggs, Richard A.; Ransdell, Sarah E.

    1986-01-01

    Presents findings of a study of scientists on the Wason four-card selection task, finding little understanding of the effect of disconfirmatory data in assessing conditionals. Found performance influenced by problem content. Explains performance as memory-cueing plus reasoning-by-analogy. (JM)

  8. Who Multi-Tasks and Why? Multi-Tasking Ability, Perceived Multi-Tasking Ability, Impulsivity, and Sensation Seeking

    OpenAIRE

    Sanbonmatsu, David M.; Strayer, David L.; Nathan Medeiros-Ward; Watson, Jason M.

    2013-01-01

    The present study examined the relationship between personality and individual differences in multi-tasking ability. Participants enrolled at the University of Utah completed measures of multi-tasking activity, perceived multi-tasking ability, impulsivity, and sensation seeking. In addition, they performed the Operation Span in order to assess their executive control and actual multi-tasking ability. The findings indicate that the persons who are most capable of multi-tasking effectively are ...

  9. Who Multi-Tasks and Why? Multi-Tasking Ability, Perceived Multi-Tasking Ability, Impulsivity, and Sensation Seeking

    Science.gov (United States)

    Sanbonmatsu, David M.; Strayer, David L.; Medeiros-Ward, Nathan; Watson, Jason M.

    2013-01-01

    The present study examined the relationship between personality and individual differences in multi-tasking ability. Participants enrolled at the University of Utah completed measures of multi-tasking activity, perceived multi-tasking ability, impulsivity, and sensation seeking. In addition, they performed the Operation Span in order to assess their executive control and actual multi-tasking ability. The findings indicate that the persons who are most capable of multi-tasking effectively are not the persons who are most likely to engage in multiple tasks simultaneously. To the contrary, multi-tasking activity as measured by the Media Multitasking Inventory and self-reported cell phone usage while driving were negatively correlated with actual multi-tasking ability. Multi-tasking was positively correlated with participants’ perceived ability to multi-task ability which was found to be significantly inflated. Participants with a strong approach orientation and a weak avoidance orientation – high levels of impulsivity and sensation seeking – reported greater multi-tasking behavior. Finally, the findings suggest that people often engage in multi-tasking because they are less able to block out distractions and focus on a singular task. Participants with less executive control - low scorers on the Operation Span task and persons high in impulsivity - tended to report higher levels of multi-tasking activity. PMID:23372720

  10. Who multi-tasks and why? Multi-tasking ability, perceived multi-tasking ability, impulsivity, and sensation seeking.

    Directory of Open Access Journals (Sweden)

    David M Sanbonmatsu

    Full Text Available The present study examined the relationship between personality and individual differences in multi-tasking ability. Participants enrolled at the University of Utah completed measures of multi-tasking activity, perceived multi-tasking ability, impulsivity, and sensation seeking. In addition, they performed the Operation Span in order to assess their executive control and actual multi-tasking ability. The findings indicate that the persons who are most capable of multi-tasking effectively are not the persons who are most likely to engage in multiple tasks simultaneously. To the contrary, multi-tasking activity as measured by the Media Multitasking Inventory and self-reported cell phone usage while driving were negatively correlated with actual multi-tasking ability. Multi-tasking was positively correlated with participants' perceived ability to multi-task ability which was found to be significantly inflated. Participants with a strong approach orientation and a weak avoidance orientation--high levels of impulsivity and sensation seeking--reported greater multi-tasking behavior. Finally, the findings suggest that people often engage in multi-tasking because they are less able to block out distractions and focus on a singular task. Participants with less executive control--low scorers on the Operation Span task and persons high in impulsivity--tended to report higher levels of multi-tasking activity.

  11. Who multi-tasks and why? Multi-tasking ability, perceived multi-tasking ability, impulsivity, and sensation seeking.

    Science.gov (United States)

    Sanbonmatsu, David M; Strayer, David L; Medeiros-Ward, Nathan; Watson, Jason M

    2013-01-01

    The present study examined the relationship between personality and individual differences in multi-tasking ability. Participants enrolled at the University of Utah completed measures of multi-tasking activity, perceived multi-tasking ability, impulsivity, and sensation seeking. In addition, they performed the Operation Span in order to assess their executive control and actual multi-tasking ability. The findings indicate that the persons who are most capable of multi-tasking effectively are not the persons who are most likely to engage in multiple tasks simultaneously. To the contrary, multi-tasking activity as measured by the Media Multitasking Inventory and self-reported cell phone usage while driving were negatively correlated with actual multi-tasking ability. Multi-tasking was positively correlated with participants' perceived ability to multi-task ability which was found to be significantly inflated. Participants with a strong approach orientation and a weak avoidance orientation--high levels of impulsivity and sensation seeking--reported greater multi-tasking behavior. Finally, the findings suggest that people often engage in multi-tasking because they are less able to block out distractions and focus on a singular task. Participants with less executive control--low scorers on the Operation Span task and persons high in impulsivity--tended to report higher levels of multi-tasking activity.

  12. Formative Research on the Heuristic Task Analysis.

    Science.gov (United States)

    Reigeluth, Charles M.; Lee, Ji-Yeon; Peterson, Bruce; Chavez, Michael

    Corporate and educational settings increasingly require decision-making, problem-solving and other complex cognitive skills to handle ill-structured, or heuristic, tasks, but the growing need for heuristic task expertise has outpaced the refinement of task analysis methods for heuristic expertise. The Heuristic Task Analysis (HTA) Method was…

  13. Cosmetology: Task Analyses. Competency-Based Education.

    Science.gov (United States)

    Henrico County Public Schools, Glen Allen, VA. Virginia Vocational Curriculum Center.

    These task analyses are designed to be used in combination with the "Trade and Industrial Education Service Area Resource" in order to implement competency-based education in the cosmetology program in Virginia. The task analysis document contains the task inventory, suggested task sequence lists, and content outlines for the secondary…

  14. The role of the medial caudate nucleus, but not the hippocampus, in a matching-to sample task for a motor response.

    Science.gov (United States)

    Kesner, Raymond P; Gilbert, Paul E

    2006-04-01

    A delayed-match-to-sample task was used to assess memory for motor responses in rats with control, hippocampus, or medial caudate nucleus (MCN) lesions. All testing was conducted on a cheeseboard maze in complete darkness using an infrared camera. A start box was positioned in the centre of the maze facing a randomly determined direction on each trial. On the sample phase, a phosphorescent object was randomly positioned to cover a baited food well in one of five equally spaced positions around the circumference of the maze forming a 180-degree arc 60 cm from the box. The rat had to displace the object to receive food and return to the start box. The box was then rotated to face a different direction. An identical baited phosphorescent object was placed in the same position relative to the start box. A second identical object was positioned to cover a different unbaited well. On the choice phase, the rat must remember the motor response made on the sample phase and make the same motor response on the choice phase to receive a reward. Hippocampus lesioned and control rats improved as a function of increased angle separation used to separate the correct object from the foil (45, 90, 135, and 180 degrees) and matched the performance of controls. However, rats with MCN lesions were impaired across all separations. Results suggest that the MCN, but not the hippocampus, supports working memory and/or a process aimed at reducing interference for motor response selection based on vector angle information.

  15. Aircrew Tasks and Cognitive Complexity

    Science.gov (United States)

    1991-11-01

    log P3 Intelligence P1 Quick reference V4 Verbal (Direct informal) (n V3 Verbal (Direc• formal) 1-.U V2 • Verbal (ICS informal) V1 I =-Verbal (ICS...Bierbaum, 1989) attd the repertoire of sc des available now includes visual, either unaided or with night vision goggles, auditory, kinesthetic , cognitive...secondary task and physiological methodologies. Physiological indices of mental workload are based on the assumption that bodily states vary in a

  16. A task scheduler for ROS

    OpenAIRE

    Pradalier, Cédric

    2017-01-01

    Developing a complete robotic system often requires combining multiple behaviours into a complexdecision grid, with elements running in sequence or in parallel, eventually interrupting each others.To solve this “age-old” problem, ROS provides two main tools:Actionlib: a client-server architecture that provides a way to specify results to be achieved.While the server works on these results, it should report progresses and ultimately reportwhen the task is completed.Smach: a python API to defin...

  17. Fuel oil quality task force

    Energy Technology Data Exchange (ETDEWEB)

    Laisy, J.; Turk, V. [R.W. Beckett Corp., Elyria, OH (United States)

    1997-09-01

    In April, 1996, the R.W. Beckett Corporation became aware of a series of apparently unrelated symptoms that made the leadership of the company concerned that there could be a fuel oil quality problem. A task force of company employees and industry consultants was convened to address the topic of current No. 2 heating oil quality and its effect on burner performance. The task force studied changes in fuel oil specifications and trends in properties that have occurred over the past few years. Experiments were performed at Beckett and Brookhaven National Laboratory to understand the effect of changes in some fuel oil properties. Studies by other groups were reviewed, and field installations were inspected to gain information about the performance of fuel oil that is currently being used in the U.S. and Canada. There was a special concern about the use of red dye in heating oils and the impact of sulfur levels due to the October, 1993 requirement of low sulfur (<0.05%) for on-highway diesel fuel. The results of the task force`s efforts were published in July, 1996. The primary conclusion of the task force was that there is not a crisis or widespread general problem with fuel oil quality. Localized problems that were seen may have been related to refinery practices and/or non-traditional fuel sources. System cleanliness is very important and the cause of many oil burner system problems. Finally, heating oil quality should get ongoing careful attention by Beckett engineering personnel and heating oil industry groups.

  18. L-histidine provokes a state-dependent memory retrieval deficit in mice re-exposed to the elevated plus-maze

    Directory of Open Access Journals (Sweden)

    K.R. Serafim

    2010-01-01

    Full Text Available The effects of L-histidine (LH on anxiety and memory retrieval were investigated in adult male Swiss Albino mice (weight 30-35 g using the elevated plus-maze. The test was performed on two consecutive days: trial 1 (T1 and trial 2 (T2. In T1, mice received an intraperitoneal injection of saline (SAL or LH before the test and were then injected again and retested 24 h later. LH had no effect on anxiety at the dose of 200 mg/kg since there was no difference between the SAL-SAL and LH-LH groups at T1 regarding open-arm entries (OAE and open-arm time (OAT (mean ± SEM; OAE: 4.0 ± 0.71, 4.80 ± 1.05; OAT: 40.55 ± 9.90, 51.55 ± 12.10, respectively; P > 0.05, Kruskal-Wallis test, or at the dose of 500 mg/kg (OAE: 5.27 ± 0.73, 4.87 ± 0.66; OAT: 63.93 ± 11.72, 63.58 ± 10.22; P > 0.05, Fisher LSD test. At T2, LH-LH animals did not reduce open-arm activity (OAE and OAT at the dose of 200 mg/kg (T1: 4.87 ± 0.66, T2: 5.47 ± 1.05; T1: 63.58 ± 10.22; T2: 49.01 ± 8.43 for OAE and OAT, respectively; P > 0.05, Wilcoxon test or at the dose of 500 mg/kg (T1: 4.80 ± 1.60, T2: 4.70 ± 1.04; T1: 51.55 ± 12.10, T2: 43.88 ± 10.64 for OAE and OAT, respectively; P > 0.05, Fisher LSD test, showing an inability to evoke memory 24 h later. These data suggest that LH does not act on anxiety but does induce a state-dependent memory retrieval deficit in mice.

  19. The Shielding Function of Task Sets and Its Relaxation during Task Switching

    Science.gov (United States)

    Dreisbach, Gesine; Wenke, Dorit

    2011-01-01

    The goal of the presented experiments was to investigate the dynamic interplay of task shielding and its relaxation during task switching. Task shielding refers to the finding that single task sets in terms of 2-choice categorization rules help shielding against distraction from irrelevant stimulus attributes. During task switching, this shielding…

  20. Kokkos' Task DAG Capabilities.

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Harold C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ibanez, Daniel Alejandro [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-09-01

    This report documents the ASC/ATDM Kokkos deliverable "Production Portable Dy- namic Task DAG Capability." This capability enables applications to create and execute a dynamic task DAG ; a collection of heterogeneous computational tasks with a directed acyclic graph (DAG) of "execute after" dependencies where tasks and their dependencies are dynamically created and destroyed as tasks execute. The Kokkos task scheduler executes the dynamic task DAG on the target execution resource; e.g. a multicore CPU, a manycore CPU such as Intel's Knights Landing (KNL), or an NVIDIA GPU. Several major technical challenges had to be addressed during development of Kokkos' Task DAG capability: (1) portability to a GPU with it's simplified hardware and micro- runtime, (2) thread-scalable memory allocation and deallocation from a bounded pool of memory, (3) thread-scalable scheduler for dynamic task DAG, (4) usability by applications.

  1. EL ESTRÉS AGUDO INTERFIERE CON LA EVOCACIÓN Y PROMUEVE LA EXTINCIÓN DE LA MEMORIA ESPACIAL EN EL LABERINTO DE BARNES High stress interfers with evocation and promotes extintion of spatial memory in the Barnes maze

    Directory of Open Access Journals (Sweden)

    JULIETA TRONCOSO

    Full Text Available Para evaluar los efectos del estrés agudo sobre la recuperación y la extinción de la memoria espacial, se utilizaron ratas entrenadas en el laberinto circular de Barnes. El entrenamiento consistió de 8 ensayos de adquisición (intervalo entre ensayos, IEE, de 5 min en donde los animales debían aprender a encontrar una caja meta ubicada en uno de los 18 agujeros del laberinto. Todos los animales adquirieron el aprendizaje espacial, ya que invirtieron menos tiempo en encontrar la caja meta y cometieron menos errores a medida que se sucedían los ensayos de entrenamiento. Veinticuatro horas después del entrenamiento se evaluó la retención y extinción del aprendizaje espacial mediante una prueba con caja meta (PCC seguida de siete pruebas sin caja (PSC, con un IEE de 5 min. Una hora y media antes de la sesión de evaluación de la memoria un grupo de animales fue sometido a estrés por restricción de movimientos durante una hora, permitiéndoles un período de recuperación de 30 min y otro grupo permaneció en su caja hogar sin manipulación (control. Los resultados indican que el estrés deteriora el proceso de evocación de la memoria espacial, ya que los animales estresados cometieron un mayor número de errores y demoraron más tiempo en encontrar la caja meta durante la PCC , respecto de los controles. Además, el estrés facilita el proceso de extinción, ya que, durante las PSCs los animales estresados no mostraron una persistencia en la exploración del agujero que, en el entrenamiento, conducía a la caja meta.To evaluate the effects of acute stress on evocation and extinction of a spatial memory task, we used rats trained in the Barnes circular maze. The training protocol consisted of eight acquisition trials (intertrial interval, ITI; 5 min where animals must learn to find an escape box placed under one of these eighteen holes of the maze. All animals learned the spatial memory task as indicated by diminished escape latency and

  2. Brain activations during bimodal dual tasks depend on the nature and combination of component tasks.

    Science.gov (United States)

    Salo, Emma; Rinne, Teemu; Salonen, Oili; Alho, Kimmo

    2015-01-01

    We used functional magnetic resonance imaging to investigate brain activations during nine different dual tasks in which the participants were required to simultaneously attend to concurrent streams of spoken syllables and written letters. They performed a phonological, spatial or "simple" (speaker-gender or font-shade) discrimination task within each modality. We expected to find activations associated specifically with dual tasking especially in the frontal and parietal cortices. However, no brain areas showed systematic dual task enhancements common for all dual tasks. Further analysis revealed that dual tasks including component tasks that were according to Baddeley's model "modality atypical," that is, the auditory spatial task or the visual phonological task, were not associated with enhanced frontal activity. In contrast, for other dual tasks, activity specifically associated with dual tasking was found in the left or bilateral frontal cortices. Enhanced activation in parietal areas, however, appeared not to be specifically associated with dual tasking per se, but rather with intermodal attention switching. We also expected effects of dual tasking in left frontal supramodal phonological processing areas when both component tasks required phonological processing and in right parietal supramodal spatial processing areas when both tasks required spatial processing. However, no such effects were found during these dual tasks compared with their component tasks performed separately. Taken together, the current results indicate that activations during dual tasks depend in a complex manner on specific demands of component tasks.

  3. Brain activations during bimodal dual tasks depend on the nature and combination of component tasks

    Directory of Open Access Journals (Sweden)

    Emma eSalo

    2015-02-01

    Full Text Available We used functional magnetic resonance imaging to investigate brain activations during nine different dual tasks in which the participants were required to simultaneously attend to concurrent streams of spoken syllables and written letters. They performed a phonological, spatial or simple (speaker-gender or font-shade discrimination task within each modality. We expected to find activations associated specifically with dual tasking especially in the frontal and parietal cortices. However, no brain areas showed systematic dual task enhancements common for all dual tasks. Further analysis revealed that dual tasks including component tasks that were according to Baddeley’s model modality atypical, that is, the auditory spatial task or the visual phonological task, were not associated with enhanced frontal activity. In contrast, for other dual tasks, activity specifically associated with dual tasking was found in the left or bilateral frontal cortices. Enhanced activation in parietal areas, however, appeared not to be specifically associated with dual tasking per se, but rather with intermodal attention switching. We also expected effects of dual tasking in left frontal supramodal phonological processing areas when both component tasks required phonological processing and in right parietal supramodal spatial processing areas when both tasks required spatial processing. However, no such effects were found during these dual tasks compared with their component tasks performed separately. Taken together, the current results indicate that activations during dual tasks depend in a complex manner on specific demands of component tasks.

  4. EFECTOS DE LA SEPARACIÓN MATERNA TEMPRANA SOBRE EL DESEMPEÑO EN EL LABERINTO EN CRUZ ELEVADO EN RATAS ADULTAS Effects of Early Maternal Separation on The Performance in the Elevated Plus Maze in Adult Rats

    Directory of Open Access Journals (Sweden)

    DIEGO ARMANDO LEÓN RODRÍGUEZ

    2012-04-01

    Full Text Available Se ha demostrado que alteraciones en la interacción madre-cría produce efectos duraderos sobre el desarrollo cerebral y comportamental; de esta forma sujetos expuestos a estrés por separación materna temprana (SMT presentan variaciones en los comportamientos indicadores de ansiedad. El objetivo del presente estudio fue investigar los efectos específicos del estrés por SMT sobre los comportamientos indicadores de ansiedad en ratas Wistar adultas machos y hembras. Las ratas fueron anidadas con ciclo luz/oscuridad invertido (7 p.m./7 a.m., agua y comida ad libitum. El procedimiento de separación se realizó dos veces diarias durante los días postnatales 1 al 21 (7:00 a 10:00 y 13:00 a 16:00 p.m.. Los comportamientos indicadores de ansiedad fueron evaluados por medio del laberinto en cruz elevado (LCE cuando las crías alcanzaron un peso de 230 g. Se encontró que el estrés por SMT tiene efectos específicos para cada sexo sobre los comportamientos relacionados con la ansiedad, las hembras separadas maternalmente presentaron un perfil ansioso menor que las no separadas y los machos separados mostraron mayor conflicto exploración/evitación. Estos resultados corroboran hallazgos preliminares de nuestro laboratorio, en los que se evidencia interacción entre la vulnerabilidad ante desafíos ambientales tempranos y los mecanismos compensatorios del cuidado materno.It has been demonstrated that disruption of mother-pup interaction during early life exerts long-lasting effects on the brain and behavioral development. Therefore subjects exposed to early maternal separation stress (MS show variations in anxiety-like behaviors. The aim of this study was to investigate the specific effects of SMT stress on anxiety-like behaviors in adult male and female Wistar rats. Rats were housed with reversed light dark cycle (light on at 7 p.m., off at 7 a.m., water and food ad libitum. Separation was carried out in postnatal days 1 to 21, twice daily in dark

  5. Influence of time pressure in a simple response task, a choice-by-location task, and the Simon task

    NARCIS (Netherlands)

    van der Lubbe, Robert Henricus Johannes; Jaśkowski, Piotr; Wauschkuhn, Bernd; Verleger, Rolf

    2001-01-01

    Examined the influence of strategy for a simple response task, a choice-by-location task, and the Simon task by varying time pressure in 11 Ss (mean age 28 yrs). Besides reaction time (RT) and accuracy, we measured response force and derived two measures from the event-related EEG potential to form

  6. Antenna pattern study, task 2

    Science.gov (United States)

    Harper, Warren

    1989-01-01

    Two electromagnetic scattering codes, NEC-BSC and ESP3, were delivered and installed on a NASA VAX computer for use by Marshall Space Flight Center antenna design personnel. The existing codes and certain supplementary software were updated, the codes installed on a computer that will be delivered to the customer, to provide capability for graphic display of the data to be computed by the use of the codes and to assist the customer in the solution of specific problems that demonstrate the use of the codes. With the exception of one code revision, all of these tasks were performed.

  7. Task Organizing for Urban Combat

    Science.gov (United States)

    1978-06-09

    states that "I • ...- • •v•Z’- quad, must fight in a large city, it should be renfo ..rz i - Engineer Cqrr’-’ct Operatlons, FM 5-100, states that, " MOBA ...reliably task organize his unit for combat. 90 The nn’ibsrs ~ sa pr r3to Sbi dev&Loped in thAZ atudy should be tested in MOBA scenrocsqti AtnSzvohr P~ ames...Heidelberg, Chief of Historical Section, Us AKýrm bap, 17 July 1952. Ketron, Inc. GaMing Models for Military Operations in Bailt-Up Areas- MOBA .. October

  8. San Joaquin River Up-Stream DO TMDL Project Task 4: MonitoringStudy Interim Task Report #3

    Energy Technology Data Exchange (ETDEWEB)

    Stringfellow, William; Borglin, Sharon; Dahlgren, Randy; Hanlon,Jeremy; Graham, Justin; Burks, Remie; Hutchinson, Kathleen

    2007-03-30

    The purpose of the Dissolved Oxygen Total Maximum Daily LoadProject (DO TMDLProject) is to provide a comprehensive understanding ofthe sources and fate of oxygen consuming materials in the San JoaquinRiver (SJR) watershed between Channel Point and Lander Avenue (upstreamSJR). When completed, this study will provide the stakeholders anunderstanding of the baseline conditions of the basin, provide input foran allocation decision, and provide the stakeholders with a tool formeasuring the impact of any waterquality management program that may beimplemented as part of the DO TMDL process. Previous studies haveidentified algal biomass as the most significant oxygen-demandingsubstance in the DO TMDL Project study-area between of Channel Point andLander Ave onthe SJR. Other oxygen-demanding substances found in theupstream SJR include ammonia and organic carbon from sources other thanalgae. The DO TMDL Project study-area contains municipalities, dairies,wetlands, cattle ranching, irrigated agriculture, and industries thatcould potentially contribute biochemical oxygen demand (BOD) to the SJR.This study is designed to discriminate between algal BOD and othersources of BOD throughout the entire upstream SJR watershed. Algalbiomass is not a conserved substance, but grows and decays in the SJR;hence, characterization of oxygen-demanding substances in the SJR isinherently complicated and requires an integrated effort of extensivemonitoring, scientific study, and modeling. In order to achieve projectobjectives, project activities were divided into a number of Tasks withspecific goals and objectives. In this report, we present the results ofmonitoring and research conducted under Task 4 of the DO TMDL Project.The major objective of Task 4 is to collect sufficient hydrologic (flow)and water quality (WQ) data to characterize the loading of algae, otheroxygen-demanding materials, and nutrients fromindividual tributaries andsub-watersheds of the upstream SJR between Mossdale and

  9. Pre-task music improves swimming performance.

    Science.gov (United States)

    Smirmaul, B P; Dos Santos, R V; Da Silva Neto, L V

    2015-12-01

    The purpose of this study was to investigate the effects of pre-task music on swimming performance and other psychological variables. A randomized counterbalanced within-subjects (experimental and control condition) design was employed. Eighteen regional level male swimmers performed two 200-m freestyle swimming time trials. Participants were exposed to either 5 minutes of self-selected music (pre-task music condition) or 5 minutes of silence (control condition) and, after 1 minute, performed the swimming task. Swimming time was significantly shorter (-1.44%) in the pre-task music condition. Listening to pre-task music increased motivation to perform the swimming task, while arousal remained unchanged. While fatigue increased after the swimming task in both conditions, vigor, ratings of perceived exertion and affective valence were unaltered. It is concluded, for the first time, that pre-task music improves swimming performance.

  10. EFFORTS Sub-task report on task 4.2: Cold forming

    DEFF Research Database (Denmark)

    Andreasen, Jan Lasson; Christensen, Thomas Vennick; Bay, Niels

    1999-01-01

    Task 4.2 is a sub-task of task 4: Physical modelling validation. In sub-task 4.2 experimental analysis of cold forming as regards form filling, interface stresses and forces and moments using sof model materials have been carried out.......Task 4.2 is a sub-task of task 4: Physical modelling validation. In sub-task 4.2 experimental analysis of cold forming as regards form filling, interface stresses and forces and moments using sof model materials have been carried out....

  11. Task-based nutrition labelling.

    Science.gov (United States)

    Dunbar, George

    2010-12-01

    Task-based interface design principles (TBI) were evaluated as a framework for designing effective nutritional labels. In two experiments a total of 123 people assembled a packed lunch, selecting components using labels in GDA or TBI format, or when given only the names of the foods. Study 1 found that a GDA label helped people make healthier choices than the product name alone, but that for a number of types of food, most people would make the same decision with or without a GDA label. Moreover, decisions were much faster when made with the name alone. Study 2 introduced a TBI label in the context of the more specific task of keeping the salt in the lunch under 1g. TBI and GDA labels reduced salt equally, but only the TBI label was as quick as the name alone. Labels that are aligned with people's specific objectives are more efficient. TBI is a potentially useful framework, that can be deployed using mobile computing. Copyright © 2010 Elsevier Ltd. All rights reserved.

  12. A Tandem Learning Approach to Task Evaluation

    OpenAIRE

    Stewart, Timothy; スチュワート, ティモシー

    2008-01-01

    This paper describes an approach to task evaluation that emerged out of the process of course development. The multi-layered approach to task evaluation described synthesizes student and teacher evaluations of tasks written in journals with more traditional course evaluation data in a reflective process of course development. Ultimately, the approach opens up dynamic insights into the appropriateness of tasks by incorporating the views of both students and teachers.The paper concludes by illu...

  13. Comparing Task Models for User Interface Design

    OpenAIRE

    Limbourg, Quentin; Vanderdonckt, Jean

    2003-01-01

    Many task models, task analysis methods, and supporting tools have been introduced in the literature and are widely used in practice. With this comes need to understand their scopes and their differences. This chapter provides a thorough review of selected, significant task models along with their method and supporting tools. For this purpose, a meta-model of each task model is expressed as an Entity-Relationship-Attribute schema (ERA) and discussed. This leads to a comparative analysis of ta...

  14. Backwards Fading to Speed Task Learning

    Science.gov (United States)

    2013-09-01

    Kalakoski, V. (2008). Effect of skill level on recall of visually presented patterns of musical patterns. Scandinavian Journal of Psychology, 48, 87...task steps). Recall that task complexity was based upon SME judgment regarding features of existing Army tasks, including number of steps, the...instructors feel Soldiers would benefit from learning, and these tasks are serial in nature (they must be completed in a specific sequence

  15. Task Switching Effects in Anticipation Timing

    Science.gov (United States)

    Fairbrother, Jeffrey T.; Brueckner, Sebastian

    2008-01-01

    To understand how task switching affects human performance, there is a need to investigate how it influences the performance of tasks other than those involving bivalent stimulus categorization. The purpose of this study, therefore, was to investigate the effects of task switching on anticipation timing performance, which typically requires…

  16. Task Difficulty in Oral Speech Act Production

    Science.gov (United States)

    Taguchi, Naoko

    2007-01-01

    This study took a pragmatic approach to examining the effects of task difficulty on L2 oral output. Twenty native English speakers and 59 Japanese students of English at two different proficiency levels produced speech acts of requests and refusals in a role play task. The task had two situation types based on three social variables:…

  17. Task Repetition and Second Language Speech Processing

    Science.gov (United States)

    Lambert, Craig; Kormos, Judit; Minn, Danny

    2017-01-01

    This study examines the relationship between the repetition of oral monologue tasks and immediate gains in L2 fluency. It considers the effect of aural-oral task repetition on speech rate, frequency of clause-final and midclause filled pauses, and overt self-repairs across different task types and proficiency levels and relates these findings to…

  18. Task-specific dystonia : pathophysiology and management

    NARCIS (Netherlands)

    Sadnicka, Anna; Kassavetis, Panagiotis; Parees, Isabel; Meppelink, Anne; Butler, Katherine; Edwards, Mark

    Task-specific dystonia is a form of isolated focal dystonia with the peculiarity of being displayed only during performance of a specific skilled motor task. This distinctive feature makes task-specific dystonia a particularly mysterious and fascinating neurological condition. In this review, we

  19. A Task Is a Task Is a Task Is a Task... Or Is It? Researching Telecollaborative Teacher Competence Development--The Need for More Qualitative Research

    Science.gov (United States)

    Müller-Hartmann, Andreas

    2016-01-01

    The concept of task has become central not only to an understanding of language learning per se, but also to the design and research of Online Intercultural Exchanges (OIEs). While research on the design of tasks in OIEs has been very productive, we still lack insights into how teachers develop competences in task design on the micro-level.…

  20. Effects of Task Complexity, Task Conditions, and Task Difficulty on the Grammatical Accuracy of EFL Learners in Written Discourse

    Directory of Open Access Journals (Sweden)

    Saeideh Ahangari

    2012-11-01

    Full Text Available Different methods of language teaching have tried to help EFL learners to develop good language skills based on their various perspectives. Research findings have underscored the effect of using task types in promoting language skills in terms of accuracy in written discourse. Therefore, this study set out to investigate whether there is an evidence of correct use of simple past tense (Accuracy based on Task Complexity (Task type :Here-and now & There-and-then,Task Conditions (Gender: Male & Female, and Task Difficulty (Proficiency: Lower-intermediate & Intermediate. Sixty Iranian English learners in a language institute participated in the study and were assigned to four groups of lower-intermediate male, lower-intermediate female, intermediate male and intermediate female. Initial homogeneity of the groups was verified using two general proficiency tests; KET for lower-intermediate and PET for intermediate. All groups in here-and-now task type were asked to write a story using simple past based on a picture strip while for there-and-then task type the participants were supposed to write about their last birthday. The results from paired samples t-test, independent samples t-test and two-way ANOVA analysis of the written data revealed significant differences in performing task types, at different proficiency levels and interaction between them. The findings have significant pedagogical implications for EFL learners to understand the relationship among Task Complexity,Task Conditions, Task Difficulty and L2 written production leading to various degrees of Accuracy.

  1. Combat Readiness Check (CRC): Development of a Dual Task Assessment Protocol to Assist with Return-to-Duty Decision-Making After Traumatic Brain Injury

    Science.gov (United States)

    2010-10-01

    benchmark tasks that inform your return to duty recommendations? - If yes, what is the nature of these tasks? ADL/IADL? Duty? What tools are available...and inhibit responses based on the nature of visual stimuli.   Description: Using a T-shaped formation, the SM is required to do a 3-5 second rush...quart Water – 1 quart Water – 1 quart Water – 1 quart Water – 1 quart 135 Water – 1 quart Footpowder Other: toothpaste

  2. TASK-1 and TASK-3 may form heterodimers in human atrial cardiomyocytes.

    Science.gov (United States)

    Rinné, Susanne; Kiper, Aytug K; Schlichthörl, Günter; Dittmann, Sven; Netter, Michael F; Limberg, Sven H; Silbernagel, Nicole; Zuzarte, Marylou; Moosdorf, Rainer; Wulf, Hinnerk; Schulze-Bahr, Eric; Rolfes, Caroline; Decher, Niels

    2015-04-01

    TASK-1 channels have emerged as promising drug targets against atrial fibrillation, the most common arrhythmia in the elderly. While TASK-3, the closest relative of TASK-1, was previously not described in cardiac tissue, we found a very prominent expression of TASK-3 in right human auricles. Immunocytochemistry experiments of human right auricular cardiomyocytes showed that TASK-3 is primarily localized at the plasma membrane. Single-channel recordings of right human auricles in the cell-attached mode, using divalent-cation-free solutions, revealed a TASK-1-like channel with a single-channel conductance of about 30pS. While homomeric TASK-3 channels were not found, we observed an intermediate single-channel conductance of about 55pS, possibly reflecting the heteromeric channel formed by TASK-1 and TASK-3. Subsequent experiments with TASK-1/TASK-3 tandem channels or with co-expressed TASK-1 and TASK-3 channels in HEK293 cells or Xenopus oocytes, supported that the 55pS channels observed in right auricles have electrophysiological characteristics of TASK-1/TASK-3 heteromers. In addition, co-expression experiments and single-channel recordings suggest that heteromeric TASK-1/TASK-3 channels have a predominant surface expression and a reduced affinity for TASK-1 blockers. In summary, the evidence for heteromeric TASK-1/TASK-3 channel complexes together with an altered pharmacologic response to TASK-1 blockers in vitro is likely to have further impact for studies isolating ITASK-1 from cardiomyocytes and for the development of drugs specifically targeting TASK-1 in atrial fibrillation treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Water, Water Everywhere

    Science.gov (United States)

    Keeler, Rusty

    2009-01-01

    Everybody knows that children love water and how great water play is for children. The author discusses ways to add water to one's playscape that fully comply with health and safety regulations and are still fun for children. He stresses the importance of creating water play that provides children with the opportunity to interact with water.

  4. Task-specific style verification

    Science.gov (United States)

    Pataki, Norbert; Cséri, Tamás; Szügyi, Zalán

    2012-09-01

    Programming antipatterns are commonly used patterns that make the code unnecessary complex and unmaintainable. However, beginner programmers such as students, often use them. Usage of antipatterns should be eliminated from source code. Many antipatterns can be detected at compilation-time with an appropriate parser tool. In this paper we argue for a new lint-like tool that does detect typical programming antipatterns, and it is extensible to task-specific verifications. This tool mainly developed to evaluate students' programs, however it can be used in industrial projects as well. Our approach based on pattern matching on abstract syntax tree provided by Clang parser. We present our description language that specifies the antipatterns.

  5. Components of competitor priming in task switching.

    Science.gov (United States)

    Teskey, Morgan L; Masson, Michael E J

    2017-11-01

    Executing an action in response to a stimulus is thought to result in the creation of an event code that integrates stimulus and action features (Allport, 1987; Hommel in Visual Cognition 5: 183-216, 1998). When switching between tasks, competitor priming occurs if a distractor stimulus cues the retrieval of a previously established event code in which that distractor is bound to a competing task, creating a source of interference with the current task whereby the observer is encouraged to apply the competing task to the distractor. We propose a second aspect of competitor priming: the misapplication of the retrieved competing task to the target stimulus. We report two task-switching experiments in which tasks applied to picture-word compound stimuli were manipulated to create conditions in which this second aspect of competitor priming could be revealed and distinguished from other sources of task- and stimulus-based priming. A substantial increase in competitor priming was observed when subjects switched between tasks that required very different processing operations and the competing task was highly relevant to the target stimulus. These results are consistent with our claim that competitor priming can result from applying the competing task either to the distractor that cued it or to the target stimulus.

  6. Caffeine improves anticipatory processes in task switching.

    Science.gov (United States)

    Tieges, Zoë; Snel, Jan; Kok, Albert; Wijnen, Jasper G; Lorist, Monicque M; Richard Ridderinkhof, K

    2006-08-01

    We studied the effects of moderate amounts of caffeine on task switching and task maintenance using mixed-task (AABB) blocks, in which participants alternated predictably between two tasks, and single-task (AAAA, BBBB) blocks. Switch costs refer to longer reaction times (RT) on task switch trials (e.g. AB) compared to task-repeat trials (e.g. BB); mixing costs refer to longer RTs in task-repeat trials compared to single-task trials. In a double-blind, within-subjects experiment, two caffeine doses (3 and 5mg/kg body weight) and a placebo were administered to 18 coffee drinkers. Both caffeine doses reduced switch costs compared to placebo. Event-related brain potentials revealed a negative deflection developing within the preparatory interval, which was larger for switch than for repeat trials. Caffeine increased this switch-related difference. These results suggest that coffee consumption improves task-switching performance by enhancing anticipatory processing such as task set updating, presumably through the neurochemical effects of caffeine on the dopamine system.

  7. In vitro and ex-vivo cellular antioxidant protection and cognitive enhancing effects of an extract of Polygonum minus Huds (Lineminus™) demonstrated in a Barnes Maze animal model for memory and learning.

    Science.gov (United States)

    George, Annie; Ng, Chee Perng; O'Callaghan, Matthew; Jensen, Gitte S; Wong, Hoi Jin

    2014-05-19

    Polygonum minus Huds.is a culinary flavouring that is common in South East Asian cuisine and as a remedy for diverse maladies ranging from indigestion to poor eyesight. The leaves of this herb have been reported to be high in antioxidants. Flavonoids which have been associated with memory, cognition and protection against neurodegeneration were found in P. minus. This study examined a P. minus aqueous extract (Lineminus™) for its antioxidant activity using the Oxygen Radical Absorbance Capacity (ORAC) assay, the ex vivo Cellular Antioxidant Protection of erythrocytes (CAP-e) assays and for potential anticholinesterase activity in vitro. Cognitive function and learning of Lineminus™ was evaluated using scopolamine induced cognition deficits in a Barnes maze, rodent model of cognition. The extract displayed in vitro antioxidant activity with a total ORAC value of 16,964 μmole TE/gram. Cellular antioxidant protection from free radical damage using the CAP-e assay, with an IC50 of 0.58 g/L for inhibition of cellular oxidative damage, was observed. The extract inhibited cholinesterase activity with an IC50 of 0.04 mg/ml with a maximum inhibition of 68%. In a rodent model of cognition using scopolamine induced cognition deficits in the Barnes maze, the extract attenuated scopolamine induced disruptions in learning at the higher dose of 100 mg/kg. These data shows that P. minus possesses antioxidant and anticholinesterase activity and demonstrated enhanced cognition in vivo. The data suggest neuroprotective properties of the extract.

  8. On the importance of Task 1 and error performance measures in PRP dual-task studies.

    Science.gov (United States)

    Strobach, Tilo; Schütz, Anja; Schubert, Torsten

    2015-01-01

    The psychological refractory period (PRP) paradigm is a dominant research tool in the literature on dual-task performance. In this paradigm a first and second component task (i.e., Task 1 and Task 2) are presented with variable stimulus onset asynchronies (SOAs) and priority to perform Task 1. The main indicator of dual-task impairment in PRP situations is an increasing Task 2-RT with decreasing SOAs. This impairment is typically explained with some task components being processed strictly sequentially in the context of the prominent central bottleneck theory. This assumption could implicitly suggest that processes of Task 1 are unaffected by Task 2 and bottleneck processing, i.e., decreasing SOAs do not increase reaction times (RTs) and error rates of the first task. The aim of the present review is to assess whether PRP dual-task studies included both RT and error data presentations and statistical analyses and whether studies including both data types (i.e., RTs and error rates) show data consistent with this assumption (i.e., decreasing SOAs and unaffected RTs and/or error rates in Task 1). This review demonstrates that, in contrast to RT presentations and analyses, error data is underrepresented in a substantial number of studies. Furthermore, a substantial number of studies with RT and error data showed a statistically significant impairment of Task 1 performance with decreasing SOA. Thus, these studies produced data that is not primarily consistent with the strong assumption that processes of Task 1 are unaffected by Task 2 and bottleneck processing in the context of PRP dual-task situations; this calls for a more careful report and analysis of Task 1 performance in PRP studies and for a more careful consideration of theories proposing additions to the bottleneck assumption, which are sufficiently general to explain Task 1 and Task 2 effects.

  9. Age-related differences in dual task performance: A cross-sectional study on women.

    Science.gov (United States)

    Brustio, Paolo R; Magistro, Daniele; Rabaglietti, Emanuela; Liubicich, Monica E

    2017-02-01

    Simultaneous performances of motor and attention-demanding tasks are common in activities of everyday life. The present cross-sectional study examined the changes and age-related differences on mobility performance with an additional cognitive or motor task, and evaluated the relative dual-task cost (DTC) on the motor performance in young, middle-aged and older women. A total of 30 young (mean age 25.12 ± 3.00 years), 30 middle-aged (mean age 47.82 ± 5.06 years) and 30 older women (mean age 72.74 ± 5.95 years) were recruited. Participants carried out: (i) single task: Timed Up & Go Test; (ii) cognitive dual-task: Timed Up & Go Test while counting backwards by three; (iii) manual dual-task: Timed Up & Go Test while carrying a glass of water. A repeated measures anova with between-factor as age groups and within-factor as tasks was carried out to assess the effect of aging on the performance of mobility tasks. DTC was calculated as ([performance in single-task - performance in dual-task] / performance in single task) × 100%. One-way ancova were carried out to compare the DTC among the three age groups. A significant interaction between age groups and task (F4,172  = 6.716, P performance under dual-task condition compared with young and middle-aged groups. Furthermore, DTC differences in cognitive task were observed in older women compared with younger and middle-aged women (F2,86  = 7.649, P performance differently across the lifespan, and could be particularly challenging in older women. Geriatr Gerontol Int 2017; 17: 315-321. © 2015 Japan Geriatrics Society.

  10. Perirhinal cortex lesions attenuate stimulus generalization in a tactual discrimination task in rats.

    Science.gov (United States)

    Ramos, Juan M J

    2014-01-01

    Response generalization to a novel stimulus occurs when the new stimulus shares common features with the stimulus used in the original learning. Given the many recent studies suggesting that the perirhinal cortex is critical for disambiguating stimuli that share representational/perceptual elements, we hypothesize that lesions sustained to this region would attenuate response generalization. In the first part of this experiment lesioned and control rats learned a feature-ambiguous tactual discrimination task until they had all reached the same level of performance. In this task animals were asked to discriminate among 3 tactual stimuli simultaneously exposed in 3 arms of a 4-arm plus-shaped maze. In the second part of this experiment, the same rats were given a generalization test 24 h after acquisition of the tactual discrimination. In the generalization test the original tactual stimulus associated with reward during the learning of the discrimination was replaced by a novel tactual stimulus while the other two remained the same. Of the 3 stimuli used in the generalization test, the novel stimulus had the highest degree of feature overlap with respect to the original target stimulus used during the learning of the discrimination. The generalization test took place over two consecutive days, with 8 trials each day. On the first day of generalization, the results indicated that the lesioned rats generalized significantly worse than the control rats during the first 4 trials, but not during the last 4 trials. On the second day of generalization, however, both groups performed the test perfectly. These findings suggest that, in addition to the well-known mnesic function in object processing, the perirhinal cortex may also be involved in perceptual functions.

  11. Manual function and performance in humans, gorillas, and orangutans during the same tool use task.

    Science.gov (United States)

    Bardo, Ameline; Cornette, Raphaël; Borel, Antony; Pouydebat, Emmanuelle

    2017-09-23

    Humans are known to possess more complex manual abilities than other primates. However, the manual abilities of primates have not been fully explored, and we still do not know if the manipulative abilities we attribute to humans are unique. The aim of this study was to compare the manual function and performance developed by humans, gorillas and orangutans while performing the same experimental tool use task. The study was conducted on 20 humans, 6 gorillas, and 7 orangutans. Each individual had to use a tool to collect food from a maze during six experimental sessions while maintaining the same unconstrained body posture condition. We quantified the different manual techniques used and the manual performance. Each species used different techniques. Humans used bimanual grip techniques, pad-to-pad precision grasping postures, and in-hand movements involving fingertips. Gorillas used unimanual grip techniques and simple in-hand movements while orangutans used a variety of strategies (e.g., hand or mouth). With these techniques, humans performed the task better than both gorillas and orangutans (e.g., by being quicker to collect the food). This study highlights other ways in which humans' manual dexterity differs from that of other species and emphasizes the distinct manipulative function of orangutans. The differences between the species could be due to the differing muscular anatomy and morphology of the hands, with hand proportion possibly placing particular biomechanical constraints on each species. The differences between gorillas and orangutans could result from their different locomotor behaviors, and we hypothesize terrestriality facilitates the development of complex manipulation. © 2017 Wiley Periodicals, Inc.

  12. Functional connectivity in a rat model of Alzheimer's disease during a working memory task.

    Science.gov (United States)

    Liu, Tiaotiao; Bai, Wenwen; Yi, Hu; Tan, Tao; Wei, Jing; Wang, Ju; Tian, Xin

    2014-01-01

    Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive loss of memory. Impairment of working memory was typically observed in AD. The concept of brain functional connectivity plays an important role in neuroscience as a useful tool to understand the organized behavior of brain. Hence, the purpose of this study is to investigate the possible mechanism of working memory deficits in AD from a new perspective of functional connectivity. Rats were randomly divided into 2 groups: Aβ injection group (Aβ₁₋₄₂-induced toxicity rat model) and control group. Multi-channel local field potentials (LFPs) were obtained from rat prefrontal cortex with implanted microelectrode arrays while the rats performed a Y-maze working memory task. The short-time Fourier transform was utilized to analyze the power changes in LFPs and sub-bands (in particular theta and low gamma bands) were extracted via band filtering. Then the Directed transfer function (DTF) method was applied to calculate the functional connections among LFPs. From the DTF calculation, the causal networks in the sub-bands were identified. DTFmean (mean of connectivity matrix elements) was used to quantify connection strength as well as global efficiency (Eglob) was calculated to quantitatively describe the efficient of information transfer in the network. Our results showed that both connection strength and efficient of information transfer increased during the working memory task in the control group; by contrast, there was no significantly change in the Aβ injection group. These findings could lead to improve the understanding of the mechanism of working memory deficits in AD.

  13. An open-source toolbox for automated phenotyping of mice in behavioral tasks

    Directory of Open Access Journals (Sweden)

    Tapan P Patel

    2014-10-01

    Full Text Available Classifying behavior patterns in mouse models of neurological, psychiatric and neurodevelopmental disorders is critical for understanding disease causality and treatment. However, complete characterization of behavior is time-intensive, prone to subjective scoring, and often requires specialized equipment. Although several reports describe automated home-cage monitoring and individual task scoring methods, we report the first open source, comprehensive toolbox for automating the scoring of several common behavior tasks used by the neuroscience community. We show this new toolbox is robust and achieves equal or better consistency when compared to manual scoring methods. We use this toolbox to study the alterations in behavior that occur following blast-induced traumatic brain injury (bTBI, and study if these behavior patterns are altered following genetic deletion of the transcription factor Ets-like kinase 1 (Elk-1. Due to the role of Elk-1 in neuronal survival and proposed role in synaptic plasticity, we hypothesized that Elk-1 deletion would improve some neurobehavioral deficits, while impairing others, following blast exposure. In Elk-1 knockout animals, deficits in open field, spatial object recognition and elevated zero maze performance after blast exposure disappeared, while new significant deficits appeared in spatial and associative memory. These are the first data suggesting a molecular mediator of anxiety deficits following blast-induced traumatic brain injury, and represent the utility of the broad screening tool we developed. More broadly, we envision this open-source toolbox will provide a more consistent and rapid analysis of behavior across many neurological diseases, promoting the rapid discovery of novel pathways mediating disease progression and treatment.

  14. Acute and chronic alcohol administration: effects on performance of zebrafish in a latent learning task.

    Science.gov (United States)

    Luchiari, Ana C; Salajan, Diana C; Gerlai, Robert

    2015-04-01

    Alcohol abuse is a major medical problem. Zebrafish have been proposed to model alcohol related human disorders. Alcohol impairs learning and memory. Here, we analyze the effects of alcohol on performance of zebrafish in a recently developed latent learning paradigm. We employ a 2×3×2 experimental design (chronic×acute alcohol treatment×path blocked). The latent learning task had two phases: one, 30min long exploration trials (16 days, 1 trial/day) with left or right path of a complex maze blocked, and two, a subsequent probe trial with all paths open leading to a goal box that now contained stimulus fish. During the 16 days each fish received one of two chronic treatments: freshwater or 0.50% (v/v%) alcohol. Subsequently, fish were immersed for 1h in one of the following solutions: 0.00 (freshwater), 0.50% or 1.00% alcohol, the acute challenge. Behavior of fish was recorded during the probe trial that commenced immediately after the acute treatment. Path choices, latency to leave the start box and to enter the goal box, time spent in the goal box, distance traveled, and duration of freezing were quantified. We found that acute exposure to 1.00% alcohol after chronic freshwater disrupted learning performance, so did exposure to freshwater after chronic alcohol treatment (withdrawal). We also found exposure to chronic alcohol to diminish the effect of subsequent acute alcohol suggesting development of tolerance. Our results demonstrate that analysis of learning performance of zebrafish allows detection of alcohol-induced functional changes. The simplicity and scalability of the employed task also imply the utility of the zebrafish in high throughput drug screens. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. The Applicability of Rhythm-Motor Tasks to a New Dual Task Paradigm for Older Adults

    Directory of Open Access Journals (Sweden)

    Soo Ji Kim

    2017-12-01

    Full Text Available Given the interplay between cognitive and motor functions during walking, cognitive demands required during gait have been investigated with regard to dual task performance. Along with the needs to understand how the type of concurrent task while walking affects gait performance, there are calls for diversified dual tasks that can be applied to older adults with varying levels of cognitive decline. Therefore, this study aimed to examine how rhythm-motor tasks affect dual task performance and gait control, compared to a traditional cognitive-motor task. Also, it examined whether rhythm-motor tasks are correlated with traditional cognitive-motor task performance and cognitive measures. Eighteen older adults without cognitive impairment participated in this study. Each participant was instructed to walk at self-paced tempo without performing a concurrent task (single walking task and walk while separately performing two types of concurrent tasks: rhythm-motor and cognitive-motor tasks. Rhythm-motor tasks included instrument playing (WalkIP, matching to rhythmic cueing (WalkRC, and instrument playing while matching to rhythmic cueing (WalkIP+RC. The cognitive-motor task involved counting forward by 3s (WalkCount.f3. In each condition, dual task costs (DTC, a measure for how dual tasks affect gait parameters, were measured in terms of walking speed and stride length. The ratio of stride length to walking speed, a measure for dynamic control of gait, was also examined. The results of this study demonstrated that the task type was found to significantly influence these measures. Rhythm-motor tasks were found to interfere with gait parameters to a lesser extent than the cognitive-motor task (WalkCount.f3. In terms of ratio measures, stride length remained at a similar level, walking speed greatly decreased in the WalkCount.f3 condition. Significant correlations between dual task-related measures during rhythm-motor and cognitive-motor tasks support the

  16. Price of Water

    Science.gov (United States)

    Survilo, Josifs; Boreiko, Dmitrijs

    2009-01-01

    There are watercourses on the globe which as yet do not deliver up their energy to the needs of the people. How much energy their waters bear, is it worth to take away this energy? Those and alike questions must be (and they are) answered before start to build hydro power station. Similar problems must be solved to control hydro power plants in most gainful way which is known as hydrothermal coordination. The notion of price of water can be met lately in technical literature as one of numerical indices of these issues. The gross price of water and net price of water are considered in this paper. Gross price of 1 t water is the price of electric energy obtained by conversion of potential energy of 1 t of water, lifted to a height of power station water head. Net price of water is the difference between gross price and total expenses determined by hydro power station building and its exploitation costs in a year related to 1 m3 of water. If net price of water is positive, it is worth building power station. The greater net price is, the more urgent is the building. Net price of water grows with water head but it continues only to some height of the dam because further increase of head sharply increases capital outlay and other exploitation expenses. To maximize net price of water, optimization of net price function can be done. Net price of water diminishes when some amount of water is diverted for other needs. When amount of diverted water is out of discussion, no controversy can emerge. However when by diverted water some goods with some monetary worth can be obtained, the task must be solved how much water can be diverted so that the water of watercourse be used to the maximum benefit. The environmental issues must be taken into account as well.

  17. Multiobjective decision-making in integrated water management

    NARCIS (Netherlands)

    Wind, H.G.; Pouwels, I.H.M.; Pouwels, I.H.M.; Witter, V.J.

    1995-01-01

    Traditionally, decision-making by water authorities in the Netherlands is largely based on intuition. Their tasks were, after all, relatively few and straight-forward. The growing number of tasks, together with the new integrated approach on water management issues, however, induces water

  18. On the importance of Task 1 and error performance measures in PRP dual-task studies

    Directory of Open Access Journals (Sweden)

    Tilo eStrobach

    2015-04-01

    Full Text Available The Psychological Refractory Period (PRP paradigm is a dominant research tool in the literature on dual-task performance. In this paradigm a first and second component task (i.e., Task 1 and 2 are presented with variable stimulus onset asynchronies (SOAs and priority to perform Task 1. The main indicator of dual-task impairment in PRP situations is an increasing Task 2-RT with decreasing SOAs. This impairment is typically explained with some task components being processed strictly sequentially in the context of the prominent central bottleneck theory. This assumption could implicitly suggest that processes of Task 1 are unaffected by Task 2 and bottleneck processing, i.e. decreasing SOAs do not increase RTs and error rates of the first task. The aim of the present review is to assess whether PRP dual-task studies included both RT and error data presentations and statistical analyses and whether studies including both data types (i.e., RTs and error rates show data consistent with this assumption (i.e., decreasing SOAs and unaffected RTs and/ or error rates in Task 1. This review demonstrates that, in contrast to RT presentations and analyses, error data is underrepresented in a substantial number of studies. Furthermore, a substantial number of studies with RT and error data showed a statistically significant impairment of Task 1 performance with decreasing SOA. Thus, these studies produced data that is not primarily consistent with the strong assumption that processes of Task 1 are unaffected by Task 2 and bottleneck processing in the context of PRP dual-task situations; this calls for a more careful report and analysis of Task 1 performance in PRP studies and for a more careful consideration of theories proposing additions to the bottleneck assumption, which are sufficiently general to explain Task 1 and Task 2 effects.

  19. Task-focused modeling in automated agriculture

    Science.gov (United States)

    Vriesenga, Mark R.; Peleg, K.; Sklansky, Jack

    1993-01-01

    Machine vision systems analyze image data to carry out automation tasks. Our interest is in machine vision systems that rely on models to achieve their designed task. When the model is interrogated from an a priori menu of questions, the model need not be complete. Instead, the machine vision system can use a partial model that contains a large amount of information in regions of interest and less information elsewhere. We propose an adaptive modeling scheme for machine vision, called task-focused modeling, which constructs a model having just sufficient detail to carry out the specified task. The model is detailed in regions of interest to the task and is less detailed elsewhere. This focusing effect saves time and reduces the computational effort expended by the machine vision system. We illustrate task-focused modeling by an example involving real-time micropropagation of plants in automated agriculture.

  20. Role of Working Memory in Task Switching

    Directory of Open Access Journals (Sweden)

    André Vandierendonck

    2012-09-01

    Full Text Available A review shows that task switching under memory load yields variable patterns of findings with some studies showing no interaction at all, while other studies provide evidence for an interaction. A model of working memory is presented consisting of a declarative storage component for instantiation of information and an executive storage module that contains task sets and task rules. The model is applied to two studies with very similar methodologies but yielding contrasting results, namely the task-span procedure (Logan, 2004 and the time-based resource sharing procedure (Liefooghe, Barrouillet, Vandierendonck, & Camos, 2008, when task switching is performed under a working memory load. The model accounts for the contradictory results, supporting the general hypothesis that task switching calls on working memory.

  1. Water and Energy Sustainability: A Balance of Government Action and Industry Innovation

    Energy Technology Data Exchange (ETDEWEB)

    Ben Grunewald

    2009-12-31

    By completing the tasks and subtasks of the project, the Ground Water Protection Council (GWPC) through its state regulatory agency members and oil and gas industry partners, will bring attention to water quality and quantity issues and make progress toward water and energy sustainability though enhanced water protection and conservation thus enhancing the viability of the domestic fossil fuel industry. The project contains 4 major independent Tasks. Task 1 - Work Plan: Water-Energy Sustainability: A Symposium on Resource Viability. Task 2 - Work Plan: A Regional Assessment of Water and Energy Sustainability. Task 3 - Work Plan: Risk Based Data Management System-Water Water and Energy Module. Task 4 - Work Plan: Identification and Assessment of States Regulatory Programs Regarding Geothermal Heating and Cooling Systems. Each task has a specific scope (details given).

  2. Intellectual productivity under task ambient lighting

    OpenAIRE

    Ishii, Hirotake; Kanagawa, Hidehiro; Shimamura, Yuta; Uchiyama, Kosuke; Miyagi, Kazune; Obayashi, Fumiaki; Shimoda, Hiroshi

    2016-01-01

    A subjective experiment was conducted to evaluate intellectual productivity in three lighting conditions: (a) conventional ambient lighting, (b) task ambient lighting with normal colour temperature (5000 K), and (c) task ambient lighting with high colour temperature (6200 K). In the experiment, cognitive tasks were given to 24 participants. The concentration time ratio, which is a quantitative and objective evaluation index of the degree of concentration, was measured. The results showed that...

  3. Pressurized fluidized-bed hydroretorting of eastern oil shales. Volume 4, Task 5, Operation of PFH on beneficiated shale, Task 6, Environmental data and mitigation analyses and Task 7, Sample procurement, preparation, and characterization: Final report, September 1987--May 1991

    Energy Technology Data Exchange (ETDEWEB)

    1992-03-01

    The objective of Task 5 (Operation of Pressurized Fluidized-Bed Hydro-Retorting (PFH) on Beneficiated Shale) was to modify the PFH process to facilitate its use for fine-sized, beneficiated Eastern shales. This task was divided into 3 subtasks: Non-Reactive Testing, Reactive Testing, and Data Analysis and Correlations. The potential environment impacts of PFH processing of oil shale must be assessed throughout the development program to ensure that the appropriate technologies are in place to mitigate any adverse effects. The overall objectives of Task 6 (Environmental Data and Mitigation Analyses) were to obtain environmental data relating to PFH and shale beneficiation and to analyze the potential environmental impacts of the integrated PFH process. The task was divided into the following four subtasks. Characterization of Processed Shales (IGT), 6.2. Water Availability and Treatment Studies, 6.3. Heavy Metals Removal and 6.4. PFH Systems Analysis. The objective of Task 7 (Sample Procurement, Preparation, and Characterization) was to procure, prepare, and characterize raw and beneficiated bulk samples of Eastern oil shale for all of the experimental tasks in the program. Accomplishments for these tasks are presented.

  4. Hemispheric asymmetries in reading Korean: task matters.

    Science.gov (United States)

    Vaid, J; Park, K

    1997-06-01

    Native Korean readers were studied in a visual half-field paradigm. Subjects were to make speeded judgments on Hangul (syllabic) and Hanzza (logographic) scripts based on phonetic or visual properties of the stimuli. A task by visual field interaction was obtained indicating that, for both scripts, responses on the phonetic task were faster in the right visual field, whereas no visual field differences were found on the visual task. Script type did not interact with visual field. The results support a task-based account of hemispheric differences in verbal processing.

  5. Guessing versus choosing an upcoming task

    Directory of Open Access Journals (Sweden)

    Thomas eKleinsorge

    2016-03-01

    Full Text Available We compared the effects of guessing versus choosing an upcoming task. In a task-switching paradigm with four tasks, two groups of participants were asked to either guess or choose which task will be presented next under otherwise identical conditions. The upcoming task corresponded to participants' guesses or choices in 75 % of the trials. However, only participants in the Choosing condition were correctly informed about this, whereas participants in the Guessing condition were told that tasks were determined at random. In the Guessing condition, we replicated previous findings of a pronounced reduction of switch costs in case of incorrect guesses. This switch cost reduction was considerably less pronounced with denied choices in the Choosing condition. We suggest that in the Choosing condition, the signaling of prediction errors associated with denied choices is attenuated because a certain proportion of denied choices is consistent with the overall representation of the situation as conveyed by task instructions. In the Guessing condition, in contrast, the mismatch of guessed and actual task is resolved solely on the level of individual trials by strengthening the representation of the actual task.

  6. Task search in a human computation market

    OpenAIRE

    Chilton, Lydia B.; Miller, Robert C.; Horton, John J.; Azenkot, Shiri

    2010-01-01

    In order to understand how a labor market for human computation functions, it is important to know how workers search for tasks. This paper uses two complementary methods to gain insight into how workers search for tasks on Mechanical Turk. First, we perform a high frequency scrape of 36 pages of search results and analyze it by looking at the rate of disappearance of tasks across key ways Mechanical Turk allows workers to sort tasks. Second, we present the results of a survey in which we pai...

  7. U.S. Preventive Services Task Force

    Science.gov (United States)

    ... for Guideline Development About the USPSTF Our Members Conflict of Interest Disclosures Task Force Resources Our ... Announcements Final Research Plan: Screening for Hepatitis B Virus Infection in ...

  8. Beads task vs. box task: The specificity of the jumping to conclusions bias.

    Science.gov (United States)

    Balzan, Ryan P; Ephraums, Rachel; Delfabbro, Paul; Andreou, Christina

    2017-09-01

    Previous research involving the probabilistic reasoning 'beads task' has consistently demonstrated a jumping-to-conclusions (JTC) bias, where individuals with delusions make decisions based on limited evidence. However, recent studies have suggested that miscomprehension may be confounding the beads task. The current study aimed to test the conventional beads task against a conceptually simpler probabilistic reasoning "box task" METHODS: One hundred non-clinical participants completed both the beads task and the box task, and the Peters et al. Delusions Inventory (PDI) to assess for delusion-proneness. The number of 'draws to decision' was assessed for both tasks. Additionally, the total amount of on-screen evidence was manipulated for the box task, and two new box task measures were assessed (i.e., 'proportion of evidence requested' and 'deviation from optimal solution'). Despite being conceptually similar, the two tasks did not correlate, and participants requested significantly less information on the beads task relative to the box task. High-delusion-prone participants did not demonstrate hastier decisions on either task; in fact, for box task, this group was observed to be significantly more conservative than low-delusion-prone group. Neither task was incentivized; results need replication with a clinical sample. Participants, and particularly those identified as high-delusion-prone, displayed a more conservative style of responding on the novel box task, relative to the beads task. The two tasks, whilst conceptually similar, appear to be tapping different cognitive processes. The implications of these results are discussed in relation to the JTC bias and the theoretical mechanisms thought to underlie it. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. The functional neuroanatomy of multitasking: combining dual tasking with a short term memory task.

    Science.gov (United States)

    Deprez, Sabine; Vandenbulcke, Mathieu; Peeters, Ron; Emsell, Louise; Amant, Frederic; Sunaert, Stefan

    2013-09-01

    Insight into the neural architecture of multitasking is crucial when investigating the pathophysiology of multitasking deficits in clinical populations. Presently, little is known about how the brain combines dual-tasking with a concurrent short-term memory task, despite the relevance of this mental operation in daily life and the frequency of complaints related to this process, in disease. In this study we aimed to examine how the brain responds when a memory task is added to dual-tasking. Thirty-three right-handed healthy volunteers (20 females, mean age 39.9 ± 5.8) were examined with functional brain imaging (fMRI). The paradigm consisted of two cross-modal single tasks (a visual and auditory temporal same-different task with short delay), a dual-task combining both single tasks simultaneously and a multi-task condition, combining the dual-task with an additional short-term memory task (temporal same-different visual task with long delay). Dual-tasking compared to both individual visual and auditory single tasks activated a predominantly right-sided fronto-parietal network and the cerebellum. When adding the additional short-term memory task, a larger and more bilateral frontoparietal network was recruited. We found enhanced activity during multitasking in components of the network that were already involved in dual-tasking, suggesting increased working memory demands, as well as recruitment of multitask-specific components including areas that are likely to be involved in online holding of visual stimuli in short-term memory such as occipito-temporal cortex. These results confirm concurrent neural processing of a visual short-term memory task during dual-tasking and provide evidence for an effective fMRI multitasking paradigm. © 2013 Elsevier Ltd. All rights reserved.

  10. Drug and alcohol task force

    Energy Technology Data Exchange (ETDEWEB)

    Gordey, T. [ConocoPhillips Canada Resources Corp., Calgary, AB (Canada); Sunstrum, M. [Enform, Calgary, AB (Canada)

    2006-07-01

    Worker absenteeism due to substance abuse costs the Alberta economy approximately $720 million a year. It is estimated that 20 per cent of all drivers in fatal crashes were using alcohol, and the use of cannabis and cocaine in Alberta has more than doubled over the last 15 years. In addition, 1 in 10 Alberta workers have reported using alcohol while at work and 4 per cent have reported using alcohol 4 hours prior to coming to work during the previous 12 months. In an effort to ensure appropriate health and safety for workers in the Canadian petroleum industry, 6 trade associations in the sector have joined together as the Enform Alcohol and Drug Initiative and are now working to develop a common approach to drug and alcohol guidelines and workplace rules. The task group will determine if existing policies and guidelines are sufficient to ensure a safe workplace and will consider standardizing the testing, application and rehabilitation of workers with respect to the use of drugs and alcohol. In the past, disciplinary actions have often been reversed because employers have not been consistent or did not follow established alcohol and drug policies or test to specific standards. Various work rules for inappropriate alcohol and drug use were reviewed, as well as education and communication strategies regarding policy content. Standards for testing criteria were discussed, as well as issues concerning duty-to-accommodate circumstances. An excerpt of concentration standards was presented. It was concluded that a matrix for companies to assess and determine safety sensitive positions is needed. refs., tabs., figs.

  11. Dual-Task Processing When Task 1 Is Hard and Task 2 Is Easy: Reversed Central Processing Order?

    Science.gov (United States)

    Leonhard, Tanja; Fernandez, Susana Ruiz; Ulrich, Rolf; Miller, Jeff

    2011-01-01

    Five psychological refractory period (PRP) experiments were conducted with an especially time-consuming first task (Experiments 1, 3, and 5: mental rotation; Experiments 2 and 4: memory scanning) and with equal emphasis on the first task and on the second (left-right tone judgment). The standard design with varying stimulus onset asynchronies…

  12. Water Rights in Bolivia — After the Water War | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2010-12-08

    Dec 8, 2010 ... Achieving Water Rights Consensus in Bolivia This was the challenge: help broker broad-based consensus on water legislation in Bolivia in the wake of violent social conflict over water rights — and after 32 previous attempts at introducing water legislation had failed. A daunting task, yet IDRC-supported ...

  13. Some Reflections on Task-Based Language Performance Assessment.

    Science.gov (United States)

    Bachman, Lyle F.

    2002-01-01

    Discusses problems in task-based language assessment, including the definition and sampling of tasks, generalizations across tasks, interpretations about broad ability and language use domains, and the notion of task difficulty. (Author/VWL)

  14. SOCIAL MEDIA MINING SHARED TASK WORKSHOP.

    Science.gov (United States)

    Sarker, Abeed; Nikfarjam, Azadeh; Gonzalez, Graciela

    2016-01-01

    Social media has evolved into a crucial resource for obtaining large volumes of real-time information. The promise of social media has been realized by the public health domain, and recent research has addressed some important challenges in that domain by utilizing social media data. Tasks such as monitoring flu trends, viral disease outbreaks, medication abuse, and adverse drug reactions are some examples of studies where data from social media have been exploited. The focus of this workshop is to explore solutions to three important natural language processing challenges for domain-specific social media text: (i) text classification, (ii) information extraction, and (iii) concept normalization. To explore different approaches to solving these problems on social media data, we designed a shared task which was open to participants globally. We designed three tasks using our in-house annotated Twitter data on adverse drug reactions. Task 1 involved automatic classification of adverse drug reaction assertive user posts; Task 2 focused on extracting specific adverse drug reaction mentions from user posts; and Task 3, which was slightly ill-defined due to the complex nature of the problem, involved normalizing user mentions of adverse drug reactions to standardized concept IDs. A total of 11 teams participated, and a total of 24 (18 for Task 1, and 6 for Task 2) system runs were submitted. Following the evaluation of the systems, and an assessment of their innovation/novelty, we accepted 7 descriptive manuscripts for publication--5 for Task 1 and 2 for Task 2. We provide descriptions of the tasks, data, and participating systems in this paper.

  15. Different neuroplasticity for task targets and distractors.

    Directory of Open Access Journals (Sweden)

    Elsie Y Spingath

    2011-01-01

    Full Text Available Adult learning-induced sensory cortex plasticity results in enhanced action potential rates in neurons that have the most relevant information for the task, or those that respond strongly to one sensory stimulus but weakly to its comparison stimulus. Current theories suggest this plasticity is caused when target stimulus evoked activity is enhanced by reward signals from neuromodulatory nuclei. Prior work has found evidence suggestive of nonselective enhancement of neural responses, and suppression of responses to task distractors, but the differences in these effects between detection and discrimination have not been directly tested. Using cortical implants, we defined physiological responses in macaque somatosensory cortex during serial, matched, detection and discrimination tasks. Nonselective increases in neural responsiveness were observed during detection learning. Suppression of responses to task distractors was observed during discrimination learning, and this suppression was specific to cortical locations that sampled responses to the task distractor before learning. Changes in receptive field size were measured as the area of skin that had a significant response to a constant magnitude stimulus, and these areal changes paralleled changes in responsiveness. From before detection learning until after discrimination learning, the enduring changes were selective suppression of cortical locations responsive to task distractors, and nonselective enhancement of responsiveness at cortical locations selective for target and control skin sites. A comparison of observations in prior studies with the observed plasticity effects suggests that the non-selective response enhancement and selective suppression suffice to explain known plasticity phenomena in simple spatial tasks. This work suggests that differential responsiveness to task targets and distractors in primary sensory cortex for a simple spatial detection and discrimination task arise from

  16. Mental engagement during cognitive and psychomotor tasks: Effects of task type, processing demands, and practice.

    Science.gov (United States)

    Pendleton, Daniel M; Sakalik, Monica L; Moore, Morgan L; Tomporowski, Phillip D

    2016-11-01

    Measures of heart rate variability (HRV) are hypothesized to provide indices of mental engagement (ME). HRV and perceived workload were measured to determine whether ME is moderated by task type, processing demands, and practice. Twenty four (22±3yrs.) participants were assigned to groups that performed either two executive-processing (EF) tasks or two non-executive processing (NEF) tasks. Across 3 sessions, participants practiced a cognitive computer-based cognitive task and a psychomotor task. HR was recorded for 5-min epochs before and during each task; workload ratings were recorded following each task. ANOVAs revealed that participants' HRV decreased when performing cognitive and psychomotor tasks; the decline was greater, however, for NEF tasks. Over sessions, HRV increased during EF but not NEF tasks; workload scores lessened during EF but not NEF tasks. ME was intensified when participants learned novel cognitive and psychomotor tasks; however, the intensity level depended on the task, and its maintenance was altered with practice. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. [Long-term drinking purified water may aggravate the inhibition of NMDA expression and spatial learning ability induced by lead on rat].

    Science.gov (United States)

    Chen, Qiang; Shu, Wei-qun; Zeng, Hui; Luo, Jiao-hua; Fu, Wen-juan

    2008-06-01

    To compare brain lead accumulation and neurotoxicity induced by lead under drinking purified water and tap water on rat. All 104 male weaning SD rats were randomly divided into eight groups, matched-four pairs according to drinking water: tap water, purified water, tap water with lead 50 mg/L(lead acetate water-solution), purified water with lead 50 mg/L, tap water with lead 200 mg/L, purified water with lead 200 mg/L, tap water with lead 800 mg/L. All were fed with normal food and environmental cognitions kept consistent Morris water maze(including Place Navigation, Spatial Probe Test, Visible Platform Trial) was measured to test rat spatial learning at the 12 and 24 week. At the end of the experiment (28 week), rats were killed and the lead of brain and blood was measured by Graphite furnace atomic absorption spectrometric method; the NR1, NR2A, NR2B of NMDAR (N-methyl-D-aspartame receptor) in hippocampus were analyzed by RT-PCR. Under the same lead exposure, no significant differences were observed in blood lead, however, brain lead level showed higher in drinking purified water group than that in tap water group. Expression of NR1, NR2A and NR2B in hippocampus of the rats drinking purified water was lower than those drinking tap water, especially at low lead exposure (50 mg/L) (P water maze, place navigation test's escape latency showed significantly prolonged at the rats drinking purified water as compared with those drinking tap water on the pairs of 50 mg/L and 200 mg/L pb2+ groups (P water, drinking purified water might increase the accumulation of brain lead, lower NR1, NR2A, NR2B expression and delay the spatial learning and memory ability under chronic lead exposure in water.

  18. Assigning sporadic tasks to unrelated machines

    NARCIS (Netherlands)

    Marchetti-Spaccamela, A.; Rutten, C.; van der Ster, S.L.; Wiese, A.

    2015-01-01

    We study the problem of assigning sporadic tasks to unrelated machines such that the tasks on each machine can be feasibly scheduled. Despite its importance for modern real-time systems, this problem has not been studied before. We present a polynomial-time algorithm which approximates the problem

  19. Brief Family Therapy: A Metaphorical Task.

    Science.gov (United States)

    de Shazer, Steve

    1980-01-01

    Presents a therapeutic procedure designed to prescribe the family's troublesome behavior pattern. A complement precedes delivering a task assignment. The metaphorical task redefines the serious complaint pattern into only one of the many options a family has for dealing with each other. A case study is presented. (Author/BEF)

  20. Distributed Task Allocation in Social Networks

    NARCIS (Netherlands)

    De Weerdt, M.M.; Zhang, Y.; Klos, T.

    2007-01-01

    This paper proposes a new variant of the task allocation problem, where the agents are connected in a social network and tasks arrive at the agents distributed over the network. We show that the complexity of this problem remains NPhard. Moreover, it is not approximable within some factor. We