Pyrethroid insecticides evoke neurotransmitter release from rabbit striatal slices

International Nuclear Information System (INIS)

Eells, J.T.; Dubocovich, M.L.

1988-01-01

The effects of the synthetic pyrethroid insecticide fenvalerate ([R,S]-alpha-cyano-3-phenoxybenzyl[R,S]-2-(4-chlorophenyl)-3- methylbutyrate) on neurotransmitter release in rabbit brain slices were investigated. Fenvalerate evoked a calcium-dependent release of [ 3 H]dopamine and [ 3 H]acetylcholine from rabbit striatal slices that was concentration-dependent and specific for the toxic stereoisomer of the insecticide. The release of [ 3 H]dopamine and [ 3 H]acetylcholine by fenvalerate was modulated by D2 dopamine receptor activation and antagonized completely by the sodium channel blocker, tetrodotoxin. These findings are consistent with an action of fenvalerate on the voltage-dependent sodium channels of the presynaptic membrane resulting in membrane depolarization, and the release of dopamine and acetylcholine by a calcium-dependent exocytotic process. In contrast to results obtained in striatal slices, fenvalerate did not elicit the release of [ 3 H]norepinephrine or [ 3 H]acetylcholine from rabbit hippocampal slices indicative of regional differences in sensitivity to type II pyrethroid actions

The effect of nucleotides and adenosine on stimulus-evoked glutamate release from rat brain cortical slices.

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Bennett, G C; Boarder, M R

2000-10-01

Evidence has previously been presented that P1 receptors for adenosine, and P2 receptors for nucleotides such as ATP, regulate stimulus-evoked release of biogenic amines from nerve terminals in the brain. Here we investigated whether adenosine and nucleotides exert presynaptic control over depolarisation-elicited glutamate release. Slices of rat brain cortex were perfused and stimulated with pulses of 46 mM K(+) in the presence of the glutamate uptake inhibitor L-trans-pyrrolidine-2,4-dicarboxylic acid (0.2 mM). High K(+) substantially increased efflux of glutamate from the slices. Basal glutamate release was unchanged by the presence of nucleotides or adenosine at concentrations of 300 microM. Adenosine, ATP, ADP and adenosine 5'-O-(3-thiotriphoshate) at 300 microM attenuated depolarisation-evoked release of glutamate. However UTP, 2-methylthio ATP, 2-methylthio ADP, and alpha,beta-methylene ATP at 300 microM had no effect on stimulated glutamate efflux. Adenosine deaminase blocked the effect of adenosine, but left the response to ATP unchanged. The A(1) antagonist 8-cyclopentyl-1, 3-dipropylxanthine antagonised the inhibitory effect of both adenosine and ATP. Cibacron blue 3GA inhibited stimulus-evoked glutamate release when applied alone. When cibacron blue 3GA was present with ATP, stimulus-evoked glutamate release was almost eliminated. However, this P2 antagonist had no effect on the inhibition by adenosine. These results show that the release of glutamate from depolarised nerve terminals of the rat cerebral cortex is inhibited by adenosine and ATP. ATP appears to act directly and not through conversion to adenosine.

SNT-1 functions as the Ca2+ sensor for tonic and evoked neurotransmitter release in C. elegans.

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Li, Lei; Liu, Haowen; Wang, Wei; Chandra, Mintu; Collins, Brett M; Hu, Zhitao

2018-05-14

Synaptotagmin-1 (Syt1) binds Ca 2+ through its tandem C2 domains (C2A and C2B) and triggers Ca 2+ -dependent neurotransmitter release. Here we show that snt-1 , the homolog of mammalian Syt1, functions as the Ca 2+ sensor for both tonic and evoked neurotransmitter release at the C. elegans neuromuscular junction. Mutations that disrupt Ca 2+ binding in double C2 domains of SNT-1 significantly impaired tonic release, whereas disrupting Ca 2+ binding in a single C2 domain had no effect, indicating that the Ca 2+ binding of the two C2 domains is functionally redundant for tonic release. Stimulus-evoked release was significantly reduced in snt-1 mutants, with prolonged release latency as well as faster rise and decay kinetics. Unlike tonic release, evoked release was triggered by Ca 2+ binding solely to the C2B domain. Moreover, we showed that SNT-1 plays an essential role in the priming process in different subpopulations of synaptic vesicles with tight or loose coupling to Ca 2+ entry. SIGNIFICANCE STATEMENT We showed that SNT-1 in C. elegans regulates evoked neurotransmitter release through Ca 2+ binding to its C2B domain, a similar way to Syt1 in the mouse CNS and the fly NMJ. However, the largely decreased tonic release in snt-1 mutants argues SNT-1 has a clamping function. Indeed, Ca 2+ -binding mutations in the C2 domains in SNT-1 significantly reduced the frequency of the miniature excitatory postsynaptic current (mEPSC), indicating that SNT-1 also acts as a Ca 2+ sensor for tonic release. Therefore, revealing the differential mechanisms between invertebrates and vertebrates will provide significant insights into our understanding how synaptic vesicle fusion is regulated. Copyright © 2018 the authors.

Dopamine versus noradrenaline in septic shock

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Bo Xu

2011-10-01

Full Text Available BackgroundThe ‘Surviving Sepsis’ Campaign guidelines recommend theuse of dopamine or noradrenaline as the first vasopressor inseptic shock. However, information that guides clinicians inchoosing between dopamine and noradrenaline as the firstvasopressor in patients with septic shock is limited.ObjectiveThis article presents a review of the literature regarding theuse of dopamine versus noradrenaline in patients with septicshock.ResultsTwo randomised controlled trials (RCT and two largeprospective cohort studies were analysed. RCT data showeddopamine was associated with increased arrhythmic events.One cohort study found dopamine was associated with higher30-day mortality. The other cohort study found noradrenalinewas associated with higher 28-day mortality.DiscussionData on the use of dopamine versus noradrenaline in patientswith septic shock is limited. Following the recent SOAP IIstudy, there is now strong evidence that the use of dopaminein septic shock is associated with significantly morecardiovascular adverse events, compared tonoradrenaline.ConclusionNoradrenaline should be used as the initial vasopressor inseptic shock to avoid the arrhythmic events associatedwith dopamine.

Tonic inhibition by orphanin FQ/nociceptin of noradrenaline neurotransmission in the amygdala

NARCIS (Netherlands)

Kawahara, Y; Hesselink, M.B.; van Scharrenburg, G; Westerink, B.H.C.

2004-01-01

The present microdialysis study investigated whether nociceptin/orphanin FQ exerts a tonic inhibition of the release of noradrenaline in the basolateral nucleus of the amygdala in awake rats. The non-peptide competitive nociceptin/orphanin FQ (N/OFQ) peptide receptor antagonist J-113397 (20 mg/kg

The distribution of 3H-(+-)noradrenaline in rabbit aortic strips after inhibition of the noradrenaline-metabolizing enzymes

International Nuclear Information System (INIS)

Henseling, M.; Eckert, E.; Trendelenburg, U.

1976-01-01

Rabbit aortic strips (nerve-free, reserpine pretreated or normal) whose noradrenaline-metabolizing enzymes were inhibited (by in vitro treatment with 0.5 mM pargyline for 30 min and by the presence of 0.1 mM U-0521) were exposed to 1.18 μM 3 H-(+-)noradrenaline for 30 min (in most experiments). At the end of the incubation some strips were used for anlysis of radioactivity (i.e., of noradrenaline and its metabolites), while for others the efflux of radioactivity was determined during 240 min of wash out with amine-free solution. An estimate of the original distribution of the amine into the various extraneuronal and neuronal compartments of the tissue was obtained by compartmental analysis of the efflux curves. Extracellular amine distributes into 'compartment I + II' (characterized by a half time for efflux of 14 C-sorbitol. The extraneuronal accumulation of noradrenaline is a quickly equilibrating process which involves compartments III and IV (with half times for efflux of 3 and 11 min, respectively). Compartment IV represents not only extraneuronally but also neuronally distributed noradrenaline. The neuronal accumulation of noradrenaline is a slowly equilibrating process which can be subdivided into axoplasmic and vesicular accumulation. The results support the view that the rate of relaxation (of strips initially exposed to noradrenaline and then washed out) is affected by the efflux of unchanged amine form extraneuronal and neuronal stores. (orig./GSE) [de

The effects of C-type natriuretic peptide on catecholamine release in the pacific spiny dogfish (Squalus acanthias).

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Montpetit, C J; McKendry, J; Perry, S F

2001-08-01

The interaction between homologous C-type natriuretic peptide (dfCNP) and catecholamine release in cardiovascular control was assessed in the marine dogfish (Squalus acanthias). This was accomplished by evaluation of the dynamics of the dfCNP-elicited secretion of catecholamines in situ and in vivo. With an in situ saline-perfused postcardinal sinus preparation, it was demonstrated that perfusion with saline containing dfCNP (10(-9) mol x L(-1)) did not affect the secretion of either noradrenaline or adrenaline. However, the presence of dfCNP in the perfusate significantly enhanced carbachol-evoked secretion of noradrenaline. In vivo, intravascular injection of dfCNP (10(-9) mol x kg(-1)) caused a biphasic pressor-depressor response consisting of a brief increase in caudal artery blood pressure (P(CA)) followed by a prolonged reduction in P(CA). Furthermore, although systemic resistance initially increased, it was subsequently maintained at baseline values in the face of persistent decreases in both P(CA) and cardiac output. Bolus injection of dfCNP elicited significant increases in plasma noradrenaline levels that peaked within 10 min; plasma adrenaline levels were unaffected. The release of noradrenaline elicited by dfCNP was unaffected by prior blockade of the renin-angiotensin system (RAS) (with the angiotensin converting enzyme inhibitor lisinopril) or by pretreatment with the nicotinic receptor blocker hexamethonium. The delayed decrease in P(CA) was not observed in the hexamethonium-treated fish. Prior blockade of beta-adrenoreceptors (with sotalol) or alpha-adrenoreceptors (with prazosin) either significantly reduced (sotalol) or abolished (prazosin) the increase in plasma noradrenaline levels after dfCNP injection. The results of this investigation demonstrate that the elevation of plasma noradrenaline levels observed in vivo following dfCNP injection is not caused by a direct effect of dfCNP on catecholamine secretion from axillary body chromaffin cells

Distribution of /sup 3/H-(+-)noradrenaline in rabbit aortic strips after inhibition of the noradrenaline-metabolizing enzymes

Energy Technology Data Exchange (ETDEWEB)

Henseling, M; Eckert, E; Trendelenburg, U [Wuerzburg Univ. (Germany, F.R.). Inst. fuer Pharmakologie und Toxikologie

1976-01-01

Rabbit aortic strips (nerve-free, reserpine pretreated or normal) whose noradrenaline-metabolizing enzymes were inhibited (by in vitro treatment with 0.5 mM pargyline for 30 min and by the presence of 0.1 mM U-0521) were exposed to 1.18 ..mu..M /sup 3/H-(+-)noradrenaline for 30 min (in most experiments). At the end of the incubation some strips were used for anlysis of radioactivity (i.e., of noradrenaline and its metabolites), while for others the efflux of radioactivity was determined during 240 min of wash out with amine-free solution. An estimate of the original distribution of the amine into the various extraneuronal and neuronal compartments of the tissue was obtained by compartmental analysis of the efflux curves. Extracellular amine distributes into 'compartment I + II' (characterized by a half time for efflux of < 1 min); compartment size and half time for efflux were similar to those obtained for /sup 14/C-sorbitol. The extraneuronal accumulation of noradrenaline is a quickly equilibrating process which involves compartments III and IV (with half times for efflux of 3 and 11 min, respectively). Compartment IV represents not only extraneuronally but also neuronally distributed noradrenaline. The neuronal accumulation of noradrenaline is a slowly equilibrating process which can be subdivided into axoplasmic and vesicular accumulation. The results support the view that the rate of relaxation (of strips initially exposed to noradrenaline and then washed out) is affected by the efflux of unchanged amine form extraneuronal and neuronal stores.

Stereoselectivity of the distribution of labelled noradrenaline in rabbit aortic strips after inhibition of the noradrenaline-metabolizing enzymes

Energy Technology Data Exchange (ETDEWEB)

Eckert, E; Henseling, M; Gescher, A; Trendelenburg, U [Wuerzburg Univ. (Germany, F.R.). Inst. fuer Pharmakologie und Toxikologie

1976-01-01

Rabbit aortic strips (nerve-free, reserpinepretreated or normal) whose noradrenaline-metabolizing enzymes were inhibited (by in vitro treatment with 0.5 mM pargyline for 30 min and by the presence of 0.1 mM U-0521) were exposed to 1.18 ..mu..M labelled (-)- or (+)noradrenaline for 30 min. At the end of the incubation period some strips were used for analysis of radioactivity (i.e., of noradrenaline and its metabolites), while for others the efflux of radioactivity was determined during 250 min of washout with amine-free solution. An estimate of the original distribution of the amine into the various extraneuronal and neuronal compartments of the tissue was obtained by compartmental analysis of the efflux curves. The mechanisms responsible for the accumulation of radioactivity in extraneuronal and axoplasmic compartments lack stereoselectivity; the rate constants for the efflux of radioactivity from these compartments are the same for (-)- and (+)noradrenaline. Despite the use of enzyme inhibitors, the 'late neuronal efflux' of radioactivity (i.e., the efflux collected between the 200th and 250th min of wash out) contained a considerable proportion of metabolites of noradrenaline. The metabolism of noradrenaline was stereoselective: while dihydroxyphenylglycol (DOPEG) was the predominant metabolite in the efflux from strips incubated with (-)noradrenaline, a considerable part of the efflux from strips incubated with the (+)isomer consisted of dihydroxymandelic acid and 'O-methylated and deaminated' metabolites (in addition to DOPEG).

Stereoselectivity of the distribution of labelled noradrenaline in rabbit aortic strips after inhibition of the noradrenaline-metabolizing enzymes

International Nuclear Information System (INIS)

Eckert, E.; Henseling, M.; Gescher, A.; Trendelenburg, U.

1976-01-01

Rabbit aortic strips (nerve-free, reserpinepretreated or normal) whose noradrenaline-metabolizing enzymes were inhibited (by in vitro treatment with 0.5 mM pargyline for 30 min and by the presence of 0.1 mM U-0521) were exposed to 1.18 μM labelled (-)- or (+)noradrenaline for 30 min. At the end of the incubation period some strips were used for analysis of radioactivity (i.e., of noradrenaline and its metabolites), while for others the efflux of radioactivity was determined during 250 min of washout with amine-free solution. An estimate of the original distribution of the amine into the various extraneuronal and neuronal compartments of the tissue was obtained by compartmental analysis of the efflux curves. The mechanisms responsible for the accumulation of radioactivity in extraneuronal and axoplasmic compartments lack stereoselectivity; the rate constants for the efflux of radioactivity from these compartments are the same for (-)- and (+)noradrenaline. Despite the use of enzyme inhibitors, the 'late neuronal efflux' of radioactivity (i.e., the efflux collected between the 200th and 250th min of wash out) contained a considerable proportion of metabolites of noradrenaline. The metabolism of noradrenaline was stereoselective: while dihydroxyphenylglycol (DOPEG) was the predominant metabolite in the efflux from strips incubated with (-)noradrenaline, a considerable part of the efflux from strips incubated with the (+)isomer consisted of dihydroxymandelic acid and 'O-methylated and deaminated' metabolites (in addition to DOPEG). (orig/GSE) [de

Action potential-evoked calcium release is impaired in single skeletal muscle fibers from heart failure patients.

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Marino DiFranco

Full Text Available Exercise intolerance in chronic heart failure (HF has been attributed to abnormalities of the skeletal muscles. Muscle function depends on intact excitation-contraction coupling (ECC, but ECC studies in HF models have been inconclusive, due to deficiencies in the animal models and tools used to measure calcium (Ca2+ release, mandating investigations in skeletal muscle from HF patients. The purpose of this study was to test the hypothesis that Ca2+ release is significantly impaired in the skeletal muscle of HF patients in whom exercise capacity is severely diminished compared to age-matched healthy volunteers.Using state-of-the-art electrophysiological and optical techniques in single muscle fibers from biopsies of the locomotive vastus lateralis muscle, we measured the action potential (AP-evoked Ca2+ release in 4 HF patients and 4 age-matched healthy controls. The mean peak Ca2+ release flux in fibers obtained from HF patients (10±1.2 µM/ms was markedly (2.6-fold and significantly (p<0.05 smaller than in fibers from healthy volunteers (28±3.3 µM/ms. This impairment in AP-evoked Ca2+ release was ubiquitous and was not explained by differences in the excitability mechanisms since single APs were indistinguishable between HF patients and healthy volunteers.These findings prove the feasibility of performing electrophysiological experiments in single fibers from human skeletal muscle, and offer a new approach for investigations of myopathies due to HF and other diseases. Importantly, we have demonstrated that one step in the ECC process, AP-evoked Ca2+ release, is impaired in single muscle fibers in HF patients.

Stress-evoked opioid release inhibits pain in major depressive disorder.

Science.gov (United States)

Frew, Ashley K; Drummond, Peter D

2008-10-15

To determine whether stress-evoked release of endogenous opioids might account for hypoalgesia in major depressive disorder (MDD), the mu-opioid antagonist naltrexone (50mg) or placebo was administered double-blind to 24 participants with MDD and to 31 non-depressed controls. Eighty minutes later participants completed a painful foot cold pressor test and, after a 5-min interval, began a 25-min arithmetic task interspersed with painful electric shocks. Ten minutes later participants completed a second cold pressor test. Negative affect was greater in participants with MDD than in non-depressed controls throughout the experiment, and increased significantly in both groups during mental arithmetic. Before the math task, naltrexone unmasked direct linear relationships between severity of depression, negative affect while resting quietly, and cold-induced pain in participants with MDD. In contrast, facilitatory effects of naltrexone on cold- and shock-induced pain were greatest in controls with the lowest depression scores. Naltrexone strengthened the relationship between negative affect and shock-induced pain during the math task, particularly in the depressed group, and heightened anxiety in both groups toward the end of the task. Thus, mu-opioid activity apparently masked a positive association between negative affect and pain in the most distressed participants. These findings suggest that psychological distress inhibits pain via stress-evoked release of opioid peptides in severe cases of MDD. In addition, tonic endogenous opioid neurotransmission could inhibit depressive symptoms and pain in people with low depression scores.

Characterization of noradrenaline release in the locus coeruleus of freely moving awake rats by in vivo microdialysis.

Science.gov (United States)

Fernández-Pastor, Begoña; Mateo, Yolanda; Gómez-Urquijo, Sonia; Javier Meana, J

2005-07-01

The origin and regulation of noradrenaline (NA) in the locus coeruleus (LC) is unknown. The neurochemical features of NA overflow (nerve impulse dependence, neurotransmitter synthesis, vesicle storage, reuptake, alpha2-adrenoceptor-mediated regulation) were characterized in the LC. Brain microdialysis was performed in awake rats. Dialysates were analyzed for NA. NA in the LC decreased via local infusion of Ca2+-free medium (-42+/-5%) or the sodium channel blocker tetrodotoxine (TTX) (-47+/-8%) but increased (333+/-40%) via KCl-induced depolarization. The tyrosine hydroxylase (TH) inhibitor alpha-methyl-p-tyrosine (250 mg kg(-1), i.p.) and the vesicle depletory drug reserpine (5 mg kg(-1), i.p.) decreased NA. Therefore, extracellular NA in the LC satisfies the criteria for an impulse flow-dependent vesicular exocytosis of neuronal origin. Local perfusion of the alpha2-adrenoceptor agonist clonidine (0.1-100 microM) decreased NA (E(max)=-79+/-5%) in the LC, whereas the opposite effect (E(max)=268+/-53%) was observed with the alpha2A-adrenoceptor antagonist BRL44408 (0.1-100 microM). This suggests a tonic modulation of NA release through local alpha2A-adrenoceptors. The selective NA reuptake inhibitor desipramine (DMI) (0.1-100 microM) administered into the LC increased NA in the LC (E(max)=223+/-40%) and simultaneously decreased NA in the cingulate cortex, confirming the modulation exerted by NA in the LC on firing activity of noradrenergic cells and on the subsequent NA release in noradrenergic terminals. Synaptic processes underlying NA release in the LC are similar to those in noradrenergic terminal areas. NA in the LC could represent local somatodendritic release, but also the presence of neurotransmitter release from collateral axon terminals.

Effect of elevated potassium ion concentrations on electrically evoked release of (/sup 3/H)acetylcholine in slices of rat hippocampus

Energy Technology Data Exchange (ETDEWEB)

Szerb, J C; Hadhazy, P; Dudar, J D [Dalhousie Univ., Halifax, Nova Scotia (Canada). Dept. of Physiology and Biophysics

1978-01-01

To establish the effect of raising the concentration of extracellular potassium ions on axonal conduction and transmitter release in a mammalian central pathway, the septohippocampal cholinergic tract, the rate of (/sup 3/H) acetylcholine release evoked by electrical stimulation was measured in rat hippocampal slices superfused with Krebs' solution containing 3-15 mM K/sup +/. The evoked release of (/sup 3/H) acetylcholine was abolished by the presence of tetrodotoxin or by the omission of Ca/sup 2 +/ in the superfusion medium, indicating that it originated from terminals depolarized by conducted action potentials. Potassium concentrations between 3 and 8 mM had no effect but 10-15 mM K/sup +/ reduced the rate of evoked release and decreased the size of the releasable pool of (/sup 3/H) acetylcholine. Decreasing the sodium content of the Krebs' solution to 97 mM or less had effects similar to those of elevated (K/sup +/). Elevated K/sup +/ (10-15 mM) reversibly reduced the size of compound action potentials in the fimbria and the alveus. The results suggest that extracellular potassium concentrations occurring under physiological conditions do not affect axonal conduction and transmitter release but that both are reduced in pathological states when extracellular (K/sup +/) above 8 mM occur.

Serotonin, dopamine and noradrenaline adjust actions of myelinated afferents via modulation of presynaptic inhibition in the mouse spinal cord.

Directory of Open Access Journals (Sweden)

David L García-Ramírez

Full Text Available Gain control of primary afferent neurotransmission at their intraspinal terminals occurs by several mechanisms including primary afferent depolarization (PAD. PAD produces presynaptic inhibition via a reduction in transmitter release. While it is known that descending monoaminergic pathways complexly regulate sensory processing, the extent these actions include modulation of afferent-evoked PAD remains uncertain. We investigated the effects of serotonin (5HT, dopamine (DA and noradrenaline (NA on afferent transmission and PAD. Responses were evoked by stimulation of myelinated hindlimb cutaneous and muscle afferents in the isolated neonatal mouse spinal cord. Monosynaptic responses were examined in the deep dorsal horn either as population excitatory synaptic responses (recorded as extracellular field potentials; EFPs or intracellular excitatory postsynaptic currents (EPSCs. The magnitude of PAD generated intraspinally was estimated from electrotonically back-propagating dorsal root potentials (DRPs recorded on lumbar dorsal roots. 5HT depressed the DRP by 76%. Monosynaptic actions were similarly depressed by 5HT (EFPs 54%; EPSCs 75% but with a slower time course. This suggests that depression of monosynaptic EFPs and DRPs occurs by independent mechanisms. DA and NA had similar depressant actions on DRPs but weaker effects on EFPs. IC50 values for DRP depression were 0.6, 0.8 and 1.0 µM for 5HT, DA and NA, respectively. Depression of DRPs by monoamines was nearly-identical in both muscle and cutaneous afferent-evoked responses, supporting a global modulation of the multimodal afferents stimulated. 5HT, DA and NA produced no change in the compound antidromic potentials evoked by intraspinal microstimulation indicating that depression of the DRP is unrelated to direct changes in the excitability of intraspinal afferent fibers, but due to metabotropic receptor activation. In summary, both myelinated afferent-evoked DRPs and monosynaptic

Cold urticaria. Dissociation of cold-evoked histamine release and urticara following cold challenge.

Science.gov (United States)

Keahey, T M; Greaves, M W

1980-02-01

Nine patients with acquired cold urticaria were studied to assess the effects of beta-adrenergic agents, xanthines, and corticosteroids on cold-evoked histamine release from skin in vivo. The patients, in all of whom an immediate urticarial response developed after cooling of the forearm, demonstrated release of histamine into the venous blood draining that forearm. Following treatment with aminophylline and albuterol in combination or prednisone alone, suppression of histamine release occurred in all but one patient. In some patients, this was accompanied by a subjective diminution in pruritus or buring, but there was no significant improvement in the ensuing edema or erythema. In one patient, total suppression of histamine release was achieved without any effect on whealing and erythema in response to cold challenge. Our results suggest that histamine is not central to the pathogenesis of vascular changes in acquired cold urticaria.

Differential Activation in Amygdala and Plasma Noradrenaline during Colorectal Distention by Administration of Corticotropin-Releasing Hormone between Healthy Individuals and Patients with Irritable Bowel Syndrome.

Directory of Open Access Journals (Sweden)

Yukari Tanaka

Full Text Available Irritable bowel syndrome (IBS often comorbids mood and anxiety disorders. Corticotropin-releasing hormone (CRH is a major mediator of the stress response in the brain-gut axis, but it is not clear how CRH agonists change human brain responses to interoceptive stimuli. We tested the hypothesis that brain activation in response to colorectal distention is enhanced after CRH injection in IBS patients compared to healthy controls. Brain H215O- positron emission tomography (PET was performed in 16 male IBS patients and 16 age-matched male controls during baseline, no distention, mild and intense distention of the colorectum using barostat bag inflation. Either CRH (2 μg/kg or saline (1:1 was then injected intravenously and the same distention protocol was repeated. Plasma adrenocorticotropic hormone (ACTH, serum cortisol and plasma noradrenaline levels were measured at each stimulation. At baseline, CRH without colorectal distention induced more activation in the right amygdala in IBS patients than in controls. During intense distention after CRH injection, controls showed significantly greater activation than IBS patients in the right amygdala. Plasma ACTH and serum cortisol secretion showed a significant interaction between drug (CRH, saline and distention. Plasma noradrenaline at baseline significantly increased after CRH injection compared to before injection in IBS. Further, plasma noradrenaline showed a significant group (IBS, controls by drug by distention interaction. Exogenous CRH differentially sensitizes brain regions of the emotional-arousal circuitry within the visceral pain matrix to colorectal distention and synergetic activation of noradrenergic function in IBS patients and healthy individuals.

Cutaneous noradrenaline measured by microdialysis in complex regional pain syndrome during whole-body cooling and heating

DEFF Research Database (Denmark)

Terkelsen, Astrid Juhl; Gierthmühlen, Janne; Petersen, Lars J.

2013-01-01

and in healthy volunteers. Seven patients and nine controls completed whole-body cooling (sympathetic activation) and heating (sympathetic inhibition) induced by a whole-body thermal suit with simultaneous measurement of the skin temperature, skin blood flow, and release of dermal noradrenaline. CRPS pain...

Objective measures of binaural masking level differences and comodulation masking release based on late auditory evoked potentials.

Science.gov (United States)

Epp, Bastian; Yasin, Ifat; Verhey, Jesko L

2013-12-01

The audibility of important sounds is often hampered due to the presence of other masking sounds. The present study investigates if a correlate of the audibility of a tone masked by noise is found in late auditory evoked potentials measured from human listeners. The audibility of the target sound at a fixed physical intensity is varied by introducing auditory cues of (i) interaural target signal phase disparity and (ii) coherent masker level fluctuations in different frequency regions. In agreement with previous studies, psychoacoustical experiments showed that both stimulus manipulations result in a masking release (i: binaural masking level difference; ii: comodulation masking release) compared to a condition where those cues are not present. Late auditory evoked potentials (N1, P2) were recorded for the stimuli at a constant masker level, but different signal levels within the same set of listeners who participated in the psychoacoustical experiment. The data indicate differences in N1 and P2 between stimuli with and without interaural phase disparities. However, differences for stimuli with and without coherent masker modulation were only found for P2, i.e., only P2 is sensitive to the increase in audibility, irrespective of the cue that caused the masking release. The amplitude of P2 is consistent with the psychoacoustical finding of an addition of the masking releases when both cues are present. Even though it cannot be concluded where along the auditory pathway the audibility is represented, the P2 component of auditory evoked potentials is a candidate for an objective measure of audibility in the human auditory system. Copyright © 2013 Elsevier B.V. All rights reserved.

Objective measures of binaural masking level differences and comodulation masking release based on late auditory evoked potentials

DEFF Research Database (Denmark)

Epp, Bastian; Yasin, Ifat; Verhey, Jesko L.

2013-01-01

at a fixed physical intensity is varied by introducing auditory cues of (i) interaural target signal phase disparity and (ii) coherent masker level fluctuations in different frequency regions. In agreement with previous studies, psychoacoustical experiments showed that both stimulus manipulations result......The audibility of important sounds is often hampered due to the presence of other masking sounds. The present study investigates if a correlate of the audibility of a tone masked by noise is found in late auditory evoked potentials measured from human listeners. The audibility of the target sound...... in a masking release (i: binaural masking level difference; ii: comodulation masking release) compared to a condition where those cues are not present. Late auditory evoked potentials (N1, P2) were recorded for the stimuli at a constant masker level, but different signal levels within the same set of listeners...

The effect of nucleotides and adenosine on stimulus-evoked glutamate release from rat brain cortical slices

OpenAIRE

Bennett, Gillian C; Boarder, Michael R

2000-01-01

Evidence has previously been presented that P1 receptors for adenosine, and P2 receptors for nucleotides such as ATP, regulate stimulus-evoked release of biogenic amines from nerve terminals in the brain. Here we investigated whether adenosine and nucleotides exert presynaptic control over depolarisation-elicited glutamate release.Slices of rat brain cortex were perfused and stimulated with pulses of 46 mM K+ in the presence of the glutamate uptake inhibitor L-trans-pyrrolidine-2,4-dicarboxyl...

Plasma clearance of noradrenaline does not change with age in normal subjects

DEFF Research Database (Denmark)

Hilsted, J; Christensen, N J; Larsen, S

1985-01-01

Noradrenaline kinetics (plasma concentrations, plasma clearance and appearance rates) were investigated in seven elderly healthy subjects and in six young healthy subjects. Forearm venous plasma noradrenaline concentrations were higher in the elderly subjects compared with the young subjects. Pla....... Plasma clearance of noradrenaline was identical in the two groups. The increase in plasma noradrenaline concentration, with age, probably reflects an increased sympathetic nervous activity.......Noradrenaline kinetics (plasma concentrations, plasma clearance and appearance rates) were investigated in seven elderly healthy subjects and in six young healthy subjects. Forearm venous plasma noradrenaline concentrations were higher in the elderly subjects compared with the young subjects...

Synaptically evoked Ca2+ release from intracellular stores is not influenced by vesicular zinc in CA3 hippocampal pyramidal neurones.

Science.gov (United States)

Evstratova, Alesya; Tóth, Katalin

2011-12-01

The co-release of neuromodulatory substances in combination with classic neurotransmitters such as glutamate and GABA from individual presynaptic nerve terminals has the capacity to dramatically influence synaptic efficacy and plasticity. At hippocampal mossy fibre synapses vesicular zinc is suggested to serve as a cotransmitter capable of regulating calcium release from internal stores in postsynaptic CA3 pyramidal cells. Here we investigated this possibility using combined intracellular ratiometric calcium imaging and patch-clamp recording techniques. In acute hippocampal slices a brief train of mossy fibre stimulation produced a large, delayed postsynaptic Ca(2+) wave that was spatially restricted to the proximal apical dendrites of CA3 pyramidal cells within stratum lucidum. This calcium increase was sensitive to intracellularly applied heparin indicating reliance upon release from internal stores and was triggered by activation of both group I metabotropic glutamate and NMDA receptors. Importantly, treatment of slices with the membrane-impermeant zinc chelator CaEDTA did not influence the synaptically evoked postsynaptic Ca(2+) waves. Moreover, mossy fibre stimulus evoked postsynaptic Ca(2+) signals were not significantly different between wild-type and zinc transporter 3 (ZnT3) knock-out animals. Considered together our data do not support a role for vesicular zinc in regulating mossy fibre evoked Ca(2+) release from CA3 pyramidal cell internal stores.

Roux-en-Y gastric bypass augments the feeding responses evoked by gastrin releasing peptides

Science.gov (United States)

Washington, Martha C.; Mhalhal, Thaer R.; Berger, Tanisha Johnson-Rouse Jose; Heath, John; Seeley, Randy; Sayegh, Ayman I.

2016-01-01

Background Roux-en-Y gastric bypass (RYGB) is the most effective method for the treatment of obesity and metabolic disease Roux-en-Y gastric bypass (RYGB) may reduce body weight by altering the feeding responses evoked by the short term satiety peptides. Materials and Methods Here, we measured meal size (MS, chow), intermeal interval (IMI) length and satiety ratio (SR, IMI/MS; food consumed per a unit of time) by the small and the large forms of gastrin releasing peptide (GRP) in rats, GRP-10 and GRP-29 (0, 0.1, 0.5 nmol/kg) infused in the celiac artery (CA, supplies stomach and upper duodenum) and the cranial mesenteric artery (CMA, supplies small and large intestine) in a RYGB rat model. Results GRP-10 reduced MS, prolonged the IMI and increased the SR only in the RYGB group, whereas GRP-29 evoked these responses by both routes and in both groups. Conclusion The RYGB procedure augments the feeding responses evoked by exogenous GRP, possibly by decreasing total food intake, increasing latency to the first meal, decreasing number of meals or altering the sites of action regulating MS and IMI length by the two peptides. PMID:27884350

Potentiation by choline of basal and electrically evoked acetylcholine release, as studied using a novel device which both stimulates and perfuses rat corpus striatum

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Farber, S. A.; Kischka, U.; Marshall, D. L.; Wurtman, R. J.

1993-01-01

We examined the release of acetylcholine (ACh) and dopamine (DA) using a novel probe through which striatal neurons could be both superfused and stimulated electrically in both anesthetized and freely moving awake animals. Optimal stimulation parameters for eliciting ACh release from cholinergic neurons differed from those required for eliciting DA release from dopaminergic terminals: at 0.6 ms pulse duration, 20 Hz and 200 microA, ACh release increased to 357 +/- 30% (P basal release rose from 117 +/- 7% to 141 +/- 5% of initial baseline levels (P basal or evoked DA release although neostigmine (10 microM) significantly elevated basal DA release (from 36.7 fmol/10 min to 71.5 fmol/10 min; P basal (from 106 +/- 7% to 154 +/- 17%; P < 0.05) and electrically evoked (from 146 +/- 13 to 262 +/- 16%; P < 0.01) ACh release.(ABSTRACT TRUNCATED AT 250 WORDS).

The dopamine beta-hydroxylase inhibitor nepicastat increases dopamine release and potentiates psychostimulant-induced dopamine release in the prefrontal cortex.

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Devoto, Paola; Flore, Giovanna; Saba, Pierluigi; Bini, Valentina; Gessa, Gian Luigi

2014-07-01

The dopamine-beta-hydroxylase inhibitor nepicastat has been shown to reproduce disulfiram ability to suppress the reinstatement of cocaine seeking after extinction in rats. To clarify its mechanism of action, we examined the effect of nepicastat, given alone or in association with cocaine or amphetamine, on catecholamine release in the medial prefrontal cortex and the nucleus accumbens, two key regions involved in the reinforcing and motivational effects of cocaine and in the reinstatement of cocaine seeking. Nepicastat effect on catecholamines was evaluated by microdialysis in freely moving rats. Nepicastat reduced noradrenaline release both in the medial prefrontal cortex and in the nucleus accumbens, and increased dopamine release in the medial prefrontal cortex but not in the nucleus accumbens. Moreover, nepicastat markedly potentiated cocaine- and amphetamine-induced extracellular dopamine accumulation in the medial prefrontal cortex but not in the nucleus accumbens. Extracellular dopamine accumulation produced by nepicastat alone or by its combination with cocaine or amphetamine was suppressed by the α2 -adrenoceptor agonist clonidine. It is suggested that nepicastat, by suppressing noradrenaline synthesis and release, eliminated the α2 -adrenoceptor mediated inhibitory mechanism that constrains dopamine release and cocaine- and amphetamine-induced dopamine release from noradrenaline or dopamine terminals in the medial prefrontal cortex. © 2012 The Authors, Addiction Biology © 2012 Society for the Study of Addiction.

Acute stress increases depolarization-evoked glutamate release in the rat prefrontal/frontal cortex: the dampening action of antidepressants.

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Laura Musazzi

2010-01-01

Full Text Available Behavioral stress is recognized as a main risk factor for neuropsychiatric diseases. Converging evidence suggested that acute stress is associated with increase of excitatory transmission in certain forebrain areas. Aim of this work was to investigate the mechanism whereby acute stress increases glutamate release, and if therapeutic drugs prevent the effect of stress on glutamate release.Rats were chronically treated with vehicle or drugs employed for therapy of mood/anxiety disorders (fluoxetine, desipramine, venlafaxine, agomelatine and then subjected to unpredictable footshock stress. Acute stress induced marked increase in depolarization-evoked release of glutamate from synaptosomes of prefrontal/frontal cortex in superfusion, and the chronic drug treatments prevented the increase of glutamate release. Stress induced rapid increase in the circulating levels of corticosterone in all rats (both vehicle- and drug-treated, and glutamate release increase was blocked by previous administration of selective antagonist of glucocorticoid receptor (RU 486. On the molecular level, stress induced accumulation of presynaptic SNARE complexes in synaptic membranes (both in vehicle- and drug-treated rats. Patch-clamp recordings of pyramidal neurons in the prefrontal cortex revealed that stress increased glutamatergic transmission through both pre- and postsynaptic mechanisms, and that antidepressants may normalize it by reducing release probability.Acute footshock stress up-regulated depolarization-evoked release of glutamate from synaptosomes of prefrontal/frontal cortex. Stress-induced increase of glutamate release was dependent on stimulation of glucocorticoid receptor by corticosterone. Because all drugs employed did not block either elevation of corticosterone or accumulation of SNARE complexes, the dampening action of the drugs on glutamate release must be downstream of these processes. This novel effect of antidepressants on the response to stress

Adeprene influence on the turnover rate of brain noradrenaline

International Nuclear Information System (INIS)

Tyutyulkova, N.I.; Gorancheva, J.I.; Ankov, V.K.

1978-01-01

The influence of Adeprene - Bulgarian antidepressant - on the content and the turnover rate of the rat brain noradrenaline was studied. The animals were injected intraperitoneally during 5 days with 20 mg/kg Adeprene. One hour after the last administration of Adeprene, Tyrosine, labelled with 14 C was injected. The animals were sacrified on the 1st, 2nd and 4th hours after the injection of 14 C-Tyrosine. The tyrosine and noradrenaline concentration were determined spectrofluorimetrically the concentration of the compounds labelled with 14 C by means of a liquid scintillator. The turnover rate constant of noradrenaline was calculated on the basis of the obtained results and the respective formula. It was established that under the influence of Adeprene, the noradrenaline concentration in the brain rises from 0,5 g/g in the control animals to 0,6 in treated mice. The turnover rate constant of noradrenaline, however, drops to 0,9 g/g/hour as compared to 0,15 g/g/hours in the controls. The determination of the turnover rate provides an idea about the intensity of utilization and synthesis of the mediator and is considered consequently as a more radiosensitive index for the neuronal activity then the total amine content. (A.B.)

Comparison of changes in the extracellular concentration of noradrenaline in rat frontal cortex induced by sibutramine or d-amphetamine: modulation by α2-adrenoceptors

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Wortley, K E; Hughes, Z A; Heal, D J; Stanford, S C

1999-01-01

The effects of sibutramine (0.25–10 mg kg−1, i.p.) on extracellular noradrenaline concentration in the frontal cortex of halothane-anaesthetized rats were compared with those of d-amphetamine (1–3 mg kg−1, i.p.) using in vivo microdialysis. The role of presynaptic α2-adrenoceptors in modulating the effects of these drugs on extracellular noradrenaline concentration were also investigated by pretreating rats with the selective α2-adrenoceptor antagonist, RX821002.Sibutramine induced a gradual and sustained increase in extracellular noradrenaline concentration. The dose-response relationship was described by a bell-shaped curve with a maximum effect at 0.5 mg kg−1. In contrast, d-amphetamine induced a rapid increase in extracellular noradrenaline concentration, the magnitude of which paralleled drug dose.Pretreatment with the α2-adrenoceptor antagonist, RX821002 (dose 3 mg kg−1, i.p.) increased by 5 fold the accumulation of extracellular noradrenaline caused by sibutramine (10 mg kg−1) and reduced the latency of sibutramine to reach its maximum effect from 144–56 min.RX821002-pretreatment increased by only 2.5 fold the increase in extracellular noradrenaline concentration caused by d-amphetamine alone (10 mg kg−1) and had no effect on the latency to reach maximum.These findings support evidence that sibutramine acts as a noradrenaline uptake inhibitor in vivo and that the effects of this drug are blunted by indirect activation of presynaptic α2-adreno-ceptors. In contrast, the rapid increase in extracellular noradrenaline concentration induced by d-amphetamine is consistent with this being mainly due to an increase in Ca2+-independent release of noradrenaline. PMID:10482917

The human immunodeficiency virus-1 protein Tat and its discrete fragments evoke selective release of acetylcholine from human and rat cerebrocortical terminals through species-specific mechanisms.

Science.gov (United States)

Feligioni, Marco; Raiteri, Luca; Pattarini, Roberto; Grilli, Massimo; Bruzzone, Santina; Cavazzani, Paolo; Raiteri, Maurizio; Pittaluga, Anna

2003-07-30

The effect of the human immunodeficiency virus-1 protein Tat was investigated on neurotransmitter release from human and rat cortical nerve endings. Tat failed to affect the release of several neurotransmitters, such as glutamate, GABA, norepinephrine, and others, but it evoked the release of [3H]ACh via increase of cytosolic [Ca2+]. In human nerve terminals, the Tat effect partly depends on Ca2+ entry through voltage-sensitive Ca2+ channels, because Cd2+ halved the Tat-evoked release. Activation of group I metabotropic glutamate receptors (mGluR) and mobilization of Ca2+ from IP3-sensitive intraterminal stores are also involved, because the Tat effect was prevented by mGluR antagonists 2-methyl-6-(phenylethynyl)pyridine hydrochloride and 7-(hydroxyimino)cyclopropa[b]chromen-1a-carboxylate ethyl ester and by the IP3 receptor antagonists heparin and xestospongin C. Furthermore, the group I selective mGlu agonist (RS)-3,5-dihydroxyphenylglycine enhanced [3H]ACh release. In rat nerve terminals, the Tat-evoked release neither depends on external Ca2+ ions entry nor on IP3-mediated mechanisms. Tat seems to cause mobilization of Ca2+ from ryanodine-sensitive internal stores because its effect was prevented by both 8-bromo-cyclic adenosine diphosphate-ribose and dantrolene. The Tat-evoked release from human synaptosomes was mimicked by the peptide sequences Tat 32-62, Tat 49-86, and Tat 41-60. In contrast, the Tat 49-86 and Tat 61-80 fragments, but not the Tat 32-62 fragment, were active in rat synaptosomes. In conclusion, Tat elicits Ca2+-dependent [3H]ACh release by species-specific intraterminal mechanisms by binding via discrete amino acid sequences to different receptive sites on human and rat cholinergic terminals.

Hypofunction of prefrontal cortex NMDA receptors does not change stress-induced release of dopamine and noradrenaline in amygdala but disrupts aversive memory.

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Del Arco, Alberto; Ronzoni, Giacomo; Mora, Francisco

2015-07-01

A dysfunction of prefrontal cortex has been associated with the exacerbated response to stress observed in schizophrenic patients and high-risk individuals to develop psychosis. The hypofunction of NMDA glutamatergic receptors induced by NMDA antagonists produces cortico-limbic hyperactivity, and this is used as an experimental model to resemble behavioural abnormalities observed in schizophrenia. The aim of the present study was to investigate whether injections of NMDA antagonists into the medial prefrontal cortex of the rat change (1) the increases of dopamine, noradrenaline and corticosterone concentrations produced by acute stress in amygdala, and (2) the acquisition of aversive memory related to a stressful event. Male Wistar rats were implanted with guide cannulae to perform microdialysis and bilateral microinjections (0.5 μl/side) of the NMDA antagonist 3-[(R)-2-carboxypiperazin-4-yl]-propyl-1-phophonic acid (CPP) (25 and 100 ng). Prefrontal injections were performed 60 min before restraint stress in microdialysis experiments, or training (footshock; 0.6 mA, 2 s) in inhibitory avoidance test. Retention latency was evaluated 24 h after training as an index of aversive memory. Acute stress increased amygdala dialysate concentrations of dopamine (160% of baseline), noradrenaline (145% of baseline) and corticosterone (170% of baseline). Prefrontal injections of CPP did not change the increases of dopamine, noradrenaline or corticosterone produced by stress. In contrast, CPP significantly reduced the retention latency in the inhibitory avoidance test. These results suggest that the hypofunction of prefrontal NMDA receptors does not change the sensitivity to acute stress of dopamine and noradrenaline projections to amygdala but impairs the acquisition of aversive memory.

The effects of inorganic lead on the spontaneous and potassium-evoked release of 3H-5-HT from rat cortical synaptosome interaction with calcium

International Nuclear Information System (INIS)

Oudar, P.; Caillard, L.; Fillion, G.

1989-01-01

Interaction of lead with the serotonergic system has been studied in vitro in rat brain synaptosomal fraction prepared from cortical tissue. Synaptosomes were loaded with 3 H-5-HT and spontaneous and K + -evoked release of the amine was examined in the presence and the absence of calcium. It was shown that lead itself induced the release of 3 H-5-HT (EC50=27 μM). This effect decreased (40%) in the presence of calcium without modification of the EC50. Moreover, lead markedly inhibited the K + -evoked release of 3 H-5-HT observed in the presence of calcium. This effect was obtained either in the presence of lead or using synaptosomes pretreated with lead and washed. These results indicate that lead interferes with neuronal 5-HT release by mechanism(s) involving calcium. (author)

Phosphatidic acid accumulation and catecholamine release in adrenal chromaffin cells: stimulation by high potassium and by nicotine, and effect of a diacylglycerol kinase inhibitor R 59 022.

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Owen, P J; Jones, J A; Boarder, M R

1991-09-01

Using primary cultures of bovine adrenal chromaffin cells labelled with 32Pi, we show that stimulation with bradykinin, nicotine, or a depolarising concentration of potassium stimulates the accumulation of [32P]phosphatidic acid. The effects of nicotine and potassium are smaller than the effect of bradykinin, and are dependent entirely on extracellular calcium. The diacylglycerol kinase inhibitor R 59 022 attenuates the formation of phosphatidic acid by nicotine and depolarising concentrations of potassium. This inhibitor also blocks the nicotine and potassium stimulation of noradrenaline release from chromaffin cells. Using 45Ca2+ influx studies, we show that the nicotine-evoked calcium influx is also attenuated by R 59 022. These observations contrast with those in another report in which we showed that bradykinin stimulation of either [32P]phosphatidic acid accumulation or noradrenaline release is not affected by R 59 022. It is likely that the calcium influx produced by nicotine and depolarising potassium is blocked by R 59 022 by a mechanism that is independent of its ability to block diacylglycerol kinase. The nicotine- and potassium-stimulated [32P]phosphatidic acid accumulation is a consequence of this calcium influx and presumably reflects calcium activation of either phospholipase C or phospholipase D.

GABA release in the zona incerta of the sheep in response to the sight and ingestion of food and salt.

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Kendrick, K M; Hinton, M R; Baldwin, B A

1991-05-31

In order to establish which neurotransmitters may influence the activity of zona incerta neurones in the sheep which respond selectively to the sight or ingestion of food, we have measured the release of amino acid and monoamine neurotransmitters from this region using microdialysis sampling. Co-ordinates for the placement of microdialysis probes in regions of the zona incerta where cells respond to the sight or ingestion of food were first established by making single-unit extracellular recordings. When animals were food-deprived results showed that release of gamma-aminobutyric acid (GABA) was increased in response to the sight and ingestion of food but not of aspartate, glutamate, taurine, noradrenaline, dopamine or serotonin. This release of GABA was absent when the animals were shown non-food objects or saw or ingested salt solutions. When the same animals were physiologically sodium-depleted GABA release was evoked by the sight and ingestion of salt solutions and release following the sight and ingestion of food was significantly reduced. These results provide further evidence that GABA is an important neurotransmitter in neural circuits controlling the regulation of food intake.

Ca2+ influx insensitive to organic Ca2+ entry blockers contributes to noradrenaline-induced contractions of the isolated guinea pig aorta

NARCIS (Netherlands)

Gouw, M. A.; Wilffert, B.; Wermelskirchen, D.; van Zwieten, P. A.

1990-01-01

We determined the contribution of intracellular Ca2+ to the noradrenaline (NA, 3 X 10(-5) mmol/l)-induced contraction of the isolated guinea pig aorta. Since only about 55% of the NA-induced contraction could be attributed to intracellular Ca2+ release, we assumed that a Ca2+ influx component

Attempt to separate the fluorescence spectra of adrenaline and noradrenaline using chemometrics

DEFF Research Database (Denmark)

Nikolajsen, Rikke P; Hansen, Åse Marie; Bro, R

2000-01-01

An investigation was conducted on whether the fluorescence spectra of the very similar catecholamines adrenaline and noradrenaline could be separated using chemometric methods. The fluorescence landscapes (several excitation and emission spectra were measured) of two data sets with respectively 16...... regression (Unfold-PLSR) on the larger data set and parallel factor analysis (PARAFAC) of the six samples of the smaller set showed that there was no difference between the fluorescence landscapes of adrenaline and noradrenaline. It can be concluded that chemometric separation of adrenaline and noradrenaline...

Ca2+influx insensitive to organic Ca2+entry blockers contributes to noradrenaline-induced contractions of the isolated guinea pig aorta

NARCIS (Netherlands)

Gouw, M.A.M.; Wilffert, B.; Wermelskirchen, D.; Van Zwieten, P.A.

1990-01-01

We determined the contribution of intracellular Ca2+to the noradrenaline (NA, 3 x 10-5mmol/l)-induced contraction of the isolated guinea pig aorta. Since only about 55% of the NA-induced contraction could be attributed to intracellular Ca2+release, we assumed that a Ca2+influx component contributes

Muscarinic receptors in separate populations of noradrenaline- and adrenaline-containing chromaffin cells

International Nuclear Information System (INIS)

Michelena, P.; Moro, M.A.; Castillo, C.J.; Garcia, A.G.

1991-01-01

We have performed binding experiments of (a)[3H]quinuclidinyl benzilate to partially purified membranes from noradrenaline- and adrenaline-containing chromaffin cells and (b) [3H]N-methyl-quinuclidinyl benzilate to acutely isolated, or 48-h cultured, chromaffin cells subpopulations. Using this approach, we obtained enough evidence to conclude (1st) that muscarinic receptors are present in both noradrenaline- and adrenaline containing cells; (2nd) that noradrenaline cells contain in fact 2-3 fold higher density of those receptors; and (3rd) that those receptors undergo plastic changes upon chronic culturing of the cells

Copper Induces Vasorelaxation and Antagonizes Noradrenaline -Induced Vasoconstriction in Rat Mesenteric Artery

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Yu-Chun Wang

2013-11-01

Full Text Available Background/Aims: Copper is an essential trace element for normal cellular function and contributes to critical physiological or pathological processes. The aim of the study was to investigate the effects of copper on vascular tone of rat mesenteric artery and compare the effects of copper on noradrenaline (NA and high K+ induced vasoconstriction. Methods: The rat mesenteric arteries were isolated and the vessel tone was measured by using multi wire myograph system in vitro. Blood pressure of carotid artery in rabbits was measured by using physiological data acquisition and analysis system in vivo. Results: Copper dose-dependently blunted NA-induced vasoconstriction of rat mesenteric artery. Copper-induced vasorelaxation was inhibited when the vessels were pretreated with NG-nitro-L-arginine methyl ester (L-NAME. Copper did not blunt high K+-induced vasoconstriction. Copper preincubation inhibited NA-evoked vasoconstriction and the inhibition was not affected by the presence of L-NAME. Copper preincubation showed no effect on high K+-evoked vasoconstriction. Copper chelator diethyldithiocarbamate trihydrate (DTC antagonized the vasoactivity induced by copper in rat mesenteric artery. In vivo experiments showed that copper injection (iv significantly decreased blood pressure of rabbits and NA or DTC injection (iv did not rescue the copper-induced hypotension and animal death. Conclusion: Copper blunted NA but not high K+-induced vasoconstriction of rat mesenteric artery. The acute effect of copper on NA-induced vasoconstriction was depended on nitric oxide (NO, but the effect of copper pretreatment on NA-induced vasoconstriction was independed on NO, suggesting that copper affected NA-induced vasoconstriction by two distinct mechanisms.

Localized infusions of the partial alpha 7 nicotinic receptor agonist SSR180711 evoke rapid and transient increases in prefrontal glutamate release

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Bortz, D M; Mikkelsen, J D; Bruno, J P

2013-01-01

The ability of local infusions of the alpha 7 nicotinic acetycholine receptor (α7 nAChR) partial agonist SSR180711 to evoke glutamate release in prefrontal cortex was determined in awake rats using a microelectrode array. Infusions of SSR180711 produced dose-dependent increases in glutamate levels...

Exposure of P. gingivalis to noradrenaline reduces bacterial growth and elevates ArgX protease activity.

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Saito, Takayuki; Inagaki, Satoru; Sakurai, Kaoru; Okuda, Katsuji; Ishihara, Kazuyuki

2011-03-01

Periodontitis, an infectious disease caused by periodontopathic bacteria, including Porphyromonas gingivalis, is reported to be accelerated by stress, under which noradrenaline levels are increased in the bloodstream. The purpose of this study was to evaluate the effects of noradrenaline on P. gingivalis. P. gingivalis was incubated in the presence of 25μM, 50μM, or 100μM adrenaline or noradrenaline at 37°C for 12, 24 or 36h and growth was evaluated by OD(660). Auto-inducer-2 (AI-2) was measured by luminescence of Vibrio harveyi BB 170. Expression of P. gingivalis genes was evaluated using a microarray and RT-PCR. Rgp activity of arg-gingipainA and B (Rgp) was measured with a synthetic substrate. Growth of P. gingivalis FDC381 was inhibited by noradrenaline at 24 and 36h. Growth inhibition by noradrenaline increased dose-dependently. Inhibition of growth partially recovered with addition of propranolol. AI-2 production from P. gingivalis showed a marked decrease with addition of noradrenaline compared with peak production levels in the control group. Microarray analysis revealed an increase in expression in 18 genes and a decrease in expression in 2 genes. Amongst these genes, expression of the protease arg-gingipainB (RgpB) gene, a major virulence factor of P. gingivalis, was further analysed. Expression of rgpB showed a significant increase with addition of noradrenaline, which was partially reduced by addition of propranolol. Cell-associated Rgp activity also increased with addition of noradrenaline. These results suggest that stressors influence the expression of the virulence factors of P. gingivalis via noradrenaline. Copyright © 2010 Elsevier Ltd. All rights reserved.

Strong activation of vascular prejunctional beta 2-adrenoceptors in freely moving rats by adrenaline released as a co-transmitter

NARCIS (Netherlands)

COPPES, RP; SMIT, J; KHALI, NN; Brouwer, F.; ZAAGSMA, J

1993-01-01

The effect of adrenaline on the electrically evoked noradrenaline overflow in the portal vein of adrenal demedullated freely moving rats was studied. Adrenaline (100 ng/min) was infused for 2 h into the portal vein. After a 1-h interval when plasma adrenaline had returned to pre-infusion

Effect of noradrenaline on production of methoxyindoles by rat pineal gland in organ culture

International Nuclear Information System (INIS)

Morton, D.J.

1987-01-01

This report examined the effect of noradrenaline on production of methoxyindoles by the pineal gland in organ culture. Pineal glands were incubated in pairs in 95μl culture medium containing 5-hydroxy [2- 14 C]tryptamine creatinine sulphate (0,1 mM) and noradrenaline (NA) (0,5-100 μM). The results indicated that noradrenaline appeared to have a characteristic action on pineal metabolism. An increase in production of both N-acetylserotonin and melatonin by the pineal after noradrenaline treatment was observed. The overall production of methoxyindoles followed a very similar trend to that of N-acetylserotonin and melatonin, which suggests some degree of noradrenergic control over HIOMT levels

Noradrenaline and isoproterenol kinetics in diabetic patients with and without autonomic neuropathy

DEFF Research Database (Denmark)

Dejgaard, Anders; Hilsted, J; Christensen, N J

1986-01-01

Noradrenaline and isoproterenol kinetics using intravenous infusion of L-3H-NA and of 3H-isoproterenol were investigated in eight Type 1 (insulin-dependent) diabetic patients without neuropathy and in eight Type 1 diabetic patients with autonomic neuropathy matched for age, sex and duration...... with autonomic failure (p less than 0.01). The disappearance of L-3H-noradrenaline from plasma after the infusion of L-3H-noradrenaline had been stopped was not different in patients with and without neuropathy. The metabolic clearance of isoproterenol was not influenced by the presence of autonomic failure...

The area postrema (AP) and the parabrachial nucleus (PBN) are important sites for salmon calcitonin (sCT) to decrease evoked phasic dopamine release in the nucleus accumbens (NAc).

Science.gov (United States)

Whiting, Lynda; McCutcheon, James E; Boyle, Christina N; Roitman, Mitchell F; Lutz, Thomas A

2017-07-01

The pancreatic hormone amylin and its agonist salmon calcitonin (sCT) act via the area postrema (AP) and the lateral parabrachial nucleus (PBN) to reduce food intake. Investigations of amylin and sCT signaling in the ventral tegmental area (VTA) and nucleus accumbens (NAc) suggest that the eating inhibitory effect of amylin is, in part, mediated through the mesolimbic 'reward' pathway. Indeed, administration of the sCT directly to the VTA decreased phasic dopamine release (DA) in the NAc. However, it is not known if peripheral amylin modulates the mesolimbic system directly or whether this occurs via the AP and PBN. To determine whether and how peripheral amylin or sCT affect mesolimbic reward circuitry we utilized fast scan cyclic voltammetry under anesthesia to measure phasic DA release in the NAc evoked by electrical stimulation of the VTA in intact, AP lesioned and bilaterally PBN lesioned rats. Amylin (50μg/kg i.p.) did not change phasic DA responses compared to saline control rats. However, sCT (50μg/kg i.p.) decreased evoked DA release to VTA-stimulation over 1h compared to saline treated control rats. Further investigations determined that AP and bilateral PBN lesions abolished the ability of sCT to suppress evoked phasic DA responses to VTA-stimulation. These findings implicate the AP and the PBN as important sites for peripheral sCT to decrease evoked DA release in the NAc and suggest that these nuclei may influence hedonic and motivational processes to modulate food intake. Copyright © 2017 Elsevier Inc. All rights reserved.

Rotational Spectra of Adrenaline and Noradrenaline

Science.gov (United States)

Cortijo, V.; López, J. C.; Alonso, J. L.

2009-06-01

The emergence of Laser Ablation Molecular Beam Fourier Transform Microwave (LA-MB-FTMW) spectroscopy has rendered accessible the gas-phase study of solid biomolecules with high melting points. Among the biomolecules to benefit from this technique, neurotransmitters have received special attention due to the lack of experimental information and their biological relevance. As a continuation of the we present the study of adrenaline and noradrenaline. The comparison between the experimental rotational and ^{14}N nuclear quadrupole coupling constants and those calculated ab initio provide a definitive test for molecular structures and confirm unambiguously the identification of four conformers of adrenaline and three conformers of noradrenaline. Their relative population in the jet has been evaluated by relative intensity measurements of selected rotational transitions. The most abundant conformer in both neurotransmitters present an extended AG configuration with a O-H\\cdotsN hydrogen bond in the side chain. J.L. Alonso, M.E. Sanz, J.C. López and V. Cortijo, J. Am. Chem. Soc. (in press), 2009

Noradrenaline and adrenaline concentrations in various vascular beds in patients with cirrhosis. Relation to haemodynamics

DEFF Research Database (Denmark)

Henriksen, Jens Henrik Sahl; Christensen, N J; Ring-Larsen, H

1981-01-01

indicates that sympathetic nervous activity is enhanced in patients with cirrhosis. Based on the above positive correlation between NA and heart rate and the significant release of NA from the kidney, it may be hypothesized that the increased sympathetic nervous activity especially involves heart and kidney......Plasma noradrenaline (NA) and adrenaline (A) concentrations were related to various haemodynamic parameters in fifteen patients with cirrhosis. In supine position at rest plasma NA and A in peripheral venous blood were significantly higher in patients with cirrhosis than in normal subjects. Mean...

Co-release of noradrenaline and dopamine in the cerebral cortex elicited by single train and repeated train stimulation of the locus coeruleus

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Saba Pierluigi

2005-05-01

Full Text Available Abstract Background Previous studies by our group suggest that extracellular dopamine (DA and noradrenaline (NA may be co-released from noradrenergic nerve terminals in the cerebral cortex. We recently demonstrated that the concomitant release of DA and NA could be elicited in the cerebral cortex by electrical stimulation of the locus coeruleus (LC. This study analyses the effect of both single train and repeated electrical stimulation of LC on NA and DA release in the medial prefrontal cortex (mPFC, occipital cortex (Occ, and caudate nucleus. To rule out possible stressful effects of electrical stimulation, experiments were performed on chloral hydrate anaesthetised rats. Results Twenty min electrical stimulation of the LC, with burst type pattern of pulses, increased NA and DA both in the mPFC and in the Occ. NA in both cortices and DA in the mPFC returned to baseline within 20 min after the end of the stimulation period, while DA in the Occ reached a maximum increase during 20 min post-stimulation and remained higher than baseline values at 220 min post-stimulation. Local perfusion with tetrodotoxin (TTX, 10 μM markedly reduced baseline NA and DA in the mPFC and Occ and totally suppressed the effect of electrical stimulation in both areas. A sequence of five 20 min stimulations at 20 min intervals were delivered to the LC. Each stimulus increased NA to the same extent and duration as the first stimulus, whereas DA remained elevated at the time next stimulus was delivered, so that baseline DA progressively increased in the mPFC and Occ to reach about 130 and 200% the initial level, respectively. In the presence of the NA transport (NAT blocker desipramine (DMI, 100 μM, multiple LC stimulation still increased extracellular NA and DA levels. Electrical stimulation of the LC increased NA levels in the homolateral caudate nucleus, but failed to modify DA level. Conclusion The results confirm and extend that LC stimulation induces a concomitant

Correlations between plasma noradrenaline concentrations, antioxidants, and neutrophil counts after submaximal resistance exercise in men

Science.gov (United States)

Ramel, A; Wagner, K; Elmadfa, I

2004-01-01

Objectives: To investigate noradrenaline concentrations, neutrophil counts, plasma antioxidants, and lipid oxidation products before and after acute resistance exercise. Methods: 17 male participants undertook a submaximal resistance exercise circuit (10 exercises; 75% of the one repetition maximum; mean (SD) exercise time, 18.6 (1.1) minutes). Blood samples were taken before and immediately after exercise and analysed for plasma antioxidants, noradrenaline, neutrophils, and lipid oxidation products. Wilcoxon's signed-rank test and Pearson's correlation coefficient were used for calculations. Results: Neutrophils, noradrenaline, fat soluble antioxidants, and lipid oxidation products increased after exercise. Noradrenaline concentrations were associated with higher antioxidant concentrations. Neutrophils were related to higher concentrations of conjugated dienes. Conclusions: Submaximal resistance exercise increases plasma antioxidants. This might reflect enhanced antioxidant defence in response to the oxidative stress of exercise, though this is not efficient for inhibiting lipid oxidation. The correlation between noradrenaline concentrations and plasma antioxidants suggests a modulating role of the stress hormone. Neutrophils are a possible source of oxidative stress after resistance exercise. PMID:15388566

[Features of noradrenaline stimulation of rat liver mitochondria respiration by ADP and calcium ions].

Science.gov (United States)

Stefankiv, Iu S; Babskyĭ, A M; Shostakovska, Y V

1995-01-01

A single administration of a physiological dose of noradrenaline to animals. in contrast to adrenaline, stimulates the respiration of mitochondria not only under oxidation of FAD-dependent Krebbs cycle substrate of the succinase but also HAD-dependent substrate of alpha-ketoglutarate. In the both cases the phosphorylation rate increases, since the action of noradrenaline, separating the respiration and oxidative phosphorylation, was not found. Noradrenaline increases the capacity of mitochondria to more actively absorb calcium ions under oxidation of succinate than under that of alpha-ketoglutarate.

Reduced plasma noradrenaline during angiotensin II-induced acute hypertension in man

DEFF Research Database (Denmark)

Henriksen, J H; Kastrup, J; Christensen, N J

1985-01-01

1. Plasma noradrenaline and adrenaline concentrations were measured in ten subjects before, during and after intravenous infusion of angiotensin II (ANG II) in order to determine the sympathoadrenal response of ANG II challenge in man. In five subjects ganglionic blockade was additionally performed...... by intravenous infusion of trimethaphan. 2. During ANG II infusion mean arterial blood pressure increased by 30% (P adrenaline decreased less. 3. During ganglionic blockade plasma noradrenaline decreased significantly (P

Excitatory effect of the A2A adenosine receptor agonist CGS-21680 on spontaneous and K+-evoked acetylcholine release at the mouse neuromuscular junction.

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Palma, A G; Muchnik, S; Losavio, A S

2011-01-13

The mechanism of action of the A2A adenosine receptor agonist 2-p-(2-carboxyethyl) phenethylamino-5'-N-ethylcarboxamidoadenosine hydrochloride (CGS-21680) in the facilitation of spontaneous (isotonic and hypertonic condition) and K+-evoked acetylcholine (ACh) release was investigated in the mouse diaphragm muscles. At isotonic condition, the CGS-21680-induced excitatory effect on miniature end-plate potential (MEPP) frequency was not modified in the presence of CdCl2 and in a medium free of Ca2+ (0Ca2+-EGTA), but it was abolished after buffering the rise of intracellular Ca2+ with 1,2-bis-(2-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid tetra(acetoxy-methyl) (BAPTA-AM) and when the Ca2+-ATPase inhibitor thapsigargin was used to deplete intracellular Ca2+ stores. CGS-21680 did not have a direct effect on the Ca2+-independent neurotransmitter-releasing machinery, since the modulatory effect on the hypertonic response was also occluded by BAPTA-AM and thapsigargin. CGS-21680 facilitation on K+-evoked ACh release was not altered by the P/Q-type voltage-dependent calcium channel (VDCC) blocker ω-Agatoxin IVA, but it was completely prevented by both, the L-type VDCC blocker nitrendipine (which is known to immobilize their gating charges), or thapsigargin, suggesting that the effects of CGS-21680 on L-type VDCC and thapsigargin-sensitive internal stores are associated. We found that the VDCC pore blocker Cd2+ (2 mM Ca2+ or 0Ca2+-EGTA) failed to affect the CGS-21680 effect in high K+ whereas nitrendipine in 0Ca2+-EGTA+Cd2+ occluded its action. The blockade of Ca2+ release from endoplasmic reticulum with ryanodine antagonized the facilitating effect of CGS-21680 in control and high K+ concentration. It is concluded that, at the mouse neuromuscular junction, activation of A2A receptors facilitates spontaneous and K+-evoked ACh release by an external Ca2+-independent mechanism but that involves mobilization of Ca2+ from internal stores: during spontaneous ACh release

The importance of the time of digitalization for the incidence of spasms evoked by ouabain in strips of human saphenous vein.

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Zerkowski, H R; Wagner, J

1982-10-01

The extent of contracture induced by ouabain on preparations of the greater saphenous vein obtained from patients undergoing elective coronary bypass surgery was investigated. The medical pretreatment of the various donor patients was similar but differed with regard to the duration of preoperative digitalization ranging from several days to months. Whereas the maximal contraction induced by noradrenaline was not influenced by prior digitalization, the contracture evoked by ouabain showed a strong dependency on the duration of preoperative digitalization. In patients without or with only short-term preoperative digitalization the spasm exerted by ouabain amounted to 48.8% and 49.2%, respectively, of the maximal contraction induced by noradrenaline, and decreased to zero in patients with long-term digitalization. From this result it is concluded that, in patients after coronary artery bypass grafting who did not receive cardiac glycosides for long-term treatment, the acute administration of glycosides may be a mechanism responsible for the early occlusion of saphenous vein bypass grafts.

Removal of urothelium affects bladder contractility and release of ATP but not release of NO in rat urinary bladder

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Boone Timothy B

2010-05-01

Full Text Available Abstract Background The objective of our work was to investigate both the contractile function and the release of ATP and NO from strips of bladder tissue after removal of the urothelium. Methods The method of removal was a gentle swabbing motion rather than a sharp surgical cutting to separate the urothelium from the smooth muscle. The contractile response and ATP and NO release were measured in intact as well as on swabbed preparations. The removal of the urothelial layer was affirmed microscopically. Results After the swabbing, the smaller contractions were evoked by electrical as well as by chemical stimulation (50 μM carbachol or 50 μM α, β meATP. Electrical stimulation, carbachol and substance P (5 μM evoked lower release of ATP in the swabbed strips than in intact strips. Although release of NO evoked by electrical stimulation or substance P was not changed, release of NO evoked by carbachol was significantly less in the swabbed preparations. Conclusion Since swabbing removes only the urothelium, the presence of the suburothelial layer may explain the difference between our findings and those of others who found an increase in contractility. Evoked release of ATP is reduced in swabbed strips, indicating that ATP derives solely from the urothelium. On the other hand, electrical stimulation and substance P evoke identical degrees of NO release in both intact and swabbed preparations, suggesting that NO can be released from the suburothelium. Conversely, carbachol-induced release of NO is lower in swabbed strips, implying that the cholinergic receptors (muscarinic or nicotinic are located in the upper layer of the urothelium.

Fluxes of lactate into, from, and among gap junction-coupled astrocytes and their interaction with noradrenaline

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Leif eHertz

2014-09-01

Full Text Available Lactate is a versatile metabolite with important roles in modulation of brain glucose utilization rate (CMRglc, diagnosis of brain-injured patients, redox- and receptor-mediated signaling, memory, and alteration of gene transcription. Neurons and astrocytes release and accumulate lactate using equilibrative monocarboxylate transporters that carry out net transmembrane transport of lactate only until intra- and extracellular levels reach equilibrium. Astrocytes have much faster lactate uptake than neurons and shuttle more lactate among gap junction-coupled astrocytes than to nearby neurons. Lactate diffusion within syncytia can provide precursors for oxidative metabolism and glutamate synthesis and facilitate its release from endfeet to perivascular space to stimulate blood flow. Lactate efflux from brain during activation underlies the large underestimation of CMRglc with labeled glucose and fall in CMRO2/CMRglc ratio. Receptor-mediated effects of lactate on locus coeruleus neurons include noradrenaline release in cerebral cortex and c-AMP-mediated stimulation of astrocytic gap junctional coupling, thereby enhancing its dispersal and release from brain. Lactate transport is essential for its multifunctional roles.

Effects of propofol and sevoflurane on isolated human umbilical arteries pre-contracted with dopamine, adrenaline and noradrenaline.

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Gunduz, Ergun; Arun, Oguzhan; Bagci, Sengal Taylan; Oc, Bahar; Salman, Alper; Yilmaz, Setenay Arzu; Celik, Cetin; Duman, Ates

2015-05-01

To assess the effects of propofol and sevoflurane on the contraction elicited by dopamine, adrenaline and noradrenaline on isolated human umbilical arteries. Umbilical arteries were cut into endothelium-denuded spiral strips and suspended in organ baths containing Krebs-Henseleit solution bubbled with O2 +CO2 mixture. Control contraction to phenylephrine (10(-5)  M) was recorded. Response curves were obtained to 10(-5)  M dopamine, 10(-5)  M adrenaline or 10(-5)  M noradrenaline. Afterwards, either cumulative propofol (10(-6)  M, 10(-5)  M and 10(-4)  M) or cumulative sevoflurane (1.2%, 2.4% and 3.6%) was added to the organ bath, and the responses were recorded. Responses are expressed percentage of phenylephrine-induced contraction (mean ± standard deviation) (P adrenaline and noradrenaline (P adrenaline. High and highest concentrations of sevoflurane caused significantly higher relaxation compared with the high and highest concentrations of propofol on the contraction elicited by noradrenaline. Dopamine, adrenaline and noradrenaline elicit contractions in human umbilical arteries, and noradrenaline causes the highest contraction. Both propofol and sevoflurane inhibit these contractions in a dose-dependent manner. Propofol caused greater relaxation in the contractions elicited by dopamine and adrenaline while sevoflurane caused greater relaxation in the contraction elicited by noradrenaline. © 2014 The Authors. Journal of Obstetrics and Gynaecology Research © 2014 Japan Society of Obstetrics and Gynecology.

The celiac ganglion modulates LH-induced inhibition of androstenedione release in late pregnant rat ovaries

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Rastrilla Ana M

2006-12-01

Full Text Available Abstract Background Although the control of ovarian production of steroid hormones is mainly of endocrine nature, there is increasing evidence that the nervous system also influences ovarian steroidogenic output. The purpose of this work was to study whether the celiac ganglion modulates, via the superior ovarian nerve, the anti-steroidogenic effect of LH in the rat ovary. Using mid- and late-pregnant rats, we set up to study: 1 the influence of the noradrenergic stimulation of the celiac ganglion on the ovarian production of the luteotropic hormone androstenedione; 2 the modulatory effect of noradrenaline at the celiac ganglion on the anti-steroidogenic effect of LH in the ovary; and 3 the involvement of catecholaminergic neurotransmitters released in the ovary upon the combination of noradrenergic stimulation of the celiac ganglion and LH treatment of the ovary. Methods The ex vivo celiac ganglion-superior ovarian nerve-ovary integrated system was used. This model allows studying in vitro how direct neural connections from the celiac ganglion regulate ovarian steroidogenic output. The system was incubated in buffer solution with the ganglion and the ovary located in different compartments and linked by the superior ovarian nerve. Three experiments were designed with the addition of: 1 noradrenaline in the ganglion compartment; 2 LH in the ovarian compartment; and 3 noradrenaline and LH in the ganglion and ovarian compartments, respectively. Rats of 15, 19, 20 and 21 days of pregnancy were used, and, as an end point, the concentration of the luteotropic hormone androstenedione was measured in the ovarian compartment by RIA at various times of incubation. For some of the experimental paradigms the concentration of various catecholamines (dihydroxyphenylalanine, dopamine, noradrenaline and adrenaline was also measured in the ovarian compartment by HPLC. Results The most relevant result concerning the action of noradrenaline in the celiac ganglion

The Dynamic cerebral autoregulatory adaptive response to noradrenaline is attenuated during systemic inflammation in humans

DEFF Research Database (Denmark)

Berg, Ronan M. G.; Plovsing, Ronni R.; Bailey, Damian M.

2015-01-01

Vasopressor support is used widely for maintaining vital organ perfusion pressure in septic shock, with implications for dynamic cerebral autoregulation (dCA). This study investigated whether a noradrenaline-induced steady state increase in mean arterial blood pressure (MAP) would enhance d......, noradrenaline administration was associated with a decrease in gain (1.18 (1.12-1.35) vs 0.93 (0.87-0.97) cm/mmHg per s; P vs 0.94 (0.81-1.10) radians; P = 0.58). After LPS, noradrenaline administration changed neither gain (0.91 (0.85-1.01) vs 0.87 (0.......81-0.97) cm/mmHg per s; P = 0.46) nor phase (1.10 (1.04-1.30) vs 1.37 (1.23-1.51) radians; P = 0.64). The improvement of dCA to a steady state increase in MAP is attenuated during an LPS-induced systemic inflammatory response. This may suggest that vasopressor treatment with noradrenaline offers no additional...

Effect of an inhibitor of noradrenaline uptake, desipramine, on cell proliferation in the intestinal crypt epithelium.

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Tutton, P J; Barkla, D H

1989-01-01

The intestinal mucosa receives an adrenergic innervation for which there is no commonly accepted function. However, in recent years, cell kinetic studies have raised the possibility that this innervation may be an important regulator of crypt cell proliferation. The effects of noradrenaline released from adrenergic nerves is terminated principally by re-uptake of the amine into the nerve and this process can be inhibited by the antidepressant drug, desipramine. In this report desipramine is shown to accelerate crypt cell proliferation in intact, but not in chemically sympathectomized rats, thus adding support to the notion that regulation of crypt cell division is an important function of the sympathetic nervous system.

[3H] glycogen hydrolysis in brain slices: responses to meurotransmitters and modulation of noradrenaline receptors

International Nuclear Information System (INIS)

Quach, T.T.; Rose, C.; Schwartz, J.C.

1978-01-01

Different agents have been investigated for their effects on [ 3 H] glycogen synthesized in mouse cortical slices. Of these noradrenaline, serotonin and histamine induced clear concentration-dependent glycogenesis. [ 3 H] glycogen hydrolysis induced by noradrenaline appears to be mediated by beta-adrenergic receptors because it is completely prevented by timolol, while phentolamine is ineffective. It seems to involve cyclic AMP because it is potentiated in the presence of isobutylmethylxanthine; in addition dibutyryl cyclic AMP (but not dibutyryl cyclic GMP) promotes glycogenolysis. Lower concentrations of noradrenaline were necessary for [ 3 H] glycogen hydrolysis (ECsub(50) 0.5μM) than for stimulation of cyclic AMP accumulation (ECsub(50) = 8μM). After subchronic reserpine treatment the concentration-response curve to noradrenaline was significantly shifted to the left (ECsub(50) = 0.09 +- 0.02 μM as compared with 0.49 +- 0.08μM in saline-pretreated mice) without modifications of either the basal [ 3 H] glycogen level, maximal glycogenolytic effect, or the dibutyryl cAMP-induced glycogenolytic response. In addition to noradrenaline, clear concentration-dependent [ 3 H] glycogen hydrolysis was observed in the presence of histamine or serotonin. In contrast to the partial [ 3 H] glycogen hydrolysis elicited by these biogenic amines, depolarization of the slices by 50 mM K + provoked a nearly total [ 3 H] glycogen hydrolysis. (author)

Neurochemical evidence that cocaine- and amphetamine-regulated transcript (CART) 55-102 peptide modulates the dopaminergic reward system by decreasing the dopamine release in the mouse nucleus accumbens.

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Rakovska, Angelina; Baranyi, Maria; Windisch, Katalin; Petkova-Kirova, Polina; Gagov, Hristo; Kalfin, Reni

2017-09-01

CART (Cocaine- and Amphetamine-Regulated Transcript) peptide is a neurotransmitter naturally occurring in the CNS and found mostly in nucleus accumbens, ventrotegmental area, ventral pallidum, amygdalae and striatum, brain regions associated with drug addiction. In the nucleus accumbens, known for its significant role in motivation, pleasure, reward and reinforcement learning, CART peptide inhibits cocaine and amphetamine-induced dopamine-mediated increases in locomotor activity and behavior, suggesting a CART peptide interaction with the dopaminergic system. Thus in the present study, we examined the effect of CART (55-102) peptide on the basal, electrical field stimulation-evoked (EFS-evoked) (30V, 2Hz, 120 shocks) and returning basal dopamine (DA) release and on the release of the DA metabolites 3,4-dihydroxyphenyl acetaldehyde (DOPAL), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 3,4-dihydroxyphenylethanol (DOPET), 3-methoxytyramine (3-MT) as well as on norepinephrine (NE) and dopamine-o-quinone (Daq) in isolated mouse nucleus accumbens, in a preparation, in which any CART peptide effects on the dendrites or soma of ventral tegmental projection neurons have been excluded. We further extended our study to assess the effect of CART (55-102) peptide on basal cocaine-induced release of dopamine and its metabolites DOPAL, DOPAC, HVA, DOPET and 3-MT as well as on NE and Daq. To analyze the amount of [ 3 H]dopamine, dopamine metabolites, Daq and NE in the nucleus accumbens superfusate, a high-pressure liquid chromatography (HPLC), coupled with electrochemical, UV and radiochemical detections was used. CART (55-102) peptide, 0.1μM, added alone, exerted: (i) a significant decrease in the basal and EFS-evoked levels of extracellular dopamine (ii) a significant increase in the EFS-evoked and returning basal levels of the dopamine metabolites DOPAC and HVA, major products of dopamine degradation and (iii) a significant decrease in the returning basal

Modulation of sibutramine-induced increases in extracellular noradrenaline concentration in rat frontal cortex and hypothalamus by α2-adrenoceptors

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Wortley, K E; Heal, D J; Stanford, S C

1999-01-01

The effects of sibutramine (0.25–10 mg kg−1 i.p.) on extracellular noradrenaline concentration in the frontal cortex and hypothalamus of freely-moving rats were investigated using microdialysis. The role of presynaptic α2-adrenoceptors in modulating the effects of sibutramine in these brain areas was also determined.Sibutramine induced an increase in extracellular noradrenaline concentration, the magnitude of which paralleled dose, in both brain areas. In the cortex, this increase was gradual and sustained, whereas in the hypothalamus it was more rapid and of shorter duration.In both the cortex and hypothalamus, pretreatment of rats with the α2-adrenoceptor antagonist RX821002 (3 mg kg−1 i.p.) potentiated increases in the accumulation of extracellular noradrenaline induced by sibutramine (10 mg kg−1 i.p.), by 7 and 10 fold respectively. RX821002 also reduced the latency of sibutramine to reach its maximum effect in the cortex, but not in the hypothalamus.Infusion of RX821002 (1 μM) via the probe increased the accumulation of extracellular noradrenaline induced by sibutramine (10 mg kg−1 i.p.) in both brain areas. In the hypothalamus, the effects of RX821002 on the accumulation of noradrenaline induced by sibutramine were 2 fold greater than those in the cortex.These findings support evidence that sibutramine inhibits the reuptake of noradrenaline in vivo, but that the accumulation of extracellular noradrenaline is limited by noradrenergic activation of presynaptic α2-adrenoceptors. Furthermore, the data suggest that terminal α2-adrenoceptors in the hypothalamus exert a greater inhibitory effect over the control of extracellular noradrenaline accumulation than do those in the cortex. PMID:10516646

Lysosomes shape Ins(1,4,5)P3-evoked Ca2+ signals by selectively sequestering Ca2+ released from the endoplasmic reticulum

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López-Sanjurjo, Cristina I.; Tovey, Stephen C.; Prole, David L.; Taylor, Colin W.

2013-01-01

Summary Most intracellular Ca2+ signals result from opening of Ca2+ channels in the plasma membrane or endoplasmic reticulum (ER), and they are reversed by active transport across these membranes or by shuttling Ca2+ into mitochondria. Ca2+ channels in lysosomes contribute to endo-lysosomal trafficking and Ca2+ signalling, but the role of lysosomal Ca2+ uptake in Ca2+ signalling is unexplored. Inhibition of lysosomal Ca2+ uptake by dissipating the H+ gradient (using bafilomycin A1), perforating lysosomal membranes (using glycyl-L-phenylalanine 2-naphthylamide) or lysosome fusion (using vacuolin) increased the Ca2+ signals evoked by receptors that stimulate inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] formation. Bafilomycin A1 amplified the Ca2+ signals evoked by photolysis of caged Ins(1,4,5)P3 or by inhibition of ER Ca2+ pumps, and it slowed recovery from them. Ca2+ signals evoked by store-operated Ca2+ entry were unaffected by bafilomycin A1. Video-imaging with total internal reflection fluorescence microscopy revealed that lysosomes were motile and remained intimately associated with the ER. Close association of lysosomes with the ER allows them selectively to accumulate Ca2+ released by Ins(1,4,5)P3 receptors. PMID:23097044

Selective potentiation of noradrenaline in the guinea-pig vas deferens by 2-(4-methylaminobutoxy) diphenylmethane hydrochloride (MCI-2016), a new psychotropic drug.

OpenAIRE

Ohizumi, Y.; Takahashi, M.; Tobe, A.

1982-01-01

In the isolated vas deferens of the guinea-pig, the effects of 2-(4-methylaminobutoxy) diphenylmethane hydrochloride (MCI-2016), a new psychotropic drug, on the contractile response to various agonists or transmural electrical stimulation and on the release of noradrenaline (NA) from the tissue were examined and compared with cocaine. MCI-2016 (3 X 10(-6)M) and cocaine (3 X 10(-5)M) produced a leftward shift (15 and 20 times, respectively) of the dose-response curves for the contractile effec...

5-HT has contrasting effects in the frontal cortex, but not the hypothalamus, on changes in noradrenaline efflux induced by the monoamine releasing-agent, d-amphetamine, and the reuptake inhibitor, BTS 54 354.

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Géranton, Sandrine M; Heal, David J; Stanford, S Clare

2004-03-01

There is extensive evidence for functional interactions between central noradrenergic and serotonergic neurones. Here, dual-probe microdialysis was used in freely-moving rats to compare the effects of 5-HT on noradrenergic transmission in the rat frontal cortex and hypothalamus. We studied the effects of the 5-HT synthesis inhibitor, para-chlorophenylalanine (pCPA; which depleted 5-HT stores in both the frontal cortex and the hypothalamus), on spontaneous efflux of noradrenaline and on the noradrenergic responses to d-amphetamine, and the monoamine reuptake inhibitor, BTS 54 354. pCPA pretreatment alone did not affect spontaneous noradrenaline efflux in either brain region, whether or not alpha2-autoreceptors were inactivated by administration of the alpha2-antagonist, atipamezole (1 mg/kg i.p). However, in the frontal cortex, pCPA pretreatment augmented the amplitude of, and prolonged, the noradrenergic response to local infusion of d-amphetamine (10 microM). In contrast, pCPA abolished the increase in cortical noradrenaline efflux induced by local infusion of BTS 54 354 (50 microM). In the hypothalamus, pCPA did not affect the amplitude of the response to either of these agents but did prolong the effects of d-amphetamine on noradrenaline efflux. These findings suggest that serotonergic transmission has complex effects on the noradrenergic response to drugs that increase noradrenergic transmission in the frontal cortex, but has less influence in the hypothalamus.

Response Surface Modelling of Noradrenaline Production in Hairy Root Culture of Purslane (Portulaca oleracea L.

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Mehdi Ghorbani

2015-03-01

Full Text Available Common purslane (Portulaca oleracea L. is an annual plant as one of the natural sources for noradrenaline hormone. In this research, hairy root culture of purslane was established by using Agrobacterium rhizogenes strain ATCC 15834. In the following, Box-Behnken model of response surface methodology (RSM was employed to optimize B5 medium for the growth of P. oleracea L. hairy root line. According to the results, modelling and optimization conditions, including sucrose, CaCl2.H2O, H2PO4 and NO3-/NH4+ concentrations on maximum dry weight (0.155 g and noradrenaline content (0.36 mg.g-1 DW was predicted. These optimal conditions predicted by RSM were confirmed the enhancement of noradrenaline production as an application potential for production by hairy root cultures.

Role of adrenal hormones in the synthesis of noradrenaline in cardiac sympathetic neurones

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Bhagat, B.

1969-01-01

1. Adrenalectomy or adrenal demedullation affected neither the levels of endogenous catecholamines in the rat heart nor the accumulation of 3H-noradrenaline 1 hr after its intravenous administration. 2. Twenty-four hours after intravenous administration of labelled amine, however, its retention was markedly reduced in the heart of adrenalectomized or demedullated rats. Ganglionic blockade prevented this reduction. 3. Rate calculations from the decline of catecholamine levels after blockade of synthesis with α-methyl-tyrosine showed that cardiac synthesis of noradrenaline increased about four-fold after demedullation and about three-fold after adrenalectomy. This increase in synthesis may compensate for the loss of circulating catecholamines. 4. There was no change in catechol-o-methyl-transferase activity, but monoamine oxidase activity was increased in the homogenates of the heart of adrenalectomized and demedullated rats. The increase in the cardiac monoamine oxidase activity was markedly greater in the adrenalectomized rats than in the demedullated rats. 5. It is suggested that adrenal cortex insufficiency may modulate the rate of synthesis of noradrenaline and monoamine oxidase activity in cardiac sympathetic neurones. PMID:5360339

TERLIPRESSIN VERSUS NORADRENALINE FOR HEPATORENAL SYNDROME. Economic evaluation under the perspective of the Brazilian Public Health System

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Ângelo Zambam de MATTOS

Full Text Available ABSTRACT Background - Terlipressin and noradrenaline are the best studied treatments for hepatorenal syndrome, and there is no evidence of superiority of one over the other regarding to efficacy. While the former drug is more costly, the latter requires admission into an intensive care unit. Objective - The aim of this study was to perform an economic evaluation, comparing treatments for hepatorenal syndrome with terlipressin and noradrenaline. Methods - For the economic evaluation, a cost-minimization analysis was performed. Direct medical costs of the two treatment strategies were compared under the perspective of the Brazilian Public Health System as the third-party payer. A probabilistic sensitivity analysis was performed. Results - The costs of treatments with terlipressin or noradrenaline were 287.77 and 2,960.45 International Dollars (Int$ respectively. Treatment using terlipressin would save Int$2,672.68 for the Public Health System for each hospital admission related to hepatorenal syndrome. In the probabilistic sensitivity analysis, it was verified that the cost of the treatment with noradrenaline could vary between Int$2,326.53 and Int$3,644.16, while costs related to the treatment using terlipressin are not variable. Conclusion - The treatment strategy using terlipressin was more economical than that using noradrenaline under the perspective of the Brazilian Public Health System as the third-party payer.

Effect of in vitro inorganic lead on dopamine release from superfused rat striatal synaptosomes

International Nuclear Information System (INIS)

Minnema, D.J.; Greenland, R.D.; Michaelson, I.A.

1986-01-01

The effect of inorganic lead in vitro in several aspects of [ 3 H]dopamine release from superfused rat striatal synaptosomes was examined. Under conditions of spontaneous release, lead (1-30 microM) induced dopamine release in a concentration-dependent manner. The onset of the lead-induced release was delayed by approximately 15-30 sec. The magnitude of dopamine release induced by lead was increased when calcium was removed from the superfusing buffer. Lead-induced release was unaffected in the presence of putative calcium, sodium, and/or potassium channel blockers (nickel, tetrodotoxin, tetraethylammonium, respectively). Depolarization-evoked dopamine release, produced by a 1-sec exposure to 61 mM potassium, was diminished at calcium concentrations below 0.254 mM. The onset of depolarization-evoked release was essentially immediate following exposure of the synaptosomes to high potassium. The combination of lead (3 or 10 microM) with high potassium reduced the magnitude of depolarization-evoked dopamine release. This depression of depolarization-evoked release by lead was greater in the presence of 0.25 mM than 2.54 mM calcium in the superfusing buffer. These findings demonstrate multiple actions of lead on synaptosomal dopamine release. Lead can induce dopamine release by yet unidentified neuronal mechanisms independent of external calcium. Lead can also reduce depolarization-evoked dopamine release by apparent competition with calcium influx at the neuronal membrane calcium channel

Stereoselectivity of presynaptic autoreceptors modulating dopamine release

International Nuclear Information System (INIS)

Arbilla, S.; Langer, S.Z.

1981-01-01

The effects of the (R)- and (S)-enantiomers of sulpiride and butaclamol were studied on the spontaneous and field stimulation-evoked release of total radioactivity from slices of rabbit caudate nucleus prelabelled with [ 3 H]dopamine. (S)-Sulpiride in concentrations ranging from 0.01-1μM enhanced the electrically evoked release of [ 3 H]dopamine while (R)-sulpiride was 10 times less potent than (S)-sulpiride. Exposure to (S)-butaclamol (0.1-1 μM) but not to (R)-butaclamol (0.1-10μM) enhanced the field-stimulated release of [ 3 H]dopamine. The facilitatory effects of (S)- and (R)-sulpiride and (S)-butaclamol on the stimulated release of the labelled neurotransmitter were observed under conditions in which these drugs did not modify the spontaneous outflow of radioactivity. Only the active enantiomers of sulpiride and butaclamol antagonized the inhibition by apomorphine (1μM) of the stimulated release of [ 3 H]dopamine. Our results indicate that the presynaptic inhibitory dopamine autoreceptors modulating the stimulation-evoked release of [ 3 H]dopamine in the caudate nucleus are, like the classical postsynaptic dopamine receptors, chemically stereoselective. (Auth.)

Contrasting Roles of Dopamine and Noradrenaline in the Motivational Properties of Social Play Behavior in Rats.

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Achterberg, E J Marijke; van Kerkhof, Linda W M; Servadio, Michela; van Swieten, Maaike M H; Houwing, Danielle J; Aalderink, Mandy; Driel, Nina V; Trezza, Viviana; Vanderschuren, Louk J M J

2016-02-01

Social play behavior, abundant in the young of most mammalian species, is thought to be important for social and cognitive development. Social play is highly rewarding, and as such, the expression of social play depends on its pleasurable and motivational properties. Since the motivational properties of social play have only sporadically been investigated, we developed a setup in which rats responded for social play under a progressive ratio schedule of reinforcement. Dopaminergic neurotransmission plays a key role in incentive motivational processes, and both dopamine and noradrenaline have been implicated in the modulation of social play behavior. Therefore, we investigated the role of dopamine and noradrenaline in the motivation for social play. Treatment with the psychostimulant drugs methylphenidate and cocaine increased responding for social play, but suppressed its expression during reinforced play periods. The dopamine reuptake inhibitor GBR-12909 increased responding for social play, but did not affect its expression, whereas the noradrenaline reuptake inhibitor atomoxetine decreased responding for social play as well as its expression. The effects of methylphenidate and cocaine on responding for social play, but not their play-suppressant effects, were blocked by pretreatment with the dopamine receptor antagonist α-flupenthixol. In contrast, pretreatment with the α2-adrenoceptor antagonist RX821002 prevented the play-suppressant effect of methylphenidate, but left its effect on responding for social play unaltered. In sum, the present study introduces a novel method to study the incentive motivational properties of social play behavior in rats. Using this paradigm, we demonstrate dissociable roles for dopamine and noradrenaline in social play behavior: dopamine stimulates the motivation for social play, whereas noradrenaline negatively modulates the motivation for social play behavior and its expression.

Food-dependent exercise-induced anaphylaxis with a high level of plasma noradrenaline.

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Kato, Yukihiko; Nagai, Ayako; Saito, Masuyoshi; Ito, Tomonobu; Koga, Michiyuki; Tsuboi, Ryoji

2007-02-01

Ingesting certain foods sometimes triggers anaphylaxis when followed by exercise (food-dependent exercise-induced anaphylaxis, FDEIA). Specific food-induced mucocutaneous urticaria may also progress to anaphylaxis (oral allergy syndrome, OAS). A positive skin test and/or radioallergosorbent test (RAST) to the foods suggest involvement of immunoglobulin (Ig)E-anaphylaxis in both disorders. The triggering foods and initial target organs are usually different in each case. In the present study, a 32-year-old male reported dyspnea accompanied by wheals, and symptoms of low blood pressure while walking after eating Chinese noodles and donuts. He also reported uncomfortable sensations in his mouth and throat after ingesting melon. Exercise challenge tests were administered. Serum histamine, plasma adrenaline, noradrenaline and dopamine were measured pre- and post-test. No symptoms were induced by exercise or by the ingestion of any single food item before exercise. However, numerous wheals appeared when exercise followed the combined ingestion of foods. Likewise, the sequence of eating pancakes and then exercising resulted in numerous wheals and anaphylaxis. Olopatadine hydrochloride and ketotifen fumarate completely inhibited this anaphylaxis. The skin prick tests resulted in fruit-induced erythema and wheals. The results of these tests with wheat, butter and sugar were negative, and no symptoms were induced by the exercise test after ingestion of watermelon, melon or apple. The anaphylactoid symptoms were accompanied by a significant increase of plasma noradrenaline. In this case, not only wheat, but sugar and butter may induce the onset of FDEIA. There was no significant correlation between the intensity of the symptoms and the serum histamine levels in the present case. Noradrenaline may be involved in the onset of FDEIA, since noradrenaline may selectively inhibit T-helper (Th)1 functions while favoring Th2 responses. The tests showed no cross-reactivity between the

Adrenaline but not noradrenaline is a determinant of exercise-induced lipid mobilization in human subcutaneous adipose tissue

DEFF Research Database (Denmark)

Glisezinski, I. de; Larrouy, D.; Bajzova, M.

2009-01-01

The relative contribution of noradrenaline (norepinephrine) and adrenaline (epinephrine) in the control of lipid mobilization in subcutaneous adipose tissue (SCAT) during exercise was evaluated in men treated with a somatostatin analogue, octreotide. Eight lean and eight obese young men matched...... of octreotide suppressed plasma insulin and growth hormone levels at rest and during exercise. It blocked the exercise-induced increase in plasma adrenaline while that of noradrenaline was unchanged. Plasma natriuretic peptides (NPs) level was higher at rest and during exercise under octreotide infusion in lean...... individuals. In conclusion, blockade of beta-adrenergic receptors during exercise performed during infusion of octreotide (blocking the exercise-induced rise in adrenaline but not that of noradrenaline) does not alter the exercise-induced lipolysis. This suggests that adrenaline is the main adrenergic agent...

Interactions Between SNAP-25 and Synaptotagmin-1 Are Involved in Vesicle Priming, Clamping Spontaneous and Stimulating Evoked Neurotransmission

DEFF Research Database (Denmark)

Schupp, Melanie; Malsam, Jörg; Ruiter, Marvin

2016-01-01

between region I (vesicle priming) and region II (evoked release). Spontaneous release was disinhibited by region I mutations and found to correlate with defective complexin (Cpx) clamping in an in vitro fusion assay, pointing to an interdependent role of synaptotagmin and Cpx in release clamping...... triggering, depend on direct SNARE complex interaction. SIGNIFICANCE STATEMENT: The function of synaptotagmin-1 (syt-1):soluble NSF attachment protein receptor (SNARE) interactions during neurotransmission remains unclear. We mutated SNAP-25 within the recently identified region I and region II...... was disinhibited by region I mutation and found to correlate with defective complexin (Cpx) clamping in vitro, pointing to an interdependent role of synaptotagmin and Cpx in release clamping. Therefore, vesicle priming, clamping spontaneous release, and eliciting evoked release are three different functions of syt...

The neuropharmacology of serotonin and noradrenaline in depression.

Science.gov (United States)

Nutt, David J

2002-06-01

Several classes of antidepressant drug exist, divided into three broad families, the monoamine reuptake inhibitors, the monoamine oxidase inhibitors and the monoamine receptor antagonists. All these drugs have a common pharmacological effect, to raise the synaptic concentrations of noradrenaline and serotonin. Although different drugs have different relative selectivity for noradrenaline and serotonin systems, these two neurotransmitter pathways work in parallel and in a coherent manner to produce the same final antidepressant response. The lag-time in the onset of action of antidepressants can be explained by the activation of inhibitory autoreceptors on serotonergic and noradrenergic neurones which initially attenuate the effects of antidepressants on synaptic transmitter levels. Over time, these autoreceptors desensitize, allowing the emergence of an overt antidepressant response. This theory has led to the proposition that antagonists at these autoreceptors such as pindolol may be useful adjuncts to antidepressant treatment, in order to hasten the appearance of a clinical response. Evidence for the clinical validity of this idea remains equivocal, however. The use of central monoamine depletion studies has demonstrated that it is elevated synaptic monoamine levels themselves, rather than some downstream postsynaptic changes in, for example, receptor sensitivity, that are responsible for the therapeutic effect of antidepressant drugs. Taken together, the data collected over the last 40 years have allowed the emergence of a unified monoamine hypothesis of antidepressant drug action.

Presynaptic beta-adrenoceptors in guinea pig papillary muscle: evidence for adrenaline-mediated positive feedback on noradrenergic transmission

International Nuclear Information System (INIS)

Valenta, B.; Singer, E.A.

1991-01-01

Guinea pig papillary muscles were preincubated in the presence of 5 x 10 - 9 mol/L unlabeled noradrenaline or adrenaline then incubated with ( 3 H)-noradrenaline and superfused. Electrical field stimulation with 180 pulses delivered at 1 or 3 Hz was used to induce overflow of radioactivity. Comparison of the effects of preexposure of the tissue to adrenaline or noradrenaline revealed that adrenaline incubation caused an enhancement of stimulation-evoked overflow of ( 3 H)noradrenaline and a reduction of the effect of exogenously added isoprenaline. Furthermore, the selective beta 2-adrenoceptor antagonist ICI 118,551 (10 - 7 mol/L), but not the selective beta 1-adrenoceptor antagonist ICI 89,406 (10 - 7 mol/L), reduced electrically evoked overflow of ( 3 H)noradrenaline in tissue preincubated with adrenaline but not in tissue preincubated with noradrenaline. The overflow-reducing effect of ICI 118.551 occurred at stimulation with 3 Hz but not at stimulation with 1 Hz. The present results support the hypothesis that noradrenergic transmission in guinea pig papillary muscle is facilitated via beta 2-adrenoceptors, and that adrenaline may serve as transmitter in this positive feedback mechanism after its incorporation into sympathetic nerves

Comparative evaluation of two radioenzymatic procedures designed to determine noradrenaline in the plasma (COMT assay and PNMT assay)

International Nuclear Information System (INIS)

Barth, A.

1984-01-01

A comparative evaluation of two radioenzymatic procedures to determine the concentration of noradrenaline in the plasma - with linearity, sensitivity, specifity and accuracy serving as test criteria - led to the following results: In view of a probability of error in the order of 2% both methods were judged to show a satisfactory sensitivity. The specific of the COMT assay, by contrast with that of the PNMT assay, was found to be wanting, as the noradrenaline measurements in the presence of other biogenic amines were biassed in such a way that the values determined were higher than the actual concentrations. During antihypertensive treatment even minimal changes in the noradrenaline concentration can be ascertained on a quantitative basis. If suitable hardware is available, the COMT assay permits up to 25 single determinations to be carried out per day, while the number of double determinations is restricted to 7 per day. One advantage, however, lies in the fact that several catecholamines in the plasma can be detected simultaneously, if required. In cases where the noradrenaline concentration alone is to be determined for clinical purposes, preference should be given to the PNMT assay, as both tests showed equal linearity and sensitivity. (TRV) [de

[The effect of prolonged treatment of hypertensive rats with antihypertensive drugs of various actions on the arterial tension and noradrenaline level in the myocardium, brain and aortal].

Science.gov (United States)

Kiriakov, A; Khlebarova, M; Staneva-stoicheva, D; Panova, I

1975-01-01

The authors examined the changes in arterial blood pressure and the content of Noradrenaline in the myocardium, brain and aorta of rats with hypertension due to nephrectomy and treatment with desoxycorticosterone and NaCl, and after a chronic 6-month treatment of hypertension with various antihypertensive means. The most significant reduction of noradrenaline in the three of the examined tissues was found in rats, which received dic. sulfyram (100 mg/kg per os). Clondine (10 mkg/kg, per os) manifested the strongest hypotensive effect and lowered the level of noradrenaline in the myocardium, while it was raised in the aorta. Reserpine (10 mkg/kg, s. c) induced a clear reduction of Noradrenaline content in the brain, but an increase in the other two tissues. Insignificant hypotensive effect was observed in animals, treated with guanetidine (0.5 mg/kg, per os), which did not affect substantially noradrenaline in the examined organs. The increase of noradrenaline level was established in the three of the organs of animals, treated with alpha-methyl-DOFA (25 mg/kg, per os). Furosemide (1 mg/kg, s.c.) induced a statistically significant elevation of noradrenaline in the aorta, but was noneffective to noradrenaline in the myocardium and brain.

Antidepressant drugs specifically inhibiting noradrenaline reuptake enhance recognition memory in rats.

Science.gov (United States)

Feltmann, Kristin; Konradsson-Geuken, Åsa; De Bundel, Dimitri; Lindskog, Maria; Schilström, Björn

2015-12-01

Patients suffering from major depression often experience memory deficits even after the remission of mood symptoms, and many antidepressant drugs do not affect, or impair, memory in animals and humans. However, some antidepressant drugs, after a single dose, enhance cognition in humans (Harmer et al., 2009). To compare different classes of antidepressant drugs for their potential as memory enhancers, we used a version of the novel object recognition task in which rats spontaneously forget objects 24 hr after their presentation. Antidepressant drugs were injected systemically 30 min before or directly after the training phase (Session 1 [S1]). Post-S1 injections were used to test for specific memory-consolidation effects. The noradrenaline reuptake inhibitors reboxetine and atomoxetine, as well as the serotonin noradrenaline reuptake inhibitor duloxetine, injected prior to S1 significantly enhanced recognition memory. In contrast, the serotonin reuptake inhibitors citalopram and paroxetine and the cyclic antidepressant drugs desipramine and mianserin did not enhance recognition memory. Post-S1 injection of either reboxetine or citalopram significantly enhanced recognition memory, indicating an effect on memory consolidation. The fact that citalopram had an effect only when injected after S1 suggests that it may counteract its own consolidation-enhancing effect by interfering with memory acquisition. However, pretreatment with citalopram did not attenuate reboxetine's memory-enhancing effect. The D1/5-receptor antagonist SCH23390 blunted reboxetine's memory-enhancing effect, indicating a role of dopaminergic transmission in reboxetine-induced recognition memory enhancement. Our results suggest that antidepressant drugs specifically inhibiting noradrenaline reuptake enhance cognition and may be beneficial in the treatment of cognitive symptoms of depression. (c) 2015 APA, all rights reserved).

Magnetic restricted-access microspheres for extraction of adrenaline, dopamine and noradrenaline from biological samples

International Nuclear Information System (INIS)

Xiao, Deli; Liu, Shubo; Liang, Liyun; Bi, Yanping

2016-01-01

Epoxy propyl bonded magnetic microspheres were prepared by atomic layer deposition using Fe 3 O 4 -SiO 2 microspheres as a core support material. Then, a restricted-access magnetic sorbent was prepared that contains diol groups on the external surface and m-aminophenylboronic acid groups on the internal surface. This kind of microspheres achieved excellent specific adsorption of the ortho-dihydroxy compounds (dopamine, adrenaline and noradrenaline). Following desorption with sorbitol, the ortho-dihydroxy compounds were quantified by HPLC. The limits of detection for dopamine, adrenaline and noradrenaline were 0.074, 0.053 and 0.095 μg mL −1 , respectively. Recoveries from spiked mice serum samples range from 80.2 to 89.1 %. (author)

Stress Alone or associated with Ethanol Induces Prostanoid Release in Rat Aorta via α2-Adrenoceptor

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Baptista, Rafaela de Fátima Ferreira [Departamento de Farmacologia - Instituto de Biociências - Universidade Estadual Paulista - UNESP - São Paulo, SP (Brazil); Laboratório de Farmacologia - Faculdade de Medicina de Marília - FAMEMA, SP (Brazil); Taipeiro, Elane de Fátima [Laboratório de Farmacologia - Faculdade de Medicina de Marília - FAMEMA, SP (Brazil); Queiroz, Regina Helena Costa [Departamento de Análise Clínica - Toxicológica e Ciência de Alimentos - Faculdade de Ciências Farmacêuticas - USP, São Paulo, SP (Brazil); Chies, Agnaldo Bruno [Departamento de Farmacologia - Instituto de Biociências - Universidade Estadual Paulista - UNESP - São Paulo, SP (Brazil); Laboratório de Farmacologia - Faculdade de Medicina de Marília - FAMEMA, SP (Brazil); Cordellini, Sandra, E-mail: cordelli@ibb.unesp.br [Departamento de Farmacologia - Instituto de Biociências - Universidade Estadual Paulista - UNESP - São Paulo, SP (Brazil)

2014-03-15

Stress and ethanol are both, independently, important cardiovascular risk factors. To evaluate the cardiovascular risk of ethanol consumption and stress exposure, isolated and in association, in male adult rats. Rats were separated into 4 groups: Control, ethanol (20% in drinking water for 6 weeks), stress (immobilization 1h day/5 days a week for 6 weeks) and stress/ethanol. Concentration-responses curves to noradrenaline - in the absence and presence of yohimbine, L-NAME or indomethacin - or to phenylephrine were determined in thoracic aortas with and without endothelium. EC50 and maximum response (n=8-12) were compared using two-way ANOVA/Bonferroni method. Either stress or stress in association with ethanol consumption increased the noradrenaline maximum responses in intact aortas. This hyper-reactivity was eliminated by endothelium removal or by the presence of either indomethacin or yohimbine, but was not altered by the presence of L-NAME. Meanwhile, ethanol consumption did not alter the reactivity to noradrenaline. The phenylephrine responses in aortas both with and without endothelium also remained unaffected regardless of protocol. Chronic stress increased rat aortic responses to noradrenaline. This effect is dependent upon the vascular endothelium and involves the release of vasoconstrictor prostanoids via stimulation of endothelial alpha-2 adrenoceptors. Moreover, chronic ethanol consumption appeared to neither influence noradrenaline responses in rat thoracic aorta, nor did it modify the increase of such responses observed as a consequence of stress exposure.

Stress Alone or associated with Ethanol Induces Prostanoid Release in Rat Aorta via α2-Adrenoceptor

International Nuclear Information System (INIS)

Baptista, Rafaela de Fátima Ferreira; Taipeiro, Elane de Fátima; Queiroz, Regina Helena Costa; Chies, Agnaldo Bruno; Cordellini, Sandra

2014-01-01

Stress and ethanol are both, independently, important cardiovascular risk factors. To evaluate the cardiovascular risk of ethanol consumption and stress exposure, isolated and in association, in male adult rats. Rats were separated into 4 groups: Control, ethanol (20% in drinking water for 6 weeks), stress (immobilization 1h day/5 days a week for 6 weeks) and stress/ethanol. Concentration-responses curves to noradrenaline - in the absence and presence of yohimbine, L-NAME or indomethacin - or to phenylephrine were determined in thoracic aortas with and without endothelium. EC50 and maximum response (n=8-12) were compared using two-way ANOVA/Bonferroni method. Either stress or stress in association with ethanol consumption increased the noradrenaline maximum responses in intact aortas. This hyper-reactivity was eliminated by endothelium removal or by the presence of either indomethacin or yohimbine, but was not altered by the presence of L-NAME. Meanwhile, ethanol consumption did not alter the reactivity to noradrenaline. The phenylephrine responses in aortas both with and without endothelium also remained unaffected regardless of protocol. Chronic stress increased rat aortic responses to noradrenaline. This effect is dependent upon the vascular endothelium and involves the release of vasoconstrictor prostanoids via stimulation of endothelial alpha-2 adrenoceptors. Moreover, chronic ethanol consumption appeared to neither influence noradrenaline responses in rat thoracic aorta, nor did it modify the increase of such responses observed as a consequence of stress exposure

Role of glycogenolysis in memory and learning: regulation by noradrenaline, serotonin and ATP

Directory of Open Access Journals (Sweden)

Marie Elizabeth Gibbs

2016-01-01

Full Text Available This paper reviews the role played by glycogen breakdown (glycogenolysis and glycogen re-synthesis in memory processing in two different chick brain regions, (1 the hippocampus and (2 the avian equivalent of the mammalian cortex, the intermediate medial mesopallium (IMM. Memory processing is regulated by the neuromodulators noradrenaline and serotonin soon after training and glycogen breakdown and re-synthesis are involved. In day-old domestic chicks, memory formation is dependent on the breakdown of glycogen (glycogenolysis at three specific times during the first 60 min after learning (around 2.5, 30 and 55 min. The chicks learn to discriminate in a single trial between beads of two colours and tastes. Inhibition of glycogen breakdown by the inhibitor of glycogen phosphorylase 1,4-dideoxy-1,4-imino-D-arabinitol (DAB given at specific times prior to the formation of long-term memory prevents memory forming. Noradrenergic stimulation of cultured chicken astrocytes by a selective β2-adrenergic (AR agonist reduces glycogen levels and we believe that in vivo this triggers memory consolidation at the second stage of glycogenolysis. Serotonin acting at 5-HT2B receptors acts on the first stage, but not on the second. We have shown that noradrenaline, acting via post-synaptic α2-ARs, is also responsible for the synthesis of glycogen and our experiments suggest that there is a readily accessible labile pool of glycogen in astrocytes which is depleted within 10 min if glycogen synthesis is inhibited. Endogenous ATP promotion of memory consolidation at 2.5 and 30 min is also dependent on glycogen breakdown. ATP acts at P2Y1 receptors and the action of thrombin suggests that it causes the release of internal calcium ([Ca2+]i] in astrocytes. Glutamate and GABA, the primary neurotransmitters in the brain, cannot be synthesized in neurons de novo. Neurons rely on astrocytic glutamate synthesis, requiring glycogenolysis.

Expression of the capacity to release [3H]norepinephrine by neural crest cultures

International Nuclear Information System (INIS)

Maxwell, G.D.; Sietz, P.D.

1983-01-01

Cultures of trunk neural crest cells from quail embryos were tested for their ability to release [ 3 H]norepinephrine [( 3 H]NE) in response to depolarization. After 7 days in vitro, exposure of the cultures to either the alkaloid veratridine or 40 mM K+ results in the evoked release of [ 3 H]NE. The release evoked by veratridine is blocked in the presence of tetrodotoxin. The release evoked by increased K+ is blocked by the calcium antagonist cobalt. Release in response to the nicotinic cholinergic agonist 1,1-dimethyl-4-phenylpiperazine was also observed. The amount of evoked release is highly correlated with the number of histochemically demonstrable catecholamine-containing cells in a given culture. Autoradiography reveals that the radioactivity taken up by these cultures is located in a subpopulation of cells whose morphology resembles that of the histochemically detectable catecholamine-containing cell population. Whereas capacity for the release of [ 3 H] NE is readily detectable after 7 days in vitro, it is detectable only with difficulty after 4 days in vitro. There is a greater than 6-fold increase in uptake capacity over the period of 4 to 7 days in vitro. These results demonstrate that neural crest cultures grown without their normal synaptic inputs or targets can exhibit the capacity for stimulus secretion coupling characteristic of synaptic neurotransmitter release

Na+-independent, nifedipine-resistant rat afferent arteriolar Ca2+ responses to noradrenaline

DEFF Research Database (Denmark)

Salomonsson, Max; Braunstein, Thomas Hartig; von Holstein-Rathlou, Niels-Henrik

2010-01-01

Abstract Aim: In rat afferent arterioles we investigated the role of Na(+) entry in noradrenaline (NA)-induced depolarization and voltage-dependent Ca(2+) entry together with the importance of the transient receptor potential channel (TRPC) subfamily for non-voltage-dependent Ca(2+) entry. Methods...

Noradrenaline, oxymetazoline and phorbol myristate acetate induce distinct functional actions and phosphorylation patterns of α1A-adrenergic receptors.

Science.gov (United States)

Alcántara-Hernández, Rocío; Hernández-Méndez, Aurelio; Romero-Ávila, M Teresa; Alfonzo-Méndez, Marco A; Pupo, André S; García-Sáinz, J Adolfo

2017-12-01

In LNCaP cells that stably express α 1A -adrenergic receptors, oxymetazoline increased intracellular calcium and receptor phosphorylation, however, this agonist was a weak partial agonist, as compared to noradrenaline, for calcium signaling. Interestingly, oxymetazoline-induced receptor internalization and desensitization displayed greater effects than those induced by noradrenaline. Phorbol myristate acetate induced modest receptor internalization and minimal desensitization. α 1A -Adrenergic receptor interaction with β-arrestins (colocalization/coimmunoprecipitation) was induced by noradrenaline and oxymetazoline and, to a lesser extent, by phorbol myristate acetate. Oxymetazoline was more potent and effective than noradrenaline in inducing ERK 1/2 phosphorylation. Mass spectrometric analysis of immunopurified α 1A -adrenergic receptors from cells treated with adrenergic agonists and the phorbol ester clearly showed that phosphorylated residues were present both at the third intracellular loop and at the carboxyl tail. Distinct phosphorylation patterns were observed under the different conditions. The phosphorylated residues were: a) Baseline and all treatments: T233; b) noradrenaline: S220, S227, S229, S246, S250, S389; c) oxymetazoline: S227, S246, S381, T384, S389; and d) phorbol myristate acetate: S246, S250, S258, S351, S352, S401, S402, S407, T411, S413, T451. Our novel data, describing the α 1A -AR phosphorylation sites, suggest that the observed different phosphorylation patterns may participate in defining adrenoceptor localization and action, under the different conditions examined. Copyright © 2017 Elsevier B.V. All rights reserved.

Scent-evoked nostalgia.

Science.gov (United States)

Reid, Chelsea A; Green, Jeffrey D; Wildschut, Tim; Sedikides, Constantine

2015-01-01

Can scents evoke nostalgia; what might be the psychological implications of such an evocation? Participants sampled 12 scents and rated the extent to which each scent was familiar, arousing and autobiographically relevant, as well as the extent to which each scent elicited nostalgia. Participants who were high (compared to low) in nostalgia proneness reported more scent-evoked nostalgia, and scents elicited greater nostalgia to the extent that they were arousing, familiar and autobiographically relevant. Scent-evoked nostalgia predicted higher levels of positive affect, self-esteem, self-continuity, optimism, social connectedness and meaning in life. In addition, scent-evoked nostalgia was characterised by more positive emotions than either non-nostalgic autobiographical memories or non-nostalgic non-autobiographical memories. Finally, scent-evoked nostalgia predicted in-the-moment feelings of personal (general or object-specific) nostalgia. The findings represent a foray into understanding the triggers and affective signature of scent-evoked nostalgia.

Splanchnic and renal elimination and release of catecholamines in cirrhosis. Evidence of enhanced sympathetic nervous activity in patients with decompensated cirrhosis

DEFF Research Database (Denmark)

Ring-Larsen, H; Kanstrup, I L; Christensen, N J

1984-01-01

Plasma noradrenaline (NA) and adrenaline (A) concentrations were determined in different vascular areas in 32 patients with cirrhosis and in nine controls during a right sided heart, liver, and renal vein catheterisation. The patients were divided into four groups: (I) Compensated (without ascites......, respectively, the three last mentioned values being significantly raised (p less than 0.01). Median arterial adrenaline concentrations were not significantly increased. In patients arterial-hepatic venous extraction ratios of noradrenaline and adrenaline were on the average 25% (p less than 0.01) and 20% (p...... differences were significantly increased in groups II, III and IV (0.47, 0.53 and 0.68 nmol/l, p less than 0.01), indicating a significant net release of noradrenaline from the kidneys in recompensated and decompensated patients. Renal extraction of adrenaline was normal. In conclusion, increased arterial...

Endothelial and Neuronal Nitric Oxide Activate Distinct Pathways on Sympathetic Neurotransmission in Rat Tail and Mesenteric Arteries.

Directory of Open Access Journals (Sweden)

Joana Beatriz Sousa

Full Text Available Nitric oxide (NO seems to contribute to vascular homeostasis regulating neurotransmission. This work aimed at assessing the influence of NO from different sources and respective intracellular pathways on sympathetic neurotransmission, in two vascular beds. Electrically-evoked [3H]-noradrenaline release was assessed in rat mesenteric and tail arteries in the presence of NO donors or endothelial/neuronal nitric oxide synthase (NOS inhibitors. The influence of NO on adenosine-mediated effects was also studied using selective antagonists for adenosine receptors subtypes. Location of neuronal NOS (nNOS was investigated by immunohistochemistry (with specific antibodies for nNOS and for Schwann cells and Confocal Microscopy. Results indicated that: 1 in mesenteric arteries, noradrenaline release was reduced by NO donors and it was increased by nNOS inhibitors; the effect of NO donors was only abolished by the adenosine A1 receptors antagonist; 2 in tail arteries, noradrenaline release was increased by NO donors and it was reduced by eNOS inhibitors; adenosine receptors antagonists were devoid of effect; 3 confocal microscopy showed nNOS staining in adventitial cells, some co-localized with Schwann cells. nNOS staining and its co-localization with Schwann cells were significantly lower in tail compared to mesenteric arteries. In conclusion, in mesenteric arteries, nNOS, mainly located in Schwann cells, seems to be the main source of NO influencing perivascular sympathetic neurotransmission with an inhibitory effect, mediated by adenosine A1 receptors activation. Instead, in tail arteries endothelial NO seems to play a more relevant role and has a facilitatory effect, independent of adenosine receptors activation.

Membrane permeable C-terminal dopamine transporter peptides attenuate amphetamine-evoked dopamine release

DEFF Research Database (Denmark)

Rickhag, Karl Mattias; Owens, WA; Winkler, Marie-Therese

2013-01-01

The dopamine transporter (DAT) is responsible for sequestration of extracellular dopamine (DA). The psychostimulant amphetamine (AMPH) is a DAT substrate, which is actively transported into the nerve terminal, eliciting vesicular depletion and reversal of DA transport via DAT. Here, we investigate......-terminal protein-protein interactions are critical for AMPH-evoked DA efflux and suggest that it may be possible to target protein-protein interactions to modulate transporter function and interfere with psychostimulant effects....

Regarding the unitary theory of agonist and antagonist action at presynaptic adrenoceptors.

Science.gov (United States)

Kalsner, S; Abdali, S A

2001-06-01

1. The linkage between potentiation of field stimulation-induced noradrenaline release and blockade of the presynaptic inhibitory effect of exogenous noradrenaline by a presynaptic antagonist was examined in superfused rabbit aorta preparations. 2. Rauwolscine clearly potentiated the release of noradrenaline in response to 100 pulses at 2 Hz but reduced the capacity of noradrenaline to inhibit transmitter release to a questionable extent, and then only when comparisons were made with untreated, rather then to rauwolscine-treated, controls. 3. Aortic preparations exposed for 60 min to rauwolscine followed by superfusion with antagonist-free Krebs for 60 min retained the potentiation of stimulation-induced transmitter release but no antagonism of the noradrenaline-induced inhibition could be detected at either of two noradrenaline concentrations when comparisons were made with rauwolscine treated controls. 4. Comparisons of the inhibitory effect of exogenous noradrenaline (1.8 x 10-6 M) on transmitter efflux in the presence and absence of rauwolscine pretreatment revealed that the antagonist enhanced rather than antagonized the presynaptic inhibition by noradrenaline. 5 It is concluded that the unitary hypothesis that asserts that antagonist enhancement of transmitter release and its blockade of noradrenaline induced inhibition are manifestations of a unitary event are not supportable.

The modulatory effects of noradrenaline on vagal control of heart rate in the dogfish, Squalus acanthias.

Science.gov (United States)

Agnisola, Claudio; Randall, David J; Taylor, Edwin W

2003-01-01

The possible interactions between inhibitory vagal control of the heart and circulating levels of catecholamines in dogfish (Squalus acanthias) were studied using an in situ preparation of the heart, which retained intact its innervation from centrally cut vagus nerves. The response to peripheral vagal stimulation typically consisted of an initial cardiac arrest, followed by an escape beat, leading to renewed beating at a mean heart rate lower than the prestimulation rate (partial recovery). Cessation of vagal stimulation led to a transient increase in heart rate, above the prestimulation rate. This whole response was completely abolished by 10(-4) M atropine (a muscarinic cholinergic antagonist). The degree of vagal inhibition was evaluated in terms of both the initial, maximal cardiac interval and the mean heart rate during partial recovery, both expressed as a percentage of the prestimulation heart rate. The mean prestimulation heart rate of this preparation (36+/-4 beats min(-1)) was not affected by noradrenaline but was significantly reduced by 10(-4) M nadolol (a beta-adrenergic receptor antagonist), suggesting the existence of a resting adrenergic tone arising from endogenous catecholamines. The degree of vagal inhibition of heart rate varied with the rate of stimulation and was increased by the presence of 10(-8) M noradrenaline (the normal in vivo level in routinely active fish), while 10(-7) M noradrenaline (the in vivo level measured in disturbed or deeply hypoxic fish) reduced the cardiac response to vagal stimulation. In the presence of 10(-7) M noradrenaline, 10(-4) M nadolol further reduced the vagal response, while 10(-4) M nadolol + 10(-4) M phentolamine had no effect, indicating a complex interaction between adrenoreceptors, possibly involving presynaptic modulation of vagal inhibition.

Stress at birth: plasma noradrenaline concentrations of women in labour and in cord blood.

Science.gov (United States)

Messow-Zahn, K; Sarafoff, M; Riegel, K P

1978-03-15

Radioenzymatically measured plasma noradrenaline concentrations, present at birth in umbilical veins of 19 healthy, 17 acutely asphyxiated, and 9 chronically distressed newborn infants were found to be elevated above maternal values proportional to the degree of distress and to plasma H ion concentrations.

The Relevance of AgRP Neuron-Derived GABA Inputs to POMC Neurons Differs for Spontaneous and Evoked Release.

Science.gov (United States)

Rau, Andrew R; Hentges, Shane T

2017-08-02

Hypothalamic agouti-related peptide (AgRP) neurons potently stimulate food intake, whereas proopiomelanocortin (POMC) neurons inhibit feeding. Whether AgRP neurons exert their orexigenic actions, at least in part, by inhibiting anorexigenic POMC neurons remains unclear. Here, the connectivity between GABA-releasing AgRP neurons and POMC neurons was examined in brain slices from male and female mice. GABA-mediated spontaneous IPSCs (sIPSCs) in POMC neurons were unaffected by disturbing GABA release from AgRP neurons either by cell type-specific deletion of the vesicular GABA transporter or by expression of botulinum toxin in AgRP neurons to prevent vesicle-associated membrane protein 2-dependent vesicle fusion. Additionally, there was no difference in the ability of μ-opioid receptor (MOR) agonists to inhibit sIPSCs in POMC neurons when MORs were deleted from AgRP neurons, and activation of the inhibitory designer receptor hM4Di on AgRP neurons did not affect sIPSCs recorded from POMC neurons. These approaches collectively indicate that AgRP neurons do not significantly contribute to the strong spontaneous GABA input to POMC neurons. Despite these observations, optogenetic stimulation of AgRP neurons reliably produced evoked IPSCs in POMC neurons, leading to the inhibition of POMC neuron firing. Thus, AgRP neurons can potently affect POMC neuron function without contributing a significant source of spontaneous GABA input to POMC neurons. Together, these results indicate that the relevance of GABAergic inputs from AgRP to POMC neurons is state dependent and highlight the need to consider different types of transmitter release in circuit mapping and physiologic regulation. SIGNIFICANCE STATEMENT Agouti-related peptide (AgRP) neurons play an important role in driving food intake, while proopiomelanocortin (POMC) neurons inhibit feeding. Despite the importance of these two well characterized neuron types in maintaining metabolic homeostasis, communication between these

Noradrenaline concentration and turnover in nuclei of the hypothalamus and the medulla oblongata at two stages in the development of renal hypertension in the rat

NARCIS (Netherlands)

Wijnen, H.J.L.M.; Kloet, E.R. de; Versteeg, D.H.G.; Jong, Wybren de

1980-01-01

The noradrenaline concentration and the α-methyl-para-tyrosine (α-MPT)-induced disappearance of noradrenaline were determined in several nuclei of the hypothalamus and the medulla oblongata of renal hypertensive rats (two-kidney Goldblatt hypertension). A decreased α-MPT-induced disappearance of

Inhibition of serotonin release by bombesin-like peptides in rat hypothalamus in vitro

International Nuclear Information System (INIS)

Saporito, M.S.; Warwick, R.O. Jr.

1989-01-01

We investigated the activity of bombesin (BN), neuromedin-C (NM-C) and neuromedin-B (NM-B) on serotonin (5-HT) release and reuptake in rat hypothalamus (HYP) in vitro. BN and NM-C but not NM-B decreased K + evoked 3 H-5-HT release from superfused HYP slices by 25%. Bacitracin, a nonspecific peptidase inhibitor, reversed the inhibitory effect of BN on K + evoked 3 H-5-HT release. Phosphoramidon (PAN, 10 μM) an endopeptidase 24.11 inhibitor, abolished the inhibitory effect of BN, but not NM-C, on K + evoked 3 H-5-HT release. The peptidyl dipeptidase A inhibitor enalaprilat (ENP, 10 μM), enhanced both BN and NM-C inhibition of 3 H-5-HT release. Bestatin (BST, 10 μM) had no effect on BN or NM-C inhibitory activity on 3 H-5-HT release. Neither BN, NM-C nor NM-B affected reuptake of 3 H-5-HT into HYP synaptosomes alone or in combination with any of the peptidase inhibitors, nor did these peptides alter the ability of fluoxetine to inhibit 3 H-5-HT uptake

Sleep-wake sensitive mechanisms of adenosine release in the basal forebrain of rodents: an in vitro study.

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Robert Edward Sims

Full Text Available Adenosine acting in the basal forebrain is a key mediator of sleep homeostasis. Extracellular adenosine concentrations increase during wakefulness, especially during prolonged wakefulness and lead to increased sleep pressure and subsequent rebound sleep. The release of endogenous adenosine during the sleep-wake cycle has mainly been studied in vivo with microdialysis techniques. The biochemical changes that accompany sleep-wake status may be preserved in vitro. We have therefore used adenosine-sensitive biosensors in slices of the basal forebrain (BFB to study both depolarization-evoked adenosine release and the steady state adenosine tone in rats, mice and hamsters. Adenosine release was evoked by high K(+, AMPA, NMDA and mGlu receptor agonists, but not by other transmitters associated with wakefulness such as orexin, histamine or neurotensin. Evoked and basal adenosine release in the BFB in vitro exhibited three key features: the magnitude of each varied systematically with the diurnal time at which the animal was sacrificed; sleep deprivation prior to sacrifice greatly increased both evoked adenosine release and the basal tone; and the enhancement of evoked adenosine release and basal tone resulting from sleep deprivation was reversed by the inducible nitric oxide synthase (iNOS inhibitor, 1400 W. These data indicate that characteristics of adenosine release recorded in the BFB in vitro reflect those that have been linked in vivo to the homeostatic control of sleep. Our results provide methodologically independent support for a key role for induction of iNOS as a trigger for enhanced adenosine release following sleep deprivation and suggest that this induction may constitute a biochemical memory of this state.

Functional adaptation of the human β-cells after frequent exposure to noradrenaline

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Dela, Flemming

2015-01-01

KEY POINTS: Trained people produce less insulin than untrained; there is an adaptation of the insulin-producing cells to the trained state. The mechanism behind this adaptation is not known, but some sort of memory must be introduced into the insulin-producing cells. Here it is shown that this me......KEY POINTS: Trained people produce less insulin than untrained; there is an adaptation of the insulin-producing cells to the trained state. The mechanism behind this adaptation is not known, but some sort of memory must be introduced into the insulin-producing cells. Here it is shown...... that this memory is introduced by 10 daily intravenous infusions of noradrenaline, mimicking the increases that occur during a 10 day training programme. Thus, after the infusion period, the subjects produced less insulin in response to the same stimulus. It is concluded that exercise-induced increases...... in noradrenaline is most likely the stimulus that introduces a memory in the insulin-producing cells. ABSTRACT: Physical training decreases glucose- and arginine-stimulated insulin secretion. The mechanism by which the pancreatic β-cells adapt to the training status of the individual is not known. We hypothesized...

Protein kinase A mediates adenosine A2a receptor modulation of neurotransmitter release via synapsin I phosphorylation in cultured cells from medulla oblongata.

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Matsumoto, Joao Paulo Pontes; Almeida, Marina Gomes; Castilho-Martins, Emerson Augusto; Costa, Maisa Aparecida; Fior-Chadi, Debora Rejane

2014-08-01

Synaptic transmission is an essential process for neuron physiology. Such process is enabled in part due to modulation of neurotransmitter release. Adenosine is a synaptic modulator of neurotransmitter release in the Central Nervous System, including neurons of medulla oblongata, where several nuclei are involved with neurovegetative reflexes. Adenosine modulates different neurotransmitter systems in medulla oblongata, specially glutamate and noradrenaline in the nucleus tractussolitarii, which are involved in hypotensive responses. However, the intracellular mechanisms involved in this modulation remain unknown. The adenosine A2a receptor modulates neurotransmitter release by activating two cAMP protein effectors, the protein kinase A and the exchange protein activated by cAMP. Therefore, an in vitro approach (cultured cells) was carried out to evaluate modulation of neurotransmission by adenosine A2a receptor and the signaling intracellular pathway involved. Results show that the adenosine A2a receptor agonist, CGS 21680, increases neurotransmitter release, in particular, glutamate and noradrenaline and such response is mediated by protein kinase A activation, which in turn increased synapsin I phosphorylation. This suggests a mechanism of A2aR modulation of neurotransmitter release in cultured cells from medulla oblongata of Wistar rats and suggest that protein kinase A mediates this modulation of neurotransmitter release via synapsin I phosphorylation. Copyright © 2014 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

A search for presynaptic inhibitory histamine receptors in guinea-pig tissues: Further H3 receptors but no evidence for H4 receptors.

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Petri, Doris; Schlicker, Eberhard

2016-07-01

The histamine H4 receptor is coupled to Gi/o proteins and expressed on inflammatory cells and lymphoid tissues; it was suggested that this receptor also occurs in the brain or on peripheral neurones. Since many Gi/o protein-coupled receptors, including the H3 receptor, serve as presynaptic inhibitory receptors, we studied whether the sympathetic neurones supplying four peripheral tissues and the cholinergic neurones in the hippocampus from the guinea-pig are equipped with release-modulating H4 and H3 receptors. For this purpose, we preincubated tissue pieces from the aorta, atrium, renal cortex and vas deferens with (3)H-noradrenaline and hippocampal slices with (3)H-choline and determined the electrically evoked tritium overflow. The stimulation-evoked overflow in the five superfused tissues was inhibited by the muscarinic receptor agonist oxotremorine, which served as a positive control, but not affected by the H4 receptor agonist 4-methylhistamine. The H3 receptor agonist R-α-methylhistamine inhibited noradrenaline release in the peripheral tissues without affecting acetylcholine release in the hippocampal slices. Thioperamide shifted the concentration-response curve of histamine in the aorta and the renal cortex to the right, yielding apparent pA2 values of 8.0 and 8.1, respectively, which are close to its affinity at other H3 receptors but higher by one log unit than its pKi at the H4 receptor of the guinea-pig. In conclusion, histamine H4 receptors could not be identified in five experimental models of the guinea-pig that are suited for the detection of presynaptic inhibitory receptors whereas H3 receptors could be shown in the peripheral tissues but not in the hippocampus. This article is part of the Special Issue entitled 'Histamine Receptors'. Copyright © 2015 Elsevier Ltd. All rights reserved.

Lead-Induced Atypical Parkinsonism in Rats: Behavioral, Electrophysiological, and Neurochemical Evidence for a Role of Noradrenaline Depletion

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Mariam Sabbar

2018-03-01

Full Text Available Background: Lead neurotoxicity is a major health problem known as a risk factor for neurodegenerative diseases, including the manifestation of parkinsonism-like disorder. While lead is known to preferentially accumulate in basal ganglia, the mechanisms underlying behavioral disorders remain unknown. Here, we investigated the neurophysiological and biochemical correlates of motor deficits induced by sub-chronic injections of lead.Methods: Sprague Dawely rats were exposed to sub-chronic injections of lead (10 mg/kg, i.p. or to a single i.p. injection of 50 mg/kg N-(2-chloroethyl-N-ethyl-2-bromobenzylamine hydrochloride (DSP-4, a drug known to induce selective depletion of noradrenaline. Rats were submitted to a battery of behavioral tests, including the open field for locomotor activity and rotarod for motor coordination. Electrophysiological recordings were carried out in three major basal ganglia nuclei, the subthalamic nucleus (STN, globus pallidus (GP, and substantia nigra pars reticulata (SNr. At the end of experiments, post-mortem tissue level of the three monoamines (dopamine, noradrenaline, and serotonin and their metabolites has been determined using HPLC.Results: Lead intoxication significantly impaired exploratory and locomotor activity as well as motor coordination. It resulted in a significant reduction in the level of noradrenaline in the cortex and dopamine and its metabolites, DOPAC, and HVA, in the striatum. The tissue level of serotonin and its metabolite 5-HIAA was not affected in the two structures. Similarly, DSP-4, which induced a selective depletion of noradrenaline, significantly decreased exploratory, and locomotor activity as well as motor coordination. L-DOPA treatment did not improve motor deficits induced by lead and DSP-4 in the two animal groups. Electrophysiological recordings showed that both lead and DSP-4 did not change the firing rate but resulted in a switch from the regular normal firing to irregular and

[Presence of conjugated noradrenaline in the walls of the nest of Vespula germanica Linné].

Science.gov (United States)

Lecomte, J; Bourdon, V; Damas, J; Leclercq, M; Leclercq, J

1976-01-01

Conjugated noradrenaline (NA) has been identified as a constituant of the walls of a Vespid wasp: Vespula germanica Linne. Concentrations range between 1,8 mug/g (external wall) and 18 mug/g (internal structure). Probably NA originates from the saliva of the Hymenoptera.

Adverse Weather Evokes Nostalgia.

Science.gov (United States)

van Tilburg, Wijnand A P; Sedikides, Constantine; Wildschut, Tim

2018-03-01

Four studies examined the link between adverse weather and the palliative role of nostalgia. We proposed and tested that (a) adverse weather evokes nostalgia (Hypothesis 1); (b) adverse weather causes distress, which predicts elevated nostalgia (Hypothesis 2); (c) preventing nostalgia exacerbates weather-induced distress (Hypothesis 3); and (d) weather-evoked nostalgia confers psychological benefits (Hypothesis 4). In Study 1, participants listened to recordings of wind, thunder, rain, and neutral sounds. Adverse weather evoked nostalgia. In Study 2, participants kept a 10-day diary recording weather conditions, distress, and nostalgia. We also obtained meteorological data. Adverse weather perceptions were positively correlated with distress, which predicted higher nostalgia. Also, adverse natural weather was associated with corresponding weather perceptions, which predicted elevated nostalgia. (Results were mixed for rain.) In Study 3, preventing nostalgia (via cognitive load) increased weather-evoked distress. In Study 4, weather-evoked nostalgia was positively associated with psychological benefits. The findings pioneer the relevance of nostalgia as source of comfort in adverse weather.

Hispidulin inhibits the release of glutamate in rat cerebrocortical nerve terminals

International Nuclear Information System (INIS)

Lin, Tzu-Yu; Lu, Cheng-Wei; Wang, Chia-Chuan; Lu, Jyh-Feng; Wang, Su-Jane

2012-01-01

Hispidulin, a naturally occurring flavone, has been reported to have an antiepileptic profile. An excessive release of glutamate is considered to be related to neuropathology of epilepsy. We investigated whether hispidulin affected endogenous glutamate release in rat cerebral cortex nerve terminals (synaptosomes) and explored the possible mechanism. Hispidulin inhibited the release of glutamate evoked by the K + channel blocker 4-aminopyridine (4-AP). The effects of hispidulin on the evoked glutamate release were prevented by the chelation of extracellular Ca 2+ ions and the vesicular transporter inhibitor bafilomycin A1. However, the glutamate transporter inhibitor DL-threo-beta-benzyl-oxyaspartate did not have any effect on hispidulin action. Hispidulin reduced the depolarization-induced increase in cytosolic free Ca 2+ concentration ([Ca 2+ ] C ), but did not alter 4-AP-mediated depolarization. Furthermore, the effect of hispidulin on evoked glutamate release was abolished by blocking the Ca v 2.2 (N-type) and Ca v 2.1 (P/Q-type) channels, but not by blocking ryanodine receptors or mitochondrial Na + /Ca 2+ exchange. Mitogen-activated protein kinase kinase (MEK) inhibition also prevented the inhibitory effect of hispidulin on evoked glutamate release. Western blot analyses showed that hispidulin decreased the 4-AP-induced phosphorylation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) and synaptic vesicle-associated protein synapsin I, a major presynaptic substrate for ERK; this decrease was also blocked by the MEK inhibitor. Moreover, the inhibition of glutamate release by hispidulin was strongly attenuated in mice without synapsin I. These results show that hispidulin inhibits glutamate release from cortical synaptosomes in rats through the suppression of presynaptic voltage-dependent Ca 2+ entry and ERK/synapsin I signaling pathway. -- Highlights: ► Hispidulin inhibited glutamate release from rat cerebrocortical synaptosomes. ► This action did

Hispidulin inhibits the release of glutamate in rat cerebrocortical nerve terminals

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Lin, Tzu-Yu [Department of Anesthesiology, Far-Eastern Memorial Hospital, Pan-Chiao District, New Taipei, 22060, Taiwan (China); Department of Mechanical Engineering, Yuan Ze University, Taoyuan, 320, Taiwan (China); Lu, Cheng-Wei [Department of Anesthesiology, Far-Eastern Memorial Hospital, Pan-Chiao District, New Taipei, 22060, Taiwan (China); Wang, Chia-Chuan; Lu, Jyh-Feng [School of Medicine, Fu Jen Catholic University, No.510, Zhongzheng Rd., Xinzhuang Dist., New Taipei, 24205, Taiwan (China); Wang, Su-Jane, E-mail: med0003@mail.fju.edu.tw [Graduate Institute of Basic Medicine, Fu Jen Catholic University, No.510, Zhongzheng Rd., Xinzhuang Dist., New Taipei, 24205, Taiwan (China); School of Medicine, Fu Jen Catholic University, No.510, Zhongzheng Rd., Xinzhuang Dist., New Taipei, 24205, Taiwan (China)

2012-09-01

Hispidulin, a naturally occurring flavone, has been reported to have an antiepileptic profile. An excessive release of glutamate is considered to be related to neuropathology of epilepsy. We investigated whether hispidulin affected endogenous glutamate release in rat cerebral cortex nerve terminals (synaptosomes) and explored the possible mechanism. Hispidulin inhibited the release of glutamate evoked by the K{sup +} channel blocker 4-aminopyridine (4-AP). The effects of hispidulin on the evoked glutamate release were prevented by the chelation of extracellular Ca{sup 2+} ions and the vesicular transporter inhibitor bafilomycin A1. However, the glutamate transporter inhibitor DL-threo-beta-benzyl-oxyaspartate did not have any effect on hispidulin action. Hispidulin reduced the depolarization-induced increase in cytosolic free Ca{sup 2+} concentration ([Ca{sup 2+}]{sub C}), but did not alter 4-AP-mediated depolarization. Furthermore, the effect of hispidulin on evoked glutamate release was abolished by blocking the Ca{sub v}2.2 (N-type) and Ca{sub v}2.1 (P/Q-type) channels, but not by blocking ryanodine receptors or mitochondrial Na{sup +}/Ca{sup 2+} exchange. Mitogen-activated protein kinase kinase (MEK) inhibition also prevented the inhibitory effect of hispidulin on evoked glutamate release. Western blot analyses showed that hispidulin decreased the 4-AP-induced phosphorylation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) and synaptic vesicle-associated protein synapsin I, a major presynaptic substrate for ERK; this decrease was also blocked by the MEK inhibitor. Moreover, the inhibition of glutamate release by hispidulin was strongly attenuated in mice without synapsin I. These results show that hispidulin inhibits glutamate release from cortical synaptosomes in rats through the suppression of presynaptic voltage-dependent Ca{sup 2+} entry and ERK/synapsin I signaling pathway. -- Highlights: ► Hispidulin inhibited glutamate release from rat

Interaction between protein kinase C and protein kinase A can modulate transmitter release at the rat neuromuscular synapse.

Science.gov (United States)

Santafé, M M; Garcia, N; Lanuza, M A; Tomàs, M; Tomàs, J

2009-02-15

We used intracellular recording to investigate the functional interaction between protein kinase C (PKC) and protein kinase A (PKA) signal transduction cascades in the control of transmitter release in the neuromuscular synapses from adult rats. Our results indicate that: 1) PKA and PKC are independently involved in asynchronous release. 2) Evoked acetylcholine (ACh) release is enhanced with the PKA agonist Sp-8-BrcAMP and the PKC agonist phorbol ester (PMA). 3) PKA has a constitutive role in promoting a component of normal evoked transmitter release because, when the kinase is inhibited with H-89, the release diminishes. However, the PKC inhibitor calphostin C (CaC) does not affect ACh release. 4) PKA regulates neurotransmission without PKC involvement because, after PMA or CaC modulation of the PKC activity, coupling to the ACh release of PKA can normally be stimulated with Sp-8-BrcAMP or inhibited with H-89. 5) After PKA inhibition with H-89, PKC stimulation with PMA (or inhibition with CaC) does not lead to any change in evoked ACh release. However, in PKA-stimulated preparations with Sp-8-BrcAMP, PKC becomes tonically active, thus potentiating a component of release that can now be blocked with CaC. In normal conditions, therefore, PKA was able to modulate ACh release independently of PKC activity, whereas PKA stimulation caused the PKC coupling to evoked release. In contrast, PKA inhibition prevent PKC stimulation (with the phorbol ester) and coupling to ACh output. There was therefore some dependence of PKC on PKA activity in the fine control of the neuromuscular synaptic functionalism and ACh release.

Music evokes vivid autobiographical memories.

Science.gov (United States)

Belfi, Amy M; Karlan, Brett; Tranel, Daniel

2016-08-01

Music is strongly intertwined with memories-for example, hearing a song from the past can transport you back in time, triggering the sights, sounds, and feelings of a specific event. This association between music and vivid autobiographical memory is intuitively apparent, but the idea that music is intimately tied with memories, seemingly more so than other potent memory cues (e.g., familiar faces), has not been empirically tested. Here, we compared memories evoked by music to those evoked by famous faces, predicting that music-evoked autobiographical memories (MEAMs) would be more vivid. Participants listened to 30 songs, viewed 30 faces, and reported on memories that were evoked. Memories were transcribed and coded for vividness as in Levine, B., Svoboda, E., Hay, J. F., Winocur, G., & Moscovitch, M. [2002. Aging and autobiographical memory: Dissociating episodic from semantic retrieval. Psychology and Aging, 17, 677-689]. In support of our hypothesis, MEAMs were more vivid than autobiographical memories evoked by faces. MEAMs contained a greater proportion of internal details and a greater number of perceptual details, while face-evoked memories contained a greater number of external details. Additionally, we identified sex differences in memory vividness: for both stimulus categories, women retrieved more vivid memories than men. The results show that music not only effectively evokes autobiographical memories, but that these memories are more vivid than those evoked by famous faces.

Dopamine release dynamics change during adolescence and after voluntary alcohol intake.

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Sara Palm

Full Text Available Adolescence is associated with high impulsivity and risk taking, making adolescent individuals more inclined to use drugs. Early drug use is correlated to increased risk for substance use disorders later in life but the neurobiological basis is unclear. The brain undergoes extensive development during adolescence and disturbances at this time are hypothesized to contribute to increased vulnerability. The transition from controlled to compulsive drug use and addiction involve long-lasting changes in neural networks including a shift from the nucleus accumbens, mediating acute reinforcing effects, to recruitment of the dorsal striatum and habit formation. This study aimed to test the hypothesis of increased dopamine release after a pharmacological challenge in adolescent rats. Potassium-evoked dopamine release and uptake was investigated using chronoamperometric dopamine recordings in combination with a challenge by amphetamine in early and late adolescent rats and in adult rats. In addition, the consequences of voluntary alcohol intake during adolescence on these effects were investigated. The data show a gradual increase of evoked dopamine release with age, supporting previous studies suggesting that the pool of releasable dopamine increases with age. In contrast, a gradual decrease in evoked release with age was seen in response to amphetamine, supporting a proportionally larger storage pool of dopamine in younger animals. Dopamine measures after voluntary alcohol intake resulted in lower release amplitudes in response to potassium-chloride, indicating that alcohol affects the releasable pool of dopamine and this may have implications for vulnerability to addiction and other psychiatric diagnoses involving dopamine in the dorsal striatum.

Regulation of (/sup 3/H)GABA release from strips of guinea pig urinary bladder

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Shirakawa, J.; Taniyama, K.; Iwai, S.; Tanaka, C.

1988-12-01

The presence of receptors that regulate the release of gamma-aminobutyric acid (GABA) was studied in strips of the guinea pig urinary bladder. GABA (10(-8)-10(-5) M) and muscimol (10(-8)-10(-5) M), but not baclofen (10(-5) M), reduced the Ca2+-dependent, tetrodotoxin-resistant release of (/sup 3/H)GABA evoked by high K+ from the urinary bladder strips preloaded with (/sup 3/H)GABA. The inhibitory effect of muscimol was antagonized by bicuculline and potentiated by diazepam, clonazepam, and pentobarbital sodium. The potentiating effect of clonazepam was antagonized by Ro 15-1788. Acetylcholine (ACh) inhibited the high K+-evoked release of (/sup 3/H)GABA. The inhibitory effect of ACh was antagonized by atropine sulfate and pirenzepine but not by hexamethonium. Norepinephrine (NE) inhibited the evoked release of (/sup 3/H)GABA. The inhibitory effect of NE was mimicked by clonidine, but not by phenylephrine, and was antagonized by yohimbine but not by prazosin. These results provide evidence that the release of GABA from strips of guinea pig urinary bladder is regulated via the bicuculline-sensitive GABAA receptor, M1-muscarinic, and alpha 2-adrenergic receptors.

Light-controlled relaxation of the rat penile corpus cavernosum using NOBL-1, a novel nitric oxide releaser

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Yuji Hotta

2016-05-01

Full Text Available Purpose: To investigate whether relaxation of the rat penile corpus cavernosum could be controlled with NOBL-1, a novel, lightcontrollable nitric oxide (NO releaser. Materials and Methods: Fifteen-week-old male Wistar-ST rats were used. The penile corpus cavernosum was prepared and used in an isometric tension study. After noradrenaline (10−5 M achieved precontraction, the penile corpus cavernosum was irradiated by light (470–500 nm with and without NOBL-1 (10−6 M. In addition, we noted rats’ responses to light with vardenafil (10−6 M, a phosphodiesterase-5 (PDE-5 inhibitor. Next, responses to light in the presence of a guanylate cyclase inhibitor, ODQ (1H-[1,2,4] oxadiazolo[4,3-a]quinoxalin-1-one (10−5 M, were measured. All measurements were performed in pretreated L-NAME (10−4 M conditions to inhibit endogenous NO production. Results: Corpus cavernosal smooth muscle, precontracted with noradrenaline, was unchanged by light irradiation in the absence of NOBL-1. However, in the presence of NOBL-1, corpus cavernosal smooth muscle, precontracted with noradrenaline, relaxed in response to light irradiation. After blue light irradiation ceased, tension returned. In addition, the light response was obviously enhanced in the presence of a PDE-5 inhibitor. Conclusions: This study showed that rat corpus cavernosal smooth muscle relaxation can be light-controlled using NOBL-1, a novel, light sensitive NO releaser. Though further in vivo studies are needed to investigate possible usefulness, NOBL-1 may be prove to be a useful tool for erectile dysfunction therapy, specifically in the field of penile rehabilitation.

Proprioceptive evoked gamma oscillations

DEFF Research Database (Denmark)

Arnfred, S.M.; Hansen, Lars Kai; Parnas, J.

2007-01-01

A proprioceptive stimulus consisting of a weight change of a handheld load has recently been shown to elicit an evoked potential. Previously, somatosensory gamma oscillations have only been evoked by electrical stimuli. We conjectured that a natural proprioceptive stimulus also would be able...... to evoke gamma oscillations. EEG was recorded using 64 channels in 14 healthy subjects. In each of three runs a stimulus of 100 g load increment in each hand was presented in 120 trials. Data were wavelet transformed and runs collapsed. Inter-trial phase coherence (ITPC) was computed as the best measure...

Acid stimulation (sour taste elicits GABA and serotonin release from mouse taste cells.

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Yijen A Huang

Full Text Available Several transmitter candidates including serotonin (5-HT, ATP, and norepinephrine (NE have been identified in taste buds. Recently, γ-aminobutyric acid (GABA as well as the associated synthetic enzymes and receptors have also been identified in taste cells. GABA reduces taste-evoked ATP secretion from Receptor cells and is considered to be an inhibitory transmitter in taste buds. However, to date, the identity of GABAergic taste cells and the specific stimulus for GABA release are not well understood. In the present study, we used genetically-engineered Chinese hamster ovary (CHO cells stably co-expressing GABA(B receptors and Gαqo5 proteins to measure GABA release from isolated taste buds. We recorded robust responses from GABA biosensors when they were positioned against taste buds isolated from mouse circumvallate papillae and the buds were depolarized with KCl or a stimulated with an acid (sour taste. In contrast, a mixture of sweet and bitter taste stimuli did not trigger GABA release. KCl- or acid-evoked GABA secretion from taste buds was Ca(2+-dependent; removing Ca(2+ from the bathing medium eliminated GABA secretion. Finally, we isolated individual taste cells to identify the origin of GABA secretion. GABA was released only from Presynaptic (Type III cells and not from Receptor (Type II cells. Previously, we reported that 5-HT released from Presynaptic cells inhibits taste-evoked ATP secretion. Combined with the recent findings that GABA depresses taste-evoked ATP secretion, the present results indicate that GABA and 5-HT are inhibitory transmitters in mouse taste buds and both likely play an important role in modulating taste responses.

Extracting the basal extracellular dopamine concentrations from the evoked responses: re-analysis of the dopamine kinetics.

Science.gov (United States)

Chen, Kevin C; Budygin, Evgeny A

2007-08-15

Fast-scan cyclic voltammetry in conjunction with carbon fiber microelectrode has been used to study dopamine (DA) release and uptake mechanisms in rat brains because of the smaller size of the electrode and the subsecond resolution. Current voltammetry data were analyzed by a DA kinetic model assuming a zero baseline, which is in conflict with existing microdialysis findings and a recent claim of the striatal extracellular DA concentration at micromolar levels. This work applied a new analysis approach based on a modified DA kinetic model to analyze the kinetics of electrically evoked DA overflow in the caudate-putamen of anesthetized rats. The DA uptake parameters were fitted from the electrical stimulation phase, and subsequently used to calculate theoretical DA uptake rates. Comparison of the theoretical uptake rates with experimental clearance rates allows for the study of the tonic DA release process following electrical stimulations. Analyses of DA voltammetry data suggest that the locally averaged basal level of extracellular DA in the rat striatum might be confined between 95 and 220 nM. The disparate time scales in the clearance kinetics of endogenous and exogenous DA were investigated. Long-distance diffusion could only partially explain the slow clearance time course of exogenous DA. Model simulations and parameter analyses on evoked DA responses indicate that suppression of the nonevoked DA release process immediately following electrical stimulation cannot completely account for the rapid clearance of the electrically evoked DA. Inconsistency in the measured uptake strengths in the literature studying endogenous and exogenous DA remains to be investigated in the future.

Both exogenous 5-HT and endogenous 5-HT, released by fluoxetine, enhance distension evoked propulsion in guinea-pig ileum in vitro

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Rachel M Gwynne

2014-09-01

Full Text Available The roles of 5-HT3 and 5-HT4 receptors in the modulation of intestinal propulsion by luminal application of 5-HT and augmentation of endogenous 5-HT effects were studied in segments of guinea-pig ileum in vitro. Persistent propulsive contractions evoked by saline distension were examined using a modified Trendelenburg method. When 5-HT (30 nM, fluoxetine (selective serotonin reuptake inhibitor; 1 nM, 2-methyl-5-HT (5-HT3 receptor agonist; 1 mM or RS 67506 (5-HT4 receptor agonist, 1 µM was infused into the lumen, the pressure needed to initiate persistent propulsive activity fell significantly. A specific 5-HT4 receptor antagonist, SB 207266 (10 nM in lumen, abolished the effects of 5-HT, fluoxetine, and RS 67506, but not those of 2-methyl-5-HT. Granisetron (5-HT3 receptor antagonist; 1 µM in lumen abolished the effect of 5-HT, fluoxetine, RS 67506 and 2-methyl-5-HT. The NK3 receptor antagonist SR 142801 (100 nM in lumen blocked the effects of 5-HT, fluoxetine and 2-methyl-5-HT. SB 207266, granisetron and SR 142801 had no effect by themselves. Higher concentrations of fluoxetine (100 nM and 300 nM and RS 67506 (3 µM and 10 µM had no effect on the distension threshold for propulsive contractions. These results indicate that luminal application of exogenous 5-HT, or increased release of endogenous mucosal 5-HT above basal levels, acts to lower the threshold for propulsive contractions in the guinea-pig ileum via activation of 5-HT3 and 5-HT4 receptors and the release of tachykinins. The results further indicate that basal release of 5-HT is insufficient to alter the threshold for propulsive motor activity.

IGF-1 Receptor Differentially Regulates Spontaneous and Evoked Transmission via Mitochondria at Hippocampal Synapses

Science.gov (United States)

Gazit, Neta; Vertkin, Irena; Shapira, Ilana; Helm, Martin; Slomowitz, Edden; Sheiba, Maayan; Mor, Yael; Rizzoli, Silvio; Slutsky, Inna

2016-01-01

Summary The insulin-like growth factor-1 receptor (IGF-1R) signaling is a key regulator of lifespan, growth, and development. While reduced IGF-1R signaling delays aging and Alzheimer’s disease progression, whether and how it regulates information processing at central synapses remains elusive. Here, we show that presynaptic IGF-1Rs are basally active, regulating synaptic vesicle release and short-term plasticity in excitatory hippocampal neurons. Acute IGF-1R blockade or transient knockdown suppresses spike-evoked synaptic transmission and presynaptic cytosolic Ca2+ transients, while promoting spontaneous transmission and resting Ca2+ level. This dual effect on transmitter release is mediated by mitochondria that attenuate Ca2+ buffering in the absence of spikes and decrease ATP production during spiking activity. We conclude that the mitochondria, activated by IGF-1R signaling, constitute a critical regulator of information processing in hippocampal neurons by maintaining evoked-to-spontaneous transmission ratio, while constraining synaptic facilitation at high frequencies. Excessive IGF-1R tone may contribute to hippocampal hyperactivity associated with Alzheimer’s disease. Video Abstract PMID:26804996

Noise-evoked otoacoustic emissions in humans

NARCIS (Netherlands)

Maat, B; Wit, HP; van Dijk, P

2000-01-01

Click-evoked otoacoustic emissions (CEOAEs) and acoustical responses evoked by bandlimited Gaussian noise (noise-evoked otoacoustic emissions; NEOAEs) were measured in three normal-hearing subjects. For the NEOAEs the first- and second-order Wiener kernel and polynomial correlation functions up to

Olfactory Perceptual Learning Requires Action of Noradrenaline in the Olfactory Bulb: Comparison with Olfactory Associative Learning

Science.gov (United States)

Vinera, Jennifer; Kermen, Florence; Sacquet, Joëlle; Didier, Anne; Mandairon, Nathalie; Richard, Marion

2015-01-01

Noradrenaline contributes to olfactory-guided behaviors but its role in olfactory learning during adulthood is poorly documented. We investigated its implication in olfactory associative and perceptual learning using local infusion of mixed a1-ß adrenergic receptor antagonist (labetalol) in the adult mouse olfactory bulb. We reported that…

Kainate-enhanced release of D-(3H)aspartate from cerebral cortex and striatum: reversal by baclofen and pentobarbital

Energy Technology Data Exchange (ETDEWEB)

Potashner, S.J.; Gerard, D.

1983-06-01

A study was made of the actions of the excitant neurotoxin, kainic acid, on the uptake and the release of D-(2,3-3H)aspartate (D-ASP) in slices of guinea pig cerebral neocortex and striatum. The slices took up D-ASP, reaching concentrations of the amino acid in the tissue which were 14-23 times that in the medium. Subsequently, electrical stimulation of the slices evoked a Ca2+-dependent release of a portion of the D-ASP. Kainic acid (10(-5)-10(-3) M) produced a dose-dependent inhibition of D-ASP uptake. The electrically evoked release of D-ASP was increased 1.6-2.0 fold by 10(-5) and 10(-4)M kainic acid. The kainate-enlarged release was Ca2+-dependent. Dihydrokainic acid, an analogue of kainic acid with little excitatory or toxic action, did not increase D-ASP release but depressed D-ASP uptake. Attempts were made to block the action of kainic acid with baclofen and pentobarbital, compounds which depress the electrically evoked release of L-glutamate (L-GLU) and L-aspartate (L-ASP). Baclofen (4 X 10(-6)M), an antispastic drug, and pentobarbital (10(-4)M), an anesthetic agent, each inhibited the electrically evoked release of D-ASP and prevented the enhancement of the release above control levels usually produced by 10(-4)M kainic acid. It is proposed that 10(-5) and 10(-4)M kainic acid may enhance the synaptic release of L-GLU and L-ASP from neurons which use these amino acids as transmitters. This action is prevented by baclofen and pentobarbital. In view of the possibility that cell death in Huntington's disease could involve excessive depolarization of striatal and other cells by glutamate, baclofen might be effective in delaying the loss of neurons associated with this condition.

Vaginocervical stimulation enhances social recognition memory in rats via oxytocin release in the olfactory bulb.

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Larrazolo-López, A; Kendrick, K M; Aburto-Arciniega, M; Arriaga-Avila, V; Morimoto, S; Frias, M; Guevara-Guzmán, R

2008-03-27

The ability of vaginocervical stimulation (VCS) to promote olfactory social recognition memory at different stages of the ovarian cycle was investigated in female rats. A juvenile social recognition paradigm was used and memory retention tested at 30 and 300 min after an adult was exposed to a juvenile during three 4-min trials. Results showed that an intact social recognition memory was present at 30 min in animals with or without VCS and at all stages of the estrus cycle. However, whereas no animals in any stage of the estrus cycle showed retention of the specific recognition memory at 300 min, those in the proestrus/estrus phase that received VCS 10 min before the trial started did. In vivo microdialysis studies showed that there was a significant release of oxytocin after VCS in the olfactory bulb during proestrus. There was also increased oxytocin immunoreactivity within the olfactory bulb after VCS in proestrus animals compared with diestrus ones. Furthermore, when animals received an infusion of an oxytocin antagonist directly into the olfactory bulb, or a systemic administration of alpha or beta noradrenaline-antagonists, they failed to show evidence for maintenance of a selective olfactory recognition memory at 300 min. Animals with vagus or pelvic nerve section also showed no memory retention when tested after 300 min. These results suggest that VCS releases oxytocin in the olfactory bulb to enhance the social recognition memory and that this may be due to modulatory actions on noradrenaline release. The vagus and pelvic nerves are responsible for carrying the information from the pelvic area to the CNS.

Noradrenaline and Parkinson's disease

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Claire eDelaville

2011-05-01

Full Text Available Parkinson’s disease (PD is characterized by the degeneration of dopamine (DA neurons in the substantia nigra pars compacta, and motor symptoms including bradykinesia, rigidity and tremor at rest. These symptoms are manifest when around 70% of striatal DA is lost. In addition to motor deficits, PD is also characterized by the manifestation of non-motor symptoms. However, depletion of DA alone in animal models has failed to simultaneously elicit both the motor and non-motor deficits of PD because the disease is a multi-system disorder that features a profound loss of other neurotransmitter systems. There is growing evidence that additional loss of noradrenaline (NA neurons of the locus coeruleus, the principal source of NA in the brain, could be involved in the clinical expression of motor as well as in non-motor deficits. In the present review, we analyzed the latest data obtained from animal models of parkinsonism and from parkinsonian patients providing evidence for the implication of NA in the pathophysiology of PD. Recent studies have shown that NA depletion alone or combined with DA depletion resulted in motor as well as in non-motor dysfunctions. In addition, by using selective agonists and antagonists of alpha receptors we, and others, have shown that α2 receptors are implicated in the control of motor activity and that α2 receptor antagonists can improve PD motor symptoms as well as L-Dopa-induced dyskinesia. Here we provide arguments that the loss of NA neurons in PD has an impact on all PD symptoms and that the association of NAergic agents to dopaminergic medication can be beneficial in the treatment of the disease.

Lycopene depresses glutamate release through inhibition of voltage-dependent Ca2+ entry and protein kinase C in rat cerebrocortical nerve terminals.

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Lu, Cheng-Wei; Hung, Chi-Feng; Jean, Wei-Horng; Lin, Tzu-Yu; Huang, Shu-Kuei; Wang, Su-Jane

2018-05-01

Lycopene is a natural dietary carotenoid that was reported to exhibit a neuroprotective profile. Considering that excitotoxicity and cell death induced by glutamate are involved in many brain disorders, the effect of lycopene on glutamate release in rat cerebrocortical nerve terminals and the possible mechanism involved in such effect was investigated. We observed here that lycopene inhibited 4-aminopyridine (4-AP)-evoked glutamate release and intrasynaptosomal Ca 2+ concentration elevation. The inhibitory effect of lycopene on 4-AP-evoked glutamate release was markedly reduced in the presence of the Ca v 2.2 (N-type) and Ca v 2.1 (P/Q-type) channel blocker ω-conotoxin MVIIC, but was insensitive to the intracellular Ca 2+ -release inhibitors dantrolene and CGP37157. Furthermore, in the presence of the protein kinase C inhibitors GF109203X and Go6976, the action of lycopene on evoked glutamate release was prevented. These results are the first to suggest that lycopene inhibits glutamate release from rat cortical synaptosomes by suppressing presynaptic Ca 2+ entry and protein kinase C activity.

Noradrenaline spillover during exercise in active versus resting skeletal muscle in man

DEFF Research Database (Denmark)

Savard, G; Strange, S; Kiens, Bente

1987-01-01

Increases in plasma noradrenaline (NA) concentration occur during moderate to heavy exercise in man. This study was undertaken to examine the spillover of NA from both resting and contracting skeletal muscle during exercise. Six male subjects performed one-legged knee-extension so that all...... in the exercising leg than in the resting leg both during 50% and 100% leg exercise. These results suggest that contracting skeletal muscle may contribute to a larger extent than resting skeletal muscle to increasing the level of plasma NA during exercise. Contractile activity may influence the NA spillover from...

Volume Transmission in Central Dopamine and Noradrenaline Neurons and Its Astroglial Targets.

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Fuxe, Kjell; Agnati, Luigi F; Marcoli, Manuela; Borroto-Escuela, Dasiel O

2015-12-01

Already in the 1960s the architecture and pharmacology of the brainstem dopamine (DA) and noradrenaline (NA) neurons with formation of vast numbers of DA and NA terminal plexa of the central nervous system (CNS) indicated that they may not only communicate via synaptic transmission. In the 1980s the theory of volume transmission (VT) was introduced as a major communication together with synaptic transmission in the CNS. VT is an extracellular and cerebrospinal fluid transmission of chemical signals like transmitters, modulators etc. moving along energy gradients making diffusion and flow of VT signals possible. VT interacts with synaptic transmission mainly through direct receptor-receptor interactions in synaptic and extrasynaptic heteroreceptor complexes and their signaling cascades. The DA and NA neurons are specialized for extrasynaptic VT at the soma-dendrtitic and terminal level. The catecholamines released target multiple DA and adrenergic subtypes on nerve cells, astroglia and microglia which are the major cell components of the trophic units building up the neural-glial networks of the CNS. DA and NA VT can modulate not only the strength of synaptic transmission but also the VT signaling of the astroglia and microglia of high relevance for neuron-glia interactions. The catecholamine VT targeting astroglia can modulate the fundamental functions of astroglia observed in neuroenergetics, in the Glymphatic system, in the central renin-angiotensin system and in the production of long-distance calcium waves. Also the astrocytic and microglial DA and adrenergic receptor subtypes mediating DA and NA VT can be significant drug targets in neurological and psychiatric disease.

Evoked emotions predict food choice.

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Dalenberg, Jelle R; Gutjar, Swetlana; Ter Horst, Gert J; de Graaf, Kees; Renken, Remco J; Jager, Gerry

2014-01-01

In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments. Therefore, the focus within recent studies shifted towards using emotion-profiling methods that successfully can discriminate between products that are equally liked. However, it is unclear how well scores from emotion-profiling methods predict actual food choice and/or consumption. To test this, we proposed to decompose emotion scores into valence and arousal scores using Principal Component Analysis (PCA) and apply Multinomial Logit Models (MLM) to estimate food choice using liking, valence, and arousal as possible predictors. For this analysis, we used an existing data set comprised of liking and food-evoked emotions scores from 123 participants, who rated 7 unlabeled breakfast drinks. Liking scores were measured using a 100-mm visual analogue scale, while food-evoked emotions were measured using 2 existing emotion-profiling methods: a verbal and a non-verbal method (EsSense Profile and PrEmo, respectively). After 7 days, participants were asked to choose 1 breakfast drink from the experiment to consume during breakfast in a simulated restaurant environment. Cross validation showed that we were able to correctly predict individualized food choice (1 out of 7 products) for over 50% of the participants. This number increased to nearly 80% when looking at the top 2 candidates. Model comparisons showed that evoked emotions better predict food choice than perceived liking alone. However, the strongest predictive strength was achieved by the combination of evoked emotions and liking. Furthermore we showed that non-verbal food-evoked emotion scores more accurately predict food choice than verbal food-evoked emotions scores.

Investigation of the mechanisms underlying the hypophagic effects of the 5-HT and noradrenaline reuptake inhibitor, sibutramine, in the rat

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Jackson, Helen C; Bearham, M Clair; Hutchins, Lisa J; Mazurkiewicz, Sarah E; Needham, Andrew M; Heal, David J

1997-01-01

Sibutramine is a novel 5-hydroxytryptamine (5-HT) and noradrenaline reuptake inhibitor (serotonin- noradrenaline reuptake inhibitor, SNRI) which is currently being developed as a treatment for obesity. Sibutramine has been shown to decrease food intake in the rat. In this study we have used a variety of monoamine receptor antagonists to examine the pharmacological mechanisms underlying sibutramine-induced hypophagia. Individually-housed male Sprague-Dawley rats were maintained on reversed phase lighting with free access to food and water. Drugs were administered at 09 h 00 min and food intake was monitored over the following 8 h dark period. Sibutramine (10 mg kg−1, p.o.) produced a significant decrease in food intake during the 8 h following drug administration. This hypophagic response was fully antagonized by the α1-adrenoceptor antagonist, prazosin (0.3 and 1 mg kg−1, i.p.), and partially antagonized by the β1-adrenoceptor antagonist, metoprolol (3 and 10 mg kg−1, i.p.) and the 5-HT receptor antagonists, metergoline (non-selective; 0.3 mg kg−1, i.p.); ritanserin (5-HT2A/2C; 0.1 and 0.5 mg kg−1, i.p.) and SB200646 (5-HT2B/2C; 20 and 40 mg kg−1, p.o.). By contrast, the α2-adrenoceptor antagonist, RX821002 (0.3 and 1 mg kg−1, i.p.) and the β2-adrenoceptor antagonist, ICI 118,551 (3 and 10 mg kg−1, i.p.) did not reduce the decrease in food intake induced by sibutramine. These results demonstrate that β1-adrenoceptors, 5-HT2A/2C-receptors and particularly α1-adrenoceptors, are involved in the effects of sibutramine on food intake and are consistent with the hypothesis that sibutramine-induced hypophagia is related to its ability to inhibit the reuptake of both noradrenaline and 5-HT, with the subsequent activation of a variety of noradrenaline and 5-HT receptor systems. PMID:9283694

Characterization of music-evoked autobiographical memories.

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Janata, Petr; Tomic, Stefan T; Rakowski, Sonja K

2007-11-01

Despite music's prominence in Western society and its importance to individuals in their daily lives, very little is known about the memories and emotions that are often evoked when hearing a piece of music from one's past. We examined the content of music-evoked autobiographical memories (MEAMs) using a novel approach for selecting stimuli from a large corpus of popular music, in both laboratory and online settings. A set of questionnaires probed the cognitive and affective properties of the evoked memories. On average, 30% of the song presentations evoked autobiographical memories, and the majority of songs also evoked various emotions, primarily positive, that were felt strongly. The third most common emotion was nostalgia. Analyses of written memory reports found both general and specific levels of autobiographical knowledge to be represented, and several social and situational contexts for memory formation were common across many memories. The findings indicate that excerpts of popular music serve as potent stimuli for studying the structure of autobiographical memories.

Calcitonin Gene-Related Peptide Reduces Taste-Evoked ATP Secretion from Mouse Taste Buds.

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Huang, Anthony Y; Wu, Sandy Y

2015-09-16

Immunoelectron microscopy revealed that peripheral afferent nerve fibers innervating taste buds contain calcitonin gene-related peptide (CGRP), which may be as an efferent transmitter released from peripheral axon terminals. In this report, we determined the targets of CGRP within taste buds and studied what effect CGRP exerts on taste bud function. We isolated mouse taste buds and taste cells, conducted functional imaging using Fura-2, and used cellular biosensors to monitor taste-evoked transmitter release. The findings showed that a subset of Presynaptic (Type III) taste cells (53%) responded to 0.1 μm CGRP with an increase in intracellular Ca(2+). In contrast, Receptor (Type II) taste cells rarely (4%) responded to 0.1 μm CGRP. Using pharmacological tools, the actions of CGRP were probed and elucidated by the CGRP receptor antagonist CGRP(8-37). We demonstrated that this effect of CGRP was dependent on phospholipase C activation and was prevented by the inhibitor U73122. Moreover, applying CGRP caused taste buds to secrete serotonin (5-HT), a Presynaptic (Type III) cell transmitter, but not ATP, a Receptor (Type II) cell transmitter. Further, our previous studies showed that 5-HT released from Presynaptic (Type III) cells provides negative paracrine feedback onto Receptor (Type II) cells by activating 5-HT1A receptors, and reducing ATP secretion. Our data showed that CGRP-evoked 5-HT release reduced taste-evoked ATP secretion. The findings are consistent with a role for CGRP as an inhibitory transmitter that shapes peripheral taste signals via serotonergic signaling during processing gustatory information in taste buds. The taste sensation is initiated with a highly complex set of interactions between a variety of cells located within the taste buds before signal propagation to the brain. Afferent signals from the oral cavity are carried to the brain in chemosensory fibers that contribute to chemesthesis, the general chemical sensitivity of the mucus

Sensory-Evoked Intrinsic Imaging Signals in the Olfactory Bulb Are Independent of Neurovascular Coupling

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Roberto Vincis

2015-07-01

Full Text Available Functional brain-imaging techniques used in humans and animals, such as functional MRI and intrinsic optical signal (IOS imaging, are thought to largely rely on neurovascular coupling and hemodynamic responses. Here, taking advantage of the well-described micro-architecture of the mouse olfactory bulb, we dissected the nature of odor-evoked IOSs. Using in vivo pharmacology in transgenic mouse lines reporting activity in different cell types, we show that parenchymal IOSs are largely independent of neurotransmitter release and neurovascular coupling. Furthermore, our results suggest that odor-evoked parenchymal IOSs originate from changes in light scattering of olfactory sensory neuron axons, mostly due to water movement following action potential propagation. Our study sheds light on a direct correlate of neuronal activity, which may be used for large-scale functional brain imaging.

Noradrenaline might enhance assertive human social behaviours: an investigation in a flatmate relationship.

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Tse, W S; Bond, A J

2006-09-01

The aim of the present study was to explore the role of noradrenaline on the social behaviour of healthy volunteers when they were interacting with a familiar person, their flatmate. Interaction with the flatmate was explored in a cooperative game situation. Ten pairs of same-sex healthy volunteer flatmates aged 18-25 years were recruited for the experiment. All volunteers gave written informed consent and the study was approved by the institutional ethical committee. A randomised, double blind, placebo-controlled crossover trial of reboxetine versus placebo was conducted. In each of the 10 pairs of volunteers, one (subject) volunteered to take the tablets and the other (flatmate) received no treatment. Reboxetine (4 mg/bd) and placebo were administered orally as identical capsules for 2 weeks. The subjects were randomly assigned to receive either reboxetine or placebo first and there was a two-week washout period following the first treatment. At baseline and the end of each treatment, they filled in the Beck Depression Inventory (BDI), Social Adapation Self-Evaluation Scale (SASS), and Aggression Questionnaire (AQ). Then, they were instructed to play the Tangrams game. This task elicits face-valid social behaviours such as cooperation, giving commands and unilateral grasps. Analysis of covariance showed that there was a statistical trend for reboxetine treatment to increase commands (p=0.055). This study presents preliminary evidence that two weeks' enhancement of noradrenaline transmission induced by reboxetine makes healthy volunteers more self-confident and assertive.

Determination of adrenaline, noradrenaline and corticosterone in rodent blood by ion pair reversed phase UHPLC-MS/MS.

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Bergh, Marianne Skov-Skov; Bogen, Inger Lise; Andersen, Jannike Mørch; Øiestad, Åse Marit Leere; Berg, Thomas

2018-01-01

A novel ion pair reversed phase ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for simultaneous determination of the stress hormones adrenaline, noradrenaline and corticosterone in rodent blood was developed and fully validated. Separations were performed on an Acquity HSS T3 column (2.1mm i.d.×100mm, 1.8μm) with gradient elution and a runtime of 5.5min. The retention of adrenaline and noradrenaline was substantially increased by employing the ion pair reagent heptafluorobutyric acid (HFBA). Ion pair reagents are usually added to the mobile phase only, but we demonstrate for the first time that including HFBA to the sample reconstitution solvent as well, has a major impact on the chromatography of these compounds. The stability of adrenaline and corticosterone in rodent blood was investigated using the surrogate analytes adrenaline-d 3 and corticosterone-d 8 . The applicability of the described method was demonstrated by measuring the concentration of stress hormones in rodent blood samples. Copyright © 2017 Elsevier B.V. All rights reserved.

CHAPTER 1

African Journals Online (AJOL)

Dr Olaleye

Official Publication of the African Association of Physiological Sciences ... noradrenaline (NA)-evoked vascular responses in carotid circulation in rats. Furthermore, whether the .... PowerLab/8S at 100 Hz and connected to a computer by Chart ...

(-)1-(Benzofuran-2-yl)-2-propylaminopentane, [(-)BPAP], a selective enhancer of the impulse propagation mediated release of catecholamines and serotonin in the brain.

Science.gov (United States)

Knoll, J; Yoneda, F; Knoll, B; Ohde, H; Miklya, I

1999-12-01

1. The brain constituents beta-phenylethylamine (PEA) and tryptamine enhance the impulse propagation mediated transmitter release (exocytosis) from the catecholaminergic and serotoninergic neurons in the brain ('catecholaminergic/serotoninergic activity enhancer, CAE/SAE, effect'). (-)Deprenyl (Selegiline) and (-)1-phenyl-2-propylaminopentane [(-)PPAP] are amphetamine derived CAE substances devoid of the catecholamine releasing property. 2. By changing the aromatic ring in PPAP we developed highly potent and selective CAE/SAE substances, structurally unrelated to the amphetamines. Out of 65 newly synthetized compounds, a tryptamine derived structure, (-)1-(benzofuran-2-yl)-2-propylaminopentane [(-)BPAP] was selected as a potential follower of (-)deprenyl in the clinic and as a reference compound for further analysis of the CAE/SAE mechanism in the mammalian brain. 3. (-)BPAP significantly enhanced in 0.18 micromol 1(-1) concentration the impulse propagation mediated release of [(3)H]-noradrenaline and [(3)H]-dopamine and in 36 nmol 1(-1) concentration the release of [(3)H]-serotonin from the isolated brain stem of rats. The amount of catecholamines and serotonin released from isolated discrete rat brain regions (dopamine from the striatum, substantia nigra and tuberculum olfactorium, noradrenaline from the locus coeruleus and serotonin from the raphe) enhanced significantly in the presence of 10(-12) - 10(-14) M (-)BPAP. BPAP protected cultured hippocampal neurons from the neurotoxic effect of beta-amyloid in 10(-14) M concentration. In rats (-)BPAP significantly enhanced the activity of the catecholaminergic and serotoninergic neurons in the brain 30 min after acute injection of 0.1 microg kg(-1) s.c. In the shuttle box, (-)BPAP in rats was about 130 times more potent than (-)deprenyl in antagonizing tetrabenazine induced inhibition of performance.

Adrenaline release evokes hyperpnoea and an increase in ventilatory CO2 sensitivity during hypoglycaemia: a role for the carotid body.

Science.gov (United States)

Thompson, Emma L; Ray, Clare J; Holmes, Andrew P; Pye, Richard L; Wyatt, Christopher N; Coney, Andrew M; Kumar, Prem

2016-08-01

Hypoglycaemia is counteracted by release of hormones and an increase in ventilation and CO2 sensitivity to restore blood glucose levels and prevent a fall in blood pH. The full counter-regulatory response and an appropriate increase in ventilation is dependent on carotid body stimulation. We show that the hypoglycaemia-induced increase in ventilation and CO2 sensitivity is abolished by preventing adrenaline release or blocking its receptors. Physiological levels of adrenaline mimicked the effect of hypoglycaemia on ventilation and CO2 sensitivity. These results suggest that adrenaline, rather than low glucose, is an adequate stimulus for the carotid body-mediated changes in ventilation and CO2 sensitivity during hypoglycaemia to prevent a serious acidosis in poorly controlled diabetes. Hypoglycaemia in vivo induces a counter-regulatory response that involves the release of hormones to restore blood glucose levels. Concomitantly, hypoglycaemia evokes a carotid body-mediated hyperpnoea that maintains arterial CO2 levels and prevents respiratory acidosis in the face of increased metabolism. It is unclear whether the carotid body is directly stimulated by low glucose or by a counter-regulatory hormone such as adrenaline. Minute ventilation was recorded during infusion of insulin-induced hypoglycaemia (8-17 mIU kg(-1)  min(-1) ) in Alfaxan-anaesthetised male Wistar rats. Hypoglycaemia significantly augmented minute ventilation (123 ± 4 to 143 ± 7 ml min(-1) ) and CO2 sensitivity (3.3 ± 0.3 to 4.4 ± 0.4 ml min(-1)  mmHg(-1) ). These effects were abolished by either β-adrenoreceptor blockade with propranolol or adrenalectomy. In this hypermetabolic, hypoglycaemic state, propranolol stimulated a rise in P aC O2, suggestive of a ventilation-metabolism mismatch. Infusion of adrenaline (1 μg kg(-1)  min(-1) ) increased minute ventilation (145 ± 4 to 173 ± 5 ml min(-1) ) without altering P aC O2 or pH and enhanced ventilatory CO2 sensitivity (3

Activation of β-adrenergic receptors is required for elevated α1A-adrenoreceptors expression and signaling in mesenchymal stromal cells

Science.gov (United States)

Tyurin-Kuzmin, Pyotr A.; Fadeeva, Julia I.; Kanareikina, Margarita A.; Kalinina, Natalia I.; Sysoeva, Veronika Yu.; Dyikanov, Daniyar T.; Stambolsky, Dmitriy V.; Tkachuk, Vsevolod A.

2016-01-01

Sympathetic neurons are important components of mesenchymal stem cells (MSCs) niche and noradrenaline regulates biological activities of these cells. Here we examined the mechanisms of regulation of MSCs responsiveness to noradrenaline. Using flow cytometry, we demonstrated that α1A adrenergic receptors isoform was the most abundant in adipose tissue-derived MSCs. Using calcium imaging in single cells, we demonstrated that only 6.9 ± 0.8% of MSCs responded to noradrenaline by intracellular calcium release. Noradrenaline increases MSCs sensitivity to catecholamines in a transitory mode. Within 6 hrs after incubation with noradrenaline the proportion of cells responding by Ca2+ release to the fresh noradrenaline addition has doubled but declined to the baseline after 24 hrs. Increased sensitivity was due to the elevated quantities of α1A-adrenergic receptors on MSCs. Such elevation depended on the stimulation of β-adrenergic receptors and adenylate cyclase activation. The data for the first time clarify mechanisms of regulation of MSCs sensitivity to noradrenaline. PMID:27596381

Noradrenaline and dopamine levels in acute cerveau isolé in the cat.

Science.gov (United States)

Szikszay, M; Benedek, G; Obál, F; Obál, F

1980-01-01

Noradrenaline (NA) and dopamine (DA) levels were studied in the forebrain of acute immobilized cats and in cerveau isolé preparations. A gradual decrease in NA and DA was observed one and two hours after high mesencephalic transection, while the amount of NA increased in acute immobilized cats after the cessation of ether anaesthesia. These changes in NA level are consistent with the observations suggesting an inverse relationship between NA and cortical deactivation. The decrease of DA with an exaggeration of spindle activity and increased synchronizing effect of basal forebrain stimulation indicate that the spindle-increasing effect of DA suggested by several authors requires the contribution of the brain stem.

Blockade of the high-affinity noradrenaline transporter (NET) by the selective 5-HT reuptake inhibitor escitalopram: an in vivo microdialysis study in mice

Science.gov (United States)

Nguyen, Hai T; Guiard, Bruno P; Bacq, Alexandre; David, Denis J; David, Indira; Quesseveur, Gaël; Gautron, Sophie; Sanchez, Connie; Gardier, Alain M

2013-01-01

BACKGROUND AND PURPOSE Escitalopram, the S(+)-enantiomer of citalopram is the most selective 5-HT reuptake inhibitor approved. Although all 5-HT selective reuptake inhibitors (SSRIs) increase extracellular levels of 5-HT ([5-HT]ext). some also enhance, to a lesser extent, extracellular levels of noradrenaline ([NA]ext). However, the mechanisms by which SSRIs activate noradrenergic transmission in the brain remain to be determined. EXPERIMENTAL APPROACH This study examined the effects of escitalopram, on both [5-HT]ext and [NA]ext in the frontal cortex (FCx) of freely moving wild-type (WT) and mutant mice lacking the 5-HT transporter (SERT−/−) by using intracerebral microdialysis. We explored the possibilities that escitalopram enhances [NA]ext, either by a direct mechanism involving the inhibition of the low- or high-affinity noradrenaline transporters, or by an indirect mechanism promoted by [5-HT]ext elevation. The forced swim test (FST) was used to investigate whether enhancing cortical [5-HT]ext and/or [NA]ext affected the antidepressant-like activity of escitalopram. KEY RESULTS In WT mice, a single systemic administration of escitalopram produced a significant increase in cortical [5-HT]ext and [NA]ext. As expected, escitalopram failed to increase cortical [5-HT]ext in SERT−/− mice, whereas its neurochemical effects on [NA]ext persisted in these mutants. In WT mice subjected to the FST, escitalopram increased swimming parameters without affecting climbing behaviour. Finally, escitalopram, at relevant concentrations, failed to inhibit cortical noradrenaline and 5-HT uptake mediated by low-affinity monoamine transporters. CONCLUSIONS AND IMPLICATIONS These experiments suggest that escitalopram enhances, although moderately, cortical [NA]extin vivo by a direct mechanism involving the inhibition of the high-affinity noradrenaline transporter (NET). PMID:22233336

RANTES modulates the release of glutamate in human neocortex.

Science.gov (United States)

Musante, Veronica; Longordo, Fabio; Neri, Elisa; Pedrazzi, Marco; Kalfas, Fotios; Severi, Paolo; Raiteri, Maurizio; Pittaluga, Anna

2008-11-19

The effects of the recombinant chemokine human RANTES (hRANTES) on the release of glutamate from human neocortex glutamatergic nerve endings were investigated. hRANTES facilitated the spontaneous release of d [(3)H]D-aspartate ([(3)H]DASP-) by binding Pertussis toxin-sensitive G-protein-coupled receptors (GPCRs), whose activation caused Ca(2+) mobilization from inositol trisphosphate-sensitive stores and cytosolic tyrosine kinase-mediated phosphorylations. Facilitation of release switched to inhibition when the effects of hRANTES on the 12 mM K(+)-evoked [(3)H]D-ASP exocytosis were studied. Inhibition of exocytosis relied on activation of Pertussis toxin-sensitive GPCRs negatively coupled to adenylyl cyclase. Both hRANTES effects were prevented by met-RANTES, an antagonist at the chemokine receptors (CCRs) of the CCR1, CCR3, and CCR5 subtypes. Interestingly, human neocortex glutamatergic nerve endings seem to possess all three receptor subtypes. Blockade of CCR1 and CCR5 by antibodies against the extracellular domain of CCRs prevented both the hRANTES effect on [(3)H]D-ASP release, whereas blockade of CCR3 prevented inhibition, but not facilitation, of release. The effects of RANTES on the spontaneous and the evoked release of [(3)H]D-ASP were also observed in experiments with mouse cortical synaptosomes, which may therefore represent an appropriate animal model to study RANTES-induced effects on neurotransmission. It is concluded that glutamate transmission can be modulated in opposite directions by RANTES acting at distinct CCR receptor subtypes coupled to different transduction pathways, consistent with the multiple and sometimes contrasting effects of the chemokine.

The wake-promoting hypocretin/orexin neurons change their response to noradrenaline after sleep deprivation.

Science.gov (United States)

Grivel, Jeremy; Cvetkovic, Vesna; Bayer, Laurence; Machard, Danièle; Tobler, Irene; Mühlethaler, Michel; Serafin, Mauro

2005-04-20

Sleep deprivation is accompanied by the progressive development of an irresistible need to sleep, a phenomenon whose mechanism has remained elusive. Here, we identified for the first time a reflection of that phenomenon in vitro by showing that, after a short 2 h period of total sleep deprivation, the action of noradrenaline on the wake-promoting hypocretin/orexin neurons changes from an excitation to an inhibition. We propose that such a conspicuous modification of responsiveness should contribute to the growing sleepiness that accompanies sleep deprivation.

Measuring endogenous 5-HT release by emission tomography: promises and pitfalls

DEFF Research Database (Denmark)

Paterson, Louise M; Tyacke, Robin J; Nutt, David J

2010-01-01

Molecular in vivo neuroimaging techniques can be used to measure regional changes in endogenous neurotransmitters, evoked by challenges that alter synaptic neurotransmitter concentration. This technique has most successfully been applied to the study of endogenous dopamine release using positron ...

Distinct presynaptic regulation of dopamine release through NMDA receptors in striosome- and matrix-enriched areas of the rat striatum

Energy Technology Data Exchange (ETDEWEB)

Krebs, M.O.; Trovero, F.; Desban, M.; Gauchy, C.; Glowinski, J.; Kemel, M.L. (College de France, Paris (France))

1991-05-01

Striosome- and matrix-enriched striatal zones were defined in coronal and sagittal brain sections of the rat, on the basis of {sup 3}H-naloxone binding to mu-opiate receptors (a striosome-specific marker). Then, using a new in vitro microsuperfusion device, the NMDA (50 microM)-evoked release of newly synthesized {sup 3}H-dopamine ({sup 3}H-DA) was examined in these four striatal areas under Mg(2+)-free conditions. The amplitudes of the responses were different in striosomal (171 +/- 6% and 161 +/- 5% of the spontaneous release) than in matrix areas (223 +/- 6% and 248 +/- 12%), even when glycine (1 or 100 microM) was coapplied (in the presence of 1 microM strychnine). In the four areas, the NMDA-evoked release of {sup 3}H-DA was blocked completely by Mg{sup 2}{sup +} (1 mM) or (+)-5-methyl-10,11-dihydro-5H-dibenzo(a,d)cyclohepten-5,10-imine maleate (MK-801; 1 microM) and almost totally abolished by kynurenate (100 microM). Because the tetrodotoxin (TTX)-resistant NMDA-evoked release of {sup 3}H-DA was similar in striosome- (148 +/- 5% and 152 +/- 6%) or matrix-enriched (161 +/- 5% and 156 +/- 7%) areas, the indirect (TTX-sensitive) component of NMDA-evoked responses, which involves striatal neurons and/or afferent fibers, seems more important in the matrix- than in the striosome-enriched areas. The modulation of DA release by cortical glutamate and/or aspartate-containing inputs through NMDA receptors in the matrix appears thus to be partly distinct from that observed in the striosomes, providing some functional basis for the histochemical striatal heterogeneity.

Neonatal 6-hydroxydopamine treatment: Noradrenaline levels and in vitro 3H-catecholamine synthesis in discrete brain regions of adult rats

NARCIS (Netherlands)

Versteeg, D.H.G.; Ree, J.M. van; Provoost, Abraham P.; Jong, Wybren de

1974-01-01

Endogenous noradrenaline levels are elevated in medulla oblongata, mesencephalon, pons and thalamus of adult rats which had been treated with 6-hydroxydopamine on days 1, 2, 8 and 15 after birth. Levels in spinal cord, cerebellum, hippocampus/amygdala and cortex are depressed, whereas no significant

Beyond the evoked/intrinsic neural process dichotomy

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Taylor Bolt

2018-03-01

Full Text Available Contemporary functional neuroimaging research has increasingly focused on characterization of intrinsic or “spontaneous” brain activity. Analysis of intrinsic activity is often contrasted with analysis of task-evoked activity that has traditionally been the focus of cognitive neuroscience. But does this evoked/intrinsic dichotomy adequately characterize human brain function? Based on empirical data demonstrating a close functional interdependence between intrinsic and task-evoked activity, we argue that the dichotomy between intrinsic and task-evoked activity as unobserved contributions to brain activity is artificial. We present an alternative picture of brain function in which the brain’s spatiotemporal dynamics do not consist of separable intrinsic and task-evoked components, but reflect the enaction of a system of mutual constraints to move the brain into and out of task-appropriate functional configurations. According to this alternative picture, cognitive neuroscientists are tasked with describing both the temporal trajectory of brain activity patterns across time, and the modulation of this trajectory by task states, without separating this process into intrinsic and task-evoked components. We argue that this alternative picture of brain function is best captured in a novel explanatory framework called enabling constraint. Overall, these insights call for a reconceptualization of functional brain activity, and should drive future methodological and empirical efforts.

Characterization of taurine binding, uptake, and release in the rat hypothalamus

International Nuclear Information System (INIS)

Hanretta, A.T.

1985-01-01

The neurotransmitter criteria of specific receptors, inactivation, and release were experimentally examined for taurine in the hypothalamus. Specific membrane binding and synaptosomal uptake of taurine both displayed high affinity and low affinity systems. The neurotransmitter criterion of release was studied in superfused synaptosomes. Exposure of synaptosomes which had been preloaded with a concentration of [ 3 H]taurine in the high affinity uptake range (1.5 μM) to either 56 mM K + or 100 μM veratridine evoked a Ca 2+ -independent release. Exposure of synaptosomes which had been preloaded with a concentration of [ 3 H]taurine in the low affinity uptake range (2 mM) to 56 mM K + induced a Ca 2+ -independent release, whereas 100 + M veratridine did not, either in the presence or absence of Ca 2+ . Based on these results, as well as other observations, a model is proposed in which the high affinity uptake system is located on neuronal membranes and the low affinity uptake system is located on glial membranes. The mechanisms of binding, uptake, and release in relation to the cellular location of each are discussed. We conclude that the neurotransmitter criterion of activation by re-uptake is satisfied for taurine in the hypothalamus. However, the failure to demonstrate both a specific taurine receptor site and a Ca 2+ -dependent evoked release, necessitates that we conclude that taurine appears not to function as a hypothalamic neurotransmitter, at least not in the classical sense

Parallel expression of synaptophysin and evoked neurotransmitter release during development of cultured neurons

DEFF Research Database (Denmark)

Ehrhart-Bornstein, M; Treiman, M; Hansen, Gert Helge

1991-01-01

Primary cultures of GABAergic cerebral cortex neurons and glutamatergic cerebellar granule cells were used to study the expression of synaptophysin, a synaptic vesicle marker protein, along with the ability of each cell type to release neurotransmitter upon stimulation. The synaptophysin expression...... by quantitative immunoblotting and light microscope immunocytochemistry, respectively. In both cell types, a close parallelism was found between the temporal pattern of development in synaptophysin expression and neurotransmitter release. This temporal pattern differed between the two types of neurons....... The cerebral cortex neurons showed a biphasic time course of increase in synaptophysin content, paralleled by a biphasic pattern of development in their ability to release [3H]GABA in response to depolarization by glutamate or elevated K+ concentrations. In contrast, a monophasic, approximately linear increase...

Recording visual evoked potentials and auditory evoked P300 at 9.4T static magnetic field.

Science.gov (United States)

Arrubla, Jorge; Neuner, Irene; Hahn, David; Boers, Frank; Shah, N Jon

2013-01-01

Simultaneous recording of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) has shown a number of advantages that make this multimodal technique superior to fMRI alone. The feasibility of recording EEG at ultra-high static magnetic field up to 9.4 T was recently demonstrated and promises to be implemented soon in fMRI studies at ultra high magnetic fields. Recording visual evoked potentials are expected to be amongst the most simple for simultaneous EEG/fMRI at ultra-high magnetic field due to the easy assessment of the visual cortex. Auditory evoked P300 measurements are of interest since it is believed that they represent the earliest stage of cognitive processing. In this study, we investigate the feasibility of recording visual evoked potentials and auditory evoked P300 in a 9.4 T static magnetic field. For this purpose, EEG data were recorded from 26 healthy volunteers inside a 9.4 T MR scanner using a 32-channel MR compatible EEG system. Visual stimulation and auditory oddball paradigm were presented in order to elicit evoked related potentials (ERP). Recordings made outside the scanner were performed using the same stimuli and EEG system for comparison purposes. We were able to retrieve visual P100 and auditory P300 evoked potentials at 9.4 T static magnetic field after correction of the ballistocardiogram artefact using independent component analysis. The latencies of the ERPs recorded at 9.4 T were not different from those recorded at 0 T. The amplitudes of ERPs were higher at 9.4 T when compared to recordings at 0 T. Nevertheless, it seems that the increased amplitudes of the ERPs are due to the effect of the ultra-high field on the EEG recording system rather than alteration in the intrinsic processes that generate the electrophysiological responses.

Beta amyloid differently modulate nicotinic and muscarinic receptor subtypes which regulate in vitro and in vivo the release of glycine in the rat hippocampus

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Stefania eZappettini

2012-07-01

Full Text Available Using both in vitro (hippocampal synaptosomes in superfusion and in vivo (microdialysis approaches we investigated whether and to what extent β amyloid peptide 1-40 (Aβ 1-40 interferes with the cholinergic modulation of the release of glycine (GLY in the rat hippocampus. The nicotine-evoked overflow of endogenous GLY in hippocampal synaptosomes in superfusion was significantly inhibited by Aβ 1-40 (10 nM while increasing the concentration to 100 nM the inhibitory effect did not further increase. Both the Choline (Ch (α7 agonist; 1 mM and the 5-Iodo-A-85380 dihydrochloride (5IA85380, α4β2 agonist; 10 nM-evoked GLY overflow were inhibited by Aβ1-40 at 100 nM but not at 10nM concentrations. The KCl evoked [3H]GLY and [3H]Acetylcholine (ACh overflow were strongly inhibited in presence of oxotremorine; however this inhibitory muscarinic effect was not affected by Aβ1-40. The effects of Aβ1-40 on the administration of nicotine, veratridine, 5IA85380 and PHA 543613 hydrochloride (PHA543613 (a selective agonist of α7 subtypes on hippocampal endogenous GLY release in vivo were also studied. Aβ 1-40 significantly reduced (at 10 μM but not at 1 μM the nicotine evoked in vivo release of GLY. Aβ 1-40 (at 10 μM but not at 1 μM significantly inhibited the PHA543613 (1 mM-elicited GLY overflow while was ineffective on the GLY overflow evoked by 5IA85380 (1 mM. Aβ 40-1 (10 μM did not produce any inhibitory effect on nicotine evoked GLY overflow both in the in vitro and in vivo experiments. Our results indicate that a the cholinergic modulation of the release of GLY occurs by the activation of both α7 and α4β2 nicotinic ACh receptors (nAChRs as well as by the activation of inhibitory muscarinic ACh receptors (mAChRs and b Aβ 1-40 can modulate cholinergic evoked GLY release exclusively through the interaction with α7 and the α4β2 nAChR nicotinic receptors but not through mAChR subtypes.

Turnover and release of GABA in rat cortical slices: effect of a GABA-T inhibitor, gabaculine

International Nuclear Information System (INIS)

Szerb, J.C.

1982-01-01

The turnover and release of endogenous and labeled GABA were followed in rat cortical slices after incubation with [ 3 H]GABA. High performance liquid chromatography was used to measure endogenous GABA and to separate [ 3 H]GABA from its metabolites. During superfusion with 3 mM K + the slices rapidly lost their [ 3 H]GABA content while maintaining constant GABA levels. Exposure to 50 mM K + for 25 min caused an initial rapid rise in the release of both endogenous and [ 3 H]GABA followed by a more rapid decline in the release of the latter. The specific activity of released GABA was two to four times higher than that in the slices. Depolarization lead to a net synthesis of GABA. The GABA -T inhibitor, gabaculine, (5 micrometers) in vitro arrested the metabolism of [ 3 H]GABA and rapidly doubled the GABA content but did not significantly increase the high K + evoked release of endogenous GABA. In vivo pretreatment with 0.5 mM/kg gabaculine quadrupled GABA content and increased both the spontaneous and evoked release of endogenous GABA but while its Ca 2 + -dependent release increased by 50%, the Ca 2 + -independent release was enhanced sevenfold. This large Ca 2 + -independent release of GABA is likely to have different functional significance from the normal Ca 2 + -dependent release

Group I mGlu receptors potentiate synaptosomal [3H]glutamate release independently of exogenously applied arachidonic acid

International Nuclear Information System (INIS)

Reid, M.E.; Toms, N.J.; Bedingfield, J.S.; Roberts, P.J.

1999-01-01

In the current study, we have characterized group I metabotropic glutamate (mGlu) receptor enhancement of 4-aminopyridine (4AP)-evoked [ 3 H]glutamate release from rat cerebrocortical synaptosomes. The broad spectrum mGlu receptor agonist (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid ((1S,3R)-ACPD, 10 μM) increased 4AP-evoked [ 3 H]glutamate release (143.32±2.73% control) only in the presence of exogenously applied arachidonic acid; an effect reversed by the inclusion of bovine serum albumin (BSA, fatty acid free). In contrast, the selective group I mGlu receptor agonist (S)-3,5-dihydroxyphenylglycine (DHPG) potentiated (EC 50 =1.60±0.25 μM; E max =147.61±10.96% control) 4AP-evoked [ 3 H]glutamate release, in the absence of arachidonic acid. This potentiation could be abolished by either the selective mGlu 1 receptor antagonist (R,S)-1-aminoindan-1,5-dicarboxylic acid (AIDA, 1 mM) or the selective PKC inhibitor (Ro 31-8220, 10 μM) and was BSA-insensitive. The selective mGlu 5 receptor agonist (R,S)-2-chloro-5-hydroxyphenylglycine (CHPG, 300μM) was without effect. DHPG (100 μM) also potentiated both 30 mM and 50 mM K + -evoked [ 3 H]glutamate release (121.60±12.77% and 121.50±4.45% control, respectively). DHPG (100 μM) failed to influence both 4AP-stimulated 45 Ca 2+ influx and 50 mM K + -induced changes in synaptosomal membrane potential. Possible group I mGlu receptor suppression of tonic adenosine A 1 receptor, group II/III mGlu receptors or GABA B receptor activity is unlikely since 4AP-evoked [ 3 H]glutamate release was insensitive to the selective inhibitory receptor antagonists 8-cyclopentyl-1,3-dimethylxanthine, (R,S)-α-cyclopropyl-4-phosphonophenylglycine or CGP55845A, respectively. These data suggest an 'mGlu 1 receptor-like' receptor potentiates [ 3 H]glutamate release from cerebrocortical synaptosomes in the absence of exogenously applied arachidonic acid. This PKC dependent effect is unlikely to be via modulation of synaptosomal membrane

Protein kinase C involvement in the acetylcholine release reduction induced by amyloid-beta(25-35) aggregates on neuromuscular synapses.

Science.gov (United States)

Tomàs, Marta; Garcia, Neus; Santafé, Manuel M; Lanuza, Maria; Tomàs, Josep

2009-01-01

Using intracellular recording of the diaphragm muscle of adult rats, we have investigated the short-term functional effects of amyloid-beta (Abeta(25-35) peptide aggregates on the modulation of acetylcholine (ACh) release and the involvement of protein kinase C (PKC). The non-aggregated form of this peptide does not change the evoked and spontaneous transmitter release parameters on the neuromuscular synapse. However, the aggregated form of Abeta(25-35) acutely interferes with evoked quantal ACh release (approximately 40% reduction) when synaptic activity in the ex vivo neuromuscular preparation is maintained by low frequency (1 Hz) electrical stimulation. This effect is partially dependent on the activity of PKC that may have a permissive action. The end result of Abeta(25-35) is in opposition to the PKC-dependent maintenance effect on ACh release manifested in active synapses.

Ciproxifan, a histamine H{sub 3} receptor antagonist and inverse agonist, presynaptically inhibits glutamate release in rat hippocampus

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Lu, Cheng-Wei; Lin, Tzu-Yu [Department of Anesthesiology, Far-Eastern Memorial Hospital, Pan-Chiao District, New Taipei City 22060, Taiwan (China); Department of Mechanical Engineering, Yuan Ze University, Taoyuan 320, Taiwan (China); Chang, Chia-Ying [Department of Anesthesiology, Far-Eastern Memorial Hospital, Pan-Chiao District, New Taipei City 22060, Taiwan (China); Department of Chemistry, Fu Jen Catholic University, No. 510, Chung-Cheng Road, Hsin-Chuang District, New Taipei City 24205, Taiwan (China); Huang, Shu-Kuei [Department of Anesthesiology, Far-Eastern Memorial Hospital, Pan-Chiao District, New Taipei City 22060, Taiwan (China); Wang, Su-Jane, E-mail: med0003@mail.fju.edu.tw [School of Medicine, Fu Jen Catholic University, No. 510, Chung-Cheng Rd., Hsin-Chuang, New Taipei 24205, Taiwan (China); Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan City, Taiwan (China)

2017-03-15

Ciproxifan is an H{sub 3} receptor antagonist and inverse agonist with antipsychotic effects in several preclinical models; its effect on glutamate release has been investigated in the rat hippocampus. In a synaptosomal preparation, ciproxifan reduced 4-aminopyridine (4-AP)-evoked Ca{sup 2+}-dependent glutamate release and cytosolic Ca{sup 2+} concentration elevation but did not affect the membrane potential. The inhibitory effect of ciproxifan on 4-AP-evoked glutamate release was prevented by the Gi/Go-protein inhibitor pertussis toxin and Ca{sub v}2.2 (N-type) and Ca{sub v}2.1 (P/Q-type) channel blocker ω-conotoxin MVIIC, but was not affected by the intracellular Ca{sup 2+}-release inhibitors dantrolene and CGP37157. Furthermore, the phospholipase A{sub 2} (PLA{sub 2}) inhibitor OBAA, prostaglandin E{sub 2} (PGE{sub 2}), PGE2 subtype 2 (EP{sub 2}) receptor antagonist PF04418948, and extracellular signal-regulated kinase (ERK) inhibitor FR180204 eliminated the inhibitory effect of ciproxifan on glutamate release. Ciproxifan reduced the 4-AP-evoked phosphorylation of ERK and synapsin I, a presynaptic target of ERK. The ciproxifan-mediated inhibition of glutamate release was prevented in synaptosomes from synapsin I-deficient mice. Moreover, ciproxifan reduced the frequency of miniature excitatory postsynaptic currents without affecting their amplitude in hippocampal slices. Our data suggest that ciproxifan, acting through the blockade of Gi/Go protein-coupled H{sub 3} receptors present on hippocampal nerve terminals, reduces voltage-dependent Ca{sup 2+} entry by diminishing PLA{sub 2}/PGE{sub 2}/EP{sub 2} receptor pathway, which subsequently suppresses the ERK/synapsin I cascade to decrease the evoked glutamate release. - Highlights: • Ciproxifan presynaptically reduces glutamate release in the hippocampus in vitro. • Decrease in voltage-dependent Ca{sup 2+} influx is involved. • A role for the PLA{sub 2}/PGE{sub 2}/EP{sub 2} pathway in the action of

Normalization of auditory evoked potential and visual evoked potential in patients with idiot savant.

Science.gov (United States)

Chen, X; Zhang, M; Wang, J; Lou, F; Liang, J

1999-03-01

To investigate the variations of auditory evoked potentials (AEP) and visual evoked potentials (VEP) of patients with idiot savant (IS) syndrome. Both AEP and VEP were recorded from 7 patients with IS syndrome, 21 mentally retarded (MR) children without the syndrome and 21 normally age-matched controls, using a Dantec concerto SEEG-16 BEAM instrument. Both AEP and VEP of MR group showed significantly longer latencies (P1 and P2 latencies of AEP, P savant syndrome presented normalized AEP and VEP.

Apolipoprotein E4 reduces evoked hippocampal acetylcholine release in adult mice

Czech Academy of Sciences Publication Activity Database

Dolejší, Eva; Liraz, O.; Rudajev, Vladimír; Zimčík, Pavel; Doležal, Vladimír; Michaelson, D. M.

2016-01-01

Roč. 136, č. 3 (2016), s. 503-509 ISSN 0022-3042 R&D Projects: GA MŠk(CZ) LH13269 Institutional support: RVO:67985823 Keywords : acetylcholine release * Alzheimer's disease (AD) * apolipoprotein E4 (apoE4) * hippocampus Subject RIV: FH - Neurology Impact factor: 4.083, year: 2016

Visually Evoked Spiking Evolves While Spontaneous Ongoing Dynamics Persist

Science.gov (United States)

Huys, Raoul; Jirsa, Viktor K.; Darokhan, Ziauddin; Valentiniene, Sonata; Roland, Per E.

2016-01-01

Neurons in the primary visual cortex spontaneously spike even when there are no visual stimuli. It is unknown whether the spiking evoked by visual stimuli is just a modification of the spontaneous ongoing cortical spiking dynamics or whether the spontaneous spiking state disappears and is replaced by evoked spiking. This study of laminar recordings of spontaneous spiking and visually evoked spiking of neurons in the ferret primary visual cortex shows that the spiking dynamics does not change: the spontaneous spiking as well as evoked spiking is controlled by a stable and persisting fixed point attractor. Its existence guarantees that evoked spiking return to the spontaneous state. However, the spontaneous ongoing spiking state and the visual evoked spiking states are qualitatively different and are separated by a threshold (separatrix). The functional advantage of this organization is that it avoids the need for a system reorganization following visual stimulation, and impedes the transition of spontaneous spiking to evoked spiking and the propagation of spontaneous spiking from layer 4 to layers 2–3. PMID:26778982

Modulation of neurotransmitter release in the region of the caudate nucleus by diet and neurotoxins

Energy Technology Data Exchange (ETDEWEB)

Kurstjens, N P

1987-01-01

In this thesis the effects of dietary manipulation, ethanol and neurotoxins on the basal and electrically evoked release of dopamine and acetylcholine from the caudate nucleus of mature animals are presented together with an evaluation of the presynaptic acetylcholine and dopamine receptors controlling acetylcholine and dopamine release. A standardised superfusion technique was used to monitor the effect of apomorphine, in the presence of (R-S)- sulpiride or haloperidol, on the electrically induced release of (/sup 3/ H)-acetylcholine in slices of rat corpus striatum. The effect of ethanol and dietary manipulation on the basal and electrically evoke release of (/sup 3/H)-acetylfholine from rat striatal slices, in the presence of specific agonists and antagonists was evaluated. From this study it is possible to deduce that diet and neurotoxins exerted a measurable effect on the mechanisms controlling release of neurotransmitters in the region of the caudate nucleus. These changes were determined in mature animals previously considered to have cerebral activity, which was not subject to dietary fluctuaations. No changes in the activity of the presynaptic dopamine receptor of the acetylcholine nerve terminals of the striatal slice could be measured.

Selective noradrenaline depletion impairs working memory and hippocampal neurogenesis.

Science.gov (United States)

Coradazzi, Marino; Gulino, Rosario; Fieramosca, Francesco; Falzacappa, Lucia Verga; Riggi, Margherita; Leanza, Giampiero

2016-12-01

Noradrenergic neurons in the locus coeruleus play a role in learning and memory, and their loss is an early event in Alzheimer's disease pathogenesis. Moreover, noradrenaline may sustain hippocampal neurogenesis; however, whether are these events related is still unknown. Four to five weeks following the selective immunotoxic ablation of locus coeruleus neurons, young adult rats underwent reference and working memory tests, followed by postmortem quantitative morphological analyses to assess the extent of the lesion, as well as the effects on proliferation and/or survival of neural progenitors in the hippocampus. When tested in the Water Maze task, lesioned animals exhibited no reference memory deficit, whereas working memory abilities were seen significantly impaired, as compared with intact or sham-lesioned controls. Stereological analyses confirmed a dramatic noradrenergic neuron loss associated to reduced proliferation, but not survival or differentiation, of 5-bromo-2'deoxyuridine-positive progenitors in the dentate gyrus. Thus, ascending noradrenergic afferents may be involved in more complex aspects of cognitive performance (i.e., working memory) possibly via newly generated progenitors in the hippocampus. Copyright © 2016 Elsevier Inc. All rights reserved.

Brain-immune interaction accompanying odor-evoked autobiographic memory.

Science.gov (United States)

Matsunaga, Masahiro; Bai, Yu; Yamakawa, Kaori; Toyama, Asako; Kashiwagi, Mitsuyoshi; Fukuda, Kazuyuki; Oshida, Akiko; Sanada, Kazue; Fukuyama, Seisuke; Shinoda, Jun; Yamada, Jitsuhiro; Sadato, Norihiro; Ohira, Hideki

2013-01-01

The phenomenon in which a certain smell evokes a specific memory is known as the Proust phenomenon. Odor-evoked autobiographic memories are more emotional than those elicited by other sensory stimuli. The results of our previous study indicated that odor-evoked autobiographic memory accompanied by positive emotions has remarkable effects on various psychological and physiological activities, including the secretion of cytokines, which are immune-signaling molecules that modulate systemic inflammation. In this study, we aimed to clarify the neural substrates associated with the interaction between odor-evoked autobiographic memory and peripheral circulating cytokines. We recruited healthy male and female volunteers and investigated the association between brain responses and the concentration of several cytokines in the plasma by using positron emission tomography (PET) recordings when an autographic memory was evoked in participants by asking them to smell an odor that was nostalgic to them. Participants experienced positive emotions and autobiographic memories when nostalgic odors were presented to them. The levels of peripheral proinflammatory cytokines, such as the tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), were significantly reduced after experiencing odor-evoked autobiographic memory. Subtraction analysis of PET images indicated that the medial orbitofrontal cortex (mOFC) and precuneus/posterior cingulate cortex (PCC) were significantly activated during experiences of odor-evoked autobiographic memory. Furthermore, a correlation analysis indicated that activities of the mOFC and precuneus/PCC were negatively correlated with IFN-γ concentration. These results indicate that the neural networks including the precuneus/PCC and mOFC might regulate the secretion of peripheral proinflammatory cytokines during the experience of odor-evoked autobiographic memories accompanied with positive emotions.

Brain–Immune Interaction Accompanying Odor-Evoked Autobiographic Memory

Science.gov (United States)

Matsunaga, Masahiro; Bai, Yu; Yamakawa, Kaori; Toyama, Asako; Kashiwagi, Mitsuyoshi; Fukuda, Kazuyuki; Oshida, Akiko; Sanada, Kazue; Fukuyama, Seisuke; Shinoda, Jun; Yamada, Jitsuhiro; Sadato, Norihiro; Ohira, Hideki

2013-01-01

The phenomenon in which a certain smell evokes a specific memory is known as the Proust phenomenon. Odor-evoked autobiographic memories are more emotional than those elicited by other sensory stimuli. The results of our previous study indicated that odor-evoked autobiographic memory accompanied by positive emotions has remarkable effects on various psychological and physiological activities, including the secretion of cytokines, which are immune-signaling molecules that modulate systemic inflammation. In this study, we aimed to clarify the neural substrates associated with the interaction between odor-evoked autobiographic memory and peripheral circulating cytokines. We recruited healthy male and female volunteers and investigated the association between brain responses and the concentration of several cytokines in the plasma by using positron emission tomography (PET) recordings when an autographic memory was evoked in participants by asking them to smell an odor that was nostalgic to them. Participants experienced positive emotions and autobiographic memories when nostalgic odors were presented to them. The levels of peripheral proinflammatory cytokines, such as the tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), were significantly reduced after experiencing odor-evoked autobiographic memory. Subtraction analysis of PET images indicated that the medial orbitofrontal cortex (mOFC) and precuneus/posterior cingulate cortex (PCC) were significantly activated during experiences of odor-evoked autobiographic memory. Furthermore, a correlation analysis indicated that activities of the mOFC and precuneus/PCC were negatively correlated with IFN-γ concentration. These results indicate that the neural networks including the precuneus/PCC and mOFC might regulate the secretion of peripheral proinflammatory cytokines during the experience of odor-evoked autobiographic memories accompanied with positive emotions. PMID:23977312

Brain-immune interaction accompanying odor-evoked autobiographic memory.

Directory of Open Access Journals (Sweden)

Masahiro Matsunaga

Full Text Available The phenomenon in which a certain smell evokes a specific memory is known as the Proust phenomenon. Odor-evoked autobiographic memories are more emotional than those elicited by other sensory stimuli. The results of our previous study indicated that odor-evoked autobiographic memory accompanied by positive emotions has remarkable effects on various psychological and physiological activities, including the secretion of cytokines, which are immune-signaling molecules that modulate systemic inflammation. In this study, we aimed to clarify the neural substrates associated with the interaction between odor-evoked autobiographic memory and peripheral circulating cytokines. We recruited healthy male and female volunteers and investigated the association between brain responses and the concentration of several cytokines in the plasma by using positron emission tomography (PET recordings when an autographic memory was evoked in participants by asking them to smell an odor that was nostalgic to them. Participants experienced positive emotions and autobiographic memories when nostalgic odors were presented to them. The levels of peripheral proinflammatory cytokines, such as the tumor necrosis factor-α (TNF-α and interferon-γ (IFN-γ, were significantly reduced after experiencing odor-evoked autobiographic memory. Subtraction analysis of PET images indicated that the medial orbitofrontal cortex (mOFC and precuneus/posterior cingulate cortex (PCC were significantly activated during experiences of odor-evoked autobiographic memory. Furthermore, a correlation analysis indicated that activities of the mOFC and precuneus/PCC were negatively correlated with IFN-γ concentration. These results indicate that the neural networks including the precuneus/PCC and mOFC might regulate the secretion of peripheral proinflammatory cytokines during the experience of odor-evoked autobiographic memories accompanied with positive emotions.

Habituation of evoked responses is greater in patients with familial hemiplegic migraine than in controls

DEFF Research Database (Denmark)

Hansen, Jakob Møller; Bolla, M; Magis, D

2011-01-01

have associated with disturbed ion homeostasis, altered cellular excitability, neurotransmitter release, and decreased threshold for cortical spreading depression. The common forms of migraine are characterized interictally by a habituation deficit of cortical and subcortical evoked responses that has...... been attributed to neuronal dysexcitability. FHM and the common forms of migraine are thought to belong to a spectrum of migraine phenotypes with similar pathophysiology, and we therefore examined whether an abnormal habituation pattern would also be found in FHM patients....

Surplus dietary tryptophan reduces plasma cortisol and noradrenaline concentrations and enhances recovery after social stress in pigs.

Science.gov (United States)

Koopmans, Sietse Jan; Ruis, Marko; Dekker, Ruud; van Diepen, Hans; Korte, Mechiel; Mroz, Zdzislaw

2005-07-21

Social stress occurs in intensive pig farming due to aggressive behavior. This stress may be reduced at elevated dietary levels of tryptophan (TRP). In this study, we compared the effects of high (13.2%) vs. normal (3.4%) dietary TRP to large neutral amino acid (LNAA) ratios on behavior and stress hormones in catheterized pigs ( approximately 50 kg BW), which were exposed to social stress by placing them twice into the territory of a dominant pig ( approximately 60 kg) for 15 min. Pre-stress plasma TRP concentrations were 156+/-15 vs. 53+/-6 micromol/l (psocial confrontations, pigs on the high vs. normal TRP diets show a tendency towards reduced active avoidance behavior (3.2+/-1.1 vs. 6.7+/-1.2 min, psocial confrontations, the post-stress plasma cortisol, noradrenaline and adrenaline concentrations and/or curves (from +5 min to 2 h) were lower/steeper (psurplus TRP in diets for pigs (1) does not significantly affect behavior when exposed to social stress, (2) reduces basal plasma cortisol and noradrenaline concentrations, (3) does not affect the immediate hormonal response to stress, and (4) reduces the long-term hormonal response to stress. In general, pigs receiving high dietary TRP were found to be less affected by stress.

GPR40/FFAR1 deficient mice increase noradrenaline levels in the brain and exhibit abnormal behavior

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Fuka Aizawa

2016-12-01

Full Text Available The free fatty acid receptor 1 (GPR40/FFAR1 is a G protein-coupled receptor, which is activated by long chain fatty acids. We have previously demonstrated that activation of brain GPR40/FFAR1 exerts an antinociceptive effect that is mediated by the modulation of the descending pain control system. However, it is unclear whether brain GPR40/FFAR1 contributes to emotional function. In this study, we investigated the involvement of GPR40/FFAR1 in emotional behavior using GPR40/FFAR1 deficient (knockout, KO mice. The emotional behavior in wild and KO male mice was evaluated at 9–10 weeks of age by the elevated plus-maze test, open field test, social interaction test, and sucrose preference test. Brain monoamines levels were measured using LC–MS/MS. The elevated plus-maze test and open field tests revealed that the KO mice reduced anxiety-like behavior. There were no differences in locomotor activity or social behavior between the wild and KO mice. In the sucrose preference test, the KO mice showed reduction in sucrose preference and intake. The level of noradrenaline was higher in the hippocampus, medulla oblongata, hypothalamus and midbrain of KO mice. Therefore, these results suggest that brain GPR40/FFAR1 is associated with anxiety- and depression-related behavior regulated by the increment of noradrenaline in the brain.

(−)1-(Benzofuran-2-yl)-2-propylaminopentane, [(−)BPAP], a selective enhancer of the impulse propagation mediated release of catecholamines and serotonin in the brain

Science.gov (United States)

Knoll, Joseph; Yoneda, Fumio; Knoll, Berta; Ohde, Hironori; Miklya, Ildikó

1999-01-01

The brain constituents β-phenylethylamine (PEA) and tryptamine enhance the impulse propagation mediated transmitter release (exocytosis) from the catecholaminergic and serotoninergic neurons in the brain (‘catecholaminergic/serotoninergic activity enhancer, CAE/SAE, effect'). (−)Deprenyl (Selegiline) and (−)1-phenyl-2-propylaminopentane [(−)PPAP] are amphetamine derived CAE substances devoid of the catecholamine releasing property.By changing the aromatic ring in PPAP we developed highly potent and selective CAE/SAE substances, structurally unrelated to the amphetamines. Out of 65 newly synthetized compounds, a tryptamine derived structure, (−)1-(benzofuran-2-yl)-2-propylaminopentane [(−)BPAP] was selected as a potential follower of (−)deprenyl in the clinic and as a reference compound for further analysis of the CAE/SAE mechanism in the mammalian brain.(−)BPAP significantly enhanced in 0.18 μmol 1−1 concentration the impulse propagation mediated release of [3H]-noradrenaline and [3H]-dopamine and in 36 nmol 1−1 concentration the release of [3H]-serotonin from the isolated brain stem of rats. The amount of catecholamines and serotonin released from isolated discrete rat brain regions (dopamine from the striatum, substantia nigra and tuberculum olfactorium, noradrenaline from the locus coeruleus and serotonin from the raphe) enhanced significantly in the presence of 10−12–10−14 M (−)BPAP. BPAP protected cultured hippocampal neurons from the neurotoxic effect of β-amyloid in 10−14 M concentration. In rats (−)BPAP significantly enhanced the activity of the catecholaminergic and serotoninergic neurons in the brain 30 min after acute injection of 0.1 μg kg−1 s.c. In the shuttle box, (−)BPAP in rats was about 130 times more potent than (−)deprenyl in antagonizing tetrabenazine induced inhibition of performance. PMID:10588928

Neuromuscular paralysis by the basic phospholipase A2 subunit of crotoxin from Crotalus durissus terrificus snake venom needs its acid chaperone to concurrently inhibit acetylcholine release and produce muscle blockage.

Science.gov (United States)

Cavalcante, Walter L G; Noronha-Matos, José B; Timóteo, Maria A; Fontes, Marcos R M; Gallacci, Márcia; Correia-de-Sá, Paulo

2017-11-01

Crotoxin (CTX), a heterodimeric phospholipase A 2 (PLA 2 ) neurotoxin from Crotalus durissus terrificus snake venom, promotes irreversible blockade of neuromuscular transmission. Indirect electrophysiological evidence suggests that CTX exerts a primary inhibitory action on transmitter exocytosis, yet contribution of a postsynaptic action of the toxin resulting from nicotinic receptor desensitization cannot be excluded. Here, we examined the blocking effect of CTX on nerve-evoked transmitter release measured directly using radioisotope neurochemistry and video microscopy with the FM4-64 fluorescent dye. Experiments were conducted using mice phrenic-diaphragm preparations. Real-time fluorescence video microscopy and liquid scintillation spectrometry techniques were used to detect transmitter exocytosis and nerve-evoked [ 3 H]-acetylcholine ([ 3 H]ACh) release, respectively. Nerve-evoked myographic recordings were also carried out for comparison purposes. Both CTX (5μg/mL) and its basic PLA 2 subunit (CB, 20μg/mL) had biphasic effects on nerve-evoked transmitter exocytosis characterized by a transient initial facilitation followed by a sustained decay. CTX and CB reduced nerve-evoked [ 3 H]ACh release by 60% and 69%, respectively, but only the heterodimer, CTX, decreased the amplitude of nerve-evoked muscle twitches. Data show that CTX exerts a presynaptic inhibitory action on ACh release that is highly dependent on its intrinsic PLA 2 activity. Given the high safety margin of the neuromuscular transmission, one may argue that the presynaptic block caused by the toxin is not enough to produce muscle paralysis unless a concurrent postsynaptic inhibitory action is also exerted by the CTX heterodimer. Copyright © 2017. Published by Elsevier Inc.

The costo-uterine muscle of the rat contains a homogeneous population of beta-adrenoceptors.

Science.gov (United States)

Hartley, M. L.; Pennefather, J. N.

1985-01-01

The effects of two selective beta-adrenoceptor antagonists on the inhibitory responses to some sympathomimetic amines of electrically-stimulated preparations of costo-uterine muscle, taken from virgin rats, have been examined quantitatively. pA2 values for the antagonist, atenolol (beta 1-selective) and ICI 118,551 (beta 2-selective) were obtained using as agonists, fenoterol (beta 2-selective agonist) and noradrenaline (alpha- and beta-adrenoceptor agonist, beta 1-selective); and in addition, with ICI 118,551 only, isoprenaline (beta-agonist, non-selective) and adrenaline (alpha- and beta-adrenoceptor agonist, beta 2-selective). Catecholamine uptake mechanisms and alpha-adrenoceptors were not blocked in any of these experiments. Atenolol competitively antagonized the effects of fenoterol and noradrenaline to a similar extent, the pA2 values being 5.4 and 5.7, respectively. ICI 118,551 competitively antagonized the effects of fenoterol, isoprenaline, adrenaline and noradrenaline to a similar extent; pA2 values ranged from 8.7 with noradrenaline to 9.1 with isoprenaline. These results extend our previous observations which indicated that the adrenoceptors mediating inhibition of electrically-evoked contractions of costo-uterine muscle of the virgin rat are homogeneous and of the beta 2-subtype. The potency of the beta 1-selective agonist RO 363 in producing inhibition of electrically-evoked contractions of this tissue was also examined. RO 363 was 200 times less potent than isoprenaline but was a full agonist. This indicates that there is efficient coupling between beta 2-adrenoceptor activation and tissue response in this non-innervated preparation. PMID:2858239

Role of the autonomic nervous system and baroreflex in stress-evoked cardiovascular responses in rats.

Science.gov (United States)

Dos Reis, Daniel Gustavo; Fortaleza, Eduardo Albino Trindade; Tavares, Rodrigo Fiacadori; Corrêa, Fernando Morgan Aguiar

2014-07-01

Restraint stress (RS) is an experimental model to study stress-related cardiovascular responses, characterized by sustained pressor and tachycardiac responses. We used pharmacologic and surgical procedures to investigate the role played by sympathetic nervous system (SNS) and parasympathetic nervous system (PSNS) in the mediation of stress-evoked cardiovascular responses. Ganglionic blockade with pentolinium significantly reduced RS-evoked pressor and tachycardiac responses. Intravenous treatment with homatropine methyl bromide did not affect the pressor response but increased tachycardia. Pretreatment with prazosin reduced the pressor and increased the tachycardiac response. Pretreatment with atenolol did not affect the pressor response but reduced tachycardia. The combined treatment with atenolol and prazosin reduced both pressor and tachycardiac responses. Adrenal demedullation reduced the pressor response without affecting tachycardia. Sinoaortic denervation increased pressor and tachycardiac responses. The results indicate that: (1) the RS-evoked cardiovascular response is mediated by the autonomic nervous system without an important involvement of humoral factors; (2) hypertension results primarily from sympathovascular and sympathoadrenal activation, without a significant involvement of the cardiac sympathetic component (CSNS); (3) the abrupt initial peak in the hypertensive response to restraint is sympathovascular-mediated, whereas the less intense but sustained hypertensive response observed throughout the remaining restraint session is mainly mediated by sympathoadrenal activation and epinephrine release; (4) tachycardia results from CSNS activation, and not from PSNS inhibition; (5) RS evokes simultaneous CSNS and PSNS activation, and heart rate changes are a vector of both influences; (6) the baroreflex is functional during restraint, and modulates both the vascular and cardiac responses to restraint.

The postirradiation effect of noradrenaline, serotonin and dopamine on Na-K-pump activity in rat brain sections

International Nuclear Information System (INIS)

Dvoretskij, A.I.; Kulikova, I.A.

1993-01-01

Whole-body X-irradiation with doses of 0.155 and 0.310 C/kg was shown to modify in different ways the activating effects of noradrenaline and serotonin, as well as a biphase effect of dopamine of neuronal membranes. The resulting effect was a function of a combination of radiation doses and neurotransmitter concentrations and thus showed different modes of interaction between neurotransmitter and ion-transport systems of brain cells in radiation sickness

Interrupting prolonged sitting with brief bouts of light walking or simple resistance activities reduces resting blood pressure and plasma noradrenaline in type 2 diabetes.

Science.gov (United States)

Dempsey, Paddy C; Sacre, Julian W; Larsen, Robyn N; Straznicky, Nora E; Sethi, Parneet; Cohen, Neale D; Cerin, Ester; Lambert, Gavin W; Owen, Neville; Kingwell, Bronwyn A; Dunstan, David W

2016-12-01

Prolonged sitting is increasingly recognized as a ubiquitous cardiometabolic risk factor, possibly distinct from lack of physical exercise. We examined whether interrupting prolonged sitting with brief bouts of light-intensity activity reduced blood pressure (BP) and plasma noradrenaline in type 2 diabetes (T2D). In a randomized crossover trial, 24 inactive overweight/obese adults with T2D (14 men; mean ± SD; 62 ± 6 years) consumed standardized meals during 3 × 8 h conditions: uninterrupted sitting (SIT); sitting + half-hourly bouts of walking (3.2 km/h for 3-min) (light-intensity walking); and sitting + half-hourly bouts of simple resistance activities for 3 min (SRAs), each separated by 6-14 days washout. Resting seated BP was measured hourly (mean of three recordings, ≥20-min postactivity). Plasma noradrenaline was measured at 30-min intervals for the first hour after meals and hourly thereafter. Compared with SIT, mean resting SBP and DBP were significantly reduced (P light-intensity walking (mean ± SEM; -14 ± 1/-8 ± 1 mmHg) and SRA (-16 ± 1/-10 ± 1 mmHg), with a more pronounced effect for SRA (P light-intensity walking). Similarly, mean plasma noradrenaline was significantly reduced for both light-intensity walking (-0.3 ± 0.1 nmol/l) and SRA (-0.6 ± 0.1 nmol/l) versus SIT, with SRA lower than light-intensity walking (P light-intensity walking (-3 ± 1 bpm; P light-intensity walking or SRA reduces resting BP and plasma noradrenaline in adults with T2D, with SRA being more effective. Given the ubiquity of sedentary behaviors and poor adherence to structured exercise, this approach may have important implications for BP management in patients with T2D.

Potentiation by substance P of contractions of the isolated vas deferens of the mouse elicited by electric field stimulation and by drugs

International Nuclear Information System (INIS)

Blackwell, M.; James, T.A.; Starr, M.S.

1978-01-01

Isolated vasa deferentia from the mouse were opened longitudinally and suspended in Krebs solution at 37 0 C in an organ bath. Contractions of the muscle were elicited by electric field stimulation, noradrenaline (10 -6 M) and acetylcholine (10 -6 M). Continued transmural stimulation evoked a biphasic response comprising a rapid twitch followed by about 10 s later by a smaller, sustained rise in muscle tone. The amplitudes of nerve-mediated and drug-induced responses were considerably potentiated by substances P (SP) in the dose range 10 -12 to 10 -7 M. Higher concentrations of SP were directly spasmogenic. The sensitizing property of SP was dose-dependent and was usually well maintained, but always disappeared quickly on washing the preparation. In some experiments SP facilitated the twitch, but not the subsequent phase of the electrically-induced contraction or the response to externally applied noradrenaline. Phentolamine (10 -6 M) failed to block this effect of SP, but itself potentiated the nerve-mediated twitch, and completely abolished the sustained secondary contraction. Desmethylimipramine (10 -6 M) enhanced the delayed contraction but not the immediate contraction. The uptake of tritiated noradrenaline (3 x 10 -7 M) by vasa was inhibited by desmethylimipramine (10 -6 M) and increased by nialamide (3 x 10 -5 M), but was not modified by SP (10 -6 M). Nerve-mediated release of accumulated radioactivity was accelerated by phentolamine, but not by SP or desmethylimipramine. These findings suggest that SP sensitizes the muscle cells to depolarizing stimuli but that it has no facilitatory effect on sympathetic neural elements. (author)

Neuronal and glial release of (3H)GABA from the rat olfactory bulb

Energy Technology Data Exchange (ETDEWEB)

Jaffe, E.H.; Cuello, A.C.

1981-12-01

Neuronal versus glial components of the (3H)gamma-aminobutyric acid ((3H)GABA) release studies were performed with two different microdissected layers of the olfactory bulb of the rat. In some experiments substantia nigra was used as a GABAergic axonal system and the trigeminal ganglia as a peripheral glial model. Spontaneous release of (3H)GABA was always lower in neuronal elements as compared with glial cells. A veratridine-evoked release was observed from the ONL but not from the trigeminal ganglia. Tetrodotoxin (TTX) abolished the veratridine-evoked release from the ONL, which also showed a partial inhibition when high magnesium concentrations were used in a Ca2+-free solution. beta-Alanine was strongly exchanged with (3H)GABA from the ONL of animals with the olfactory nerve lesioned and from animals with no lesion; but only a small heteroexchange was found from the external plexiform layer. The beta-alanine heteroexchange was able to deplete the releasable GABA store from the ONL of lesioned animals. In nonlesioned animals and the external plexiform layer, the veratridine-stimulated release of (3H)GABA was not significantly reduced after the beta-alanine heteroexchange. Stimulation of the (3H)GABA release by high concentrations of potassium elicited a higher release rate from axonal terminals than from dendrites or glia. Neurones and glia showed a similar inhibition of (3H)GABA release when a high magnesium concentration was added to a calcium-free solution. When D-600 was used as a calcium-flux blocker no inhibition of the release was observed in glial cells, whereas an almost complete blockage was found in both neuronal preparations (substantia nigra and EPL). These results provide further evidence for differential release mechanisms of GABA from CNS neurones and glial cells.

Early and unintentional release of planned motor actions during motor cortical preparation.

Directory of Open Access Journals (Sweden)

Colum D MacKinnon

Full Text Available Voluntary movements are often preceded by a movement-related potential beginning as much as two seconds prior to the onset of movement. In light of evidence that motor actions can be prepared and initiated in less than 200 ms, the function of this early activity has remained enigmatic. We hypothesized that the movement-related potential reflects the state of preparation of the planned movement. This was tested by delivering a startling acoustic stimulus during the preparation phase of a load-release task. The cue to release the load was presented either 3.5 seconds after a warning cue (PREDICT condition or randomly between 4-12 seconds (REACT condition. Electroencephalographic, electromyographic and limb and load kinematic signals were recorded. In a subset of trials, a startle stimulus was delivered at -1500, -1000, -500, -250, -100 or 0 ms before the release cue. A contingent-negative variation (CNV waveform, with a late phase of slow-rising negativity beginning an average of 1459 ms prior to movement, was observed for the PREDICT condition but not the REACT condition. For both conditions, the startle stimulus frequently evoked the early and unintentional release of the load-release sequence. The incidence of release was significantly (p<0.001 correlated with the late phase of the CNV for the PREDICT condition but not the REACT condition. For the REACT condition, the incidence of movement release was subject-specific, constant across the preparation interval, and uncorrelated with cortical activity. The onset of movement release by the startle stimulus was significantly shorter (p<0.001 for the PREDICT compared to the REACT condition. These findings provide evidence that the late phase of the CNV reflects cortical activity mediating the progressive preparation and storage of the forthcoming movement and that during this phase an intense sensory stimulus can evoke early and unintentional release of the planned action.

Towards a neural basis of music-evoked emotions.

Science.gov (United States)

Koelsch, Stefan

2010-03-01

Music is capable of evoking exceptionally strong emotions and of reliably affecting the mood of individuals. Functional neuroimaging and lesion studies show that music-evoked emotions can modulate activity in virtually all limbic and paralimbic brain structures. These structures are crucially involved in the initiation, generation, detection, maintenance, regulation and termination of emotions that have survival value for the individual and the species. Therefore, at least some music-evoked emotions involve the very core of evolutionarily adaptive neuroaffective mechanisms. Because dysfunctions in these structures are related to emotional disorders, a better understanding of music-evoked emotions and their neural correlates can lead to a more systematic and effective use of music in therapy. Copyright 2010 Elsevier Ltd. All rights reserved.

Pressor Response to Noradrenaline in the Setting of Septic Shock: Anything New under the Sun—Dexmedetomidine, Clonidine? A Minireview

Directory of Open Access Journals (Sweden)

A. Géloën

2015-01-01

Full Text Available Progress over the last 50 years has led to a decline in mortality from ≈70% to ≈20% in the best series of patients with septic shock. Nevertheless, refractory septic shock still carries a mortality close to 100%. In the best series, the mortality appears related to multiple organ failure linked to comorbidities and/or an intense inflammatory response: shortening the period that the subject is exposed to circulatory instability may further lower mortality. Treatment aims at reestablishing circulation within a “central” compartment (i.e., brain, heart, and lung but fails to reestablish a disorganized microcirculation or an adequate response to noradrenaline, the most widely used vasopressor. Indeed, steroids, nitric oxide synthase inhibitors, or donors have not achieved overwhelming acceptance in the setting of septic shock. Counterintuitively, α2-adrenoceptor agonists were shown to reduce noradrenaline requirements in two cases of human septic shock. This has been replicated in rat and sheep models of sepsis. In addition, some data show that α2-adrenoceptor agonists lead to an improvement in the microcirculation. Evidence-based documentation of the effects of alpha-2 agonists is needed in the setting of human septic shock.

GPR40/FFAR1 deficient mice increase noradrenaline levels in the brain and exhibit abnormal behavior.

Science.gov (United States)

Aizawa, Fuka; Nishinaka, Takashi; Yamashita, Takuya; Nakamoto, Kazuo; Kurihara, Takashi; Hirasawa, Akira; Kasuya, Fumiyo; Miyata, Atsuro; Tokuyama, Shogo

2016-12-01

The free fatty acid receptor 1 (GPR40/FFAR1) is a G protein-coupled receptor, which is activated by long chain fatty acids. We have previously demonstrated that activation of brain GPR40/FFAR1 exerts an antinociceptive effect that is mediated by the modulation of the descending pain control system. However, it is unclear whether brain GPR40/FFAR1 contributes to emotional function. In this study, we investigated the involvement of GPR40/FFAR1 in emotional behavior using GPR40/FFAR1 deficient (knockout, KO) mice. The emotional behavior in wild and KO male mice was evaluated at 9-10 weeks of age by the elevated plus-maze test, open field test, social interaction test, and sucrose preference test. Brain monoamines levels were measured using LC-MS/MS. The elevated plus-maze test and open field tests revealed that the KO mice reduced anxiety-like behavior. There were no differences in locomotor activity or social behavior between the wild and KO mice. In the sucrose preference test, the KO mice showed reduction in sucrose preference and intake. The level of noradrenaline was higher in the hippocampus, medulla oblongata, hypothalamus and midbrain of KO mice. Therefore, these results suggest that brain GPR40/FFAR1 is associated with anxiety- and depression-related behavior regulated by the increment of noradrenaline in the brain. Copyright © 2016 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Plasma cortisol and noradrenalin concentrations in pigs: automated sampling of freely moving pigs housed in PigTurn versus manually sampled and restrained pigs

Science.gov (United States)

Minimizing the effects of restraint and human interaction on the endocrine physiology of animals is essential for collection of accurate physiological measurements. Our objective was to compare stress-induced cortisol (CORT) and noradrenalin (NorA) responses in automated versus manual blood sampling...

Skin denervation does not alter cortical potentials to surface concentric electrode stimulation: A comparison with laser evoked potentials and contact heat evoked potentials.

Science.gov (United States)

La Cesa, S; Di Stefano, G; Leone, C; Pepe, A; Galosi, E; Alu, F; Fasolino, A; Cruccu, G; Valeriani, M; Truini, A

2018-01-01

In the neurophysiological assessment of patients with neuropathic pain, laser evoked potentials (LEPs), contact heat evoked potentials (CHEPs) and the evoked potentials by the intraepidermal electrical stimulation via concentric needle electrode are widely agreed as nociceptive specific responses; conversely, the nociceptive specificity of evoked potentials by surface concentric electrode (SE-PREPs) is still debated. In this neurophysiological study we aimed at verifying the nociceptive specificity of SE-PREPs. We recorded LEPs, CHEPs and SE-PREPs in eleven healthy participants, before and after epidermal denervation produced by prolonged capsaicin application. We also used skin biopsy to verify the capsaicin-induced nociceptive nerve fibre loss in the epidermis. We found that whereas LEPs and CHEPs were suppressed after capsaicin-induced epidermal denervation, the surface concentric electrode stimulation of the same denervated skin area yielded unchanged SE-PREPs. The suppression of LEPs and CHEPs after nociceptive nerve fibre loss in the epidermis indicates that these techniques are selectively mediated by nociceptive system. Conversely, the lack of SE-PREP changes suggests that SE-PREPs do not provide selective information on nociceptive system function. Capsaicin-induced epidermal denervation abolishes laser evoked potentials (LEPs) and contact heat evoked potentials (CHEPs), but leaves unaffected pain-related evoked potentials by surface concentric electrode (SE-PREPs). These findings suggest that unlike LEPs and CHEPs, SE-PREPs are not selectively mediated by nociceptive system. © 2017 European Pain Federation - EFIC®.

Noradrenergic System and Memory

KAUST Repository

Zenger, Manuel; Burlet-Godinot, Sophie; Petit, Jean-Marie; Magistretti, Pierre J.

2017-01-01

There is ample evidence indicating that noradrenaline plays an important role in memory mechanisms. Noradrenaline is thought to modulate these procsses through activation of adrenergic receptors in neurons. Astrocytes that form essential partners for synaptic function, also express alpha- and beta-adrenergic receptors. In astrocytes, noradrenaline triggers metabolic actions such as the glycogenolysis leading to an increase in l-lactate formation and release. l-Lactate can be used by neurons as a sourc of energy during memory tasks and can also induc transcription of plasticity genes in neurons. Activation of β-adrenergic receptors can also trigger gliotransmitter release resulting of intracllular calcium waves. These gliotransmitters modulate the synaptic activity and thereby can modulate long-term potentiation mechanisms. In summary, recnt evidencs indicate that noradrenaline exerts its memory-promoting effects through different modes of action both on neurons and astrocytes.

Noradrenergic System and Memory

KAUST Repository

Zenger, Manuel

2017-07-22

There is ample evidence indicating that noradrenaline plays an important role in memory mechanisms. Noradrenaline is thought to modulate these procsses through activation of adrenergic receptors in neurons. Astrocytes that form essential partners for synaptic function, also express alpha- and beta-adrenergic receptors. In astrocytes, noradrenaline triggers metabolic actions such as the glycogenolysis leading to an increase in l-lactate formation and release. l-Lactate can be used by neurons as a sourc of energy during memory tasks and can also induc transcription of plasticity genes in neurons. Activation of β-adrenergic receptors can also trigger gliotransmitter release resulting of intracllular calcium waves. These gliotransmitters modulate the synaptic activity and thereby can modulate long-term potentiation mechanisms. In summary, recnt evidencs indicate that noradrenaline exerts its memory-promoting effects through different modes of action both on neurons and astrocytes.

Group I mGlu receptors potentiate synaptosomal [{sup 3}H]glutamate release independently of exogenously applied arachidonic acid

Energy Technology Data Exchange (ETDEWEB)

Reid, M.E.; Toms, N.J.; Bedingfield, J.S.; Roberts, P.J. [Department of Pharmacology, School of Medical Sciences, University of Bristol, University Walk, Bristol, BS8 1TD (United Kingdom)

1999-04-01

In the current study, we have characterized group I metabotropic glutamate (mGlu) receptor enhancement of 4-aminopyridine (4AP)-evoked [{sup 3}H]glutamate release from rat cerebrocortical synaptosomes. The broad spectrum mGlu receptor agonist (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid ((1S,3R)-ACPD, 10 {mu}M) increased 4AP-evoked [{sup 3}H]glutamate release (143.32{+-}2.73% control) only in the presence of exogenously applied arachidonic acid; an effect reversed by the inclusion of bovine serum albumin (BSA, fatty acid free). In contrast, the selective group I mGlu receptor agonist (S)-3,5-dihydroxyphenylglycine (DHPG) potentiated (EC{sub 50}=1.60{+-}0.25 {mu}M; E{sub max}=147.61{+-}10.96% control) 4AP-evoked [{sup 3}H]glutamate release, in the absence of arachidonic acid. This potentiation could be abolished by either the selective mGlu{sub 1} receptor antagonist (R,S)-1-aminoindan-1,5-dicarboxylic acid (AIDA, 1 mM) or the selective PKC inhibitor (Ro 31-8220, 10 {mu}M) and was BSA-insensitive. The selective mGlu{sub 5} receptor agonist (R,S)-2-chloro-5-hydroxyphenylglycine (CHPG, 300{mu}M) was without effect. DHPG (100 {mu}M) also potentiated both 30 mM and 50 mM K{sup +}-evoked [{sup 3}H]glutamate release (121.60{+-}12.77% and 121.50{+-}4.45% control, respectively). DHPG (100 {mu}M) failed to influence both 4AP-stimulated {sup 45}Ca{sup 2+} influx and 50 mM K{sup +}-induced changes in synaptosomal membrane potential. Possible group I mGlu receptor suppression of tonic adenosine A{sub 1} receptor, group II/III mGlu receptors or GABA{sub B} receptor activity is unlikely since 4AP-evoked [{sup 3}H]glutamate release was insensitive to the selective inhibitory receptor antagonists 8-cyclopentyl-1,3-dimethylxanthine, (R,S)-{alpha}-cyclopropyl-4-phosphonophenylglycine or CGP55845A, respectively. These data suggest an 'mGlu{sub 1} receptor-like' receptor potentiates [{sup 3}H]glutamate release from cerebrocortical synaptosomes in the absence of

M-octopamine injected into the paraventricular nucleus induces eating in rats: a comparison with noradrenaline-induced eating.

OpenAIRE

Fletcher, P. J.; Paterson, I. A.

1989-01-01

1. The effects on food intake in rats of injection of m- and p-octopamine into the paraventricular nucleus (PVN) of the hypothalamus were examined, and compared to the effects of noradrenaline (NA). 2. m-Octopamine injected into the PVN induced a dose-dependent increase in food intake, with the maximal effect occurring at a dose of 25 nmol. p-Octopamine did not elicit eating unless it was administered to animals pretreated with the monoamine oxidase inhibitor, pargyline. 3. The effects of pre...

Glucagon releases Ca2+ from a FCCP-sensitive pool

International Nuclear Information System (INIS)

Kraus-Friedmann, N.

1986-01-01

The effects of physiological levels of glucagon on Ca 2+ efflux were examined in the perfused rat liver. Two methods were used to estimate Ca 2+ efflux: (1) prior labeling of the Ca 2+ pools with 45 Ca 2+ , and (2) measurement of perfusate Ca 2+ with atomic absorption. According to both methods, glucagon administration at the physiological level evoked Ca 2+ release. In order to identify the hormone-sensitive Ca 2+ pool, a method employed by several laboratories was used. In this method, mitochondrial Ca 2+ is released by FCCP, (carbonyl-cyanide 4 (trifluoro/methoxy) phenylhydrazone), a mitochondrial uncoupler. The effect of hormones on Ca 2+ release after such uncoupler administration is measured. A decreased release is taken as an indication that the pool is entirely or partially mitochondrial. FCCP released 90 +/- 29 nmoles Ca 2+ /gr wet liver. Glucagon (5 x 10 -9 M) released 107 +/- 45 nmoles Ca 2+ /gr wet liver before and 26 +/- 9 nmoles Ca 2+ /gr wet liver after FCCP. These data indicate that glucagon releases Ca 2+ mostly from the mitochondria

Insulin-releasing action of the novel antidiabetic agent BTS 67 582.

Science.gov (United States)

McClenaghan, N H; Flatt, P R; Bailey, C J

1998-02-01

1. BTS 67582 (1,1-dimethyl-2-(2-morpholinophenyl)guanidine fumarate) is a novel antidiabetic agent with a short-acting insulin-releasing effect. This study examined its mode of action in the clonal B-cell line BRIN-BD11. 2. BTS 67582 increased insulin release from BRIN-BD11 cells in a concentration-dependent manner (10[-8] to 10[-4] M) at both non-stimulating (1.1 mM) and stimulating (16.7 mM) concentrations of glucose. 3. BTS 67582 (10[-4] M) potentiated the insulin-releasing effect of a depolarizing concentration of K+ (30 mM), whereas the K+ channel openers pinacidil (400 microM) and diazoxide (300 microM) inhibited BTS 67582-induced release. 4. Suppression of Ca+ channel activity with verapamil (20 microM) reduced the insulin-releasing effect of BTS 67582 (10[-4] M). 5. BTS 67582 (10[-4] M) potentiated insulin release induced by amino acids (10 mM), and enhanced the combined stimulant effects of glucose plus either the fatty acid palmitate (10 mM), or agents which raise intracellular cyclic AMP concentrations (25 microM forskolin and 1 mM isobutylmethylxanthine), or the cholinoceptor agonist carbachol (100 microM). 6. Inhibition of glucose-stimulated insulin release by adrenaline or noradrenaline (10 microM) was partially reversed by BTS 67582 (10[-4] M). 7. These data suggest that the insulin-releasing effect of BTS 67582 involves regulation of ATP-sensitive K+ channel activity and Ca2+ influx, and that the drug augments the stimulant effects of nutrient insulin secretagogues and agents which enhance adenylate cyclase and phospholipase C. BTS 67582 may also exert insulin-releasing effects independently of ATP-sensitive K+ channel activity.

Phasic dopamine release drives rapid activation of striatal D2-receptors

Science.gov (United States)

Marcott, Pamela F; Mamaligas, Aphroditi A; Ford, Christopher P

2014-01-01

Summary Striatal dopamine transmission underlies numerous goal-directed behaviors. Medium spiny neurons (MSNs) are a major target of dopamine in the striatum. However, as dopamine does not directly evoke a synaptic event in MSNs, the time course of dopamine signaling in these cells remains unclear. To examine how dopamine release activates D2-receptors on MSNs, G-protein activated inwardly rectifying potassium (GIRK2; Kir 3.2) channels were virally overexpressed in the striatum and the resulting outward currents were used as a sensor of D2-receptor activation. Electrical and optogenetic stimulation of dopamine terminals evoked robust D2-receptor inhibitory post-synaptic currents (IPSCs) in GIRK2-expressing MSNs that occurred in under a second. Evoked D2-IPSCs could be driven by repetitive stimulation and were not occluded by background dopamine tone. Together, the results indicate that D2-receptors on MSNs exhibit functional low affinity and suggest that striatal D2-receptors can encode both tonic and phasic dopamine signals. PMID:25242218

Brainstem Auditory Evoked Potential in HIV-Positive Adults.

Science.gov (United States)

Matas, Carla Gentile; Samelli, Alessandra Giannella; Angrisani, Rosanna Giaffredo; Magliaro, Fernanda Cristina Leite; Segurado, Aluísio C

2015-10-20

To characterize the findings of brainstem auditory evoked potential in HIV-positive individuals exposed and not exposed to antiretroviral treatment. This research was a cross-sectional, observational, and descriptive study. Forty-five HIV-positive individuals (18 not exposed and 27 exposed to the antiretroviral treatment - research groups I and II, respectively - and 30 control group individuals) were assessed through brainstem auditory evoked potential. There were no significant between-group differences regarding wave latencies. A higher percentage of altered brainstem auditory evoked potential was observed in the HIV-positive groups when compared to the control group. The most common alteration was in the low brainstem. HIV-positive individuals have a higher percentage of altered brainstem auditory evoked potential that suggests central auditory pathway impairment when compared to HIV-negative individuals. There was no significant difference between individuals exposed and not exposed to antiretroviral treatment.

Psychological and physiological responses to odor-evoked autobiographic memory.

Science.gov (United States)

Matsunaga, Masahiro; Isowa, Tokiko; Yamakawa, Kaori; Kawanishi, Yoko; Tsuboi, Hirohito; Kaneko, Hiroshi; Sadato, Norihiro; Oshida, Akiko; Katayama, Atsushi; Kashiwagi, Mitsuyoshi; Ohira, Hideki

2011-01-01

The "Proust phenomenon" occurs when a certain smell evokes a specific memory. Recent studies have demonstrated that odor-evoked autobiographic memories are more emotional than those elicited by other sensory stimuli because of the direct neural communication between the olfactory system and the amygdala. The amygdala is known to regulate various physiological activities including the endocrine and immune systems; therefore, odor-evoked autobiographic memory may trigger various psychological and physiological responses; however, the responses elicited by this memory remains obscure. In this study, we aimed to investigate the psychological and physiological responses accompanying odor-evoked autobiographic memory. We recruited healthy male and female volunteers and investigated changes in their mood states and autonomic nervous, endocrine, and immune activities when autobiographic memory was evoked in the participants by asking them to smell an odor(s) that was nostalgic to them. The autobiographic memories associated with positive emotion resulted in increased positive mood states, such as comfort and happiness, and decreased negative mood states, such as anxiety. Furthermore, heart rate was decreased, skin-conductance level was increased, and peripheral interleukin-2 level was decreased after smelling the nostalgic odor. These psychological and physiological responses were significantly correlated. The present study suggests that odor-evoked autobiographic memory along with a positive feeling induce various physiological responses, including the autonomic nervous and immune activities. To the best of our knowledge, the present study is the first to observe an interaction between odor-evoked autobiographic memories and immune function.

Accumulation of radioactivity after repeated infusion of 3H-adrenaline and 3H-noradrenaline in the rat as a model animal.

Science.gov (United States)

Lepschy, M; Filip, T; Palme, R G

2014-10-01

Besides enzymatic inactivation, catecholamines bind non-enzymatically and irreversible to proteins. The physiological impact of these catecholamine adducts is still unclear. We therefore collected basic data about the distribution of catecholamine adducts in the rat after repeated intravenous administration of (3)H-adrenaline and (3)H-noradrenaline. In all animals radioactivity in blood increased until the last injection on Day 7 and decreased then slowly close to background values (plasma) or remained higher (erythrocytes). In all sampled tissues radioactivity could be found, but only in hair high amounts remained present even after 3 weeks. Half-life of rat serum albumin loaded with (3)H-adrenaline or (3)H-noradrenaline was not altered. This study provides basic knowledge about the distribution of catecholamines or their adducts, but physiological effects could not be demonstrated. However, for the first time deposition and accumulation of catecholamines (adducts) in the hair could be proven, suggesting that hair might be used for evaluating long term stress. Copyright © 2014 Elsevier Ltd. All rights reserved.

Acid and stretch, but not capsaicin, are effective stimuli for ATP release in the porcine bladder mucosa: Are ASIC and TRPV1 receptors involved?

Science.gov (United States)

Sadananda, Prajni; Kao, Felicity C L; Liu, Lu; Mansfield, Kylie J; Burcher, Elizabeth

2012-05-15

Stretch-evoked ATP release from the bladder mucosa is a key event in signaling bladder fullness. Our aim was to examine whether acid and capsaicin can also release ATP and to determine the receptors involved, using agonists and antagonists at TRPV1 and acid-sensing ion channels (ASICs). Strips of porcine bladder mucosa were exposed to acid, capsaicin or stretch. Strip tension was monitored. Bath fluid was collected for ATP measurement. Gene expression of ASICs and TRPV1 in porcine bladders was quantified using quantitative real-time PCR (qRT-PCR). Stretch stimulus (150% of original length) repeatedly and significantly increased ATP release to approximately 45 times basal release. Acid (pH 6.5, 6.0, 5.6) contracted mucosal strips and also increased ATP release up to 30-fold, without evidence of desensitization. Amiloride (0.3 μM) reduced the acid-evoked ATP release by approximately 70%, while capsazepine (10 μM) reduced acid-evoked ATP release at pH 6.0 and pH 5.6 (by 68% and 61%, respectively). Capsaicin (0.1-10 μM) was ineffective in causing ATP release, and also failed to contract porcine mucosal or detrusor strips. Gene expression for ASIC1, ASIC2, ASIC3 and TRPV1 was seen in the lateral wall, dome, trigone and neck of both detrusor and mucosa. In conclusion, stretch and acid induce ATP release in the porcine bladder mucosa, but capsaicin is ineffective. The pig bladder is a well-known model for the human bladder, however these data suggest that it should be used with caution, particularly for TRPV1 related studies. Copyright © 2012 Elsevier B.V. All rights reserved.

Modulation of release of [3H]acetylcholine in the major pelvic ganglion of the rat.

Science.gov (United States)

Somogyi, G T; de Groat, W C

1993-06-01

Cholinergic modulation of [3H]acetylcholine release evoked by electrical stimulation was studied in the rat major pelvic ganglion, which was prelabeled with [3H]choline. Acetylcholine (ACh) release was independent of the frequency of stimulation; 0.3 Hz produced the same volley output as 10 Hz. Tetrodotoxin (1 microM) or omission of Ca2+ from the medium abolished ACh release. The M1 receptor agonist (4-hydroxy-2-butynyl)-1-trimethylammonium m-chlorocarbanilate chloride (McN-A 343, 50 microM) increased release (by 136%), whereas the M2 muscarinic agonist oxotremorine (1 microM) decreased ACh release (by 22%). The muscarinic antagonists, atropine (1 microM) or pirenzepine (M1 selective, 1 microM), did not change ACh release. However, pirenzepine (1 microM) blocked the facilitatory effect of McN-A 343, and atropine (1 microM) blocked the inhibitory effect of oxotremorine. The cholinesterase inhibitor physostigmine (1-5 microM), the nicotinic agonist 1,1-dimethyl-4-phenylpiperazinium (DMPP, 10 microM), and the nicotinic antagonist D-tubocurarine (50 microM) did not change ACh release. 4-Aminopyridine, a K+ channel blocker, significantly increased the release (by 146%). Seven days after decentralization of the major pelvic ganglion, the evoked release of ACh was abolished. It is concluded that release of ACh occurs from the preganglionic nerve terminals rather than from the cholinergic cell bodies and is not modulated by actions of endogenous ACh on either muscarinic or nicotinic autoreceptors. These data confirm and extend previous electrophysiological findings indicating that synapses in the major pelvic ganglion have primarily a relay function.

Evoked acoustic emission

DEFF Research Database (Denmark)

Elberling, C; Parbo, J; Johnsen, N J

1985-01-01

Stimulated acoustic emissions were recorded in response to tonal stimuli at 60 dB p.e. SPL in a small group of normal-hearing adults. Power spectral analysis reveals that the evoked activity from each ear contains energy in preferential frequency bands and the change of stimulus frequency has only...

Facilitation of granule cell epileptiform activity by mossy fiber-released zinc in the pilocarpine model of temporal lobe epilepsy.

Science.gov (United States)

Timofeeva, Olga; Nadler, J Victor

2006-03-17

Recurrent mossy fiber synapses in the dentate gyrus of epileptic brain facilitate the synchronous firing of granule cells and may promote seizure propagation. Mossy fiber terminals contain and release zinc. Released zinc inhibits the activation of NMDA receptors and may therefore oppose the development of granule cell epileptiform activity. Hippocampal slices from rats that had experienced pilocarpine-induced status epilepticus and developed a recurrent mossy fiber pathway were used to investigate this possibility. Actions of released zinc were inferred from the effects of chelation with 1 mM calcium disodium EDTA (CaEDTA). When granule cell population bursts were evoked by mossy fiber stimulation in the presence of 6 mM K(+) and 30 microM bicuculline, CaEDTA slowed the rate at which evoked bursting developed, but did not change the magnitude of the bursts once they had developed fully. The effects of CaEDTA were then studied on the pharmacologically isolated NMDA receptor- and AMPA/kainate receptor-mediated components of the fully developed bursts. CaEDTA increased the magnitude of NMDA receptor-mediated bursts and reduced the magnitude of AMPA/kainate receptor-mediated bursts. CaEDTA did not affect the granule cell bursts evoked in slices from untreated rats by stimulating the perforant path in the presence of bicuculline and 6 mM K(+). These results suggest that zinc released from the recurrent mossy fibers serves mainly to facilitate the recruitment of dentate granule cells into population bursts.

Deep brain stimulation results in local glutamate and adenosine release: investigation into the role of astrocytes.

Science.gov (United States)

Tawfik, Vivianne L; Chang, Su-Youne; Hitti, Frederick L; Roberts, David W; Leiter, James C; Jovanovic, Svetlana; Lee, Kendall H

2010-08-01

Several neurological disorders are treated with deep brain stimulation; however, the mechanism underlying its ability to abolish oscillatory phenomena associated with diseases as diverse as Parkinson's disease and epilepsy remain largely unknown. To investigate the role of specific neurotransmitters in deep brain stimulation and determine the role of non-neuronal cells in its mechanism of action. We used the ferret thalamic slice preparation in vitro, which exhibits spontaneous spindle oscillations, to determine the effect of high-frequency stimulation on neurotransmitter release. We then performed experiments using an in vitro astrocyte culture to investigate the role of glial transmitter release in high-frequency stimulation-mediated abolishment of spindle oscillations. In this series of experiments, we demonstrated that glutamate and adenosine release in ferret slices was able to abolish spontaneous spindle oscillations. The glutamate release was still evoked in the presence of the Na channel blocker tetrodotoxin, but was eliminated with the vesicular H-ATPase inhibitor bafilomycin and the calcium chelator 2-bis(2-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid tetrakis acetoxymethyl ester. Furthermore, electrical stimulation of purified primary astrocytic cultures was able to evoke intracellular calcium transients and glutamate release, and bath application of 2-bis (2-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid tetrakis acetoxymethyl ester inhibited glutamate release in this setting. Vesicular astrocytic neurotransmitter release may be an important mechanism by which deep brain stimulation is able to achieve clinical benefits.

Brainstem evoked potentials in infantile spasms

International Nuclear Information System (INIS)

Miyazaki, Masahito; Hashimoto, Toshiaki; Murakawa, Kazuyoshi; Tayama, Masanobu; Kuroda, Yasuhiro

1992-01-01

In ten patients with infantile spasms, brainstem evoked potentials and MRI examinations were performed to evaluate the brainstem involvement. The result of short latency somatosensory evoked potentials (SSEP) following the right median nerve stimulation revealed abnormal findings including the absence or low amplitudes of the waves below wave P3 and delayed central conduction time in 7 of the ten patients. The result of auditory brainstem responses (ABR) revealed abnormal findings including low amplitudes of wave V, prolonged interpeak latency of waves I-V and absence of the waves below wave IV in 5 of the ten patients. The result of the MRI examinations revealed various degrees of the brainstem atrophy in 6 of the ten patients, all of whom showed abnormal brainstem evoked potentials. The result of this study demonstrates that patients with infantile spasms are frequently associated with brainstem dysfunction and raises the possibility that brainstem atrophy might be a cause of infantile spasms. (author)

Metabolic control of vesicular glutamate transport and release.

Science.gov (United States)

Juge, Narinobu; Gray, John A; Omote, Hiroshi; Miyaji, Takaaki; Inoue, Tsuyoshi; Hara, Chiaki; Uneyama, Hisayuki; Edwards, Robert H; Nicoll, Roger A; Moriyama, Yoshinori

2010-10-06

Fasting has been used to control epilepsy since antiquity, but the mechanism of coupling between metabolic state and excitatory neurotransmission remains unknown. Previous work has shown that the vesicular glutamate transporters (VGLUTs) required for exocytotic release of glutamate undergo an unusual form of regulation by Cl(-). Using functional reconstitution of the purified VGLUTs into proteoliposomes, we now show that Cl(-) acts as an allosteric activator, and the ketone bodies that increase with fasting inhibit glutamate release by competing with Cl(-) at the site of allosteric regulation. Consistent with these observations, acetoacetate reduced quantal size at hippocampal synapses and suppresses glutamate release and seizures evoked with 4-aminopyridine in the brain. The results indicate an unsuspected link between metabolic state and excitatory neurotransmission through anion-dependent regulation of VGLUT activity. Copyright © 2010 Elsevier Inc. All rights reserved.

Sustained prejunctional facilitation of noradrenergic neurotransmission by adrenaline as a co-transmitter in the portal vein of freely moving rats

NARCIS (Netherlands)

COPPES, RP; Freie, I.; SMIT, J; ZAAGSMA, J

1994-01-01

1 The duration of the facilitatory effect of adrenaline on the electrically evoked overflow of noradrenaline was studied in the portal vein of permanently adreno-demedullated freely moving rats. 2 Rats were infused with adrenaline (20 or 100 ng min(-1)) for 2 h. After an interval of 1 h, when plasma

Acacetin inhibits glutamate release and prevents kainic acid-induced neurotoxicity in rats.

Directory of Open Access Journals (Sweden)

Tzu-Yu Lin

Full Text Available An excessive release of glutamate is considered to be a molecular mechanism associated with several neurological diseases that causes neuronal damage. Therefore, searching for compounds that reduce glutamate neurotoxicity is necessary. In this study, the possibility that the natural flavone acacetin derived from the traditional Chinese medicine Clerodendrum inerme (L. Gaertn is a neuroprotective agent was investigated. The effect of acacetin on endogenous glutamate release in rat hippocampal nerve terminals (synaptosomes was also investigated. The results indicated that acacetin inhibited depolarization-evoked glutamate release and cytosolic free Ca(2+ concentration ([Ca(2+]C in the hippocampal nerve terminals. However, acacetin did not alter synaptosomal membrane potential. Furthermore, the inhibitory effect of acacetin on evoked glutamate release was prevented by the Cav2.2 (N-type and Cav2.1 (P/Q-type channel blocker known as ω-conotoxin MVIIC. In a kainic acid (KA rat model, an animal model used for excitotoxic neurodegeneration experiments, acacetin (10 or 50 mg/kg was administrated intraperitoneally to the rats 30 min before the KA (15 mg/kg intraperitoneal injection, and subsequently induced the attenuation of KA-induced neuronal cell death and microglia activation in the CA3 region of the hippocampus. The present study demonstrates that the natural compound, acacetin, inhibits glutamate release from hippocampal synaptosomes by attenuating voltage-dependent Ca(2+ entry and effectively prevents KA-induced in vivo excitotoxicity. Collectively, these data suggest that acacetin has the therapeutic potential for treating neurological diseases associated with excitotoxicity.

Can visual evoked potentials be used in biometric identification?

Science.gov (United States)

Power, Alan J; Lalor, Edmund C; Reilly, Richard B

2006-01-01

Due to known differences in the anatomical structure of the visual pathways and generators in different individuals, the use of visual evoked potentials offers the possibility of an alternative to existing biometrics methods. A study based on visual evoked potentials from 13 individuals was carried out to assess the best combination of temporal, spectral and AR modeling features to realize a robust biometric. From the results it can be concluded that visual evoked potentials show considerable biometric qualities, with classification accuracies reaching a high of 86.54% and that a specific temporal and spectral combination was found to be optimal. Based on these results the visual evoked potential may be a useful tool in biometric identification when used in conjunction with more established biometric methods.

Binaural interaction in auditory evoked potentials: Brainstem, middle- and long-latency components

OpenAIRE

McPherson, DL; Starr, A

1993-01-01

Binaural interaction occurs in the auditory evoked potentials when the sum of the monaural auditory evoked potentials are not equivalent to the binaural evoked auditory potentials. Binaural interaction of the early- (0-10 ms), middle- (10-50 ms) and long-latency (50-200 ms) auditory evoked potentials was studied in 17 normal young adults. For the early components, binaural interaction was maximal at 7.35 ms accounting for a reduction of 21% of the amplitude of the binaural evoked potentials. ...

Synaptically evoked glutamate transporter currents in Spinal Dorsal Horn Astrocytes

Directory of Open Access Journals (Sweden)

Dougherty Patrick M

2009-07-01

Full Text Available Abstract Background Removing and sequestering synaptically released glutamate from the extracellular space is carried out by specific plasma membrane transporters that are primarily located in astrocytes. Glial glutamate transporter function can be monitored by recording the currents that are produced by co-transportation of Na+ ions with the uptake of glutamate. The goal of this study was to characterize glutamate transporter function in astrocytes of the spinal cord dorsal horn in real time by recording synaptically evoked glutamate transporter currents. Results Whole-cell patch clamp recordings were obtained from astrocytes in the spinal substantia gelatinosa (SG area in spinal slices of young adult rats. Glutamate transporter currents were evoked in these cells by electrical stimulation at the spinal dorsal root entry zone in the presence of bicuculline, strychnine, DNQX and D-AP5. Transporter currents were abolished when synaptic transmission was blocked by TTX or Cd2+. Pharmacological studies identified two subtypes of glutamate transporters in spinal astrocytes, GLAST and GLT-1. Glutamate transporter currents were graded with stimulus intensity, reaching peak responses at 4 to 5 times activation threshold, but were reduced following low-frequency (0.1 – 1 Hz repetitive stimulation. Conclusion These results suggest that glutamate transporters of spinal astrocytes could be activated by synaptic activation, and recording glutamate transporter currents may provide a means of examining the real time physiological responses of glial cells in spinal sensory processing, sensitization, hyperalgesia and chronic pain.

Running Reduces Uncontrollable Stress-Evoked Serotonin and Potentiates Stress-Evoked Dopamine Concentrations in the Rat Dorsal Striatum.

Directory of Open Access Journals (Sweden)

Peter J Clark

Full Text Available Accumulating evidence from both the human and animal literature indicates that exercise reduces the negative consequences of stress. The neurobiological etiology for this stress protection, however, is not completely understood. Our lab reported that voluntary wheel running protects rats from expressing depression-like instrumental learning deficits on the shuttle box escape task after exposure to unpredictable and inescapable tail shocks (uncontrollable stress. Impaired escape behavior is a result of stress-sensitized serotonin (5-HT neuron activity in the dorsal raphe (DRN and subsequent excessive release of 5-HT into the dorsal striatum following exposure to a comparatively mild stressor. However, the possible mechanisms by which exercise prevents stress-induced escape deficits are not well characterized. The purpose of this experiment was to test the hypothesis that exercise blunts the stress-evoked release of 5-HT in the dorsal striatum. Changes to dopamine (DA levels were also examined, since striatal DA signaling is critical for instrumental learning and can be influenced by changes to 5-HT activity. Adult male F344 rats, housed with or without running wheels for 6 weeks, were either exposed to tail shock or remained undisturbed in laboratory cages. Twenty-four hours later, microdialysis was performed in the medial (DMS and lateral (DLS dorsal striatum to collect extracellular 5-HT and DA before, during, and following 2 mild foot shocks. We report wheel running prevents foot shock-induced elevation of extracellular 5-HT and potentiates DA concentrations in both the DMS and DLS approximately 24 h following exposure to uncontrollable stress. These data may provide a possible mechanism by which exercise prevents depression-like instrumental learning deficits following exposure to acute stress.

Impact of substance P on the correlation of spike train evoked by electro acupuncture

International Nuclear Information System (INIS)

Jin, Chen; Zhang, Xuan; Wang, Jiang; Guo, Yi; Zhao, Xue; Guo, Yong-Ming

2016-01-01

Highlights: • We analyze spike trains induced by EA before and after inhibiting SP in PC6 area. • Inhibiting SP leads to an increase of spiking rate of median nerve. • SP may modulate membrane potential to affect the spiking rate. • SP has an influence on long-range correlation of spike train evoked by EA. • SP play an important role in EA-induced neural spiking and encoding. - Abstract: Substance P (SP) participates in the neural signal transmission evoked by electro-acupuncture (EA). This paper investigates the impact of SP on the correlation of spike train in the median nerve evoked by EA at 'Neiguan' acupoint (PC6). It shows that the spiking rate and interspike interval (ISI) distribution change obviously after inhibiting SP. This variation of spiking activity indicates that SP affects the temporal structure of spike train through modulating the action potential on median nerve filaments. Furtherly, the correlation coefficient and scaling exponent are considered to measure the correlation of spike train. Scaled Windowed Variance (SWV) method is applied to calculate scaling exponent which quantifies the long-range correlation of the neural electrical signals. It is found that the correlation coefficients of ISI increase after inhibiting SP released. In addition, the scaling exponents of neuronal spike train have significant differences between before and after inhibiting SP. These findings demonstrate that SP has an influence on the long-range correlation of spike train. Our results indicate that SP may play an important role in EA-induced neural spiking and encoding.

Slow cortical evoked potentials after noise exposure

Energy Technology Data Exchange (ETDEWEB)

von Wedel, H; Opitz, H J

1979-07-01

Human cortical evoked potentials under conditions of stimuation are registrated in the post-stimulatory phase of a five minutes lasting equally masking white noise (90 dB HL). Changes of the evoked potentials during adaptation, possible analogy with high tone losses after noise representation and the origin of tinnitus are examined. Stimulation was started 3 sec after the off-effect of the noise. For five minutes periodically tone bursts were represented. Each train of stimulation consists of tone bursts of three frequencies: 2 kcs, 4 kcs, 8 kcs. The 0.5 sec lasting tones were separated by pauses of 2 sec. During the experiment stimulation and analysis were controlled by a computer. Changes in latency and amplitudes of the cortical evoked potentials were registered. Changes of the adaptation patterns as a function of the poststimulatory time are discussed.

The Paradox of Music-Evoked Sadness: An Online Survey

Science.gov (United States)

Taruffi, Liila; Koelsch, Stefan

2014-01-01

This study explores listeners’ experience of music-evoked sadness. Sadness is typically assumed to be undesirable and is therefore usually avoided in everyday life. Yet the question remains: Why do people seek and appreciate sadness in music? We present findings from an online survey with both Western and Eastern participants (N = 772). The survey investigates the rewarding aspects of music-evoked sadness, as well as the relative contribution of listener characteristics and situational factors to the appreciation of sad music. The survey also examines the different principles through which sadness is evoked by music, and their interaction with personality traits. Results show 4 different rewards of music-evoked sadness: reward of imagination, emotion regulation, empathy, and no “real-life” implications. Moreover, appreciation of sad music follows a mood-congruent fashion and is greater among individuals with high empathy and low emotional stability. Surprisingly, nostalgia rather than sadness is the most frequent emotion evoked by sad music. Correspondingly, memory was rated as the most important principle through which sadness is evoked. Finally, the trait empathy contributes to the evocation of sadness via contagion, appraisal, and by engaging social functions. The present findings indicate that emotional responses to sad music are multifaceted, are modulated by empathy, and are linked with a multidimensional experience of pleasure. These results were corroborated by a follow-up survey on happy music, which indicated differences between the emotional experiences resulting from listening to sad versus happy music. This is the first comprehensive survey of music-evoked sadness, revealing that listening to sad music can lead to beneficial emotional effects such as regulation of negative emotion and mood as well as consolation. Such beneficial emotional effects constitute the prime motivations for engaging with sad music in everyday life. PMID:25330315

The paradox of music-evoked sadness: an online survey.

Directory of Open Access Journals (Sweden)

Liila Taruffi

Full Text Available This study explores listeners' experience of music-evoked sadness. Sadness is typically assumed to be undesirable and is therefore usually avoided in everyday life. Yet the question remains: Why do people seek and appreciate sadness in music? We present findings from an online survey with both Western and Eastern participants (N = 772. The survey investigates the rewarding aspects of music-evoked sadness, as well as the relative contribution of listener characteristics and situational factors to the appreciation of sad music. The survey also examines the different principles through which sadness is evoked by music, and their interaction with personality traits. Results show 4 different rewards of music-evoked sadness: reward of imagination, emotion regulation, empathy, and no "real-life" implications. Moreover, appreciation of sad music follows a mood-congruent fashion and is greater among individuals with high empathy and low emotional stability. Surprisingly, nostalgia rather than sadness is the most frequent emotion evoked by sad music. Correspondingly, memory was rated as the most important principle through which sadness is evoked. Finally, the trait empathy contributes to the evocation of sadness via contagion, appraisal, and by engaging social functions. The present findings indicate that emotional responses to sad music are multifaceted, are modulated by empathy, and are linked with a multidimensional experience of pleasure. These results were corroborated by a follow-up survey on happy music, which indicated differences between the emotional experiences resulting from listening to sad versus happy music. This is the first comprehensive survey of music-evoked sadness, revealing that listening to sad music can lead to beneficial emotional effects such as regulation of negative emotion and mood as well as consolation. Such beneficial emotional effects constitute the prime motivations for engaging with sad music in everyday life.

The paradox of music-evoked sadness: an online survey.

Science.gov (United States)

Taruffi, Liila; Koelsch, Stefan

2014-01-01

This study explores listeners' experience of music-evoked sadness. Sadness is typically assumed to be undesirable and is therefore usually avoided in everyday life. Yet the question remains: Why do people seek and appreciate sadness in music? We present findings from an online survey with both Western and Eastern participants (N = 772). The survey investigates the rewarding aspects of music-evoked sadness, as well as the relative contribution of listener characteristics and situational factors to the appreciation of sad music. The survey also examines the different principles through which sadness is evoked by music, and their interaction with personality traits. Results show 4 different rewards of music-evoked sadness: reward of imagination, emotion regulation, empathy, and no "real-life" implications. Moreover, appreciation of sad music follows a mood-congruent fashion and is greater among individuals with high empathy and low emotional stability. Surprisingly, nostalgia rather than sadness is the most frequent emotion evoked by sad music. Correspondingly, memory was rated as the most important principle through which sadness is evoked. Finally, the trait empathy contributes to the evocation of sadness via contagion, appraisal, and by engaging social functions. The present findings indicate that emotional responses to sad music are multifaceted, are modulated by empathy, and are linked with a multidimensional experience of pleasure. These results were corroborated by a follow-up survey on happy music, which indicated differences between the emotional experiences resulting from listening to sad versus happy music. This is the first comprehensive survey of music-evoked sadness, revealing that listening to sad music can lead to beneficial emotional effects such as regulation of negative emotion and mood as well as consolation. Such beneficial emotional effects constitute the prime motivations for engaging with sad music in everyday life.

Genetic influence demonstrated for MEG-recorded somatosensory evoked responses

NARCIS (Netherlands)

van 't Ent, D.; van Soelen, I.L.C.; Stam, K.J.; de Geus, E.J.C.; Boomsma, D.I.

2010-01-01

We tested for a genetic influence on magnetoencephalogram (MEG)-recorded somatosensory evoked fields (SEFs) in 20 monozygotic (MZ) and 14 dizygotic (DZ) twin pairs. Previous electroencephalogram (EEG) studies that demonstrated a genetic contribution to evoked responses generally focused on

Visually Evoked Spiking Evolves While Spontaneous Ongoing Dynamics Persist

DEFF Research Database (Denmark)

Huys, Raoul; Jirsa, Viktor K; Darokhan, Ziauddin

2016-01-01

attractor. Its existence guarantees that evoked spiking return to the spontaneous state. However, the spontaneous ongoing spiking state and the visual evoked spiking states are qualitatively different and are separated by a threshold (separatrix). The functional advantage of this organization...

Chronic cobalt-induced epilepsy: noradrenaline ionophoresis and adrenoceptor binding studies in the rat cerebral cortex

International Nuclear Information System (INIS)

Bregman, B.; Le Saux, F.; Maurin, Y.; Trottier, S.; Chauvel, P.

1985-01-01

Several studies indicate that brain noradrenaline (NA) depletion facilitates the occurrence of epileptogenic syndromes in various animal models. In cobalt-induced epilepsy in the rat, seizure activity is associated with a cortical NA denervation. In order to search for cortical adrenoceptor modifications, inonophoretic studies and adrenoceptor binding assays were performed. At the period of maximal seizure activity, there was a significant supersensitivity of cortial neurons to the ionophoretic application of NA. An increase in the density of β-adrenoceptor binding sites was observed. No modification in α 1 - and α 2 -adrenoceptor binding sites was found. This suggests that in cobalt-induced epilepsy there is a denervation supersensitivity which rests on a selective involvement of β-adrenoceptors. (Author)

Cold urticaria: inhibition of cold-induced histamine release by doxantrazole.

Science.gov (United States)

Bentley-Phillips, C B; Eady, R A; Greaves, M W

1978-10-01

Thirteen patients with cold urticaria were studied to assess the effect of the systemic drug doxantrazole, which has actions resembling disodium cromoglycate, on cold evoked histamine release. The patients, all of whom developed an immediate local whealing response after cooling of the forearm, demonstrated release of histamine into venous blood draining that forearm. Following doxantrazole treatment, significant suppression of histamine release occurred. In some but not all patients this was accompanied by diminution of urtication in response to cooling. A double-blind study was carried out in 3 subjects, all of whom showed diminished cold-stimulated histamine release after doxantrazole. Two of these showed clinical improvement. Doxantrazole had no effect on erythema due to intradermal histamine, but did suppress the erythematous reaction to intradermal injection of compound 48/80. Our results suggest that doxantrazole or related anti-allergic agents might be useful in the treatment of cold urticaria.

Gastrin release: Antrum microdialysis reveals a complex neural control

DEFF Research Database (Denmark)

Ericsson, P; Håkanson, R; Rehfeld, Jens F.

2010-01-01

in both serum and microdialysate. Food intake induced a 2- to 3-fold increase in serum gastrin, while gastrin in antral microdialysate increased 10- to 15-fold. In unilaterally vagotomized rats (fasted, 3 days post-op.), food evoked a prompt peak gastrin release followed by a gradual decline on the intact......We used microdialysis to monitor local gastrin release in response to food, acid blockade and acute vagal excitation. For the first time, gastrin release has been monitored continuously in intact conscious rats in a physiologically relevant experimental setting in a fashion that minimizes...... in serum regardless of the prandial state. The rats were conscious during microdialysis except when subjected to electrical vagal stimulation. Acid blockade (omeprazole treatment of freely fed rats for 4 days), or bilateral sectioning of the abdominal vagal trunks (fasted, 3 days post-op.), raised...

High-frequency stimulation-induced peptide release synchronizes arcuate kisspeptin neurons and excites GnRH neurons

Science.gov (United States)

Qiu, Jian; Nestor, Casey C; Zhang, Chunguang; Padilla, Stephanie L; Palmiter, Richard D

2016-01-01

Kisspeptin (Kiss1) and neurokinin B (NKB) neurocircuits are essential for pubertal development and fertility. Kisspeptin neurons in the hypothalamic arcuate nucleus (Kiss1ARH) co-express Kiss1, NKB, dynorphin and glutamate and are postulated to provide an episodic, excitatory drive to gonadotropin-releasing hormone 1 (GnRH) neurons, the synaptic mechanisms of which are unknown. We characterized the cellular basis for synchronized Kiss1ARH neuronal activity using optogenetics, whole-cell electrophysiology, molecular pharmacology and single cell RT-PCR in mice. High-frequency photostimulation of Kiss1ARH neurons evoked local release of excitatory (NKB) and inhibitory (dynorphin) neuropeptides, which were found to synchronize the Kiss1ARH neuronal firing. The light-evoked synchronous activity caused robust excitation of GnRH neurons by a synaptic mechanism that also involved glutamatergic input to preoptic Kiss1 neurons from Kiss1ARH neurons. We propose that Kiss1ARH neurons play a dual role of driving episodic secretion of GnRH through the differential release of peptide and amino acid neurotransmitters to coordinate reproductive function. DOI: http://dx.doi.org/10.7554/eLife.16246.001 PMID:27549338

Noradrenaline decreases spike voltage threshold and induces electrographic sharp waves in turtle medial cortex in vitro.

Science.gov (United States)

Lorenzo, Daniel; Velluti, Julio C

2004-01-01

The noradrenergic modulation of neuronal properties has been described at different levels of the mammalian brain. Although the anatomical characteristics of the noradrenergic system are well known in reptiles, functional data are scarce. In our study the noradrenergic modulation of cortical electrogenesis in the turtle medial cortex was studied in vitro using a combination of field and intracellular recordings. Turtle EEG consists of a low voltage background interspersed by spontaneous large sharp waves (LSWs). Noradrenaline (NA, 5-40 microM) induced (or enhanced) the generation of LSWs in a dose-dependent manner. Pharmacological experiments suggest the participation of alpha and beta receptors in this effect. In medial cortex neurons NA induced a hyperpolarization of the resting potential and a decrease of input resistance. Both effects were observed also after TTX treatment. Noradrenaline increased the response of the cells to depolarizing pulses, resulting in an upward shift of the frequency/current relation. In most cells the excitability change was mediated by a decrease of the spike voltage threshold resulting in the reduction of the amount of depolarization needed to fire the cell (voltage threshold minus resting potential). As opposed to the mechanisms reported in mammalian neurons, no changes in the frequency adaptation or the post-train afterhyperpolarization were observed. The NA effects at the cellular level were not reproduced by noradrenergic agonists. Age- and species-dependent properties in the pharmacology of adrenergic receptors could be involved in this result. Cellular effects of NA in turtle cortex are similar to those described in mammals, although the increase in cellular excitability seems to be mediated by a different mechanism. Copyright 2004 S. Karger AG, Basel

Joint angle affects volitional and magnetically-evoked neuromuscular performance differentially.

Science.gov (United States)

Minshull, C; Rees, D; Gleeson, N P

2011-08-01

This study examined the volitional and magnetically-evoked neuromuscular performance of the quadriceps femoris at functional knee joint angles adjacent to full extension. Indices of volitional and magnetically-evoked neuromuscular performance (N=15 healthy males, 23.5 ± 2.9 years, 71.5 ± 5.4 kg, 176.5 ± 5.5 cm) were obtained at 25°, 35° and 45° of knee flexion. Results showed that volitional and magnetically-evoked peak force (PF(V) and P(T)F(E), respectively) and electromechanical delay (EMD(V) and EMD(E), respectively) were enhanced by increased knee flexion. However, greater relative improvements in volitional compared to evoked indices of neuromuscular performance were observed with increasing flexion from 25° to 45° (e.g. EMD(V), EMD(E): 36% vs. 11% improvement, respectively; F([2,14])=6.8, pjoint positions. These findings suggest that the extent of the relative differential between volitional and evoked neuromuscular performance capabilities is joint angle-specific and not correlated with performance capabilities at adjacent angles, but tends to be smaller with increased flexion. As such, effective prediction of volitional from evoked performance capabilities at both analogous and adjacent knee joint positions would lack robustness. Copyright © 2011 Elsevier Ltd. All rights reserved.

International Evoked Potentials Symposium

CERN Document Server

1980-01-01

The past decade has seen great progress in the measurement of evoked potentials in man; a steady increase in our understanding of their charac­ teristics, their origins and their usefulness; and a growing application in the field of clinical diagnosis. The topic is a truly multidisciplinary one. Important research contributions have been made by workers of many different backgrounds and clinical applications span the specialities. This book represents a revised and updated version of the work originally presented at the international evoked potential symposium held in Nottingham 4-6 1978. The Nottingham Symposium provided a forum for a state-of-the-art discussion amongst workers from many different disciplines and from many different countries. For each major topic in the field an expert review set the scene for discussion of current research presentations. This format is retained in the book: the chapters in Part A provide the context in which the research presented in Part B is set. The task of selecting m...

Chronic sleep restriction induces long-lasting changes in adenosine and noradrenaline receptor density in the rat brain.

Science.gov (United States)

Kim, Youngsoo; Elmenhorst, David; Weisshaupt, Angela; Wedekind, Franziska; Kroll, Tina; McCarley, Robert W; Strecker, Robert E; Bauer, Andreas

2015-10-01

Although chronic sleep restriction frequently produces long-lasting behavioural and physiological impairments in humans, the underlying neural mechanisms are unknown. Here we used a rat model of chronic sleep restriction to investigate the role of brain adenosine and noradrenaline systems, known to regulate sleep and wakefulness, respectively. The density of adenosine A1 and A2a receptors and β-adrenergic receptors before, during and following 5 days of sleep restriction was assessed with autoradiography. Rats (n = 48) were sleep-deprived for 18 h day(-1) for 5 consecutive days (SR1-SR5), followed by 3 unrestricted recovery sleep days (R1-R3). Brains were collected at the beginning of the light period, which was immediately after the end of sleep deprivation on sleep restriction days. Chronic sleep restriction increased adenosine A1 receptor density significantly in nine of the 13 brain areas analysed with elevations also observed on R3 (+18 to +32%). In contrast, chronic sleep restriction reduced adenosine A2a receptor density significantly in one of the three brain areas analysed (olfactory tubercle which declined 26-31% from SR1 to R1). A decrease in β-adrenergic receptors density was seen in substantia innominata and ventral pallidum which remained reduced on R3, but no changes were found in the anterior cingulate cortex. These data suggest that chronic sleep restriction can induce long-term changes in the brain adenosine and noradrenaline receptors, which may underlie the long-lasting neurocognitive impairments observed in chronic sleep restriction. © 2015 European Sleep Research Society.

Critical investigation of the separation of noradrenaline and adrenaline from urine samples using Al2O3 as adsorbant

International Nuclear Information System (INIS)

Neidhart, B.; Kringe, K.-P.; Deutschmann, P.

1983-01-01

A critical investigation of the separation of free noradrenaline and adrenaline from urine samples revealed serious errors during sample pretreatment using Al 2 O 3 as adsorbent. An exact and rapid pH adjustment of the sample, using thymol-blue as indicator, proved to be the chief prerequisite for precise and accurate results. Increasing temperature and pH favour the oxidative decomposition of the catecholamines during routine analysis. This was examined, using the radiotracer method and liquid scintillation counting. (author)

Increased Contractile Response to Noradrenaline Induced By Factors Associated with the Metabolic Syndrome in Cultured Small Mesenteric Arteries

DEFF Research Database (Denmark)

Blædel, Martin; Sams, Anette; Boonen, Harrie C M

2016-01-01

UNLABELLED: This study investigated the effect of the metabolic syndrome associated risk factors hyperglycemia (glucose [Glc]), hyperinsulinemia (insulin [Ins]) and low-grade inflammation (tumor necrosis factor α [TNFα]) on the vasomotor responses of resistance arteries. Isolated small mesenteric...... arteries from 3-month-old Sprague-Dawley rats, were suspended for 21-23 h in tissue cultures containing either elevated Glc (30 mmol/l), Ins (100 nmol/l), TNFα (100 ng/ml) or combinations thereof. After incubation, the vascular response to noradrenaline (NA), phenylephrine, isoprenaline and NA...... in vascular tone....

Noradrenaline represses PPAR (peroxisome-proliferator-activated receptor) gamma2 gene expression in brown adipocytes: intracellular signalling and effects on PPARgamma2 and PPARgamma1 protein levels

DEFF Research Database (Denmark)

Lindgren, Eva M; Nielsen, Ronni; Petrovic, Natasa

2004-01-01

phases, with the highest mRNA levels being found at the time of transition between the phases. PPARgamma2 mRNA levels were downregulated by noradrenaline treatment (EC50, 0.1 microM) in both proliferative and differentiating cells, with a lagtime of 1 h and lasting up to 4 h, after which expression...... was thus to investigate the influence of noradrenaline on PPARgamma gene expression in brown adipocytes. In primary cultures of brown adipocytes, PPARgamma2 mRNA levels were 20-fold higher than PPARgamma1 mRNA levels. PPARgamma expression occurred during both the proliferation and the differentiation...... gradually recovered. The down-regulation was beta-adrenoceptor-induced and intracellularly mediated via cAMP and protein kinase A; the signalling pathway did not involve phosphoinositide 3-kinase, Src, p38 mitogen-activated protein kinase or extracellular-signal-regulated kinases 1 and 2. Treatment...

Cortical evoked potentials to an auditory illusion: binaural beats.

Science.gov (United States)

Pratt, Hillel; Starr, Arnold; Michalewski, Henry J; Dimitrijevic, Andrew; Bleich, Naomi; Mittelman, Nomi

2009-08-01

To define brain activity corresponding to an auditory illusion of 3 and 6Hz binaural beats in 250Hz or 1000Hz base frequencies, and compare it to the sound onset response. Event-Related Potentials (ERPs) were recorded in response to unmodulated tones of 250 or 1000Hz to one ear and 3 or 6Hz higher to the other, creating an illusion of amplitude modulations (beats) of 3Hz and 6Hz, in base frequencies of 250Hz and 1000Hz. Tones were 2000ms in duration and presented with approximately 1s intervals. Latency, amplitude and source current density estimates of ERP components to tone onset and subsequent beats-evoked oscillations were determined and compared across beat frequencies with both base frequencies. All stimuli evoked tone-onset P(50), N(100) and P(200) components followed by oscillations corresponding to the beat frequency, and a subsequent tone-offset complex. Beats-evoked oscillations were higher in amplitude with the low base frequency and to the low beat frequency. Sources of the beats-evoked oscillations across all stimulus conditions located mostly to left lateral and inferior temporal lobe areas in all stimulus conditions. Onset-evoked components were not different across stimulus conditions; P(50) had significantly different sources than the beats-evoked oscillations; and N(100) and P(200) sources located to the same temporal lobe regions as beats-evoked oscillations, but were bilateral and also included frontal and parietal contributions. Neural activity with slightly different volley frequencies from left and right ear converges and interacts in the central auditory brainstem pathways to generate beats of neural activity to modulate activities in the left temporal lobe, giving rise to the illusion of binaural beats. Cortical potentials recorded to binaural beats are distinct from onset responses. Brain activity corresponding to an auditory illusion of low frequency beats can be recorded from the scalp.

Brain correlates of music-evoked emotions.

Science.gov (United States)

Koelsch, Stefan

2014-03-01

Music is a universal feature of human societies, partly owing to its power to evoke strong emotions and influence moods. During the past decade, the investigation of the neural correlates of music-evoked emotions has been invaluable for the understanding of human emotion. Functional neuroimaging studies on music and emotion show that music can modulate activity in brain structures that are known to be crucially involved in emotion, such as the amygdala, nucleus accumbens, hypothalamus, hippocampus, insula, cingulate cortex and orbitofrontal cortex. The potential of music to modulate activity in these structures has important implications for the use of music in the treatment of psychiatric and neurological disorders.

Dopamine and noradrenaline efflux in the prefrontal cortex in the light and dark period: Effects of novelty and handling and comparison to the nucleus accumbens

NARCIS (Netherlands)

Feenstra, M. G.; Botterblom, M. H.; Mastenbroek, S.

2000-01-01

We used on-line microdialysis measurements of dopamine and noradrenaline extracellular concentrations in the medial prefrontal cortex of awake, freely moving rats during the dark and the light period of the day to study whether (i) basal efflux would be higher in the active, dark period than in the

An inventory and update of jealousy-evoking partner behaviours in modern society.

NARCIS (Netherlands)

Dijkstra, Pieternel; Barelds, Dick P. H.; Groothof, Hinke A. K.

2010-01-01

The goal of the present study was to identify the most important jealousy-evoking partner behaviours and to examine the extent to which these behaviours evoke jealousy. Based on the literature, a questionnaire was constructed containing 42 jealousy-evoking partner behaviours, including a partner's

Temperature and nucleotide dependence of calcium release by myo-inositol 1,4,5-trisphosphate in cultured vascular smooth muscle cells

International Nuclear Information System (INIS)

Smith, J.B.; Smith, L.; Higgins, B.L.

1985-01-01

Inositol 1,4,5-trisphosphate (IP3) rapidly increased 45 Ca 2+ efflux from a nonmitochondrial organelle in cultured vascular smooth muscle cells that were permeabilized with saponin. A nucleotide, preferably ATP, was essential for IP3-evoked 45 Ca 2+ release. Two nonhydrolyzable ATP analogues satisfied the nucleotide requirement for IP3-evoked 45 Ca 2+ release. IP3 strongly stimulated 45 Ca 2+ efflux at low temperatures (1 to 15 degrees C). Decreasing the temperature from 37 to 4 degrees C inhibited the rate of IP3-stimulated efflux by only about 33%. The failure of such low temperatures to strongly inhibit IP3-induced 45 Ca 2+ efflux suggests that IP3 activated a Ca 2+ channel, rather than a carrier, by a ligand-binding, rather than a metabolic, reaction

Pharmacological and biochemical characterization of the D-1 dopamine receptor mediating acetylcholine release in rabbit retina

International Nuclear Information System (INIS)

Hensler, J.G.; Cotterell, D.J.; Dubocovich, M.L.

1987-01-01

Superfusion with dopamine (0.1 microM-10 mM) evokes calcium-dependent [ 3 H]acetylcholine release from rabbit retina labeled in vitro with [ 3 H]choline. This effect is antagonized by the D-1 dopamine receptor antagonist SCH 23390. Activation or blockade of D-2 dopamine, alpha-2 or beta receptors did not stimulate or attenuate the release of [ 3 H]acetylcholine from rabbit retina. Dopamine receptor agonists evoke the release of [ 3 H]acetylcholine with the following order of potency: apomorphine ≤ SKF(R)82526 3 H]acetylcholine: SCH 23390 (IC50 = 1 nM) 3 H]acetylcholine release is characteristic of the D-1 dopamine receptor. These potencies were correlated with the potencies of dopamine receptor agonists and antagonists at the D-1 dopamine receptor in rabbit retina as labeled by [ 3 H]SCH 23390, or as determined by adenylate cyclase activity. [ 3 H]SCH 23390 binding in rabbit retinal membranes was stable, saturable and reversible. Scatchard analysis of [ 3 H]SCH 23390 saturation data revealed a single high affinity binding site (Kd = 0.175 +/- 0.002 nM) with a maximum binding of 482 +/- 12 fmol/mg of protein. The potencies of dopamine receptor agonists to stimulate [ 3 H]acetylcholine release were correlated with their potencies to stimulate adenylate cyclase (r = 0.784, P less than .05, n = 7) and with their affinities at [ 3 H]SCH 23390 binding sites (r = 0.755, P < .05, n = 8)

Music-evoked emotions: principles, brain correlates, and implications for therapy.

Science.gov (United States)

Koelsch, Stefan

2015-03-01

This paper describes principles underlying the evocation of emotion with music: evaluation, resonance, memory, expectancy/tension, imagination, understanding, and social functions. Each of these principles includes several subprinciples, and the framework on music-evoked emotions emerging from these principles and subprinciples is supposed to provide a starting point for a systematic, coherent, and comprehensive theory on music-evoked emotions that considers both reception and production of music, as well as the relevance of emotion-evoking principles for music therapy. © 2015 New York Academy of Sciences.

Spinal mechanism of micturition reflex inhibition by naftopidil in rats.

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Sugaya, Kimio; Nishijima, Saori; Kadekawa, Katsumi; Ashitomi, Katsuhiro; Ueda, Tomoyuki; Yamamoto, Hideyuki

2014-10-29

We investigated the spinal mechanism through which naftopidil inhibits the micturition reflex by comparing the effects of noradrenaline and naftopidil in rats. The following were investigated: the influence of oral naftopidil on plasma monoamine and amino acid levels, the distribution of oral 14C-naftopidil, the effects of intravenous (IV) or intrathecal (IT) injection of noradrenaline or naftopidil on isovolumetric bladder contractions, amino acid levels in the lumbosacral spinal cord after IT noradrenaline or naftopidil, and the effects of IT naftopidil and strychnine and/or bicuculline on isovolumetric bladder contractions. Oral naftopidil decreased the plasma adrenaline level, while it increased the serotonin and glycine levels. After oral administration, 14C-naftopidil was detected in the spinal cord and cerebrum, as well as in plasma and the prostate gland. When the bladder volume was below the threshold for isovolumetric reflex contractions, IV (0.1mg) or IT (0.1μg) noradrenaline evoked bladder contractions, but IV (1mg) or IT (0.01-1μg) naftopidil did not. When the bladder volume was above the threshold for isovolumetric reflex contractions, IV or IT noradrenaline transiently abolished bladder contractions. IT noradrenaline decreased the levels of glycine and gamma-aminobutyric acid (GABA) in the lumbosacral cord, while IT naftopidil increased the GABA level. IT strychnine and/or bicuculline blocked the inhibitory effect of IT naftopidil on bladder contractions. Naftopidil inhibits the micturition reflex by blocking α1 receptors, as well as by the activation of serotonergic, glycinergic, and GABAergic neurons in the central nervous system. Copyright © 2014 Elsevier Inc. All rights reserved.

Vibration and muscle contraction affect somatosensory evoked potentials

OpenAIRE

Cohen, LG; Starr, A

1985-01-01

We recorded potentials evoked by specific somatosensory stimuli over peripheral nerve, spinal cord, and cerebral cortex. Vibration attenuated spinal and cerebral potentials evoked by mixed nerve and muscle spindle stimulation; in one subject that was tested, there was no effect on cutaneous input. Presynaptic inhibition of Ia input in the spinal cord and muscle spindle receptor occupancy are probably the responsible mechanisms. In contrast, muscle contraction attenuated cerebral potentials to...

The Aversive Agent Lithium Chloride Suppresses Phasic Dopamine Release Through Central GLP-1 Receptors.

Science.gov (United States)

Fortin, Samantha M; Chartoff, Elena H; Roitman, Mitchell F

2016-02-01

Unconditioned rewarding stimuli evoke phasic increases in dopamine concentration in the nucleus accumbens (NAc) while discrete aversive stimuli elicit pauses in dopamine neuron firing and reductions in NAc dopamine concentration. The unconditioned effects of more prolonged aversive states on dopamine release dynamics are not well understood and are investigated here using the malaise-inducing agent lithium chloride (LiCl). We used fast-scan cyclic voltammetry to measure phasic increases in NAc dopamine resulting from electrical stimulation of dopamine cell bodies in the ventral tegmental area (VTA). Systemic LiCl injection reduced electrically evoked dopamine release in the NAc of both anesthetized and awake rats. As some behavioral effects of LiCl appear to be mediated through glucagon-like peptide-1 receptor (GLP-1R) activation, we hypothesized that the suppression of phasic dopamine by LiCl is GLP-1R dependent. Indeed, peripheral pretreatment with the GLP-1R antagonist exendin-9 (Ex-9) potently attenuated the LiCl-induced suppression of dopamine. Pretreatment with Ex-9 did not, however, affect the suppression of phasic dopamine release by the kappa-opioid receptor agonist, salvinorin A, supporting a selective effect of GLP-1R stimulation in LiCl-induced dopamine suppression. By delivering Ex-9 to either the lateral or fourth ventricle, we highlight a population of central GLP-1 receptors rostral to the hindbrain that are involved in the LiCl-mediated suppression of NAc dopamine release.

Amphetamine Paradoxically Augments Exocytotic Dopamine Release and Phasic Dopamine Signals

Science.gov (United States)

Daberkow, DP; Brown, HD; Bunner, KD; Kraniotis, SA; Doellman, MA; Ragozzino, ME; Garris, PA; Roitman, MF

2013-01-01

Drugs of abuse hijack brain reward circuitry during the addiction process by augmenting action potential-dependent phasic dopamine release events associated with learning and goal-directed behavior. One prominent exception to this notion would appear to be amphetamine (AMPH) and related analogs, which are proposed instead to disrupt normal patterns of dopamine neurotransmission by depleting vesicular stores and promoting non-exocytotic dopamine efflux via reverse transport. This mechanism of AMPH action, though, is inconsistent with its therapeutic effects and addictive properties - which are thought to be reliant on phasic dopamine signaling. Here we used fast-scan cyclic voltammetry in freely moving rats to interrogate principal neurochemical responses to AMPH in the striatum and relate these changes to behavior. First, we showed that AMPH dose-dependently enhanced evoked dopamine responses to phasic-like current pulse trains for up to two hours. Modeling the data revealed that AMPH inhibited dopamine uptake but also unexpectedly potentiated vesicular dopamine release. Second, we found that AMPH increased the amplitude, duration and frequency of spontaneous dopamine transients, the naturally occurring, non-electrically evoked, phasic increases in extracellular dopamine. Finally, using an operant sucrose reward paradigm, we showed that low-dose AMPH augmented dopamine transients elicited by sucrose-predictive cues. However, operant behavior failed at high-dose AMPH, which was due to phasic dopamine hyperactivity and the decoupling of dopamine transients from the reward predictive cue. These findings identify up-regulation of exocytotic dopamine release as a key AMPH action in behaving animals and support a unified mechanism of abused drugs to activate phasic dopamine signaling. PMID:23303926

Muscle synergies evoked by microstimulation are preferentially encoded during behavior

Directory of Open Access Journals (Sweden)

Simon Alexander Overduin

2014-03-01

Full Text Available Electrical microstimulation studies provide some of the most direct evidence for the neural representation of muscle synergies. These synergies, i.e. coordinated activations of groups of muscles, have been proposed as building blocks for the construction of motor behaviors by the nervous system. Intraspinal or intracortical microstimulation has been shown to evoke muscle patterns that can be resolved into a small set of synergies similar to those seen in natural behavior. However, questions remain about the validity of microstimulation as a probe of neural function, particularly given the relatively long trains of supratheshold stimuli used in these studies. Here, we examined whether muscle synergies evoked during intracortical microstimulation in two rhesus macaques were similarly encoded by nearby motor cortical units during a purely voluntary behavior involving object reach, grasp, and carry movements. At each microstimulation site we identified the synergy most strongly evoked among those extracted from muscle patterns evoked over all microstimulation sites. For each cortical unit recorded at the same microstimulation site, we then identified the synergy most strongly encoded among those extracted from muscle patterns recorded during the voluntary behavior. We found that the synergy most strongly evoked at an intracortical microstimulation site matched the synergy most strongly encoded by proximal units more often than expected by chance. These results suggest a common neural substrate for microstimulation-evoked motor responses and for the generation of muscle patterns during natural behaviors.

The involuntary nature of music-evoked autobiographical memories in Alzheimer's disease.

Science.gov (United States)

El Haj, Mohamad; Fasotti, Luciano; Allain, Philippe

2012-03-01

The main objective of this paper was to examine the involuntary nature of music-evoked autobiographical memories. For this purpose, young adults, older adults, and patients with a clinical diagnosis of probable Alzheimer's disease (AD) were asked to remember autobiographical events in two conditions: after being exposed to their own chosen music, and in silence. Compared to memories evoked in silence, memories evoked in the "Music" condition were found to be more specific, accompanied by more emotional content and impact on mood, and retrieved faster. In addition, these memories engaged less executive processes. Thus, with all these characteristics and the fact that they are activated by a perceptual cue (i.e., music), music-evoked autobiographic memories have all the features to be considered as involuntary memories. Our paper reveals several characteristics of music-evoked autobiographical memories in AD patients and offers a theoretical background for this phenomenon. Copyright © 2012 Elsevier Inc. All rights reserved.

The effects of compound stimulus extinction and inhibition of noradrenaline reuptake on the renewal of alcohol seeking

Science.gov (United States)

Furlong, T M; Pan, M J; Corbit, L H

2015-01-01

Alcohol-related stimuli can trigger relapse of alcohol-seeking behaviors even after extended periods of abstinence. Extinction of such stimuli can reduce their impact on relapse; however, the expression of extinction can be disrupted when testing occurs outside the context where extinction learning took place, an effect termed renewal. Behavioral and pharmacological methods have recently been shown to augment extinction learning; yet, it is not known whether the improved expression of extinction following these treatments remains context-dependent. Here we examined whether two methods, compound–stimulus extinction and treatment with the noradrenaline reuptake inhibitor atomoxetine, would reduce the vulnerability of extinction to a change in context. Following alcohol self-administration, responding was extinguished in a distinct context. After initial extinction, further extinction was given to a target stimulus presented in compound with another alcohol-predictive stimulus intended to augment prediction error (Experiment 1) or after a systemic injection of atomoxetine (1.0 mg kg−1; Experiment 2). A stimulus extinguished as part of a compound elicited less responding than a stimulus receiving equal extinction alone regardless of whether animals were tested in the training or extinction context; however, reliable renewal was not observed in this paradigm. Importantly, atomoxetine enhanced extinction relative to controls even in the presence of a reliable renewal effect. Thus, extinction of alcohol-seeking behavior can be improved by extinguishing multiple alcohol-predictive stimuli or enhancing noradrenaline neurotransmission during extinction training. Importantly, both methods improve extinction even when the context is changed between extinction training and test, and thus could be utilized to enhance the outcome of extinction-based treatments for alcohol-use disorders. PMID:26327688

Evidence that two stereochemically different alpha-2 adrenoceptors modulate norepinephrine release in rat cerebral cortex

Energy Technology Data Exchange (ETDEWEB)

Harsing, L.G. Jr.; Vizi, E.S. (Institute of Experimental Medicine, Budapest (Hungary))

1991-01-01

Cerebral cortex slices from the rat were loaded with (3H)norepinephrine ((3H)NE) and superfused in order to measure the release of radioactivity at rest and in response to electrical stimulation. The (-)-isomer and the (+)-isomer of CH-38083 (7,8-(methylenedioxy)-14- alpha-hydroxyalloberbane HCl), a selective alpha-2-adrenoceptor antagonist with an alloberbane skeleton, increased the electrically induced release of (3H)NE in a concentration-dependent manner, and a similar effect was observed with racemic CH-38083 and idazoxan. The stereoisomers of CH-38083 applied in a concentration range of 10(-8) to 10(-6) mol/l were equipotent in facilitating stimulation-evoked (3H)NE release: concentrations needed to enhance tritium outflow by 50% were 1.3 X 10(-7) mol/l for (-)-CH-38083 and 1.4 X 10(-7) mol/l for (+)-CH-38083. Exogenous NE decreased the electrically stimulated release of (3H)NE, and the stereoisomers of CH-38083 antagonized this inhibition with different potencies: the dissociation constant (KB) values for (-)-isomer and for (+)-isomer of CH-38083 were 14.29 and 97.18 nmol/l. These data indicate that presynaptic alpha-2 adrenoceptors that are available for NE released from axon terminals do not show stereospecificity toward enantiomers of CH-38083, whereas those that are occupied by exogenous NE are much more sensitive toward (-)-CH-38083. The alpha-1 adrenoceptor antagonist prazosin also differentiated between the alpha-2 adrenoceptor subtypes: prazosin (10(-6) mol/l) did not alter the increase of electrically induced (3H)NE release evoked by (-)- and (+)-CH-38083; however, in its presence, the stereoisomers of CH-38083 failed to antagonize the inhibitory effect of exogenous NE on its own release.

Inwardly rectifying potassium channels influence Drosophila wing morphogenesis by regulating Dpp release.

Science.gov (United States)

Dahal, Giri Raj; Pradhan, Sarala Joshi; Bates, Emily Anne

2017-08-01

Loss of embryonic ion channel function leads to morphological defects, but the underlying reason for these defects remains elusive. Here, we show that inwardly rectifying potassium (Irk) channels regulate release of the Drosophila bone morphogenetic protein Dpp in the developing fly wing and that this is necessary for developmental signaling. Inhibition of Irk channels decreases the incidence of distinct Dpp-GFP release events above baseline fluorescence while leading to a broader distribution of Dpp-GFP. Work by others in different cell types has shown that Irk channels regulate peptide release by modulating membrane potential and calcium levels. We found calcium transients in the developing wing, and inhibition of Irk channels reduces the duration and amplitude of calcium transients. Depolarization with high extracellular potassium evokes Dpp release. Taken together, our data implicate Irk channels as a requirement for regulated release of Dpp, highlighting the importance of the temporal pattern of Dpp presentation for morphogenesis of the wing. © 2017. Published by The Company of Biologists Ltd.

Gender differences in binaural speech-evoked auditory brainstem response: are they clinically significant?

Science.gov (United States)

Jalaei, Bahram; Azmi, Mohd Hafiz Afifi Mohd; Zakaria, Mohd Normani

2018-05-17

Binaurally evoked auditory evoked potentials have good diagnostic values when testing subjects with central auditory deficits. The literature on speech-evoked auditory brainstem response evoked by binaural stimulation is in fact limited. Gender disparities in speech-evoked auditory brainstem response results have been consistently noted but the magnitude of gender difference has not been reported. The present study aimed to compare the magnitude of gender difference in speech-evoked auditory brainstem response results between monaural and binaural stimulations. A total of 34 healthy Asian adults aged 19-30 years participated in this comparative study. Eighteen of them were females (mean age=23.6±2.3 years) and the remaining sixteen were males (mean age=22.0±2.3 years). For each subject, speech-evoked auditory brainstem response was recorded with the synthesized syllable /da/ presented monaurally and binaurally. While latencies were not affected (p>0.05), the binaural stimulation produced statistically higher speech-evoked auditory brainstem response amplitudes than the monaural stimulation (p0.80), substantive gender differences were noted in most of speech-evoked auditory brainstem response peaks for both stimulation modes. The magnitude of gender difference between the two stimulation modes revealed some distinct patterns. Based on these clinically significant results, gender-specific normative data are highly recommended when using speech-evoked auditory brainstem response for clinical and future applications. The preliminary normative data provided in the present study can serve as the reference for future studies on this test among Asian adults. Copyright © 2018 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Cholinergic induction of input-specific late-phase LTP via localized Ca2+ release in the visual cortex.

Science.gov (United States)

Cho, Kwang-Hyun; Jang, Hyun-Jong; Jo, Yang-Hyeok; Singer, Wolf; Rhie, Duck-Joo

2012-03-28

Acetylcholine facilitates long-term potentiation (LTP) and long-term depression (LTD), substrates of learning, memory, and sensory processing, in which acetylcholine also plays a crucial role. Ca(2+) ions serve as a canonical regulator of LTP/LTD but little is known about the effect of acetylcholine on intracellular Ca(2+) dynamics. Here, we investigated dendritic Ca(2+) dynamics evoked by synaptic stimulation and the resulting LTP/LTD in layer 2/3 pyramidal neurons of the rat visual cortex. Under muscarinic stimulation, single-shock electrical stimulation (SES) inducing ∼20 mV EPSP, applied via a glass electrode located ∼10 μm from the basal dendrite, evoked NMDA receptor-dependent fast Ca(2+) transients and the subsequent Ca(2+) release from the inositol 1,4,5-trisphosphate (IP(3))-sensitive stores. These secondary dendritic Ca(2+) transients were highly localized within 10 μm from the center (SD = 5.0 μm). The dendritic release of Ca(2+) was a prerequisite for input-specific muscarinic LTP (LTPm). Without the secondary Ca(2+) release, only muscarinic LTD (LTDm) was induced. D(-)-2-amino-5-phosphopentanoic acid and intracellular heparin blocked LTPm as well as dendritic Ca(2+) release. A single burst consisting of 3 EPSPs with weak stimulus intensities instead of the SES also induced secondary Ca(2+) release and LTPm. LTPm and LTDm were protein synthesis-dependent. Furthermore, LTPm was confined to specific dendritic compartments and not inducible in distal apical dendrites. Thus, cholinergic activation facilitated selectively compartment-specific induction of late-phase LTP through IP(3)-dependent Ca(2+) release.

Neural processes mediating the preparation and release of focal motor output are suppressed or absent during imagined movement

Science.gov (United States)

Eagles, Jeremy S.; Carlsen, Anthony N.

2016-01-01

Movements that are executed or imagined activate a similar subset of cortical regions, but the extent to which this activity represents functionally equivalent neural processes is unclear. During preparation for an executed movement, presentation of a startling acoustic stimulus (SAS) evokes a premature release of the planned movement with the spatial and temporal features of the tasks essentially intact. If imagined movement incorporates the same preparatory processes as executed movement, then a SAS should release the planned movement during preparation. This hypothesis was tested using an instructed-delay cueing paradigm during which subjects were required to rapidly release a handheld weight while maintaining the posture of the arm or to perform first-person imagery of the same task while holding the weight. In a subset of trials, a SAS was presented at 1500, 500, or 200 ms prior to the release cue. Task-appropriate preparation during executed and imagined movements was confirmed by electroencephalographic recording of a contingent negative variation waveform. During preparation for executed movement, a SAS often resulted in premature release of the weight with the probability of release progressively increasing from 24 % at −1500 ms to 80 % at −200 ms. In contrast, the SAS rarely (movement. However, the SAS frequently evoked the planned postural response (suppression of bicep brachii muscle activity) irrespective of the task or timing of stimulation (even during periods of postural hold without preparation). These findings provide evidence that neural processes mediating the preparation and release of the focal motor task (release of the weight) are markedly attenuated or absent during imagined movement and that postural and focal components of the task are prepared independently. PMID:25744055

The impact of acute stress on hormones and cytokines, and how their recovery is affected by music-evoked positive mood.

Science.gov (United States)

Koelsch, Stefan; Boehlig, Albrecht; Hohenadel, Maximilian; Nitsche, Ines; Bauer, Katrin; Sack, Ulrich

2016-03-29

Stress and recovery from stress significantly affect interactions between the central nervous system, endocrine pathways, and the immune system. However, the influence of acute stress on circulating immune-endocrine mediators in humans is not well known. Using a double-blind, randomized study design, we administered a CO2 stress test to n = 143 participants to identify the effects of acute stress, and recovery from stress, on serum levels of several mediators with immune function (IL-6, TNF-α, leptin, and somatostatin), as well as on noradrenaline, and two hypothalamic-pituitary-adrenal axis hormones (ACTH and cortisol). Moreover, during a 1 h-recovery period, we repeatedly measured these serum parameters, and administered an auditory mood-induction protocol with positive music and a neutral control stimulus. The acute stress elicited increases in noradrenaline, ACTH, cortisol, IL-6, and leptin levels. Noradrenaline and ACTH exhibited the fastest and strongest stress responses, followed by cortisol, IL-6 and leptin. The music intervention was associated with more positive mood, and stronger cortisol responses to the acute stressor in the music group. Our data show that acute (CO2) stress affects endocrine, immune and metabolic functions in humans, and they show that mood plays a causal role in the modulation of responses to acute stress.

Music-Evoked Emotions—Current Studies

Science.gov (United States)

Schaefer, Hans-Eckhardt

2017-01-01

The present study is focused on a review of the current state of investigating music-evoked emotions experimentally, theoretically and with respect to their therapeutic potentials. After a concise historical overview and a schematic of the hearing mechanisms, experimental studies on music listeners and on music performers are discussed, starting with the presentation of characteristic musical stimuli and the basic features of tomographic imaging of emotional activation in the brain, such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), which offer high spatial resolution in the millimeter range. The progress in correlating activation imaging in the brain to the psychological understanding of music-evoked emotion is demonstrated and some prospects for future research are outlined. Research in psychoneuroendocrinology and molecular markers is reviewed in the context of music-evoked emotions and the results indicate that the research in this area should be intensified. An assessment of studies involving measuring techniques with high temporal resolution down to the 10 ms range, as, e.g., electroencephalography (EEG), event-related brain potentials (ERP), magnetoencephalography (MEG), skin conductance response (SCR), finger temperature, and goose bump development (piloerection) can yield information on the dynamics and kinetics of emotion. Genetic investigations reviewed suggest the heredity transmission of a predilection for music. Theoretical approaches to musical emotion are directed to a unified model for experimental neurological evidence and aesthetic judgment. Finally, the reports on musical therapy are briefly outlined. The study concludes with an outlook on emerging technologies and future research fields. PMID:29225563

Stimulator with arbitrary waveform for auditory evoked potentials

International Nuclear Information System (INIS)

Martins, H R; Romao, M; Placido, D; Provenzano, F; Tierra-Criollo, C J

2007-01-01

The technological improvement helps many medical areas. The audiometric exams involving the auditory evoked potentials can make better diagnoses of auditory disorders. This paper proposes the development of a stimulator based on Digital Signal Processor. This stimulator is the first step of an auditory evoked potential system based on the ADSP-BF533 EZ KIT LITE (Analog Devices Company - USA). The stimulator can generate arbitrary waveform like Sine Waves, Modulated Amplitude, Pulses, Bursts and Pips. The waveforms are generated through a graphical interface programmed in C++ in which the user can define the parameters of the waveform. Furthermore, the user can set the exam parameters as number of stimuli, time with stimulation (Time ON) and time without stimulus (Time OFF). In future works will be implemented another parts of the system that includes the acquirement of electroencephalogram and signal processing to estimate and analyze the evoked potential

Stimulator with arbitrary waveform for auditory evoked potentials

Energy Technology Data Exchange (ETDEWEB)

Martins, H R; Romao, M; Placido, D; Provenzano, F; Tierra-Criollo, C J [Universidade Federal de Minas Gerais (UFMG), Departamento de Engenharia Eletrica (DEE), Nucleo de Estudos e Pesquisa em Engenharia Biomedica NEPEB, Av. Ant. Carlos, 6627, sala 2206, Pampulha, Belo Horizonte, MG, 31.270-901 (Brazil)

2007-11-15

The technological improvement helps many medical areas. The audiometric exams involving the auditory evoked potentials can make better diagnoses of auditory disorders. This paper proposes the development of a stimulator based on Digital Signal Processor. This stimulator is the first step of an auditory evoked potential system based on the ADSP-BF533 EZ KIT LITE (Analog Devices Company - USA). The stimulator can generate arbitrary waveform like Sine Waves, Modulated Amplitude, Pulses, Bursts and Pips. The waveforms are generated through a graphical interface programmed in C++ in which the user can define the parameters of the waveform. Furthermore, the user can set the exam parameters as number of stimuli, time with stimulation (Time ON) and time without stimulus (Time OFF). In future works will be implemented another parts of the system that includes the acquirement of electroencephalogram and signal processing to estimate and analyze the evoked potential.

Evoking prescribed spike times in stochastic neurons

Science.gov (United States)

Doose, Jens; Lindner, Benjamin

2017-09-01

Single cell stimulation in vivo is a powerful tool to investigate the properties of single neurons and their functionality in neural networks. We present a method to determine a cell-specific stimulus that reliably evokes a prescribed spike train with high temporal precision of action potentials. We test the performance of this stimulus in simulations for two different stochastic neuron models. For a broad range of parameters and a neuron firing with intermediate firing rates (20-40 Hz) the reliability in evoking the prescribed spike train is close to its theoretical maximum that is mainly determined by the level of intrinsic noise.

Effect of forskolin and prostaglandin E1 on stimulus secretion coupling in cultured bovine adrenal chromaffin cells.

Science.gov (United States)

Marriott, D; Adams, M; Boarder, M R

1988-02-01

Treatment of adrenal chromaffin cells with forskolin (0.1-10 microM) stimulated cyclic AMP levels, reduced the maximal stimulation of release of noradrenaline by nicotine, and increased release in response to elevated external potassium and the calcium ionophore A23187. The presence of the phosphodiesterase inhibitor Ro 20-17-24 with forskolin potentiated both the stimulation of cyclic AMP and the inhibition of nicotine-induced noradrenaline release. Dibutyryl cyclic AMP, and the elevation of cyclic AMP with prostaglandin E1, also attenuated nicotine-stimulated release. However, when the stimulation of intracellular cyclic AMP production by prostaglandin E1 was potentiated by low levels of forskolin, there was not a concomitant potentiation of effect on noradrenaline release. Dideoxyforskolin, an analogue of forskolin which does not stimulate adenylate cyclase, inhibited both potassium- and nicotine-stimulated release, probably by a mechanism unrelated to the action of forskolin in these experiments. Using Fura-2 to estimate free intracellular calcium levels, both forskolin and dideoxyforskolin (at 10 microM) reduced the calcium transient in response to nicotine. These results support a model in which elevation of cyclic AMP inhibits the activation of nicotinic receptors, but augments stimulus secretion coupling downstream of calcium entry. The data, however, do not indicate a simple relationship between total intracellular cyclic AMP levels and the attenuation of nicotinic stimulation of release.

Visual evoked potentials in patients after methanol poisoning.

Science.gov (United States)

Urban, Pavel; Zakharov, Sergey; Diblík, Pavel; Pelclová, Daniela; Ridzoň, Petr

2016-01-01

We report the results of the visual evoked potentials (VEP) examination in patients after severe poisoning by methanol. The group of 47 patients (38 males and 9 females) was assembled out of persons who survived an outbreak of poisoning by the methanol adulterated alcohol beverages, which happened in the Czech Republic in 2012-2013. The visual evoked potentials examination was performed using monocular checkerboard pattern-reversal stimulation. Two criteria of abnormality were chosen: missing evoked response, and wave P1 latency > 117 ms. Non-parametric statistical methods (median, range, and the median test) were used to analyze factors influencing the VEP abnormality. The visual evoked potential was abnormal in 20 patients (43%), 5 of them had normal visual acuity on the Snellen chart. The VEP abnormality did not correlate significantly with initial serum concentrations of methanol, formic acid or lactate; however, it showed statistically significant inverse relation to the initial serum pH: the subgroup with the abnormal VEP had significantly lower median pH in comparison with the subgroup with the normal VEP (7.16 vs. 7.34, p = 0.04). The abnormality was not related to chronic alcohol abuse. The visual evoked potentials examination appeared sensitive enough to detected even subclinical impairment of the optic system. Metabolic acidosis is likely to be the key factor related to the development of visual damage induced by methanol. The examination performed with a delay of 1-9 months after the poisoning documented the situation relatively early after the event. It is considered as a baseline for the planned long-term follow-up of the patients, which will make it possible to assess the dynamics of the observed changes, their reversibility, and the occurrence of potential late sequelae. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

TRPM7 is required within zebrafish sensory neurons for the activation of touch-evoked escape behaviors

Science.gov (United States)

Low, Sean E.; Amburgey, Kimberly; Horstick, Eric; Linsley, Jeremy; Sprague, Shawn M.; Cui, Wilson W.; Zhou, Weibin; Hirata, Hiromi; Saint-Amant, Louis; Hume, Richard I.; Kuwada, John Y.

2011-01-01

Mutations in the gene encoding TRPM7 (trpm7), a member of the TRP superfamily of cation channels that possesses an enzymatically active kinase at its carboxyl terminus, cause the touch-unresponsive zebrafish mutant touchdown. We identified and characterized a new allele of touchdown, as well as two previously reported alleles, and found that all three alleles harbor mutations which abolish channel activity. Through the selective restoration of TRPM7 expression in sensory neurons we found that TRPM7’s kinase activity, and selectivity for divalent cations over monovalent cations, were dispensable for touch-evoked activation of escape behaviors in zebrafish. Additional characterization revealed that sensory neurons were present and capable of responding to tactile stimuli in touchdown mutants, indicating that TRPM7 is not required for sensory neuron survival or mechanosensation. Finally, exposure to elevated concentrations of divalent cations was found to restore touch-evoked behaviors in touchdown mutants. Collectively these findings are consistent with a role for zebrafish TRPM7 within sensory neurons in the modulation of neurotransmitter release at central synapses, similar to that proposed for mammalian TRPM7 at peripheral synapses. PMID:21832193

Brief note about plasma catecholamines kinetics and submaximal exercise in untrained standardbreds

Directory of Open Access Journals (Sweden)

Paolo Baragli

2010-03-01

Full Text Available Four untrained standardbred horses performed a standardized exercise test on the treadmill and an automated blood collection system programmed to obtain blood samples every 15 s was used for blood collection in order to evaluate the kinetics of adrenaline and noradrenaline. The highest average values obtained for adrenaline and noradrenaline were 15.0 ± 3.0 and 15.8 ± 2.8 nmol/l respectively, with exponential accumulation of adrenaline (r = 0.977 and noradrenaline (r = 0.976 during the test. Analysis of the correlation between noradrenaline and adrenaline for each phase of the test shows that correlation coefficient decreases as the intensity of exercise increases (from r = 0.909 to r = 0.788. This suggests that during submaximal exercise, the process for release, distribution and clearance of adrenaline into blood circulation differs from that of noradrenaline.

Evoked Emotions Predict Food Choice

NARCIS (Netherlands)

Dalenberg, Jelle R.; Gutjar, Swetlana; ter Horst, Gert J.; de Graaf, Kees; Renken, Remco J.; Jager, Gerry

2014-01-01

In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments.

The effects of curiosity-evoking events on activity enjoyment.

Science.gov (United States)

Isikman, Elif; MacInnis, Deborah J; Ülkümen, Gülden; Cavanaugh, Lisa A

2016-09-01

Whereas prior literature has studied the positive effects of curiosity-evoking events that are integral to focal activities, we explore whether and how a curiosity-evoking event that is incidental to a focal activity induces negative outcomes for enjoyment. Four experiments and 1 field study demonstrate that curiosity about an event that is incidental to an activity in which individuals are engaged, significantly affects enjoyment of a concurrent activity. The reason why is that curiosity diverts attention away from the concurrent activity and focuses attention on the curiosity-evoking event. Thus, curiosity regarding an incidental event decreases enjoyment of a positive focal activity but increases enjoyment of a negative focal activity. PsycINFO Database Record (c) 2016 APA, all rights reserved

Electrical stimulation of the isolated rat intestine in the presence of nutrient stimulus enhances glucagon-like peptide-1 release

International Nuclear Information System (INIS)

Schwartz, Ann; Ort, Tatiana; Kajekar, Radhika; Hornby, Pamela J; Wade, Paul R

2010-01-01

The release of small intestinal hormones by constituents of ingested food, such as fatty acids, is integral to post-prandial responses that reduce food intake. Recent evidence suggests that small intestinal electrical stimulation reduces food intake, although the mechanism of action is debated. To test the hypothesis that intestinal stimulation directly alters hormone release locally we used isolated rat distal ileum and measured glucagon-like peptide-1 (GLP-1) released in the presence or absence of linoleic acid (LA) and electrical field stimulation (EFS). Intact segments were oriented longitudinally between bipolar stimulating electrodes in organ bath chambers containing modified Krebs–Ringers bicarbonate (KRB) buffer including protease inhibitors. Incubation in LA (3 mg ml −1 ) for 45 min increased GLP-1 concentration (21.9 ± 2.6 pM versus KRB buffer alone 3.6 ± 0.1 pM). Eleven electrical stimulation conditions were tested. In the presence of LA none of the stimulation conditions inhibited LA-evoked GLP-1 release, whereas two high frequency short pulse widths (14 V, 20 Hz, 5 ms and 14 V, 40 Hz, 5 ms) and one low frequency long pulse width (14 V, 0.4 Hz, 300 ms) EFS conditions enhanced LA-evoked GLP-1 release by >250%. These results are consistent with a local effect of intestinal electrical stimulation to enhance GLP-1 release in response to luminal nutrients in the intestines. Enhancing hormone release could improve the efficacy of intestinal electrical stimulation and provide a potential treatment for obesity and metabolic conditions

High frequency oscillations evoked by peripheral magnetic stimulation.

Science.gov (United States)

Biller, S; Simon, L; Fiedler, P; Strohmeier, D; Haueisen, J

2011-01-01

The analysis of somatosensory evoked potentials (SEP) and / or fields (SEF) is a well-established and important tool for investigating the functioning of the peripheral and central human nervous system. A standard technique to evoke SEPs / SEFs is the stimulation of the median nerve by using a bipolar electrical stimulus. We aim at an alternative stimulation technique enabling stimulation of deep nerve structures while reducing patient stress and error susceptibility. In the current study, we apply a commercial transcranial magnetic stimulation system for peripheral magnetic stimulation of the median nerve. We compare the results of simultaneously recorded EEG signals to prove applicability of our technique to evoke SEPs including low frequency components (LFC) as well as high frequency oscillations (HFO). Therefore, we compare amplitude, latency and time-frequency characteristics of the SEP of 14 healthy volunteers after electric and magnetic stimulation. Both low frequency components and high frequency oscillations were detected. The HFOs were superimposed onto the primary cortical response N20. Statistical analysis revealed significantly lower amplitudes and increased latencies for LFC and HFO components after magnetic stimulation. The differences indicate the inability of magnetic stimulation to elicit supramaximal responses. A psycho-perceptual evaluation showed that magnetic stimulation was less unpleasant for 12 out of the 14 volunteers. In conclusion, we showed that LFC and HFO components related to median nerve stimulation can be evoked by peripheral magnetic stimulation.

Stress-restress evokes sustained iNOS activity and altered GABA levels and NMDA receptors in rat hippocampus

DEFF Research Database (Denmark)

Harvey, Brian H; Oosthuizen, Frasia; Brand, Linda

2004-01-01

. The NOS isoform involved, and the role of stress-mediated corticosterone release in NOS activation, was verified with the administration of selective iNOS and nNOS inhibitors, aminoguanidine (50 mg/kg/day i.p.) and 7-nitroindazole (12.5 mg/kg/day i.p.), and the steroid synthesis inhibitor, ketoconazole...... (24 mg/kg/day i.p.), administered for 21 days prior to and during the stress procedure. RESULTS: Stress evoked a sustained increase in NOS activity, but reduced NMDA receptor density and total GABA levels. Aminoguanidine or ketoconazole, but not 7-nitroindazole or saline, blocked stress-induced NOS...

Effect of MK-801 on methamphetamine-induced dopaminergic neurotoxicity: long-term attenuation of methamphetamine-induced dopamine release

Energy Technology Data Exchange (ETDEWEB)

Kim, Sang Eun; Kim, Yu Ri; Hwang, Se Hwan [Sungkyunkwan Univ., School of Medicine, Seoul (Korea, Republic of)

2001-08-01

Repeated administration of methamphetamine (METH) produces high extracellular levels of dopamine (DA) and subsequent striatal DA terminal damage. The effect of MK-801, a noncompetitive N-methyl-D-aspartate receptor antagonist, on METH-induced changes in DA transporter (DAT) and DA release evoked by an acute METH challenge was evaluated in rodent striatum using [{sup 3}H] WIN 38,428 ex vivo auto-radiography and in vivo microdialysis. Four injections of METH (10 mg/kg, i.p.), each given 2 h apart, produced 71% decrease in DAT levels in mouse striatum 3 d after administration. Pretreatment with MK-801 (2.5 g/kg, i.p.) 15 min before each of the four METH injections protected completely against striatal DAT depletions. Four injections of MK-801 alone did not significantly change striatal DAT levels. Striatal DA release evoked by an acute METH challenge (4mg/kg, i.p.) at 3 d after repeated administration of METH in rats was decreased but significant compared with controls, which was attenuated by repeated pretreatment with MK-801. Also, repeated injections of MK-801 alone attenuated acute METH-induced striatal DA release 3 d after administration. These results suggest that repeated administration of MK-801 may exert a preventive effect against METH-induced DA terminal injury through long-term attenuation of DA release induced by METH and other stimuli.

Effect of MK-801 on methamphetamine-induced dopaminergic neurotoxicity: long-term attenuation of methamphetamine-induced dopamine release

International Nuclear Information System (INIS)

Kim, Sang Eun; Kim, Yu Ri; Hwang, Se Hwan

2001-01-01

Repeated administration of methamphetamine (METH) produces high extracellular levels of dopamine (DA) and subsequent striatal DA terminal damage. The effect of MK-801, a noncompetitive N-methyl-D-aspartate receptor antagonist, on METH-induced changes in DA transporter (DAT) and DA release evoked by an acute METH challenge was evaluated in rodent striatum using [ 3 H] WIN 38,428 ex vivo auto-radiography and in vivo microdialysis. Four injections of METH (10 mg/kg, i.p.), each given 2 h apart, produced 71% decrease in DAT levels in mouse striatum 3 d after administration. Pretreatment with MK-801 (2.5 g/kg, i.p.) 15 min before each of the four METH injections protected completely against striatal DAT depletions. Four injections of MK-801 alone did not significantly change striatal DAT levels. Striatal DA release evoked by an acute METH challenge (4mg/kg, i.p.) at 3 d after repeated administration of METH in rats was decreased but significant compared with controls, which was attenuated by repeated pretreatment with MK-801. Also, repeated injections of MK-801 alone attenuated acute METH-induced striatal DA release 3 d after administration. These results suggest that repeated administration of MK-801 may exert a preventive effect against METH-induced DA terminal injury through long-term attenuation of DA release induced by METH and other stimuli

Histamine H3 Receptors Decrease Dopamine Release in the Ventral Striatum by Reducing the Activity of Striatal Cholinergic Interneurons.

Science.gov (United States)

Varaschin, Rafael Koerich; Osterstock, Guillaume; Ducrot, Charles; Leino, Sakari; Bourque, Marie-Josée; Prado, Marco A M; Prado, Vania Ferreira; Salminen, Outi; Rannanpää Née Nuutinen, Saara; Trudeau, Louis-Eric

2018-04-15

Histamine H 3 receptors are widely distributed G i -coupled receptors whose activation reduces neuronal activity and inhibits release of numerous neurotransmitters. Although these receptors are abundantly expressed in the striatum, their modulatory role on activity-dependent dopamine release is not well understood. Here, we observed that histamine H 3 receptor activation indirectly diminishes dopamine overflow in the ventral striatum by reducing cholinergic interneuron activity. Acute brain slices from C57BL/6 or channelrhodopsin-2-transfected DAT-cre mice were obtained, and dopamine transients evoked either electrically or optogenetically were measured by fast-scan cyclic voltammetry. The H 3 agonist α-methylhistamine significantly reduced electrically- evoked dopamine overflow, an effect blocked by the nicotinic acetylcholine receptor antagonist dihydro-β-erythroidine, suggesting involvement of cholinergic interneurons. None of the drug treatments targeting H 3 receptors affected optogenetically evoked dopamine overflow, indicating that direct H 3 -modulation of dopaminergic axons is unlikely. Next, we used qPCR and confirmed the expression of histamine H 3 receptor mRNA in cholinergic interneurons, both in ventral and dorsal striatum. Activation of H 3 receptors by α-methylhistamine reduced spontaneous firing of cholinergic interneurons in the ventral, but not in the dorsal striatum. Resting membrane potential and number of spontaneous action potentials in ventral-striatal cholinergic interneurons were significantly reduced by α-methylhistamine. Acetylcholine release from isolated striatal synaptosomes, however, was not altered by α-methylhistamine. Together, these results indicate that histamine H 3 receptors are important modulators of dopamine release, specifically in the ventral striatum, and that they do so by decreasing the firing rate of cholinergic neurons and, consequently, reducing cholinergic tone on dopaminergic axons. Copyright © 2018 IBRO

Steady-state evoked potentials possibilities for mental-state estimation

Science.gov (United States)

Junker, Andrew M.; Schnurer, John H.; Ingle, David F.; Downey, Craig W.

1988-01-01

The use of the human steady-state evoked potential (SSEP) as a possible measure of mental-state estimation is explored. A method for evoking a visual response to a sum-of-ten sine waves is presented. This approach provides simultaneous multiple frequency measurements of the human EEG to the evoking stimulus in terms of describing functions (gain and phase) and remnant spectra. Ways in which these quantities vary with the addition of performance tasks (manual tracking, grammatical reasoning, and decision making) are presented. Models of the describing function measures can be formulated using systems engineering technology. Relationships between model parameters and performance scores during manual tracking are discussed. Problems of unresponsiveness and lack of repeatability of subject responses are addressed in terms of a need for loop closure of the SSEP. A technique to achieve loop closure using a lock-in amplifier approach is presented. Results of a study designed to test the effectiveness of using feedback to consciously connect humans to their evoked response are presented. Findings indicate that conscious control of EEG is possible. Implications of these results in terms of secondary tasks for mental-state estimation and brain actuated control are addressed.

Synaptic glutamate release by postnatal rat serotonergic neurons in microculture.

Science.gov (United States)

Johnson, M D

1994-02-01

Serotonergic neurons are thought to play a role in depression and obsessive compulsive disorder. However, their functional transmitter repertoire is incompletely known. To investigate this repertoire, intracellular recordings were obtained from 132 cytochemically identified rat mesopontine serotonergic neurons that had re-established synapses in microcultures. Approximately 60% of the neurons evoked excitatory glutamatergic potentials in themselves or in target neurons. Glutamatergic transmission was frequently observed in microcultures containing a solitary serotonergic neuron. Evidence for co-release of serotonin and glutamate from single raphe neurons was also obtained. However, evidence for gamma-aminobutyric acid release by serotonergic neurons was observed in only two cases. These findings indicate that many cultured serotonergic neurons form glutamatergic synapses and may explain several observations in slices and in vivo.

Central noradrenaline transporter availability in highly obese, non-depressed individuals

Energy Technology Data Exchange (ETDEWEB)

Hesse, Swen; Sabri, Osama [University of Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Leipzig University Medical Centre, Integrated Treatment and Research Centre (IFB) Adiposity Diseases, Leipzig (Germany); Becker, Georg-Alexander; Bresch, Anke; Luthardt, Julia; Patt, Marianne; Meyer, Philipp M. [University of Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Rullmann, Michael [University of Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Leipzig University Medical Centre, Integrated Treatment and Research Centre (IFB) Adiposity Diseases, Leipzig (Germany); Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig (Germany); Hankir, Mohammed K.; Zientek, Franziska; Reissig, Georg; Fenske, Wiebke K. [Leipzig University Medical Centre, Integrated Treatment and Research Centre (IFB) Adiposity Diseases, Leipzig (Germany); Arelin, Katrin [Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig (Germany); University of Leipzig, Day Clinic for Cognitive Neurology, Leipzig (Germany); Lobsien, Donald [University of Leipzig, Department of Neuroradiology, Leipzig (Germany); Mueller, Ulrich [University of Cambridge, Department of Psychiatry and Behavioural and Clinical Neuroscience Institute, Cambridge (United Kingdom); Baldofski, S.; Hilbert, Anja [Leipzig University Medical Centre, Integrated Treatment and Research Centre (IFB) Adiposity Diseases, Leipzig (Germany); University of Leipzig, Department of Medical Psychology and Medical Sociology, Leipzig (Germany); Blueher, Matthias [University of Leipzig, Department of Internal Medicine, Leipzig (Germany); Fasshauer, Mathias; Stumvoll, Michael [Leipzig University Medical Centre, Integrated Treatment and Research Centre (IFB) Adiposity Diseases, Leipzig (Germany); University of Leipzig, Department of Internal Medicine, Leipzig (Germany); Ding, Yu-Shin [New York University School of Medicine, Departments of Radiology and Psychiatry, New York, NY (United States)

2017-06-15

The brain noradrenaline (NA) system plays an important role in the central nervous control of energy balance and is thus implicated in the pathogenesis of obesity. The specific processes modulated by this neurotransmitter which lead to obesity and overeating are still a matter of debate. We tested the hypothesis that in vivo NA transporter (NAT) availability is changed in obesity by using positron emission tomography (PET) and S,S-[{sup 11}C]O-methylreboxetine (MRB) in twenty subjects comprising ten highly obese (body mass index BMI > 35 kg/m{sup 2}), metabolically healthy, non-depressed individuals and ten non-obese (BMI < 30 kg/m{sup 2}) healthy controls. Overall, we found no significant differences in binding potential (BP{sub ND}) values between obese and non-obese individuals in the investigated brain regions, including the NAT-rich thalamus (0.40 ± 0.14 vs. 0.41 ± 0.18; p = 0.84) though additional discriminant analysis correctly identified individual group affiliation based on regional BP{sub ND} in all but one (control) case. Furthermore, inter-regional correlation analyses indicated different BP{sub ND} patterns between both groups but this did not survive testing for multiple comparions. Our data do not find an overall involvement of NAT changes in human obesity. However, preliminary secondary findings of distinct regional and associative patterns warrant further investigation. (orig.)

Central noradrenaline transporter availability in highly obese, non-depressed individuals

International Nuclear Information System (INIS)

Hesse, Swen; Sabri, Osama; Becker, Georg-Alexander; Bresch, Anke; Luthardt, Julia; Patt, Marianne; Meyer, Philipp M.; Rullmann, Michael; Hankir, Mohammed K.; Zientek, Franziska; Reissig, Georg; Fenske, Wiebke K.; Arelin, Katrin; Lobsien, Donald; Mueller, Ulrich; Baldofski, S.; Hilbert, Anja; Blueher, Matthias; Fasshauer, Mathias; Stumvoll, Michael; Ding, Yu-Shin

2017-01-01

The brain noradrenaline (NA) system plays an important role in the central nervous control of energy balance and is thus implicated in the pathogenesis of obesity. The specific processes modulated by this neurotransmitter which lead to obesity and overeating are still a matter of debate. We tested the hypothesis that in vivo NA transporter (NAT) availability is changed in obesity by using positron emission tomography (PET) and S,S-["1"1C]O-methylreboxetine (MRB) in twenty subjects comprising ten highly obese (body mass index BMI > 35 kg/m"2), metabolically healthy, non-depressed individuals and ten non-obese (BMI < 30 kg/m"2) healthy controls. Overall, we found no significant differences in binding potential (BP_N_D) values between obese and non-obese individuals in the investigated brain regions, including the NAT-rich thalamus (0.40 ± 0.14 vs. 0.41 ± 0.18; p = 0.84) though additional discriminant analysis correctly identified individual group affiliation based on regional BP_N_D in all but one (control) case. Furthermore, inter-regional correlation analyses indicated different BP_N_D patterns between both groups but this did not survive testing for multiple comparions. Our data do not find an overall involvement of NAT changes in human obesity. However, preliminary secondary findings of distinct regional and associative patterns warrant further investigation. (orig.)

Prolactin releasing effect of sulpiride isomers in rats and man

Energy Technology Data Exchange (ETDEWEB)

Mueller, E E; Stefanini, E; Spano, P F [Cagliari Univ. (Italy). Inst. of Pharmacology and Pharmacognosy; Camanni, F; Massara, F [Turin Univ. (Italy). Chair of Endocrinology; Locatelli, V; Cocchi, D

1979-01-01

Sulpiride, an antipsychotropic drug of the benzamide class, reportedly displaces stereospecifically (/sup 3/H)-butyrophenones from putative dopamine (DA) binding sites in rat striatum. To evaluate if sulpiride displays the same stereospecifity in the inhibition of pituitary DA receptors, the effect of the two(-)-and (+)-sulpiride isomers was tested with regard to their ability to stimulate prolactin (PRL) secretion in rats and man and to displace (/sup 3/H)-spiroperidol bound to rat anterior pituitary receptors. In male rats, (-)-sulpiride at doses of 0.1 and 0.1 mg/kg i.p., induced a maximum PRL-releasing effect, not different from that evoked by a dose of 10 mg/kg of the compound. (+)-Sulpiride was active only at the dose of 10mg/kg i.p., and its PRL-releasing effect was superimposable to that evoked by the same dose of (-)-sulpiride. Similarily, in 8 normal subjects (4 men and 4 women) only (-)-sulpiride was active as PRL releaser when the low dose of 0.25 mg i.v. was used; when the higher dose of sulpiride was used (4.0 mg i.v.), it induced a rise in plasma PRL of the same entity for both isomers at early post-injection times (15-30 min) but greater with the (-)-isomer at the following time intervals (45-120 min). (-)-Sulpiride displaced (/sup 3/H)-spiroperidol bound to rat anterior pituitary homogenates with a potency about 100 times greater as that showed by (+)-sulpiride. In all, these data indicate that sulpiride isomers display at the level of pituitary DA receptors for PRL control the same stereospecifity exhibited on a population of striatal DA receptors.

Lead intoxication induces noradrenaline depletion, motor nonmotor disabilities, and changes in the firing pattern of subthalamic nucleus neurons.

Science.gov (United States)

Sabbar, M; Delaville, C; De Deurwaerdère, P; Benazzouz, A; Lakhdar-Ghazal, N

2012-05-17

Lead intoxication has been suggested as a high risk factor for the development of Parkinson disease. However, its impact on motor and nonmotor functions and the mechanism by which it can be involved in the disease are still unclear. In the present study, we studied the effects of lead intoxication on the following: (1) locomotor activity using an open field actimeter and motor coordination using the rotarod test, (2) anxiety behavior using the elevated plus maze, (3) "depression-like" behavior using sucrose preference test, and (4) subthalamic nucleus (STN) neuronal activity using extracellular single unit recordings. Male Sprague-Dawley rats were treated once a day with lead acetate or sodium acetate (20 mg/kg/d i.p.) during 3 weeks. The tissue content of monoamines was used to determine alteration of these systems at the end of experiments. Results show that lead significantly reduced exploratory activity, locomotor activity and the time spent on the rotarod bar. Furthermore, lead induced anxiety but not "depressive-like" behavior. The electrophysiological results show that lead altered the discharge pattern of STN neurons with an increase in the number of bursting and irregular cells without affecting the firing rate. Moreover, lead intoxication resulted in a decrease of tissue noradrenaline content without any change in the levels of dopamine and serotonin. Together, these results show for the first time that lead intoxication resulted in motor and nonmotor behavioral changes paralleled by noradrenaline depletion and changes in the firing activity of STN neurons, providing evidence consistent with the induction of atypical parkinsonian-like deficits. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

In vivo neurochemical characterization of clothianidin induced striatal dopamine release.

Science.gov (United States)

Faro, L R F; Oliveira, I M; Durán, R; Alfonso, M

2012-12-16

Clothianidin (CLO) is a neonicotinoid insecticide with selective action on nicotinic acetylcholine receptors. The aim of this study was to determine the neurochemical basis for CLO-induced striatal dopamine release using the microdialysis technique in freely moving and conscious rats. Intrastriatal administration of CLO (3.5mM), produced an increase in both spontaneous (2462 ± 627% with respect to basal values) and KCl-evoked (4672 ± 706% with respect to basal values) dopamine release. This effect was attenuated in Ca(2+)-free medium, and was prevented in reserpine pre-treated animals or in presence of tetrodotoxin (TTX). To investigate the involvement of dopamine transporter (DAT), the effect of CLO was observed in presence of nomifensine. The coadministration of CLO and nomifensine produced an additive effect on striatal dopamine release. The results suggest that the effect of CLO on striatal dopamine release is predominantly mediated by an exocytotic mechanism, Ca(2+), vesicular and TTX-dependent and not by a mechanism mediated by dopamine transporter. Published by Elsevier Ireland Ltd.

Odor-evoked inhibition of olfactory sensory neurons drives olfactory perception in Drosophila.

Science.gov (United States)

Cao, Li-Hui; Yang, Dong; Wu, Wei; Zeng, Xiankun; Jing, Bi-Yang; Li, Meng-Tong; Qin, Shanshan; Tang, Chao; Tu, Yuhai; Luo, Dong-Gen

2017-11-07

Inhibitory response occurs throughout the nervous system, including the peripheral olfactory system. While odor-evoked excitation in peripheral olfactory cells is known to encode odor information, the molecular mechanism and functional roles of odor-evoked inhibition remain largely unknown. Here, we examined Drosophila olfactory sensory neurons and found that inhibitory odors triggered outward receptor currents by reducing the constitutive activities of odorant receptors, inhibiting the basal spike firing in olfactory sensory neurons. Remarkably, this odor-evoked inhibition of olfactory sensory neurons elicited by itself a full range of olfactory behaviors from attraction to avoidance, as did odor-evoked olfactory sensory neuron excitation. These results indicated that peripheral inhibition is comparable to excitation in encoding sensory signals rather than merely regulating excitation. Furthermore, we demonstrated that a bidirectional code with both odor-evoked inhibition and excitation in single olfactory sensory neurons increases the odor-coding capacity, providing a means of efficient sensory encoding.

Norepinephrine-evoked pain in fibromyalgia. A randomized pilot study [ISRCTN70707830

Directory of Open Access Journals (Sweden)

Casanova Jose-Miguel

2002-01-01

Full Text Available Abstract Background Fibromyalgia syndrome displays sympathetically maintained pain features such as frequent post-traumatic onset and stimuli-independent pain accompanied by allodynia and paresthesias. Heart rate variability studies showed that fibromyalgia patients have changes consistent with ongoing sympathetic hyperactivity. Norepinephrine-evoked pain test is used to assess sympathetically maintained pain syndromes. Our objective was to define if fibromyalgia patients have norepinephrine-evoked pain. Methods Prospective double blind controlled study. Participants: Twenty FM patients, and two age/sex matched control groups; 20 rheumatoid arthritis patients and 20 healthy controls. Ten micrograms of norepinephrine diluted in 0.1 ml of saline solution were injected in a forearm. The contrasting substance, 0.1 ml of saline solution alone, was injected in the opposite forearm. Maximum local pain elicited during the 5 minutes post-injection was graded on a visual analog scale (VAS. Norepinephrine-evoked pain was diagnosed when norepinephrine injection induced greater pain than placebo injection. Intensity of norepinephrine-evoked pain was calculated as the difference between norepinephrine minus placebo-induced VAS scores. Results Norepinephrine-evoked pain was seen in 80 % of FM patients (95% confidence intervals 56.3 – 94.3%, in 30 % of rheumatoid arthritis patients and in 30 % of healthy controls (95% confidence intervals 11.9 – 54.3 (p Conclusions Fibromyalgia patients have norepinephrine-evoked pain. This finding supports the hypothesis that fibromyalgia may be a sympathetically maintained pain syndrome.

Objective correlate of subjective pain perception by contact heat-evoked potentials.

Science.gov (United States)

Granovsky, Yelena; Granot, Michal; Nir, Rony-Reuven; Yarnitsky, David

2008-01-01

The method of pain-evoked potentials has gained considerable acceptance over the last 3 decades regarding its objectivity, repeatability, and quantifiability. The present study explored whether the relationship between pain-evoked potentials and pain psychophysics obtained by contact heat stimuli is similar to those observed for the conventionally used laser stimulation. Evoked potentials (EPs) were recorded in response to contact heat stimuli at different body sites in 24 healthy volunteers. Stimuli at various temperatures were applied to the forearm (43 degrees C, 46 degrees C, 49 degrees C, and 52 degrees C) and leg (46 degrees C and 49 degrees C). The amplitudes of both components (N2 and P2) were strongly associated with the intensity of the applied stimuli and with subjective pain perception. Yet, regression analysis revealed pain perception and not stimulus intensity as the major contributing factor. A significant correlation was found between the forearm and the leg for both psychophysics and EPs amplitude. Contact heat can generate readily distinguishable evoked potentials on the scalp, consistent between upper and lower limbs. Although these potentials bear positive correlation with both stimulus intensity and pain magnitude, the latter is the main contributor to the evoked brain response.

Effects of single cycle binaural beat duration on auditory evoked potentials.

Science.gov (United States)

Mihajloski, Todor; Bohorquez, Jorge; Özdamar, Özcan

2014-01-01

Binaural beat (BB) illusions are experienced as continuous central pulsations when two sounds with slightly different frequencies are delivered to each ear. It has been shown that steady-state auditory evoked potentials (AEPs) to BBs can be captured and investigated. The authors recently developed a new method of evoking transient AEPs to binaural beats using frequency modulated stimuli. This methodology was able to create single BBs in predetermined intervals with varying carrier frequencies. This study examines the effects of the BB duration and the frequency modulating component of the stimulus on the binaural beats and their evoked potentials. Normal hearing subjects were tested with a set of four durations (25, 50, 100, and 200 ms) with two stimulation configurations, binaural dichotic (binaural beats) and diotic (frequency modulation). The results obtained from the study showed that out of the given durations, the 100 ms beat, was capable of evoking the largest amplitude responses. The frequency modulation effect showed a decrease in peak amplitudes with increasing beat duration until their complete disappearance at 200 ms. Even though, at 200 ms, the frequency modulation effects were not present, the binaural beats were still perceived and captured as evoked potentials.

Radioenzymatic assay of plasma adrenaline and noradrenaline: evidence for a catechol-O-methyltransferase (COMT) inhibiting factor associated with essential hypertension

International Nuclear Information System (INIS)

Hoffmann, J.J.M.L.; Willemsen, J.J.; Thien, Th.; Benraad, Th.J.

1982-01-01

During the evaluation of a modified radioenzymatic determination of plasma adrenaline and noradrenaline, it has been found that there exists a highly significant (p 0 C, but only in plasma from patients with essential hypertension. Plasma from normotensive persons exhibits a complete lack of correlation between these factors. The consequences of the hypertension-associated COMT-inhibiting factor for the assays' specifications are discussed and data are presented for comparison with a recently-described uremia-associated COMT-inhibitor (Demassieux et al, Clin Chim Acta 115, 377-391; 1981). (Auth.)

Role of autoinhibitory feedback in cardiac sympathetic transmission

International Nuclear Information System (INIS)

Angus, J.A.; Korner, P.I.; Jackman, G.P.; Bobik, A.; Kopin, I.J.

1984-01-01

The relationship between two indices of transmitter release measured simultaneously and the frequency of 4 field pulses (0.125-2 Hz) were obtained from superfused guinea pig right atria after labelling with 3 H-noradrenaline. The relationships between 3 H-efflux or rate responses and frequency were hyperbolic. Autoinhibitory feedback did not play a role since phentolamine (1 microM) did not alter the 3 H-efflux or rate responses to 4 field pulses that gave 50-60% of the maximum rate response. In the presence of neuronal uptake block (desipramine (0.1 microM) phentolamine enhanced 3 H-efflux and rate responses to 4 field pulses at all frequencies. In the absence of desipramine prolonged trains of field pulses (8-12 pulses) at low frequency (0.25 Hz) were not sufficient to activate autoinhibitory feedback. At 2 Hz phentolamine enhanced both responses at 12 field pulses. We conclude that in the right atrium autoinhibitory feedback plays little role in the modulation of transmitter release at levels of stimulation that cause 50-60% of maximum tissue response. The presence of neuronal uptake inhibition or high stimulus strengths are necessary to evoke autoinhibitory feedback

Frequency-Dependent Modulation of Dopamine Release by Nicotine and Dopamine D1 Receptor Ligands: An In Vitro Fast Cyclic Voltammetry Study in Rat Striatum.

Science.gov (United States)

Goutier, W; Lowry, J P; McCreary, A C; O'Connor, J J

2016-05-01

Nicotine is a highly addictive drug and exerts this effect partially through the modulation of dopamine release and increasing extracellular dopamine in regions such as the brain reward systems. Nicotine acts in these regions on nicotinic acetylcholine receptors. The effect of nicotine on the frequency dependent modulation of dopamine release is well established and the purpose of this study was to investigate whether dopamine D1 receptor (D1R) ligands have an influence on this. Using fast cyclic voltammetry and rat corticostriatal slices, we show that D1R ligands are able to modulate the effect of nicotine on dopamine release. Nicotine (500 nM) induced a decrease in dopamine efflux at low frequency (single pulse or five pulses at 10 Hz) and an increase at high frequency (100 Hz) electrical field stimulation. The D1R agonist SKF-38393, whilst having no effect on dopamine release on its own or on the effect of nicotine upon multiple pulse evoked dopamine release, did significantly prevent and reverse the effect of nicotine on single pulse dopamine release. Interestingly similar results were obtained with the D1R antagonist SCH-23390. In this study we have demonstrated that the modulation of dopamine release by nicotine can be altered by D1R ligands, but only when evoked by single pulse stimulation, and are likely working via cholinergic interneuron driven dopamine release.

Relationship between calcium entry and ACh release in K+ -stimulated rat brain synaptosomes

International Nuclear Information System (INIS)

Suszkiw, J.B.; O'Leary, M.E.; Toth, G.P.

1986-01-01

This paper examines the pattern of Ca ++ entry-dependent ACh release in relation to the kinetics of Ca ++ entry, and its inactivation in rat brain synaptosomes exposed to 50 mM K 0 + for short and prolonged durations. Intrasynaptosomal ACh was radiolabeled from tritium-choline in the presence of 20 um Paraoxon to inhibit the acetylcholinesterase activity. The release of tritium-ACh was studied in superfused synaptosomal beds formed on glass microfiber filters and by rapid filtration. The intermittent stimulation of superfused synaptosomal beds by 3-min pulses of 50 mM K + evoked decremental output of tritium-ACh which reached nearly undetectable levels after the fifth stimulus

Electrically induced release of acetylcholine from denervated Schwann cells.

Science.gov (United States)

Dennis, M J; Miledi, R

1974-03-01

1. Focal electrical stimulation of Schwann cells at the end-plates of denervated frog muscles elicited slow depolarizations of up to 30 mV in the muscle fibres. This response is referred to as a Schwann-cell end-plate potential (Schwann-e.p.p.).2. Repeated stimulation sometimes evoked further Schwann-e.p.p.s, but they were never sustained for more than 30 pulses. Successive e.p.p.s varied in amplitude and time course independently of the stimulus.3. The Schwann-e.p.p.s were reversibly blocked by curare, suggesting that they result from a release of acetylcholine (ACh) by the Schwann cells.4. ACh release by electrical stimulation did not seem to occur in quantal form and was not dependent on the presence of calcium ions in the external medium; nor was it blocked by tetrodotoxin.5. Stimulation which caused release of ACh also resulted in extensive morphological disruption of the Schwann cells, as seen with both light and electron microscopy.6. It is concluded that electrical stimulation of denervated Schwann cells causes break-down of the cell membrane and releases ACh, presumably in molecular form.

A Telehealth System for Remote Auditory Evoked Potential Monitoring

OpenAIRE

Millan, Jorge; Yunda, Leonardo

2013-01-01

A portable, Internet-based EEG/Auditory Evoked Potential (AEP) monitoring system was developed for remote electrophysiological studies during sleep. The system records EEG/AEP simultaneously at the subject?s home for increased comfort and flexibility. The system provides simultaneous recording and remote viewing of EEG, EMG and EOG waves and allows on-line averaging of auditory evoked potentials. The design allows the recording of all major AEP components (brainstem, middle and late latency E...

The Role of Odor-Evoked Memory in Psychological and Physiological Health.

Science.gov (United States)

Herz, Rachel S

2016-07-19

This article discusses the special features of odor-evoked memory and the current state-of-the-art in odor-evoked memory research to show how these unique experiences may be able to influence and benefit psychological and physiological health. A review of the literature leads to the conclusion that odors that evoke positive autobiographical memories have the potential to increase positive emotions, decrease negative mood states, disrupt cravings, and reduce physiological indices of stress, including systemic markers of inflammation. Olfactory perception factors and individual difference characteristics that would need to be considered in therapeutic applications of odor-evoked-memory are also discussed. This article illustrates how through the experimentally validated mechanisms of odor-associative learning and the privileged neuroanatomical relationship that exists between olfaction and the neural substrates of emotion, odors can be harnessed to induce emotional and physiological responses that can improve human health and wellbeing.

The Role of Odor-Evoked Memory in Psychological and Physiological Health

Directory of Open Access Journals (Sweden)

Rachel S. Herz

2016-07-01

Full Text Available This article discusses the special features of odor-evoked memory and the current state-of-the-art in odor-evoked memory research to show how these unique experiences may be able to influence and benefit psychological and physiological health. A review of the literature leads to the conclusion that odors that evoke positive autobiographical memories have the potential to increase positive emotions, decrease negative mood states, disrupt cravings, and reduce physiological indices of stress, including systemic markers of inflammation. Olfactory perception factors and individual difference characteristics that would need to be considered in therapeutic applications of odor-evoked-memory are also discussed. This article illustrates how through the experimentally validated mechanisms of odor-associative learning and the privileged neuroanatomical relationship that exists between olfaction and the neural substrates of emotion, odors can be harnessed to induce emotional and physiological responses that can improve human health and wellbeing.

Thought-evoking approaches in engineering problems

CERN Document Server

2014-01-01

In creating the value-added product in not distant future, it is necessary and inevitable to establish a holistic and though-evoking approach to the engineering problem, which should be at least associated with the inter-disciplinary knowledge and thought processes across the whole engineering spheres. It is furthermore desirable to integrate it with trans-disciplinary aspects ranging from manufacturing culture, through liberal-arts engineering, and industrial sociology.   The thought-evoking approach can be exemplified and typified by representative engineering problems: unveiling essential features in ‘Tangential Force Ratio and Interface Pressure’, prototype development for ‘Bio-mimetic Needle’ and application of ‘Water-jet Machining to Artificial Hip Joint’, product innovation in ‘Heat Sink for Computer’, application of ‘Graph Theory’ to similarity evaluation of production systems, leverage among reciprocity attributes in ‘Industrial and Engineering Designs for Machine Enclosure’,...

Speech-evoked auditory brainstem responses in children with hearing loss.

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Koravand, Amineh; Al Osman, Rida; Rivest, Véronique; Poulin, Catherine

2017-08-01

The main objective of the present study was to investigate subcortical auditory processing in children with sensorineural hearing loss. Auditory Brainstem Responses (ABRs) were recorded using click and speech/da/stimuli. Twenty-five children, aged 6-14 years old, participated in the study: 13 with normal hearing acuity and 12 with sensorineural hearing loss. No significant differences were observed for the click-evoked ABRs between normal hearing and hearing-impaired groups. For the speech-evoked ABRs, no significant differences were found for the latencies of the following responses between the two groups: onset (V and A), transition (C), one of the steady-state wave (F), and offset (O). However, the latency of the steady-state waves (D and E) was significantly longer for the hearing-impaired compared to the normal hearing group. Furthermore, the amplitude of the offset wave O and of the envelope frequency response (EFR) of the speech-evoked ABRs was significantly larger for the hearing-impaired compared to the normal hearing group. Results obtained from the speech-evoked ABRs suggest that children with a mild to moderately-severe sensorineural hearing loss have a specific pattern of subcortical auditory processing. Our results show differences for the speech-evoked ABRs in normal hearing children compared to hearing-impaired children. These results add to the body of the literature on how children with hearing loss process speech at the brainstem level. Copyright © 2017 Elsevier B.V. All rights reserved.

Relationship between respiratory failure and plasma noradrenaline levels in amyotrophic lateral sclerosis.

Science.gov (United States)

Yamashita, A; Koike, Y; Takahashi, A; Hirayama, M; Murakami, N; Sobue, G

1997-08-01

We evaluated plasma noradrenaline (NA) levels at test and during head-up tilt test in 20 patients with sporadic amyotrophic lateral sclerosis (ALS). Their fasting plasma NA levels ranged from 195 to 4227 pg/ml. The average plasma NA level was 483 pg/ml in five ambulatory patients, 341 in two wheelchair-bound patients, 1264 in 11 bedridden patients, and 208 in two respirator-dependent patients whose disability grading was the worst among the four groups. Arterial carbon dioxide (PCO2) was evaluated as a measure of respiratory function. The coefficient of correlation between PCO2 and plasma NA was r = 0.654 (p respiratory failure or lower motor neuron dysfunction may relate to the elevation of plasma NA levels. In the two bedridden patients, plasma NA levels and heart rate at rest increased significantly as the disease progressed. Cardiovascular responses to head-up tilting were normal. These data suggest that the elevation of plasma NA levels may be related to progression of respiratory failure and lower motor neuron dysfunction. In conclusion, sympathetic hyperactivity in ALS is considered to be not primary, but secondary to somatic motor disabilities and respiratory failure.

Behavioral analyses of wind-evoked escape of the cricket, Gryllodes sigillatus.

Science.gov (United States)

Kanou, Masamichi; Konishi, Atsuko; Suenaga, Rie

2006-04-01

The wind-evoked escape behavior of the cricket Gryllodes sigillatus was investigated using an air puff stimulus. A high velocity air puff elicited the escape behavior in many crickets. The crickets tended to escape away from the stimulus source, but the direction was not accurately oriented 180 degrees from the stimulus. After bilateral cercal ablation, only a few crickets showed wind-evoked escape behavior, and their response rates did not increase even 19 days after ablation. Therefore, information on air motion detected by cercal filiform hairs is essential for triggering wind-evoked behavior. After unilateral cercal ablation, the 81.3% response rate of intact crickets decreased to 16.5%, that is, it decreased to almost 20% that of intact crickets. One week after unilateral cercal ablation, the response rate recovered to more than 60% that of intact crickets. However, the accuracy rate of the escape direction of G. sigillatus showed no change even immediately after the unilateral cercal ablation. Therefore, both cerci are not necessarily required to determine the escape direction. The behavioral characteristics of wind-evoked escape of G. sigillatus are compared with those of another species of cricket, Gryllus bimaculatus. The two species of cricket employ different strategies for wind-evoked escape.

Skinfold thickness affects the isometric knee extension torque evoked by Neuromuscular Electrical Stimulation.

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Medeiros, Flávia V A; Vieira, Amilton; Carregaro, Rodrigo L; Bottaro, Martim; Maffiuletti, Nicola A; Durigan, João L Q

2015-01-01

Subcutaneous adipose tissue may influence the transmission of electrical stimuli through to the skin, thus affecting both evoked torque and comfort perception associated with neuromuscular electrical stimulation (NMES). This could seriously affect the effectiveness of NMES for either rehabilitation or sports purposes. To investigate the effects of skinfold thickness (SFT) on maximal NMES current intensity, NMES-evoked torque, and NMES-induced discomfort. First, we compared NMES current intensity, NMES-induced discomfort, and NMES-evoked torque between two subgroups of subjects with thicker (n=10; 20.7 mm) vs. thinner (n=10; 29.4 mm) SFT. Second, we correlated SFT to NMES current intensity, NMES-induced discomfort, and NMES-evoked knee extension torque in 20 healthy women. The NMES-evoked torque was normalized to the maximal voluntary contraction (MVC) torque. The discomfort induced by NMES was assessed with a visual analog scale (VAS). NMES-evoked torque was 27.5% lower in subjects with thicker SFT (p=0.01) while maximal current intensity was 24.2% lower in subjects with thinner SFT (p=0.01). A positive correlation was found between current intensity and SFT (r=0.540, p=0.017). A negative correlation was found between NMES-evoked torque and SFT (r=-0.563, p=0.012). No significant correlation was observed between discomfort scores and SFT (rs=0.15, p=0.53). These results suggest that the amount of subcutaneous adipose tissue (as reflected by skinfold thickness) affected NMES current intensity and NMES-evoked torque, but had no effect on discomfort perception. Our findings may help physical therapists to better understand the impact of SFT on NMES and to design more rational stimulation strategies.

Pharmacology of Bradykinin-Evoked Coughing in Guinea Pigs.

Science.gov (United States)

Hewitt, Matthew M; Adams, Gregory; Mazzone, Stuart B; Mori, Nanako; Yu, Li; Canning, Brendan J

2016-06-01

Bradykinin has been implicated as a mediator of the acute pathophysiological and inflammatory consequences of respiratory tract infections and in exacerbations of chronic diseases such as asthma. Bradykinin may also be a trigger for the coughing associated with these and other conditions. We have thus set out to evaluate the pharmacology of bradykinin-evoked coughing in guinea pigs. When inhaled, bradykinin induced paroxysmal coughing that was abolished by the bradykinin B2 receptor antagonist HOE 140. These cough responses rapidly desensitized, consistent with reports of B2 receptor desensitization. Bradykinin-evoked cough was potentiated by inhibition of both neutral endopeptidase and angiotensin-converting enzyme (with thiorphan and captopril, respectively), but was largely unaffected by muscarinic or thromboxane receptor blockade (atropine and ICI 192605), cyclooxygenase, or nitric oxide synthase inhibition (meclofenamic acid and N(G)-nitro-L-arginine). Calcium influx studies in bronchopulmonary vagal afferent neurons dissociated from vagal sensory ganglia indicated that the tachykinin-containing C-fibers arising from the jugular ganglia mediate bradykinin-evoked coughing. Also implicating the jugular C-fibers was the observation that simultaneous blockade of neurokinin2 (NK2; SR48968) and NK3 (SR142801 or SB223412) receptors nearly abolished the bradykinin-evoked cough responses. The data suggest that bradykinin induces coughing in guinea pigs by activating B2 receptors on bronchopulmonary C-fibers. We speculate that therapeutics targeting the actions of bradykinin may prove useful in the treatment of cough. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Presynaptic membrane receptors in acetylcholine release modulation in the neuromuscular synapse.

Science.gov (United States)

Tomàs, Josep; Santafé, Manel M; Garcia, Neus; Lanuza, Maria A; Tomàs, Marta; Besalduch, Núria; Obis, Teresa; Priego, Mercedes; Hurtado, Erica

2014-05-01

Over the past few years, we have studied, in the mammalian neuromuscular junction (NMJ), the local involvement in transmitter release of the presynaptic muscarinic ACh autoreceptors (mAChRs), purinergic adenosine autoreceptors (P1Rs), and trophic factor receptors (TFRs; for neurotrophins and trophic cytokines) during development and in the adult. At any given moment, the way in which a synapse works is largely the logical outcome of the confluence of these (and other) metabotropic signalling pathways on intracellular kinases, which phosphorylate protein targets and materialize adaptive changes. We propose an integrated interpretation of the complementary function of these receptors in the adult NMJ. The activity of a given receptor group can modulate a given combination of spontaneous, evoked, and activity-dependent release characteristics. For instance, P1Rs can conserve resources by limiting spontaneous quantal leak of ACh (an A1 R action) and protect synapse function, because stimulation with adenosine reduces the magnitude of depression during repetitive activity. The overall outcome of the mAChRs seems to contribute to upkeep of spontaneous quantal output of ACh, save synapse function by decreasing the extent of evoked release (mainly an M2 action), and reduce depression. We have also identified several links among P1Rs, mAChRs, and TFRs. We found a close dependence between mAChR and some TFRs and observed that the muscarinic group has to operate correctly if the tropomyosin-related kinase B receptor (trkB) is also to operate correctly, and vice versa. Likewise, the functional integrity of mAChRs depends on P1Rs operating normally. Copyright © 2014 Wiley Periodicals, Inc.

Do video games evoke specific types of epileptic seizures?

Science.gov (United States)

Piccioli, Marta; Vigevano, Federico; Buttinelli, Carla; Kasteleijn-Nolst Trenité, Dorothée G A

2005-11-01

We determined whether epileptic clinical manifestations evoked by playing video games (VG) differ from those evoked by intermittent photic stimulation (IPS) or striped patterns (P). We exposed nine children who had TV- and VG-evoked seizures in daily life to 12 VG after standardized photic stimulation and pattern stimulation. Their EEGs were recorded continuously, analyzed, and then correlated with a video of their behavior. Similar types of clinical signs were seen during VG, P, and IPS, but the signs we observed were more subtle during the VG. Eight patients showed a clear lateralization. A new observation was the lowering of the eyelids to a state of half-closed. Our study suggests that the type of visual stimulus provoking a photoparoxysmal response or seizure is not particularly relevant. The children belonged to different epilepsy groups, and our findings add to the discussion on the boundaries of the epilepsy types.

Awareness during anaesthesia for surgery requiring evoked potential monitoring: A pilot study

Directory of Open Access Journals (Sweden)

Pritish J Korula

2017-01-01

Full Text Available Background: Evoked potential monitoring such as somatosensory-evoked potential (SSEP or motor-evoked potential (MEP monitoring during surgical procedures in proximity to the spinal cord requires minimising the minimum alveolar concentrations (MACs below the anaesthetic concentrations normally required (1 MAC to prevent interference in amplitude and latency of evoked potentials. This could result in awareness. Our primary objective was to determine the incidence of awareness while administering low MAC inhalational anaesthetics for these unique procedures. The secondary objective was to assess the adequacy of our anaesthetic technique from neurophysiologist′s perspective. Methods: In this prospective observational pilot study, 61 American Society of Anesthesiologists 1 and 2 patients undergoing spinal surgery for whom intraoperative evoked potential monitoring was performed were included; during the maintenance phase, 0.7-0.8 MAC of isoflurane was targeted. We evaluated the intraoperative depth of anaesthesia using a bispectral (BIS index monitor as well as the patients response to surgical stimulus (PRST scoring system. Post-operatively, a modified Bruce questionnaire was used to verify awareness. The adequacy of evoked potential readings was also assessed. Results: Of the 61 patients, no patient had explicit awareness. Intraoperatively, 19 of 61 patients had a BIS value of above sixty at least once, during surgery. There was no correlation with PRST scoring and BIS during surgery. Fifty-four out of 61 patient′s evoked potential readings were deemed ′good′ or ′fair′ for the conduct of electrophysiological monitoring. Conclusions: This pilot study demonstrates that administering low MAC inhalational anaesthetics to facilitate evoked potential monitoring does not result in explicit awareness. However, larger studies are needed to verify this. The conduct of SSEP electrophysiological monitoring was satisfactory with the use of this

Transmitter modulation of spike-evoked calcium transients in arousal related neurons

DEFF Research Database (Denmark)

Kohlmeier, Kristi Anne; Leonard, Christopher S

2006-01-01

Nitric oxide synthase (NOS)-containing cholinergic neurons in the laterodorsal tegmentum (LDT) influence behavioral and motivational states through their projections to the thalamus, ventral tegmental area and a brainstem 'rapid eye movement (REM)-induction' site. Action potential-evoked intracel......Nitric oxide synthase (NOS)-containing cholinergic neurons in the laterodorsal tegmentum (LDT) influence behavioral and motivational states through their projections to the thalamus, ventral tegmental area and a brainstem 'rapid eye movement (REM)-induction' site. Action potential......-evoked intracellular calcium transients dampen excitability and stimulate NO production in these neurons. In this study, we investigated the action of several arousal-related neurotransmitters and the role of specific calcium channels in these LDT Ca(2+)-transients by simultaneous whole-cell recording and calcium...... of cholinergic LDT neurons and that inhibition of spike-evoked Ca(2+)-transients is a common action of neurotransmitters that also activate GIRK channels in these neurons. Because spike-evoked calcium influx dampens excitability, our findings suggest that these 'inhibitory' transmitters could boost firing rate...

Do Puzzle Pieces and Autism Puzzle Piece Logos Evoke Negative Associations?

Science.gov (United States)

Gernsbacher, Morton Ann; Raimond, Adam R.; Stevenson, Jennifer L.; Boston, Jilana S.; Harp, Bev

2018-01-01

Puzzle pieces have become ubiquitous symbols for autism. However, puzzle-piece imagery stirs debate between those who support and those who object to its use because they believe puzzle-piece imagery evokes negative associations. Our study empirically investigated whether puzzle pieces evoke negative associations in the general public.…

Ebselen increases cytosolic free Ca2+ concentration, stimulates glutamate release and increases GFAP content in rat hippocampal astrocytes

International Nuclear Information System (INIS)

Salazar, Miguel; Pariente, Jose Antonio; Salido, Gines Maria; Gonzalez, Antonio

2008-01-01

We have investigated the effect of the seleno-organic compound and radical scavenger ebselen on rat hippocampal astrocytes in culture. Throughout our study we carried out determinations of [Ca 2+ ] c in fura-2-loaded cells by single cell imaging, glutamate secretion employing an enzymatic-based assay and GFAP expression, which was monitorized by immunocytochemistry and confocal microscopy. Our results show that ebselen (1-20 μM) dose dependently increases [Ca 2+ ] c , stimulates glutamate release and increases GFAP content, a hallmark of astrocyte reactivity. Ebselen did not alter significantly cell viability as assayed by determination of LDH release into the extracellular medium. Ebselen-evoked glutamate release and increase in GFAP content were Ca 2+ -dependent, because incubation of astrocytes in the absence of extracellular Ca 2+ (medium containing 0.5 mM EGTA) and in the presence of the intracellular Ca 2+ chelator BAPTA (10 μM) significantly reduced ebselen-evoked changes in these parameters. The effects of ebselen we have observed may underline various signalling pathways which are important for cell proliferation, differentiation and function. However, aberrations in astroglial physiology could significantly compromise brain function, due to their role as modulators of neuron activity. Therefore, we consider that careful attention should be paid when employing ebselen as a prophylactic agent against brain damage

Raynaud's phenomenon

DEFF Research Database (Denmark)

Nielsen, S L; Christensen, N J; Olsen, N

1980-01-01

. The forearm venous concentration of noradrenaline was lower and adrenaline concentration higher in the sympathectomized patients than in the other groups (p less than 0,05). Noradrenaline showed a significant increase during body cooling in normals and primary Raynaud's (p less than 0......The reaction to body and finger cooling was recorded in seven patients with relapse of primary Raynaud's phenomenon after sufficiently performed bilateral upper thoracic sympathectomy and for comparison in eight young women with primary Raynaud's phenomenon as well as in seven normal women......,05). There was no significant correlation between the vasoconstrictor response to cooling of a finger and the noradrenaline concentration probably due to the fact that skin vasoconstriction impeded release of noradrenaline from the skin. The relapse of Raynaud's phenomenon after surgically sufficient sympathectomy could...

Influence of acute treatment with sibutramine on the sympathetic neurotransmission of the young rat vas deferens.

Science.gov (United States)

de Souza, Bruno Palmieri; da Silva, Edilson Dantas; Jurkiewicz, Aron; Jurkiewicz, Neide Hyppolito

2014-09-05

The effects of acute treatment with sibutramine on the peripheral sympathetic neurotransmission in vas deferens of young rats were still not evaluated. Therefore, we carried out this study in order to verify the effects of acute sibutramine treatment on the neuronal- and exogenous agonist-induced contractions of the young rat vas deferens. Young 45-day-old male Wistar rats were pretreated with sibutramine 6 mg/kg and after 4h the vas deferens was used for experiment. The acute treatment with sibutramine was able to increase the potency (pD2) of noradrenaline and phenylephrine. Moreover, the efficacy (Emax) of noradrenaline was increased while the efficacy of serotonin and nicotine were decreased. The maximum effect induced by a single concentration of tyramine was diminished in the vas deferens from treated group. Moreover, the leftward shift of the noradrenaline curves promoted by uptake blockers (cocaine and corticosterone) and β-adrenoceptor antagonist (propranolol) was reduced in the vas deferens of treated group. The initial phasic and secondary tonic components of the neuronal-evoked contractions of vas deferens from treated group at the frequencies of 2 Hz were decreased. Moreover, only the initial phasic component at 5 Hz was diminished by the acute treatment with sibutramine. In conclusion, we showed that the acute treatment with sibutramine in young rats was able to affect the peripheral sympathetic nervous system by inhibition of noradrenaline uptake and reduction of the neuronal content of this neurotransmitter, leading to an enhancement of vas deferens sensitivity to noradrenaline. Copyright © 2014 Elsevier B.V. All rights reserved.

Refractory episodic vertigo: role of intratympanic gentamicin and vestibular evoked myogenic potentials,

Directory of Open Access Journals (Sweden)

Erika Celis-Aguilar

Full Text Available Abstract Introduction: Even today, the treatment of intractable vertigo remains a challenge. Vestibular ablation with intratympanic gentamicin stands as a good alternative in the management of refractory vertigo patients. Objective: To control intractable vertigo through complete saccular and horizontal canal vestibular ablation with intratympanic gentamicin treatment. Methods: Patients with refractory episodic vertigo were included. The inclusion criteria were: unilateral ear disease, moderate to profound sensorineural hearing loss, and failure to other treatments. Included patients underwent 0.5-0.8 mL of gentamicin intratympanic application at a 30 mg/mL concentration. Vestibular ablation was confirmed by the absence of response on cervical vestibular evoked myogenic potentials and no response on caloric tests. Audiometry, electronystagmography with iced water, and vestibular evoked myogenic potentials were performed in all patients. Results: Ten patients were included; nine patients with Meniere's disease and one patient with (late onset delayed hydrops. Nine patients showed an absent response on vestibular evoked myogenic potentials and no response on caloric tests. The only patient with low amplitude on cervical vestibular evoked myogenic potentials had vertigo recurrence. Vertigo control was achieved in 90% of the patients. One patient developed hearing loss >30 dB. Conclusions: Cervical vestibular evoked myogenic potentials confirmed vestibular ablation in patients treated with intratympanic gentamicin. High-grade vertigo control was due to complete saccular and horizontal canal ablation (no response to iced water in electronystagmography and no response on cervical vestibular evoked myogenic potentials.

Phantom somatosensory evoked potentials following selective intraneural electrical stimulation in two amputees.

Science.gov (United States)

Granata, Giuseppe; Di Iorio, Riccardo; Romanello, Roberto; Iodice, Francesco; Raspopovic, Stanisa; Petrini, Francesco; Strauss, Ivo; Valle, Giacomo; Stieglitz, Thomas; Čvančara, Paul; Andreu, David; Divoux, Jean-Louis; Guiraud, David; Wauters, Loic; Hiairrassary, Arthur; Jensen, Winnie; Micera, Silvestro; Rossini, Paolo Maria

2018-06-01

The aim of the paper is to objectively demonstrate that amputees implanted with intraneural interfaces are truly able to feel a sensation in the phantom hand by recording "phantom" somatosensory evoked potentials from the corresponding brain areas. We implanted four transverse intrafascicular multichannel electrodes, available with percutaneous connections to a multichannel electrical stimulator, in the median and ulnar nerves of two left trans-radial amputees. Two channels of the implants that were able to elicit sensations during intraneural nerve stimulation were chosen, in both patients, for recording somatosensory evoked potentials. We recorded reproducible evoked responses by stimulating the median and the ulnar nerves in both cases. Latencies were in accordance with the arrival of somatosensory information to the primary somatosensory cortex. Our results provide evidence that sensations generated by intraneural stimulation are truly perceived by amputees and located in the phantom hand. Moreover, our results strongly suggest that sensations perceived in different parts of the phantom hand result in different evoked responses. Somatosensory evoked potentials obtained by selective intraneural electrical stimulation in amputee patients are a useful tool to provide an objective demonstration of somatosensory feedback in new generation bidirectional prostheses. Copyright © 2018. Published by Elsevier B.V.

An inventory and update of jealousy-evoking partner behaviours in modern society.

Science.gov (United States)

Dijkstra, Pieternel; Barelds, Dick P H; Groothof, Hinke A K

2010-01-01

The goal of the present study was to identify the most important jealousy-evoking partner behaviours and to examine the extent to which these behaviours evoke jealousy. Based on the literature, a questionnaire was constructed containing 42 jealousy-evoking partner behaviours, including a partner's extra-dyadic involvement with someone else by means of modern communication devices, such as the Internet. A second study examined the extent to which undergraduates and a community sample experienced jealousy in response to these partner behaviours. Results showed that explicit unfaithful behaviours evoked most feelings of jealousy, followed by a partner's emotional or romantic involvement with someone else by means of modern communication devices. In general, older individuals responded with less jealousy in response to a partner's unfaithful and suspicious behaviours. Clinical implications are discussed. (c) 2009 John Wiley & Sons, Ltd.

Evoked Brain Activity and Personnel Performance

Science.gov (United States)

1987-10-01

Shucard and Horn (1972), Galbraith, Gliddon, and Busk (1970), and Callaway (1975), the latter using Navy recruits. Callaway’s own work was reported at...G.C., Gliddon, J.B., & Busk , J. (1970). Visual evoked responses in mentally retarded and nonretarded subjects. American Journal of Mental Deficiency

Evoked potentials in pediatric cerebral malaria

Directory of Open Access Journals (Sweden)

Minal Bhanushali

2011-12-01

Full Text Available Cortical evoked potentials (EP provide localized data regarding brain function and may offer prognostic information and insights into the pathologic mechanisms of malariamediated cerebral injury. As part of a prospective cohort study, we obtained somatosensory evoked potentials (SSEPs and brainstem auditory EPs (AEPs within 24 hours of admission on 27 consecutive children admitted with cerebral malaria (CM. Children underwent follow-up for 12 months to determine if they had any long term neurologic sequelae. EPs were obtained in 27 pediatric CM admissions. Two children died. Among survivors followed an average of 514 days, 7/25 (28.0% had at least one adverse neurologic outcome. Only a single subject had absent cortical EPs on admission and this child had a good neurologic outcome. Among pediatric CM survivors, cortical EPs are generally intact and do not predict adverse neurologic outcomes. Further study is needed to determine if alterations in cortical EPs can be used to predict a fatal outcome in CM.

Laser-evoked coloration in polymers

International Nuclear Information System (INIS)

Zheng, H.Y.; Rosseinsky, David; Lim, G.C.

2005-01-01

Laser-evoked coloration in polymers has long been a major aim of polymer technology for potential applications in product surface decoration, marking personalised images and logos. However, the coloration results reported so far were mostly attributed to laser-induced thermal-chemical reactions. The laser-irradiated areas are characterized with grooves due to material removal. Furthermore, only single color was laser-induced in any given polymer matrix. To induce multiple colors in a given polymer matrix with no apparent surface material removal is most desirable and challenging and may be achieved through laser-induced photo-chemical reactions. However, little public information is available at present. We report that two colors of red and green have been produced on an initially transparent CPV/PVA samples through UV laser-induced photo-chemical reactions. This is believed the first observation of laser-induced multiple-colors in the given polymer matrix. It is believed that the colorants underwent photo-effected electron transfer with suitable electron donors from the polymers to change from colorless bipyridilium Bipm 2+ to the colored Bipm + species. The discovery may lead to new approaches to the development of laser-evoked multiple coloration in polymers

Refractory episodic vertigo: role of intratympanic gentamicin and vestibular evoked myogenic potentials.

Science.gov (United States)

Celis-Aguilar, Erika; Hinojosa-González, Ramon; Vales-Hidalgo, Olivia; Coutinho-Toledo, Heloisa

Even today, the treatment of intractable vertigo remains a challenge. Vestibular ablation with intratympanic gentamicin stands as a good alternative in the management of refractory vertigo patients. To control intractable vertigo through complete saccular and horizontal canal vestibular ablation with intratympanic gentamicin treatment. Patients with refractory episodic vertigo were included. The inclusion criteria were: unilateral ear disease, moderate to profound sensorineural hearing loss, and failure to other treatments. Included patients underwent 0.5-0.8mL of gentamicin intratympanic application at a 30mg/mL concentration. Vestibular ablation was confirmed by the absence of response on cervical vestibular evoked myogenic potentials and no response on caloric tests. Audiometry, electronystagmography with iced water, and vestibular evoked myogenic potentials were performed in all patients. Ten patients were included; nine patients with Meniere's disease and one patient with (late onset) delayed hydrops. Nine patients showed an absent response on vestibular evoked myogenic potentials and no response on caloric tests. The only patient with low amplitude on cervical vestibular evoked myogenic potentials had vertigo recurrence. Vertigo control was achieved in 90% of the patients. One patient developed hearing loss >30dB. Cervical vestibular evoked myogenic potentials confirmed vestibular ablation in patients treated with intratympanic gentamicin. High-grade vertigo control was due to complete saccular and horizontal canal ablation (no response to iced water in electronystagmography and no response on cervical vestibular evoked myogenic potentials). Copyright © 2016 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Role of transglutaminase in insulin release. Study with glycine and sarcosine methylesters

International Nuclear Information System (INIS)

Sener, A.; Dunlop, M.E.; Gomis, R.; Mathias, P.C.; Malaisse-Lagae, F.; Malaisse, W.J.

1985-01-01

The Ca2+-responsive enzyme transglutaminase, which catalyzes the cross-bridging of proteins, is present in pancreatic islet cells, but its participation in the process of insulin release remains to be documented. Glycine methylester (1.0-10.0 mM) inhibited, in a dose-related manner, transglutaminase activity in rat pancreatic islet homogenates, decreased [ 14 C]methylamine incorporation into endogenous proteins of intact islets, and caused a rapid and reversible inhibition of insulin release evoked by D-glucose, while failing to affect D-[U- 14 C]glucose oxidation. Glycine methylester also inhibited insulin release induced by other nutrient or nonnutrient secretagogues. Sarcosine methylester failed to affect transglutaminase activity, [ 14 C]methylamine incorporation, and insulin release. Both methylesters mobilized 45 Ca from prelabeled intact islets, from membranes of islet cells, liver or brain, and from artificial lipid multilayers, this Ca mobilization being apparently unrelated to changes in transglutaminase activity. It is proposed that, in the pancreatic B cell, transglutaminase participates in the machinery controlling the access of secretory granules to the exocytotic sites

A comparison of auditory evoked potentials to acoustic beats and to binaural beats.

Science.gov (United States)

Pratt, Hillel; Starr, Arnold; Michalewski, Henry J; Dimitrijevic, Andrew; Bleich, Naomi; Mittelman, Nomi

2010-04-01

The purpose of this study was to compare cortical brain responses evoked by amplitude modulated acoustic beats of 3 and 6 Hz in tones of 250 and 1000 Hz with those evoked by their binaural beats counterparts in unmodulated tones to indicate whether the cortical processes involved differ. Event-related potentials (ERPs) were recorded to 3- and 6-Hz acoustic and binaural beats in 2000 ms duration 250 and 1000 Hz tones presented with approximately 1 s intervals. Latency, amplitude and source current density estimates of ERP components to beats-evoked oscillations were determined and compared across beat types, beat frequencies and base (carrier) frequencies. All stimuli evoked tone-onset components followed by oscillations corresponding to the beat frequency, and a subsequent tone-offset complex. Beats-evoked oscillations were higher in amplitude in response to acoustic than to binaural beats, to 250 than to 1000 Hz base frequency and to 3 Hz than to 6 Hz beat frequency. Sources of the beats-evoked oscillations across all stimulus conditions located mostly to left temporal lobe areas. Differences between estimated sources of potentials to acoustic and binaural beats were not significant. The perceptions of binaural beats involve cortical activity that is not different than acoustic beats in distribution and in the effects of beat- and base frequency, indicating similar cortical processing. Copyright 2010 Elsevier B.V. All rights reserved.

Study on change of multi-modally evoked potentials in nasopharyngeal carcinoma patients after radiotherapy

International Nuclear Information System (INIS)

Qin Ling; Chen Jiaxin; Zhang Lixiang; Wang Tiejian; Han Min; Lu Xiaoling

2001-01-01

Objective: To investigate possible changes of multi-modally evoked potentials in nasopharyngeal carcinoma patients after radiotherapy. Methods: Altogether 48 nasopharyngeal carcinoma patients receiving primary conventional external beam irradiation were examined before and after radiotherapy to determine their brainstem auditory-evoked potential (BAEP), short-latency somatosensory-evoked potential (SLSEP) and pattern reversal visual-evoked potential (PRVEP). Results: In comparison with the conditions before radiotherapy, in different periods after radiotherapy abnormal peak latency and interval latency difference were found in BAEP, SLSEP and PRVEP. Conclusion: Nasopharyngeal carcinoma after radiotherapy may cause abnormal function of nerve conduction in early periods, which can be showed by BAEP, SLSEP, PRVEP, and injury can be timely detected if the three evoked potentials are used together. Thus authors suggest BAEP, SLSEP, PRVEP should be examined in nasopharyngeal carcinoma patients during and after the radiotherapy so as to find early damage in auditory somatosensory and visual conduction pathways

Blockade of chloride channels by DIDS stimulates renin release and inhibits contraction of afferent arterioles

DEFF Research Database (Denmark)

Jensen, B L; Skøtt, O

1996-01-01

or without ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid] and DIDS were not additive. In the absence of chloride, basal renin release was suppressed and the stimulatory effect of DIDS was abolished. The DIDS-induced enhancement of renin release was not dependent on bicarbonate....... Norepinephrine (5 x 10(-7)-1 x 10(-6) M) and angiotensin II (1 x 10(-8)-10(-6) M) evoked reversible and dose-dependent contractions of microperfused rabbit afferent arterioles. DIDS (0.5 mM) did not affect the basal diameter of the arterioles but strongly inhibited the response to angiotensin II and attenuated...

Activation of presynaptic oxytocin receptors enhances glutamate release in the ventral hippocampus of prenatally restraint stressed rats.

Science.gov (United States)

Mairesse, Jérôme; Gatta, Eleonora; Reynaert, Marie-Line; Marrocco, Jordan; Morley-Fletcher, Sara; Soichot, Marion; Deruyter, Lucie; Camp, Gilles Van; Bouwalerh, Hammou; Fagioli, Francesca; Pittaluga, Anna; Allorge, Delphine; Nicoletti, Ferdinando; Maccari, Stefania

2015-12-01

Oxytocin receptors are known to modulate synaptic transmission and network activity in the hippocampus, but their precise function has been only partially elucidated. Here, we have found that activation of presynaptic oxytocin receptor with the potent agonist, carbetocin, enhanced depolarization-evoked glutamate release in the ventral hippocampus with no effect on GABA release. This evidence paved the way for examining the effect of carbetocin treatment in "prenatally restraint stressed" (PRS) rats, i.e., the offspring of dams exposed to repeated episodes of restraint stress during pregnancy. Adult PRS rats exhibit an anxious/depressive-like phenotype associated with an abnormal glucocorticoid feedback regulation of the hypothalamus-pituitary-adrenal (HPA) axis, and, remarkably, with a reduced depolarization-evoked glutamate release in the ventral hippocampus. Chronic systemic treatment with carbetocin (1mg/kg, i.p., once a day for 2-3 weeks) in PRS rats corrected the defect in glutamate release, anxiety- and depressive-like behavior, and abnormalities in social behavior, in the HPA response to stress, and in the expression of stress-related genes in the hippocampus and amygdala. Of note, carbetocin treatment had no effect on these behavioral and neuroendocrine parameters in prenatally unstressed (control) rats, with the exception of a reduced expression of the oxytocin receptor gene in the amygdala. These findings disclose a novel function of oxytocin receptors in the hippocampus, and encourage the use of oxytocin receptor agonists in the treatment of stress-related psychiatric disorders in adult life. Copyright © 2015 Elsevier Ltd. All rights reserved.

Tramadol Extended-Release for the Management of Pain due to Osteoarthritis

Science.gov (United States)

Guetti, Cristiana; Paladini, Antonella; Varrassi, Giustino

2013-01-01

Current knowledge on pathogenesis of osteoarticular pain, as well as the consequent several, especially on the gastrointestinal, renal, and cardiovascular systems, side effects of NSAIDs, makes it difficult to perform an optimal management of this mixed typology of pain. This is especially observable in elderly patients, the most frequently affected by osteoarthritis (OA). Tramadol is an analgesic drug, the action of which has a twofold action. It has a weak affinity to mu opioid receptors and, at the same time, can result in inhibition of the reuptake of noradrenaline and serotonin in nociceptorial descending inhibitory control system. These two mechanisms, “opioidergic” and “nonopioidergic,” are the grounds for contrasting certain types of pain that are generally less responsive to opioids, such as neuropathic pain or mixed OA pain. The extended-release formulation of tramadol has good efficacy and tolerability and acts through a dosing schedule that allows a high level of patients compliance to therapies with a good recovery outcome for the patients' functional status. PMID:27335872

Index finger somatosensory evoked potentials in blind Braille readers.

Science.gov (United States)

Giriyappa, Dayananda; Subrahmanyam, Roopakala Mysore; Rangashetty, Srinivasa; Sharma, Rajeev

2009-01-01

Traditionally, vision has been considered the dominant modality in our multi-sensory perception of the surrounding world. Sensory input via non-visual tracts becomes of greater behavioural relevance in totally blind individuals to enable effective interaction with the world around them. These include audition and tactile perceptions, leading to an augmentation in these perceptions when compared with normal sighted individuals. The objective of the present work was to study the index finger somatosensory evoked potentials (SEPs) in totally blind and normal sighted individuals. SEPs were recorded in 15 Braille reading totally blind females and compared with 15 age-matched normal sighted females. Latency and amplitudes of somatosensory evoked potential waveforms (N9, N13, and N20) were measured. Amplitude of N20 SEP (a cortical somatosensory evoked potential) was significantly larger in the totally blind than in normal sighted individuals (p Braille reading right index finger. Totally blind Braille readers have larger N20 amplitude, suggestive of greater somatosensory cortical representation of the Braille reading index finger.

Changes in acetylcholine content, release and muscarinic receptors in rat hippocampus under cold stress

International Nuclear Information System (INIS)

Fatranska, M.; Budai, D.; Gulya, K; Kvetnansky, R.

1989-01-01

The aim was to study the mechanism of the previously established decrease in acetylcholine (ACh) concentration in the rat hippocampus under cold stress. Male rats were exposed for 14 days to cold (5 degree C) or kept (controls) at room temperature (24 degree C). Acetylcholine content, release and muscarinic receptor binding were investigated in the hippocampus. Cold exposure resulted in a decrease of ACh concentration in the dorsal hippocampus. Moreover, the potassium-evoked release of ACh from hippocampal slices was increased and an increase of maximal binding capacity of [ 3 H](-) quinuclidinyl benzilate in the dorsal hippocampus of cold exposed animals was also observed. Thus the decrease of hippocampal ACh concentration under cold exposure is probably due to its increased release. On balance then, our results demonstrate that cold stress in the rat induces significant activation of the hippocampal cholinergic system

Omega-conotoxin- and nifedipine-insensitive voltage-operated calcium channels mediate K(+)-induced release of pro-thyrotropin-releasing hormone-connecting peptides Ps4 and Ps5 from perifused rat hypothalamic slices.

Science.gov (United States)

Valentijn, K; Tranchand Bunel, D; Vaudry, H

1992-07-01

The rat thyrotropin-releasing hormone (TRH) precursor (prepro-TRH) contains five copies of the TRH progenitor sequence linked together by intervening sequences. Recently, we have shown that the connecting peptides prepro-TRH-(160-169) (Ps4) and prepro-TRH-(178-199) (Ps5) are released from rat hypothalamic neurones in response to elevated potassium concentrations, in a calcium-dependent manner. In the present study, the role of voltage-operated calcium channels in potassium-induced release of Ps4 and Ps5 was investigated, using a perifusion system for rat hypothalamic slices. The release of Ps4 and Ps5 stimulated by potassium (70 mM) was blocked by the inorganic ions Co2+ (2.6 mM) and Ni2+ (5 mM). In contrast, the stimulatory effect of KCl was insensitive to Cd2+ (100 microM). The dihydropyridine antagonist nifedipine (10 microM) had no effect on K(+)-evoked release of Ps4 and Ps5. Furthermore, the response to KCl was not affected by nifedipine (10 microM) in combination with diltiazem (1 microM), a benzothiazepine which increases the affinity of dihydropyridine antagonists for their receptor. The dihydropyridine agonist BAY K 8644, at concentrations as high as 1 mM, did not stimulate the basal secretion of Ps4 and Ps5. In addition, BAY K 8644 had no potentiating effect on K(+)-induced release of Ps4 and Ps5. The marine cone snail toxin omega-conotoxin, a blocker of both L- and N-type calcium channels had no effect on the release of Ps4 and Ps5 stimulated by potassium. Similarly, the omega-conopeptide SNX-111, a selective blocker of N-type calcium channels, did not inhibit the stimulatory effect of potassium. The release of Ps4 and Ps5 evoked by high K+ was insensitive to the non-selective calcium channel blocker verapamil (20 microM). Amiloride (1 microM), a putative blocker of T-type calcium channels, did not affect KCl-induced secretion of the two connecting peptides. Taken together, these results indicate that two connecting peptides derived from the pro-TRH, Ps

Newborn hearing screening with transient evoked otoacoustic emissions and automatic auditory brainstem response

Directory of Open Access Journals (Sweden)

Renata Mota Mamede de Carvallo

2008-09-01

Full Text Available Objective: The aim of the present investigation was to check Transient Evoked Otoacoustic Emissions and Automatic Auditory Brainstem Response tests applied together in regular nurseries and Newborn Intensive Care Units (NICU, as well as to describe and compare the results obtained in both groups. Methods: We tested 150 newborns from regular nurseries and 70 from NICU. Rresults: The newborn hearing screening results using Transient Evoked Otoacoustic Emissions and Automatic Auditory Brainstem Response tests could be applied to all babies. The “pass” result for the group of babies from the nursery was 94.7% using Transient Evoked Otoacoustic Emissions and 96% using Automatic Auditory Brainstem Response. The newborn intensive care unit group obtained 87.1% on Transient Evoked Otoacoustic Emissions and 80% on the Automatic Auditory Brainstem Response, and there was no statistical difference between the procedures when the groups were evaluated individually. However, comparing the groups, Transient Evoked Otoacoustic Emissions were presented in 94.7% of the nursery babies and in 87.1% in the group from the newborn intensive care unit. Considering the Automatic Auditory Brainstem Response, we found 96 and 87%, respectively. Cconclusions: Transient Evoked Otoacoustic Emissions and Automatic Auditory Brainstem Response had similar “pass” and “fail” results when the procedures were applied to neonates from the regular nursery, and the combined tests were more precise to detect hearing impairment in the newborn intensive care unit babies.

Sex differences in the jealousy-evoking nature of a rival's body build

NARCIS (Netherlands)

Dijkstra, Pieternel; Buunk, Abraham (Bram)

This study among 185 college students showed that potential rivals with a relatively low waist-to-hip ratio (WHR) evoked more jealousy in women than in men. In contrast, rivals with a relatively high shoulder-to-hip ratio (SHR) evoked more jealousy in men than in women, particularly when the rival

Enhanced brainstem and cortical evoked response amplitudes: single-trial covariance analysis.

Science.gov (United States)

Galbraith, G C

2001-06-01

The purpose of the present study was to develop analytic procedures that improve the definition of sensory evoked response components. Such procedures could benefit all recordings but would especially benefit difficult recordings where many trials are contaminated by muscle and movement artifacts. First, cross-correlation and latency adjustment analyses were applied to the human brainstem frequency-following response and cortical auditory evoked response recorded on the same trials. Lagged cross-correlation functions were computed, for each of 17 subjects, between single-trial data and templates consisting of the sinusoid stimulus waveform for the brainstem response and the subject's own smoothed averaged evoked response P2 component for the cortical response. Trials were considered in the analysis only if the maximum correlation-squared (r2) exceeded .5 (negatively correlated trials were thus included). Identical correlation coefficients may be based on signals with quite different amplitudes, but it is possible to assess amplitude by the nonnormalized covariance function. Next, an algorithm is applied in which each trial with negative covariance is matched to a trial with similar, but positive, covariance and these matched-trial pairs are deleted. When an evoked response signal is present in the data, the majority of trials positively correlate with the template. Thus, a residual of positively correlated trials remains after matched covariance trials are deleted. When these residual trials are averaged, the resulting brainstem and cortical responses show greatly enhanced amplitudes. This result supports the utility of this analysis technique in clarifying and assessing evoked response signals.

Viral vector-mediated overexpression of estrogen receptor-alpha in striatum enhances the estradiol-induced motor activity in female rats and estradiol-modulated GABA release.

Science.gov (United States)

Schultz, Kristin N; von Esenwein, Silke A; Hu, Ming; Bennett, Amy L; Kennedy, Robert T; Musatov, Sergei; Toran-Allerand, C Dominique; Kaplitt, Michael G; Young, Larry J; Becker, Jill B

2009-02-11

Classical estrogen receptor-signaling mechanisms involve estradiol binding to intracellular nuclear receptors [estrogen receptor-alpha (ERalpha) and estrogen receptor-beta (ERbeta)] to promote changes in protein expression. Estradiol can also exert effects within seconds to minutes, however, a timescale incongruent with genomic signaling. In the brain, estradiol rapidly potentiates stimulated dopamine release in the striatum of female rats and enhances spontaneous rotational behavior. Furthermore, estradiol rapidly attenuates the K(+)-evoked increase of GABA in dialysate. We hypothesize that these rapid effects of estradiol in the striatum are mediated by ERalpha located on the membrane of medium spiny GABAergic neurons. This experiment examined whether overexpression of ERalpha in the striatum would enhance the effect of estradiol on rotational behavior and the K(+)-evoked increase in GABA in dialysate. Ovariectomized female rats were tested for rotational behavior or underwent microdialysis experiments after unilateral intrastriatal injections of a recombinant adeno-associated virus (AAV) containing the human ERalpha cDNA (AAV.ERalpha) into the striatum; controls received either the same vector into areas outside the striatum or an AAV containing the human alkaline phosphatase gene into the striatum (AAV.ALP). Animals that received AAV.ERalpha in the striatum exhibited significantly greater estradiol-induced contralateral rotations compared with controls and exhibited behavioral sensitization of contralateral rotations induced by a low-dose of amphetamine. ERalpha overexpression also enhanced the inhibitory effect of estradiol on K(+)-evoked GABA release suggesting that disinhibition of dopamine release from terminals in the striatum resulted in the enhanced rotational behavior.

Is Urgent Evoke a Digital Ba?

DEFF Research Database (Denmark)

Wichmand, Mette

2018-01-01

of such a platform, the World Bank’s online game Urgent Evoke, which has been designed with the pur- pose of engaging citizens in developing innovative solutions for sociopolitical problems like poverty. The analysis is based on Nonaka’s concept of Ba, which means “place” and is described as a platform for advancing...

The radioenzymatic determination of adrenaline and noradrenaline in plasma and its use in the diagnostic of pheochromocytomas

International Nuclear Information System (INIS)

Neuhaus, C.P.E.

1982-01-01

The radioenzymatic determination of adrenaline and noradrenaline in human plasma for the diagnosis of pheochromocytomas was put to use after improvements were made with respect to extraction and separation steps. The plasma catecholamines at rest were distinctly higher in patients with pheochromocytomas. The plasma catecholamine level showed a significant increase as well with the glucagon test between the second and fifth minute. The method was not well suited for the localisation diagnostic where the plasma catecholamines were determined in selectively taken blood from the lower vena cava. Overall, however, the radioenzymatic determination of catecholamines in plasma proved itself to be a relatively ponderous, but exact and sensitive method for the measuring of basal catecholamine level and its changes. In the clinical area it is used as a valuable supplement to the contemporary diagnostic of pheochromocytomas. (orig./TRV) [de

Cell-specific gain modulation by synaptically released zinc in cortical circuits of audition.

Science.gov (United States)

Anderson, Charles T; Kumar, Manoj; Xiong, Shanshan; Tzounopoulos, Thanos

2017-09-09

In many excitatory synapses, mobile zinc is found within glutamatergic vesicles and is coreleased with glutamate. Ex vivo studies established that synaptically released (synaptic) zinc inhibits excitatory neurotransmission at lower frequencies of synaptic activity but enhances steady state synaptic responses during higher frequencies of activity. However, it remains unknown how synaptic zinc affects neuronal processing in vivo. Here, we imaged the sound-evoked neuronal activity of the primary auditory cortex in awake mice. We discovered that synaptic zinc enhanced the gain of sound-evoked responses in CaMKII-expressing principal neurons, but it reduced the gain of parvalbumin- and somatostatin-expressing interneurons. This modulation was sound intensity-dependent and, in part, NMDA receptor-independent. By establishing a previously unknown link between synaptic zinc and gain control of auditory cortical processing, our findings advance understanding about cortical synaptic mechanisms and create a new framework for approaching and interpreting the role of the auditory cortex in sound processing.

Evoked Emotions Predict Food Choice

OpenAIRE

Dalenberg, Jelle R.; Gutjar, Swetlana; ter Horst, Gert J.; de Graaf, Kees; Renken, Remco J.; Jager, Gerry

2014-01-01

In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments. Therefore, the focus within recent studies shifted towards using emotion-profiling methods that successfully can discriminate between products that are equally liked. However, it is unclear how well ...

Measuring endogenous 5-HT release by emission tomography: promises and pitfalls

DEFF Research Database (Denmark)

Paterson, Louise M; Tyacke, Robin J; Nutt, David J

2010-01-01

Molecular in vivo neuroimaging techniques can be used to measure regional changes in endogenous neurotransmitters, evoked by challenges that alter synaptic neurotransmitter concentration. This technique has most successfully been applied to the study of endogenous dopamine release using positron......, with reference to the dopaminergic system. Studies that aim to image acute, endogenous 5-HT release or depletion at 5-HT receptor targets are summarised, with particular attention to studies in humans. Radiotracers targeting the 5-HT(1A), 5-HT(2A), and 5-HT(4) receptors and the serotonin reuptake transporter...... have been explored for their sensitivity to 5-HT fluctuations, but with mixed outcomes; tracers for these targets cannot reliably image endogenous 5-HT in humans. Shortcomings in our basic knowledge of the mechanisms underlying changes in binding potential are addressed, and suggestions are made...

Myopic (HD-PTP, PTPN23) selectively regulates synaptic neuropeptide release.

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Bulgari, Dinara; Jha, Anupma; Deitcher, David L; Levitan, Edwin S

2018-02-13

Neurotransmission is mediated by synaptic exocytosis of neuropeptide-containing dense-core vesicles (DCVs) and small-molecule transmitter-containing small synaptic vesicles (SSVs). Exocytosis of both vesicle types depends on Ca 2+ and shared secretory proteins. Here, we show that increasing or decreasing expression of Myopic (mop, HD-PTP, PTPN23), a Bro1 domain-containing pseudophosphatase implicated in neuronal development and neuropeptide gene expression, increases synaptic neuropeptide stores at the Drosophila neuromuscular junction (NMJ). This occurs without altering DCV content or transport, but synaptic DCV number and age are increased. The effect on synaptic neuropeptide stores is accounted for by inhibition of activity-induced Ca 2+ -dependent neuropeptide release. cAMP-evoked Ca 2+ -independent synaptic neuropeptide release also requires optimal Myopic expression, showing that Myopic affects the DCV secretory machinery shared by cAMP and Ca 2+ pathways. Presynaptic Myopic is abundant at early endosomes, but interaction with the endosomal sorting complex required for transport III (ESCRT III) protein (CHMP4/Shrub) that mediates Myopic's effect on neuron pruning is not required for control of neuropeptide release. Remarkably, in contrast to the effect on DCVs, Myopic does not affect release from SSVs. Therefore, Myopic selectively regulates synaptic DCV exocytosis that mediates peptidergic transmission at the NMJ.

Viral Vector Mediated Over-Expression of Estrogen Receptor–α in Striatum Enhances the Estradiol-induced Motor Activity in Female Rats and Estradiol Modulated GABA Release

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Schultz, Kristin N.; von Esenwein, Silke A.; Hu, Ming; Bennett, Amy L.; Kennedy, Robert T.; Musatov, Sergei; Toran-Allerand, C. Dominique; Kaplitt, Michael G.; Young, Larry J.; Becker, Jill B.

2009-01-01

Classical estrogen receptor signaling mechanisms involve estradiol binding to intracellular nuclear receptors (estrogen receptor-α (ERα) and estrogen receptor-β (ERβ)) to promote changes in protein expression. Estradiol can also exert effects within seconds to minutes, however, a timescale incongruent with genomic signaling. In the brain, estradiol rapidly potentiates stimulated dopamine release in the striatum of female rats and enhances spontaneous rotational behavior. Furthermore, estradiol rapidly attenuates the K+- evoked increase of GABA in dialysate. We hypothesize that these rapid effects of estradiol in the striatum are mediated by ERα located on the membrane of medium spiny GABAergic neurons. This experiment examined whether over-expression of ERα in the striatum would enhance the effect of estradiol on rotational behavior and the K+- evoked increase in GABA in dialysate. Ovariectomized female rats were tested for rotational behavior or underwent microdialysis experiments after unilateral intrastriatal injections of a recombinant adeno-associated virus (AAV) containing the human ERα cDNA (AAV.ERα) into the striatum; controls received either the same vector into areas outside the striatum or an AAV containing the human alkaline phosphatase gene into the striatum (AAV.ALP). Animals that received AAV.ERα in the striatum exhibited significantly greater estradiol-induced contralateral rotations compared to controls and exhibited behavioral sensitization of contralateral rotations induced by a low dose of amphetamine. ERα over-expression also enhanced the inhibitory effect of estradiol on K+- evoked GABA release suggesting that disinhibition of dopamine release from terminals in the striatum resulted in the enhanced rotational behavior. PMID:19211896

Effect of peripherally and cortically evoked swallows on jaw reflex responses in anesthetized rabbits.

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Suzuki, Taku; Yoshihara, Midori; Sakai, Shogo; Tsuji, Kojun; Nagoya, Kouta; Magara, Jin; Tsujimura, Takanori; Inoue, Makoto

2018-05-03

This study aimed to investigate whether the jaw-opening (JOR) and jaw-closing reflexes (JCR) are modulated during not only peripherally, but also centrally, evoked swallowing. Experiments were carried out on 24 adult male Japanese white rabbits. JORs were evoked by trigeminal stimulation at 1 Hz for 30 sec. In the middle 10 sec, either the superior laryngeal nerve (SLN) or cortical swallowing area (Cx) was simultaneously stimulated to evoke swallowing. The peak-to-peak JOR amplitude was reduced during the middle and late 10-sec periods (i.e., during and after SLN or Cx stimulation), and the reduction was dependent on the current intensity of SLN/Cx stimulation: greater SLN/Cx stimulus current resulted in greater JOR inhibition. The reduction rate was significantly greater during Cx stimulation than during SLN stimulation. The amplitude returned to baseline 2 min after 10-sec SLN/Cx stimulation. The effect of co-stimulation of SLN and Cx was significantly greater than that of SLN stimulation alone. There were no significant differences in any parameters of the JCR between conditions. These results clearly showed that JOR responses were significantly suppressed, not only during peripherally evoked swallowing but also during centrally evoked swallowing, and that the inhibitory effect is likely to be larger during centrally compared with peripherally evoked swallowing. The functional implications of these results are discussed. Copyright © 2018. Published by Elsevier B.V.

The Relationship of Visual Evoked Potential Asymmetries to the Performance of Sonar Operators

Science.gov (United States)

1981-08-11

also been related to EP variability. Schizophrenic adults and patients with Korsakoff’s Syndrome have shown higher evoked potential variability than...average evoked response in Korsakoff patients. J. Psychiatry Res. 6: 253-260, 1969. Santoro, T. and D. Fender. Rules for the perception of

Raynaud's phenomenon: peripheral catecholamine concentration and effect of sympathectomy.

Science.gov (United States)

Nielsen, S L; Christensen, N J; Olsen, N; Lassen, N A

1980-01-01

The reaction to body and finger cooling was recorded in seven patients with relapse of primary Raynaud's phenomenon after sufficiently performed bilateral upper thoracic sympathectomy and for comparison in eight young women with primary Raynaud's phenomenon as well as in seven normal women. The forearm venous concentration of noradrenaline was lower and adrenaline concentration higher in the sympathectomized patients than in the other groups (p less than 0,05). Noradrenaline showed a significant increase during body cooling in normals and primary Raynaud's (p less than 0,05). There was no significant correlation between the vasoconstrictor response to cooling of a finger and the noradrenaline concentration probably due to the fact that skin vasoconstriction impeded release of noradrenaline from the skin. The relapse of Raynaud's phenomenon after surgically sufficient sympathectomy could not be treated by reserpine or alfa-adrenergic receptor blockers in two patients in whom this was tried.

Measurement of release of endogenous GABA and catabolites of [3H]GABA from synaptosomal preparations using ion-exchange chromatography

International Nuclear Information System (INIS)

Grove, J.; Gardner, C.R.; Richards, M.H.

1982-01-01

Picomole quantities of endogenous GABA in acidified superfusates of synaptosomal preparations have been measured using micro-bore ion-exchange chromatography and post-column formation of the fluorescent iso-indole derivative. Using this technique superfusates have been analyzed directly, without further manipulations, to investigate the release of endogenous GABA. Spontaneous release of GABA was 2-5 pmol/200 microliters superfusate increasing to 20 pmol/200 microliters with potassium stimulation. When gamma-vinyl GABA (RMI 71754), an inhibitor of GABA-T was injected into rats (750 mg/kg) and synaptosomes prepared the potassium-evoked release of GABA was increased 3-fold compared to controls. Chromatographic separations and measurement of release of endogenous and radiolabeled GABA allowed the real specific activity of released GABA to be calculated. Only when 500 microM amino-oxyacetic acid was added during isolation of synaptosomes was the specific activity of released GABA the same as the initial specific activity

Motor Function and Dopamine Release Measurements in Transgenic Huntington’s Disease Model Rats

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Ortiz, Andrea N.; Osterhaus, Gregory L.; Lauderdale, Kelli; Mahoney, Luke; Fowler, Stephen C.; von Hörsten, Stephan; Riess, Olaf; Johnson, Michael A.

2013-01-01

Huntington’s disease (HD) is a fatal, genetic, neurodegenerative disorder characterized by deficits in motor and cognitive function. Here, we have quantitatively characterized motor deficiencies and dopamine release dynamics in transgenic HD model rats. Behavioral analyses were conducted using a newly-developed force-sensing runway and a previously-developed force-plate actometer. Gait disturbances were readily observed in transgenic HD rats at 12 to 15 months of age. Additionally, dopamine system challenge by ip injection of amphetamine also revealed that these rats were resistant to the expression of focused stereotypy compared to wild-type controls. Moreover, dopamine release, evoked by the application of single and multiple electrical stimulus pulses applied at different frequencies, and measured using fast-scan cyclic voltammetry at carbon-fiber microelectrodes, was diminished in transgenic HD rats compared to age-matched wild-type control rats. Collectively, these results underscore the potential contribution of dopamine release alterations to the expression of motor impairments in transgenic HD rats. PMID:22418060

Inhibition of K+ permeability diminishes alpha 2-adrenoceptor mediated effects on norepinephrine release

International Nuclear Information System (INIS)

Zimanyi, I.; Folly, G.; Vizi, E.S.

1988-01-01

The effect of two different potassium channel blockers, 4-aminopyridine (4-AP) and quinine, on the alpha 2-adrenoceptor mediated modulation of norepinephrine (NE) release was investigated. Pairs of mouse vasa deferentia were loaded with 3 H-norepinephrine ( 3 H-NE), superfused continuously, and stimulated electrically. 4-AP (5.3 x 10(-4) M), and quinine (10(-5) M) enhanced the stimulation-evoked release of tritium significantly. The electrically induced release of radioactivity was reduced by alpha 2-adrenoceptor agonists (1-NE and xylazine) and enhanced by the alpha 2-adrenoceptor antagonist yohimbine. Both effects were affected markedly by 4-AP or quinine: the depressant action of 1-NA and xylazine was partially antagonized and the facilitatory effect of yohimbine was completely abolished during the blockade of the potassium channels. It is suggested that the blockade of the potassium permeability counteracts negative feedback modulation; therefore, it seems likely that the stimulation of alpha 2-adrenoceptors leads to an enhanced potassium permeability and hyperpolarization of varicose axon terminals

alpha7 and non-alpha7 nicotinic acetylcholine receptors modulate dopamine release in vitro and in vivo in the rat prefrontal cortex.

Science.gov (United States)

Livingstone, Phil D; Srinivasan, Jayaraman; Kew, James N C; Dawson, Lee A; Gotti, Cecilia; Moretti, Milena; Shoaib, Mohammed; Wonnacott, Susan

2009-02-01

Nicotine enhances attentional and working memory aspects of executive function in the prefrontal cortex (PFC) where dopamine plays a major role. Here, we have determined the nicotinic acetylcholine receptor (nAChR) subtypes that can modulate dopamine release in rat PFC using subtype-selective drugs. Nicotine and 5-Iodo-A-85380 (beta2* selective) elicited [(3)H]dopamine release from both PFC and striatal prisms in vitro and dopamine overflow from medial PFC in vivo. Blockade by dihydro-beta-erythroidine supports the participation of beta2* nAChRs. However, insensitivity of nicotine-evoked [(3)H]dopamine release to alpha-conotoxin-MII in PFC prisms suggests no involvement of alpha6beta2* nAChRs, in contrast to the striatum, and this distinction is supported by immunoprecipitation of nAChR subunits from these tissues. The alpha7 nAChR-selective agonists choline and Compound A also promoted dopamine release from PFC in vitro and in vivo, and their effects were enhanced by the alpha7 nAChR-selective allosteric potentiator PNU-120596 and blocked by specific antagonists. DNQX and MK801 inhibited [(3)H]dopamine release evoked by choline and PNU-120596, suggesting crosstalk between alpha7 nAChRs, glutamate and dopamine in the PFC. In vivo, systemic (but not local) administration of PNU-120596, in the absence of agonist, facilitated dopamine overflow in the medial PFC, consistent with the activation of extracortical alpha7 nAChRs by endogenous acetylcholine or choline. These data establish that both beta2* and alpha7 nAChRs can modulate dopamine release in the PFC in vitro and in vivo. Through their distinct actions on dopamine release, these nAChR subtypes could contribute to executive function, making them specific therapeutic targets for conditions such as schizophrenia and attention deficit hyperactivity disorder.

Effect of α-bungarotoxin and etorphine on acetylcholine-evoked release of endogenous and radiolabeled catecholamines from primary culture of adrenal chromaffin cells

International Nuclear Information System (INIS)

Kageyama, H.; Guidotti, A.

1984-01-01

Cell cultures of adrenal medulla have become an important research tool to study basic processes that regulate catecholamine storage, release and synthesis. Release has been studied either by labeling with [ 3 H]norepinephrine and measuring release of radioactivity or by measuring the endogenous catecholamines released with HPLC. Acetylcholine (5X10 -6 -10 -4 M) appears to release preferentially norepinephrine, although the cells store more epinephrine than norepinephrine. Etorphine and α-bungarotoxin antagonize the release of catecholamines elicited by acetylcholine. This inhibitory action appears to be greater when the measurement of endogenous catecholamines rather than radioactive norepinephrine is used to monitor the action of acetylcholine. The data suggest that the measurement of endogenous catecholamines by HPLC is preferable to the [ 3 H]NE loading and release technique, especially when analyzing the effects of low concentrations of drugs that are thought to affect nicotinic receptor function. (Auth.)

Conduction velocity of the human spinothalamic tract as assessed by laser evoked potentials

DEFF Research Database (Denmark)

Cruccu, G.; Iannetti, G. D.; Agostino, R.

2000-01-01

To study the conduction velocity of the spinothalamic tract (STT) we delivered CO2 laser pulses, evoking pinprick sensations, to the skin overlying the vertebral spinous processes at different spinal levels from C5 to T10 and recorded evoked potentials (LEPs) in 15 healthy human subjects...

Evidence that 5-hydroxytryptamine3 receptors mediate cytotoxic drug and radiation-evoked emesis

International Nuclear Information System (INIS)

Miner, W.D.; Sanger, G.J.; Turner, D.H.

1987-01-01

The involvement of 5-hydroxytryptamine (5-HT) 5-HT 3 receptors in the mechanisms of severe emesis evoked by cytotoxic drugs or by total body irradiation have been studied in ferrets. Anti-emetic compounds tested were domperidone (a dopamine antagonist), metoclopramide (a gastric motility stimulant and dopamine antagonist at conventional doses, a 5-HT 3 receptor antagonist at higher doses) and BRL 24924 (a potent gastric motility stimulant and a 5-HT 3 receptor antagonist). Domperidone or metoclopramide prevented apomorphine-evoked emesis, whereas BRL 24924 did not. Similar doses of domperidone did not prevent emesis evoked by cis-platin or by total body irradiation, whereas metoclopramide or BRL 24924 greatly reduced or prevented these types of emesis. Metoclopramide and BRL 24924 also prevented emesis evoked by a combination of doxorubicin and cyclophosphamide. These results are discussed in terms of a fundamental role for 5-HT 3 receptors in the mechanisms mediating severely emetogenic cancer treatment therapies. (author)

Interhemispheric Asymmetries in Visual Evoked Potential Amplitude

Science.gov (United States)

1980-06-12

Layne, 1965) and of patients with Korsakoff’s syndrome (Malerstein and Callaway, 1969) . In the schizophrenics, the high variability is related to poor...communication. Malerstein, A. J., Callaway, E. Two-tone average evoked response in Korsakoff patients. J. Psychiatr. Res. 6: 253-260, 1969. Marsh, G

Visual cortical somatosensory and brainstem auditory evoked potentials following incidental irradiation of the rhombencephalon

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Nightingale, S. (Royal Victoria Infirmary, Newcastle upon Tyne (UK)); Schofield, I.S.; Dawes, P.J.D.K. (Newcastle upon Tyne Univ. (UK). Newcastle General Hospital)

1984-01-01

Visual, cortical somatosensory and brainstem auditory evoked potentials were recorded before incidental irradiation of the rhombencephalon during radiotherapy in and around the middle ear, and at 11 weeks and eight months after completion of treatment. No patient experienced neurological symptoms during this period. No consistent changes in evoked potentials were found. The failure to demonstrate subclinical radiation-induced demyelination suggests either that the syndrome of early-delayed radiation rhombencephalopathy occurs in an idiosyncratic manner, or that any subclinical lesions are not detectable by serial evoked potential recordings.

Music-evoked emotions in schizophrenia.

Science.gov (United States)

Abe, Daijyu; Arai, Makoto; Itokawa, Masanari

2017-07-01

Previous studies have reported that people with schizophrenia have impaired musical abilities. Here we developed a simple music-based assay to assess patient's ability to associate a minor chord with sadness. We further characterize correlations between impaired musical responses and psychiatric symptoms. We exposed participants sequentially to two sets of sound stimuli, first a C-major progression and chord, and second a C-minor progression and chord. Participants were asked which stimulus they associated with sadness, the first set, the second set, or neither. The severity of psychiatric symptoms was assessed using the Positive and Negative Syndrome Scale (PANSS). Study participants were 29 patients diagnosed with schizophrenia and 29 healthy volunteers matched in age, gender and musical background. 37.9% (95% confidence interval [CI]:19.1-56.7) of patients with schizophrenia associated the minor chord set as sad, compared with 97.9% (95%CI: 89.5-103.6) of controls. Four patients were diagnosed with treatment-resistant schizophrenia, and all four failed to associate the minor chord with sadness. Patients who did not recognize minor chords as sad had significantly higher scores on all PANSS subscales. A simple test allows music-evoked emotions to be assessed in schizophrenia patient, and may show potential relationships between music-evoked emotions and psychiatric symptoms. Copyright © 2016. Published by Elsevier B.V.

Right hemispheric dominance of visual phenomena evoked by intracerebral stimulation of the human visual cortex.

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Jonas, Jacques; Frismand, Solène; Vignal, Jean-Pierre; Colnat-Coulbois, Sophie; Koessler, Laurent; Vespignani, Hervé; Rossion, Bruno; Maillard, Louis

2014-07-01

Electrical brain stimulation can provide important information about the functional organization of the human visual cortex. Here, we report the visual phenomena evoked by a large number (562) of intracerebral electrical stimulations performed at low-intensity with depth electrodes implanted in the occipito-parieto-temporal cortex of 22 epileptic patients. Focal electrical stimulation evoked primarily visual hallucinations with various complexities: simple (spot or blob), intermediary (geometric forms), or complex meaningful shapes (faces); visual illusions and impairments of visual recognition were more rarely observed. With the exception of the most posterior cortical sites, the probability of evoking a visual phenomenon was significantly higher in the right than the left hemisphere. Intermediary and complex hallucinations, illusions, and visual recognition impairments were almost exclusively evoked by stimulation in the right hemisphere. The probability of evoking a visual phenomenon decreased substantially from the occipital pole to the most anterior sites of the temporal lobe, and this decrease was more pronounced in the left hemisphere. The greater sensitivity of the right occipito-parieto-temporal regions to intracerebral electrical stimulation to evoke visual phenomena supports a predominant role of right hemispheric visual areas from perception to recognition of visual forms, regardless of visuospatial and attentional factors. Copyright © 2013 Wiley Periodicals, Inc.

Administration of caffeine inhibited adenosine receptor agonist-induced decreases in motor performance, thermoregulation, and brain neurotransmitter release in exercising rats.

Science.gov (United States)

Zheng, Xinyan; Hasegawa, Hiroshi

2016-01-01

We examined the effects of an adenosine receptor agonist on caffeine-induced changes in thermoregulation, neurotransmitter release in the preoptic area and anterior hypothalamus, and endurance exercise performance in rats. One hour before the start of exercise, rats were intraperitoneally injected with either saline alone (SAL), 10 mg kg(-1) caffeine and saline (CAF), a non-selective adenosine receptor agonist (5'-N-ethylcarboxamidoadenosine [NECA]: 0.5 mg kg(-1)) and saline (NECA), or the combination of caffeine and NECA (CAF+NECA). Rats ran until fatigue on the treadmill with a 5% grade at a speed of 18 m min(-1) at 23 °C. Compared to the SAL group, the run time to fatigue (RTTF) was significantly increased by 52% following caffeine administration and significantly decreased by 65% following NECA injection (SAL: 91 ± 14.1 min; CAF: 137 ± 25.8 min; NECA: 31 ± 13.7 min; CAF+NECA: 85 ± 11.8 min; pcaffeine injection inhibited the NECA-induced decreases in the RTTF, Tcore, heat production, heat loss, and extracellular DA release. Neither caffeine nor NECA affected extracellular noradrenaline or serotonin release. These results support the findings of previous studies showing improved endurance performance and overrides in body limitations after caffeine administration, and imply that the ergogenic effects of caffeine may be associated with the adenosine receptor blockade-induced increases in brain DA release. Copyright © 2015 Elsevier Inc. All rights reserved.

Temporal processing and long-latency auditory evoked potential in stutterers.

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Prestes, Raquel; de Andrade, Adriana Neves; Santos, Renata Beatriz Fernandes; Marangoni, Andrea Tortosa; Schiefer, Ana Maria; Gil, Daniela

Stuttering is a speech fluency disorder, and may be associated with neuroaudiological factors linked to central auditory processing, including changes in auditory processing skills and temporal resolution. To characterize the temporal processing and long-latency auditory evoked potential in stutterers and to compare them with non-stutterers. The study included 41 right-handed subjects, aged 18-46 years, divided into two groups: stutterers (n=20) and non-stutters (n=21), compared according to age, education, and sex. All subjects were submitted to the duration pattern tests, random gap detection test, and long-latency auditory evoked potential. Individuals who stutter showed poorer performance on Duration Pattern and Random Gap Detection tests when compared with fluent individuals. In the long-latency auditory evoked potential, there was a difference in the latency of N2 and P3 components; stutterers had higher latency values. Stutterers have poor performance in temporal processing and higher latency values for N2 and P3 components. Copyright © 2017 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Temporal processing and long-latency auditory evoked potential in stutterers

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Raquel Prestes

Full Text Available Abstract Introduction: Stuttering is a speech fluency disorder, and may be associated with neuroaudiological factors linked to central auditory processing, including changes in auditory processing skills and temporal resolution. Objective: To characterize the temporal processing and long-latency auditory evoked potential in stutterers and to compare them with non-stutterers. Methods: The study included 41 right-handed subjects, aged 18-46 years, divided into two groups: stutterers (n = 20 and non-stutters (n = 21, compared according to age, education, and sex. All subjects were submitted to the duration pattern tests, random gap detection test, and long-latency auditory evoked potential. Results: Individuals who stutter showed poorer performance on Duration Pattern and Random Gap Detection tests when compared with fluent individuals. In the long-latency auditory evoked potential, there was a difference in the latency of N2 and P3 components; stutterers had higher latency values. Conclusion: Stutterers have poor performance in temporal processing and higher latency values for N2 and P3 components.

Pattern visual evoked potentials in malingering.

Science.gov (United States)

Nakamura, A; Akio, T; Matsuda, E; Wakami, Y

2001-03-01

We previously developed a new method for estimating objective visual acuity by means of pattern visual evoked potentials (PVEP). In this study, this method was applied to the diagnosis of malingering. Six patients ranging in age from 40 to 54 years (mean 47 years) with suspected malingering were evaluated by means of the visual evoked potential test, optokinetic nystagmus (OKN) inhibition test, and the visual field test. In the PVEP study, the stimulus consisted of black and white checkerboards (39', 26', 15', and 9') with a visual angle of 8 degrees, contrast level of 15%, and a frequency of 0.7 Hz. One hundred PVEP responses were averaged per session. Routine ophthalmic examinations were normal in all patients. Five patients had a tubularly constricted visual field, and the remaining patient had a normal visual field. The objective visual acuities of the six patients estimated from PVEP were better than their subjective visual acuities estimated with Landolt rings. Among a variety of psychophysical and electrophysiologic ancillary tests, we consider our PVEP method a useful method for objectively determining visual acuity in a patient with signs of ocular malingering.

Brainstem auditory evoked potentials in horses

Directory of Open Access Journals (Sweden)

Juliana Almeida Nogueira da Gama

2016-04-01

Full Text Available ABSTRACT: The brainstem auditory evoked potential (BAEP evaluates the integrity of the auditory pathways to the brainstem. The aim of this study was to evoke BAEPs in 21 clinically normal horses. The animals were sedated with detomidine hydrochloride (0.013mg.kg-1 BW. Earphones were inserted and rarefaction clicks at 90 dB and noise masking at 40 dB were used. After performing the test, the latencies of waves (I, II, III, IV, and V and interpeaks(I-III, III-V, and I-V were identified. The mean latencies of the waves were as follows: wave I, 2.4 ms; wave II, 2.24 ms; wave III, 3.61ms; wave IV, 4.61ms; and wave V, 5.49ms. The mean latencies of the interpeaks were as follows: I-III, 1.37ms; III-V, 1.88ms; and I-V, 3.26ms. This is the first study using BAEPs in horses in Brazil, and the observed latencies will be used as normative data for the interpretation of tests performed on horses with changes related to auditory system or neurologic abnormalities.

Clinical and evoked pain, personality traits, and emotional states: can familial confounding explain the associations?

Science.gov (United States)

Strachan, Eric; Poeschla, Brian; Dansie, Elizabeth; Succop, Annemarie; Chopko, Laura; Afari, Niloofar

2015-01-01

Pain is a complex phenomenon influenced by context and person-specific factors. Affective dimensions of pain involve both enduring personality traits and fleeting emotional states. We examined how personality traits and emotional states are linked with clinical and evoked pain in a twin sample. 99 female twin pairs were evaluated for clinical and evoked pain using the McGill Pain Questionnaire (MPQ) and dolorimetry, and completed the 120-item International Personality Item Pool (IPIP), the Positive and Negative Affect Scale (PANAS), and ratings of stress and mood. Using a co-twin control design we examined a) the relationship of personality traits and emotional states with clinical and evoked pain and b) whether genetics and common environment (i.e. familial factors) may account for the associations. Neuroticism was associated with the sensory component of the MPQ; this relationship was not confounded by familial factors. None of the emotional state measures was associated with the MPQ. PANAS negative affect was associated with lower evoked pressure pain threshold and tolerance; these associations were confounded by familial factors. There were no associations between IPIP traits and evoked pain. A relationship exists between neuroticism and clinical pain that is not confounded by familial factors. There is no similar relationship between negative emotional states and clinical pain. In contrast, the relationship between negative emotional states and evoked pain is strong while the relationship with enduring personality traits is weak. The relationship between negative emotional states and evoked pain appears to be non-causal and due to familial factors. Copyright © 2014 Elsevier Inc. All rights reserved.

Visual cortical somatosensory and brainstem auditory evoked potentials following incidental irradiation of the rhombencephalon

International Nuclear Information System (INIS)

Nightingale, S.; Schofield, I.S.; Dawes, P.J.D.K.

1984-01-01

Visual, cortical somatosensory and brainstem auditory evoked potentials were recorded before incidental irradiation of the rhombencephalon during radiotherapy in and around the middle ear, and at 11 weeks and eight months after completion of treatment. No patient experienced neurological symptoms during this period. No consistent changes in evoked potentials were found. The failure to demonstrate subclinical radiation-induced demyelination suggests either that the syndrome of early-delayed radiation rhombencephalopathy occurs in an idiosyncratic manner, or that any subclinical lesions are not detectable by serial evoked potential recordings. (author)

Proprioceptive evoked potentials in man

DEFF Research Database (Denmark)

Arnfred, S; Chen, A C; Eder, Derek N

2000-01-01

We studied cerebral evoked potentials on the scalp to the stimulation of the right hand from a change in weight of 400-480 g in ten subjects. Rise-time was 20g/10 ms, Inter Stimulus Interval 2s and stimulus duration was 100 ms. The cerebral activations were a double positive contralateral C3'/P70......). Further studies of the PEP are needed to assess the influence of load manipulations and of muscle contraction and to explore the effect of attentional manipulation....

Differential effect of ketamine and lidocaine on spontaneous and mechanical evoked pain in patients with nerve injury pain

DEFF Research Database (Denmark)

Gottrup, Hanne; Bach, Flemming Winther; Juhl, Gitte Irene

2006-01-01

ketamine, an N-methyl-D-aspartate receptor antagonist and lidocaine, a sodium channel blocker, on spontaneous pain, brush-evoked pain, and pinprick-evoked pain in patients with nerve injury pain. METHODS: Twenty patients participated in two randomized, double-blinded, placebo-controlled, crossover...... experiments in which they, on four different days, received a 30-minute intravenous infusion of ketamine (0.24 mg/kg), lidocaine (5 mg/kg), or saline. Ongoing pain, pain evoked by brush and repetitive pinprick stimuli, and acetone was measured before, during, and after infusion. RESULTS: Ketamine...... significantly reduced ongoing pain and evoked pain to brush and pinprick, whereas lidocaine only reduced evoked pain to repetitive pinprick stimuli. In individual patients, there was no correlation between the pain-relieving effect of lidocaine and ketamine on ongoing or mechanically evoked pains. CONCLUSIONS...

Secretion of [Met]enkephalyl-Arg6-Phe7-related peptides and catecholamines from bovine adrenal chromaffin cells: modification by changes in cyclic AMP and by treatment with reserpine.

Science.gov (United States)

Adams, M; Boarder, M R

1987-07-01

Investigations into the effects of culturing bovine adrenal chromaffin cells in the presence (72 h) of dibutyryl cyclic AMP, forskolin, and reserpine on the level and release of [Met]enkephalyl-Arg6-Phe7 immunoreactivity, noradrenaline, and adrenaline are reported. The assay for [Met]enkephalyl-Arg6-Phe7 immunoreactivity recognises both peptide B, the 31-amino acid carboxy-terminal segment of proenkephalin, and its heptapeptide fragment, [Met]enkephalyl-Arg6-Phe7. Treatments that elevate cyclic AMP increase the amount of peptide immunoreactivity in these cells; this is predominantly peptide B-like immunoreactivity in both control cells and cyclic AMP-elevated cells. Treatment with reserpine gives no change in total immunoreactivity levels, but does not result in increased accumulation of the heptapeptide [Met]enkephalyl-Arg6-Phe7 at the expense of immunoreactivity that elutes with its immediate precursor, peptide B. Cyclic AMP treatment causes either no change or a decrease in levels of accumulated noradrenaline and adrenaline. However, the release of [Met]enkephalin-Arg6-Phe7 immunoreactivity, noradrenaline, and adrenaline is increased by 72-h pretreatment with forskolin or dibutyryl cyclic AMP, whether release is stimulated by nicotine or elevated potassium. In each case the molecular form of [Met]enkephalyl-Arg6-Phe7 immunoreactivity that is released approximately reflects the cell content. Pretreatment with reserpine has no effect on the total [Met]enkephalyl-Arg6-Phe7 immunoreactivity released, but does result in an increased release of the heptapeptide and a decrease in release of peptide B-like immunoreactivity. The studies suggest that the levels of [Met]enkephalyl-Arg6-Phe7 and peptide B available for release are controlled both at the level of proenkephalin synthesis and at the level of double-basic residue proteolysis.

Intracranial dialysis measurement of oxytocin, monoamine and uric acid release from the olfactory bulb and substantia nigra of sheep during parturition, suckling, separation from lambs and eating.

Science.gov (United States)

Kendrick, K M; Keverne, E B; Chapman, C; Baldwin, B A

1988-01-26

Intracranial dialysis was used to measure the release of oxytocin (OXY), monoamines and their metabolites and uric acid (UA) from the substantia nigra (SN) and olfactory bulb (OB) of sheep during parturition, suckling, separation from lambs and eating. Results showed that OXY concentrations increased significantly during parturition, suckling and eating in the SN and during parturition and suckling in the OB. Concentrations of dopamine (DA) increased significantly in the SN during suckling and eating and in the OB during parturition and suckling. The dopamine metabolite, homovanillic acid, also increased significantly in the SN during parturition. Concentrations of the noradrenaline metabolite, 4-hydroxy-3-methoxyphenylethan-1,2-diol (MHPG) and the purine metabolite, UA, were significantly raised during parturition, suckling and separation from the lambs in the SN and increased UA levels were also found during eating. In a separate experiment it was confirmed that OXY was detectable in homogenates of both the SN and the OB. These results show that, in the sheep, OXY and DA release in the SN is associated with maternal and ingestive behaviour whereas similar release in the OB may only be related to maternal behaviour. Release of MHPG in the SN may be associated with maternal behaviour and/or stress.

Innervation by a GABAergic neuron depresses spontaneous release in glutamatergic neurons and unveils the clamping phenotype of synaptotagmin-1

DEFF Research Database (Denmark)

Wierda, Keimpe D B; Sørensen, Jakob Balslev

2014-01-01

The role of spontaneously occurring release events in glutamatergic and GABAergic neurons and their regulation is intensely debated. To study the interdependence of glutamatergic and GABAergic spontaneous release, we compared reciprocally connected "mixed" glutamatergic/GABAergic neuronal pairs...... from mice cultured on astrocyte islands with "homotypic" glutamatergic or GABAergic pairs and autaptic neurons. We measured mEPSC and mIPSC frequencies simultaneously from both neurons. Neuronal pairs formed both interneuronal synaptic and autaptic connections indiscriminately. We find that whereas m......EPSC and mIPSC frequencies did not deviate between autaptic and synaptic connections, the frequency of mEPSCs in mixed pairs was strongly depressed compared with either autaptic neurons or glutamatergic pairs. Simultaneous imaging of synapses, or comparison to evoked release amplitudes, showed...

Auditory and visual evoked potentials during hyperoxia

Science.gov (United States)

Smith, D. B. D.; Strawbridge, P. J.

1974-01-01

Experimental study of the auditory and visual averaged evoked potentials (AEPs) recorded during hyperoxia, and investigation of the effect of hyperoxia on the so-called contingent negative variation (CNV). No effect of hyperoxia was found on the auditory AEP, the visual AEP, or the CNV. Comparisons with previous studies are discussed.

Ryanodine receptors contribute to the induction of nociceptive input-evoked long-term potentiation in the rat spinal cord slice

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Zhao Zhi-Qi

2010-01-01

Full Text Available Abstract Background Our previous study demonstrated that nitric oxide (NO contributes to long-term potentiation (LTP of C-fiber-evoked field potentials by tetanic stimulation of the sciatic nerve in the spinal cord in vivo. Ryanodine receptor (RyR is a downstream target for NO. The present study further explored the role of RyR in synaptic plasticity of the spinal pain pathway. Results By means of field potential recordings in the adult male rat in vivo, we showed that RyR antagonist reduced LTP of C-fiber-evoked responses in the spinal dorsal horn by tetanic stimulation of the sciatic nerve. Using spinal cord slice preparations and field potential recordings from superficial dorsal horn, high frequency stimulation of Lissauer's tract (LT stably induced LTP of field excitatory postsynaptic potentials (fEPSPs. Perfusion of RyR antagonists blocked the induction of LT stimulation-evoked spinal LTP, while Ins(1,4,5P3 receptor (IP3R antagonist had no significant effect on LTP induction. Moreover, activation of RyRs by caffeine without high frequency stimulation induced a long-term potentiation in the presence of bicuculline methiodide and strychnine. Further, in patch-clamp recordings from superficial dorsal horn neurons, activation of RyRs resulted in a large increase in the frequency of miniature EPSCs (mEPSCs. Immunohistochemical study showed that RyRs were expressed in the dorsal root ganglion (DRG neurons. Likewise, calcium imaging in small DRG neurons illustrated that activation of RyRs elevated [Ca2+]i in small DRG neurons. Conclusions These data indicate that activation of presynaptic RyRs play a crucial role in the induction of LTP in the spinal pain pathway, probably through enhancement of transmitter release.

The importance of neurotransmitters in the central control of the blood pressure

International Nuclear Information System (INIS)

Pfitscher-Klausmair, A.

1990-12-01

In anaesthetized cats, the nucleus tractus solitarii (NTS) and the locus coeruleus (LC) were bilaterally superfused through push-pull cannulae with artificial cerebrospinal fluid. Catecholamines were determined in the superfusate by a radioenzymatic assay, gamma-aminobutyric acid (GABA) was determined in the superfusate and homogenate with glutamate by an enzymatic and fluorimetric assay. In the NTS and LC the resting release of catecholamines varied rhythmically. To investigate the function of catecholaminergic neurons and GABAergic neurons of the NTS in cardiovascular control, the influence of experimentally induced blood pressure changes on the rates of release of the endogenous catecholamines dopamine, noradrenaline and adrenaline in the NTS was observed. The decreased noradrenaline and adrenaline release elicited by increases in blood pressure and the reduced release of dopamine induced by decreases in blood pressure suggest a hypertensive function of noradrenaline and adrenaline and a hypotensive role of dopamine at the level of the rostral and intermediate NTS. Bilateral carotid occlusion led to a very pronounced increase in the release rate of GABA in the rostral NTS. This result demonstrate the hypertensive function of GABA in the NTS. Thus underlining the importance of catecholaminergic and GABAergic neurons of the NTS in central cardiovascular control. The GABA-transaminase inhibitor Vigabatrin was injected wistar Kyoto rats and spontaneously hypertensive rats. GABA-Transaminase inhibition was accompanied by an increase of GABA concentration in the rat brain. The administration of Vigabatrin had no influence on the blood pressure but on the body wight of the rats. (Author)

Auditory brainstem activity and development evoked by apical versus basal cochlear implant electrode stimulation in children.

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Gordon, K A; Papsin, B C; Harrison, R V

2007-08-01

The role of apical versus basal cochlear implant electrode stimulation on central auditory development was examined. We hypothesized that, in children with early onset deafness, auditory development evoked by basal electrode stimulation would differ from that evoked more apically. Responses of the auditory nerve and brainstem, evoked by an apical and a basal implant electrode, were measured over the first year of cochlear implant use in 50 children with early onset severe to profound deafness who used hearing aids prior to implantation. Responses at initial stimulation were of larger amplitude and shorter latency when evoked by the apical electrode. No significant effects of residual hearing or age were found on initial response amplitudes or latencies. With implant use, responses evoked by both electrodes showed decreases in wave and interwave latencies reflecting decreased neural conduction time through the brainstem. Apical versus basal differences persisted with implant experience with one exception; eIII-eV interlatency differences decreased with implant use. Acute stimulation shows prolongation of basally versus apically evoked auditory nerve and brainstem responses in children with severe to profound deafness. Interwave latencies reflecting neural conduction along the caudal and rostral portions of the brainstem decreased over the first year of implant use. Differences in neural conduction times evoked by apical versus basal electrode stimulation persisted in the caudal but not rostral brainstem. Activity-dependent changes of the auditory brainstem occur in response to both apical and basal cochlear implant electrode stimulation.

Simultaneous determination of the content of serotonin, dopamine, noradrenaline and adrenaline in pancreatic islets isolated from fed and starved mice

International Nuclear Information System (INIS)

Hansen, S.E.; Hedeskov, C.J.

1977-01-01

A highly sensitive double isotope method for the simultaneous determination of serotonin, dopamine, noradrenaline and adrenaline has been developed. Advantages and limitations of the method are discussed. The mentioned biogenic amines are all present in isolated pancreatic islet tissue from albino mice in concentrations ranging from approximately 5-30 μmol per kg wet weight (0.8-5 x 10 -3 pmol/ng DNA). A somewhat higher content of these amines, especially dopamine, was found in pancreatic acinar tissue. The hypothesis that the impaired glucose-induced insulin secretion during starvation partly is caused by an increased content of biogenic amines in the pancreatic islets was not supported by our experiments which showed an unchanged islet content of these amines after 48 h starvation. (author)

Simultaneous determination of the content of serotonin, dopamine, noradrenaline and adrenaline in pancreatic islets isolated from fed and starved mice

Energy Technology Data Exchange (ETDEWEB)

Hansen, S E; Hedeskov, C J [Copenhagen Univ. (Denmark)

1977-01-01

A highly sensitive double isotope method for the simultaneous determination of serotonin, dopamine, noradrenaline and adrenaline has been developed. Advantages and limitations of the method are discussed. The mentioned biogenic amines are all present in isolated pancreatic islet tissue from albino mice in concentrations ranging from approximately 5-30 ..mu..mol per kg wet weight (0.8-5 x 10/sup -3/ pmol/ng DNA). A somewhat higher content of these amines, especially dopamine, was found in pancreatic acinar tissue. The hypothesis that the impaired glucose-induced insulin secretion during starvation partly is caused by an increased content of biogenic amines in the pancreatic islets was not supported by our experiments which showed an unchanged islet content of these amines after 48 h starvation.

Mice Lacking Pannexin 1 Release ATP and Respond Normally to All Taste Qualities.

Science.gov (United States)

Vandenbeuch, Aurelie; Anderson, Catherine B; Kinnamon, Sue C

2015-09-01

Adenosine triphosphate (ATP) is required for the transmission of all taste qualities from taste cells to afferent nerve fibers. ATP is released from Type II taste cells by a nonvesicular mechanism and activates purinergic receptors containing P2X2 and P2X3 on nerve fibers. Several ATP release channels are expressed in taste cells including CALHM1, Pannexin 1, Connexin 30, and Connexin 43, but whether all are involved in ATP release is not clear. We have used a global Pannexin 1 knock out (Panx1 KO) mouse in a series of in vitro and in vivo experiments. Our results confirm that Panx1 channels are absent in taste buds of the knockout mice and that other known ATP release channels are not upregulated. Using a luciferin/luciferase assay, we show that circumvallate taste buds from Panx1 KO mice normally release ATP upon taste stimulation compared with wild type (WT) mice. Gustatory nerve recordings in response to various tastants applied to the tongue and brief-access behavioral testing with SC45647 also show no difference between Panx1 KO and WT. These results confirm that Panx1 is not required for the taste evoked release of ATP or for neural and behavioral responses to taste stimuli. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Do ambient urban odors evoke basic emotions?

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Sandra Theresia Weber-Glass

2014-04-01

Full Text Available Fragrances, such as plant odors, have been shown to evoke autonomic response patterns associated with Ekman’s (Ekman et al., 1983 basic emotions happiness, surprise, anger, fear, sadness and disgust. Inducing positive emotions by odors in highly frequented public spaces could serve to improve the quality of life in urban environments. Thus, the present study evaluated the potency of ambient odors connoted with an urban environment to evoke basic emotions on an autonomic and cognitive response level. Synthetic mixtures representing the odors of disinfectant, candles / bees wax, summer air, burnt smell, vomit and musty smell as well as odorless water as a control were presented five times in random order to 30 healthy, non-smoking human subjects with intact sense of smell. Skin temperature, skin conductance, breathing rate, forearm muscle activity, blink rate and heart rate were recorded simultaneously. Subjects rated the odors in terms of pleasantness, intensity and familiarity and gave verbal labels to each odor as well as cognitive associations with the basic emotions. The results showed that the amplitude of the skin conductance response varied as a function of odor presentation. Burnt smell and vomit elicited significantly higher electrodermal responses than summer air. Also, a negative correlation was revealed between the amplitude of the skin conductance response and hedonic odor valence indicating that the magnitude of the electrodermal response increased with odor unpleasantness. The analysis of the cognitive associations between odors and basic emotions showed that candles / bees wax and summer air were specifically associated with happiness whereas burnt smell and vomit were uniquely associated with disgust. Our findings suggest that city odors may evoke specific cognitive associations of basic emotions and that autonomic activity elicited by such odors is related to odor hedonics.

Role for astroglial α1-adrenoreceptors in gliotransmission and control of synaptic plasticity in the neocortex

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Yuriy ePankratov

2015-06-01

Full Text Available Communication between neuronal and glial cells is thought to be very important for many brain functions. Acting via release of gliotransmitters, astrocytes can modulate synaptic strength. The mechanisms underlying gliotransmission remain uncertain with exocytosis being the most intriguing and debated pathway.We demonstrate that astroglial α1-adrenoreceptors are very sensitive to noradrenaline and make a significant contribution to intracellular Ca2+-signalling in layer 2/3 neocortical astrocytes. We also show that astroglial α1-adrenoreceptors are prone to desensitization upon prolonged exposure to noradrenaline.We show that within neocortical slices, α-1adrenoreceptors can activate vesicular release of ATP and D-serine from cortical astrocytes which initiate a burst of ATP receptor-mediated currents in adjacent pyramidal neurons. These purinergic currents can be inhibited by intracellular perfusion of astrocytes with Tetanus Toxin light chain, verifying their origin via astroglial exocytosis.We show that α1 adrenoreceptor-activated release of gliotransmitters is important for the induction of synaptic plasticity in the neocortex:long-term potentiation (LTP of neocortical excitatory synaptic potentials can be abolished by the selective α1-adrenoreceptor antagonist terazosin. We show that weak sub-threshold theta-burst stimulation can induce LTP when astrocytes are additionally activated by 1 μM noradrenaline. This facilitation is dependent on the activation of neuronal ATP receptors and is abolished in neocortical slices from dn-SNARE mice which have impaired glial exocytosis. Importantly, facilitation of LTP by noradrenaline can be significantly reduced by perfusion of individual astrocytes with Tetanus Toxin. Our results strongly support the physiological importance of astroglial adrenergic signalling and exocytosis of gliotransmitters for modulation of synaptic transmission and plasticity .

Evoked Electromyographically Controlled Electrical Stimulation

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Mitsuhiro Hayashibe

2016-07-01

Full Text Available Time-variant muscle responses under electrical stimulation (ES are often problematic for all the applications of neuroprosthetic muscle control. This situation limits the range of ES usage in relevant areas, mainly due to muscle fatigue and also to changes in stimulation electrode contact conditions, especially in transcutaneous ES. Surface electrodes are still the most widely used in noninvasive applications.Electrical field variations caused by changes in the stimulation contact condition markedly affect the resulting total muscle activation levels. Fatigue phenomena under functional electrical stimulation (FES are also well known source of time-varying characteristics coming from muscle response under ES. Therefore it is essential to monitor the actual muscle state and assess the expected muscle response by ES so as to improve the current ES system in favour of adaptive muscle-response-aware FES control. To deal with this issue, we have been studying a novel control technique using evoked electromyography (eEMG signals to compensate for these muscle time-variances under ES for stable neuroprosthetic muscle control. In this perspective article, I overview the background of this topic and highlight important points to be aware of when using ES to induce the desired muscle activation regardless of the time-variance. I also demonstrate how to deal with the common critical problem of ES to move toward robust neuroprosthetic muscle control with the Evoked Electromyographically Controlled Electrical Stimulation paradigm.

Controlling a stream of paranoia evoking events in a virtual reality environment.

Science.gov (United States)

Isnanda, Reza Giga; Brinkman, Willem-Paul; Veling, Wim; van der Gaag, Mark; Neerincx, Mark

2014-01-01

Although virtual reality exposure has been reported as a method to induce paranoid thought, little is known about mechanisms to control specific virtual stressors. This paper reports on a study that examines the effect of controlling the stream of potential paranoia evoking events in a virtual restaurant world. A 2-by-2 experiment with a non-clinical group (n = 24) was conducted with as two within-subject factors: (1) the cycle time (short/long) for when the computer considers activation of a paranoia evoking event and (2) the probability that a paranoia-evoking event (low/high) would be triggered at the completion of a cycle. The results showed a significant main effect for the probability factor and two-way interaction effect with the cycle time factor on the number of paranoid comments participants made and their self-reported anxiety.

Interaural difference values of vestibular evoked myogenic.

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Marziyeh Moallemi

2015-01-01

Full Text Available Migraine is a neurologic disease, which often is associated with a unilateral headache. Vestibular abnormalities are common in migraine. Vestibular evoked myogenic potentials (VEMPs assess otolith function in particular functional integrity of the saccule and the inferior vestibular nerve. We used VEMP to evaluate if the migraine headache can affect VEMP asymmetry parameters. A total of 25 patients with migraine (22 females and 3 males who were diagnosed according to the criteria of IHS-1988 were enrolled in this cross-sectional study. Control group consisted of 26 healthy participants (18 female and 8 male, without neurotological symptoms and history of migraine. The short tone burst (95 dB nHL, 500 Hz was presented to ears. VEMP was recorded with surface electromyography over the contracted ipsilateral sternocleidomastoid (SCM muscle. Although current results showed that the amplitude ratio is greater in migraine patients than normal group, there was no statistical difference between two groups in mean asymmetry parameters of VEMP. Asymmetry measurements in vestibular evoked myogenic potentials probably are not indicators of unilateral deficient in saccular pathways of migraine patients.

Associative learning in humans--conditioning of sensory-evoked brain activity.

Science.gov (United States)

Skrandies, W; Jedynak, A

2000-01-01

A classical conditioning paradigm was employed in two experiments performed on 35 human volunteers. In nine subjects, the presentation of Landolt rings (conditioned stimuli, CS + ) was paired with an electric stimulus (unconditioned stimuli, UCS) applied to the left median nerve. Neutral visual control stimuli were full circles (CS -) that were not paired with the UCS. The skin conductance response (SCR) was determined in a time interval of 5 s after onset of the visual stimuli, and it was measured in the acquisition and test phase. Associative learning was reflected by a SCR occurring selectively with CS +. The same experiment was repeated with another group of 26 adults while electroencephalogram (EEG) was recorded from 30 electrodes. For each subject, mean evoked potentials were computed. In 13 of the subjects, a conditioning paradigm was followed while the other subjects served as the control group (non-contingent stimulation). There were somatosensory and visual brain activity evoked by the stimuli. Conditioned components were identified by computing cross-correlation between evoked somatosensory components and the averaged EEG. In the visual evoked brain activity, three components with mean latencies of 105.4, 183.2, and 360.3 ms were analyzed. Somatosensory stimuli were followed by major components that occurred at mean latencies of 48.8, 132.5, 219.7, 294.8, and 374.2 ms latency after the shock. All components were analyzed in terms of latency, field strength, and topographic characteristics, and were compared between groups and experimental conditions. Both visual and somatosensory brain activity was significantly affected by classical conditioning. Our data illustrate how associative learning affects the topography of brain electrical activity elicited by presentation of conditioned visual stimuli.

The importance of neurotransmitters in the central control of the blood pressure

International Nuclear Information System (INIS)

Pfitscher-Klausmair, A.

1990-12-01

In anaesthetized cats, the nucleus tractus solitarii (NTS) and the locus coeruleus (LC) were bilaterally superfused through push-pull cannulae with artificial cerebrospinal fluid. Catecholamines were determined in the superfusate by a radioenzymatic assay, gamma-aminobutyric acid (GABA) was determined in the superfusate and homogenitate with glutamate by an enzymatic and fluorimetric assay. In the NTS and LC the resting release of catecholamines varied rhythmically. To investigate the function of catecholaminergic neurons and GABAergic neurons of the NTS in cardiovascular control, the influence of experimentally induced blood pressure changes on the rates of the endogenous catecholamines dopamine,noradrenaline and adrenaline in the NTS was observed. The decreased noradrenaline and adrenaline release elicited by increases in blood pressure and the reduced release of dopamine induced by decreases in blood pressure suggest a hypertensive function on noradrenaline and adrenaline and a hypotensive role of dopamine at the level of the rostral and intermediate NTS. Bilateral carotid occlusion led to a very pronounced increase in the release rate of GABA in the rostral NTS. This result demonstrated the hypertensive function of GABA in the NTS, thus underlining the importance of catecholaminergic and GABAergic neurons of the NTS in central cardiovascular control. The GABA-transaminase inhibitor Vigabatrin was injected in kyoto rats and spontaneously hypertensive rats. GABA-Transaminase inhibition was accompanied by an increase of GABA concentration in the rat brain. The administration of Vigabatrin had no influence on the blood pressure but on body weight of the rats. (author)

Evidence that 5-hydroxytryptamine/sub 3/ receptors mediate cytotoxic drug and radiation-evoked emesis

Energy Technology Data Exchange (ETDEWEB)

Miner, W.D.; Sanger, G.J.; Turner, D.H.

1987-08-01

The involvement of 5-hydroxytryptamine (5-HT) 5-HT/sub 3/ receptors in the mechanisms of severe emesis evoked by cytotoxic drugs or by total body irradiation have been studied in ferrets. Anti-emetic compounds tested were domperidone (a dopamine antagonist), metoclopramide (a gastric motility stimulant and dopamine antagonist at conventional doses, a 5-HT/sub 3/ receptor antagonist at higher doses) and BRL 24924 (a potent gastric motility stimulant and a 5-HT/sub 3/ receptor antagonist). Domperidone or metoclopramide prevented apomorphine-evoked emesis, whereas BRL 24924 did not. Similar doses of domperidone did not prevent emesis evoked by cis-platin or by total body irradiation, whereas metoclopramide or BRL 24924 greatly reduced or prevented these types of emesis. Metoclopramide and BRL 24924 also prevented emesis evoked by a combination of doxorubicin and cyclophosphamide. These results are discussed in terms of a fundamental role for 5-HT/sub 3/ receptors in the mechanisms mediating severely emetogenic cancer treatment therapies.

Noradrenaline and dopamine neurons in the reward/effort trade-off: a direct electrophysiological comparison in behaving monkeys.

Science.gov (United States)

Varazzani, Chiara; San-Galli, Aurore; Gilardeau, Sophie; Bouret, Sebastien

2015-05-20

Motivation determines multiple aspects of behavior, including action selection and energization of behavior. Several components of the underlying neural systems have been examined closely, but the specific role of the different neuromodulatory systems in motivation remains unclear. Here, we compare directly the activity of dopaminergic neurons from the substantia nigra pars compacta and noradrenergic neurons from the locus coeruleus in monkeys performing a task manipulating the reward/effort trade-off. Consistent with previous reports, dopaminergic neurons encoded the expected reward, but we found that they also anticipated the upcoming effort cost in connection with its negative influence on action selection. Conversely, the firing of noradrenergic neurons increased with both pupil dilation and effort production in relation to the energization of behavior. Therefore, this work underlines the contribution of dopamine to effort-based decision making and uncovers a specific role of noradrenaline in energizing behavior to face challenges. Copyright © 2015 the authors 0270-6474/15/357866-12$15.00/0.

Co-release of glutamate and GABA from single vesicles in GABAergic neurons exogenously expressing VGLUT3

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Johannes eZimmermann

2015-09-01

Full Text Available The identity of the vesicle neurotransmitter transporter expressed by a neuron largely corresponds with the primary neurotransmitter that cell releases. However, the vesicular glutamate transporter subtype 3 (VGLUT3 is mainly expressed in non-glutamatergic neurons, including cholinergic, serotonergic, or GABAergic neurons. Though a functional role for glutamate release from these non-glutamatergic neurons has been demonstrated, the interplay between VGLUT3 and the neuron’s characteristic neurotransmitter transporter, particularly in the case of GABAergic neurons, at the synaptic and vesicular level is less clear. In this study, we explore how exogenous expression of VGLUT3 in striatal GABAergic neurons affects the packaging and release of glutamate and GABA in synaptic vesicles. We found that VGLUT3 expression in isolated, autaptic GABAergic neurons leads to action potential evoked release of glutamate. Under these conditions, glutamate and GABA could be packaged together in single vesicles release either spontaneously or asynchronously. However, the presence of glutamate in GABAergic vesicles did not affect uptake of GABA itself, suggesting a lack of synergy in vesicle filling for these transmitters. Finally, we found postsynaptic detection of glutamate released from GABAergic terminals difficult when bona fide glutamatergic synapses were present, suggesting that co-released glutamate cannot induce postsynaptic glutamate receptor clustering.

(-)Deprenyl and (-)1-phenyl-2-propylaminopentane, [(-)PPAP], act primarily as potent stimulants of action potential-transmitter release coupling in the catecholaminergic neurons.

Science.gov (United States)

Knoll, J; Miklya, I; Knoll, B; Markó, R; Kelemen, K

1996-01-01

The activity of the catecholaminergic neurons in the rat brain is enhanced significantly 30 min after the subcutaneous injection of very small doses of (-)deprenyl (threshold doses: 0.01 mg/kg for noradrenergic neurons and 0.025 mg/kg for dopaminergic neurons). As a catecholaminergic activity enhancer (CAE) substance (-)deprenyl is about ten times more potent than its parent compound, (-)methamphetamine. While the (+)methamphetamine is 3-5 times more potent than (-)methamphetammine in releasing catecholamines, the (-)methamphetamine is the more potent CAE substance. The mechanism of the CAE effect of (-)deprenyl and (-)PPAP, a deprenyl-derived substance devoid of MAO inhibitory potency, was studied in rats by measuring: a) the release of catecholamines from striatum, substantia nigra, tuberculum olfactorium and locus coeruleus; b) the stimulation induced release of 3H-noradrenaline from the isolated brain stem; and c) the antagonistic effect against tetrabenazine-induced depression of learning in the shuttle box. The CAE effect was found to be unrelated: a) to the inhibition of MAO activity; b) to the inhibition of presynaptic catecholamine receptors; c) to the inhibition of the uptake of catecholamines; and d) to the release of catecholamines. It was concluded that (-)deprenyl and (-)PPAP act primarily as potent stimulants of action potential-transmitter release coupling in the catecholaminergic neurons of the brain. We show that both (-)deprenyl and (-)PPAP enhance the inward Ca2+ current in sino-auricular fibers of the frog heart. (-)PPAP was much more potent than either (+)PPAP or (-)deprenyl in this test.

Alterations in Ca2+-dependent and Ca2+-independent release of catecholamines in preparations of rat brain produced by ethanol treatment in vivo

International Nuclear Information System (INIS)

Lynch, M.A.; Pagonis, C.; Samuel, D.; Littleton, J.M.

1985-01-01

Compared to preparations from control animals, superfused striatal slice preparations from brains of rats treated chronically with ethanol released a significantly greater fraction of stored [ 3 H] dopamine on depolarisation in 40 mM K + . Similarly, the electrically-evoked release of [ 3 H]-norepinephrine from cortical slices and of [ 3 H]-dopamine from striatal slices is also increased, although with this mechanism of depolarisation the change is significant only in the case of [ 3 H] norepinephrine release. In contrast to this tendency to enhancement of Ca 2+ -dependent depolarisation-induced release, a reduced fraction of stored [ 3 H]-catecholamines was released from these preparations by the indirect sympathomimetics tyramine and (+)-amphetamine. The catecholamine release induced by these indirect sympathomimetics is largely independent of external Ca 2+ and the results are interpreted as suggesting that chronic alcohol treatment changes the distribution of catecholamine neurotransmitters between storage pools in the nerve terminal which do or do not require Ca 2+ entry for release

Adenosine receptors and muscarinic receptors cooperate in acetylcholine release modulation in the neuromuscular synapse.

Science.gov (United States)

Santafe, M M; Priego, M; Obis, T; Garcia, N; Tomàs, M; Lanuza, M A; Tomàs, J

2015-07-01

Adenosine receptors (ARs) are present in the motor terminals at the mouse neuromuscular junction. ARs and the presynaptic muscarinic acetylcholine receptors (mAChRs) share the functional control of the neuromuscular junction. We analysed their mutual interaction in transmitter release modulation. In electrophysiological experiments with unaltered synaptic transmission (muscles paralysed by blocking the voltage-dependent sodium channel of the muscle cells with μ-conotoxin GIIIB), we found that: (i) a collaborative action between different AR subtypes reduced synaptic depression at a moderate activity level (40 Hz); (ii) at high activity levels (100 Hz), endogenous adenosine production in the synaptic cleft was sufficient to reduce depression through A1 -type receptors (A1 Rs) and A2 A-type receptors (A2 A Rs); (iii) when the non-metabolizable 2-chloroadenosine (CADO) agonist was used, both the quantal content and depression were reduced; (iv) the protective effect of CADO on depression was mediated by A1 Rs, whereas A2 A Rs seemed to modulate A1 Rs; (v) ARs and mAChRs absolutely depended upon each other for the modulation of evoked and spontaneous acetylcholine release in basal conditions and in experimental conditions with CADO stimulation; (vi) the purinergic and muscarinic mechanisms cooperated in the control of depression by sharing a common pathway although the purinergic control was more powerful than the muscarinic control; and (vii) the imbalance of the ARs created by using subtype-selective and non-selective inhibitory and stimulatory agents uncoupled protein kinase C from evoked transmitter release. In summary, ARs (A1 Rs, A2 A Rs) and mAChRs (M1 , M2 ) cooperated in the control of activity-dependent synaptic depression and may share a common protein kinase C pathway. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Voltage-Induced Ca²⁺ Release in Postganglionic Sympathetic Neurons in Adult Mice.

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Hong-Li Sun

Full Text Available Recent studies have provided evidence that depolarization in the absence of extracellular Ca2+ can trigger Ca2+ release from internal stores in a variety of neuron subtypes. Here we examine whether postganglionic sympathetic neurons are able to mobilize Ca2+ from intracellular stores in response to depolarization, independent of Ca2+ influx. We measured changes in cytosolic ΔF/F0 in individual fluo-4 -loaded sympathetic ganglion neurons in response to maintained K+ depolarization in the presence (2 mM and absence of extracellular Ca2+ ([Ca2+]e. Progressive elevations in extracellular [K+]e caused increasing membrane depolarizations that were of similar magnitude in 0 and 2 mM [Ca2+]e. Peak amplitude of ΔF/F0 transients in 2 mM [Ca2+]e increased in a linear fashion as the membrane become more depolarized. Peak elevations of ΔF/F0 in 0 mM [Ca2+]e were ~5-10% of those evoked at the same membrane potential in 2 mM [Ca2+]e and exhibited an inverse U-shaped dependence on voltage. Both the rise and decay of ΔF/F0 transients in 0 mM [Ca2+]e were slower than those of ΔF/F0 transients evoked in 2 mM [Ca2+]e. Rises in ΔF/F0 evoked by high [K+]e in the absence of extracellular Ca2+ were blocked by thapsigargin, an inhibitor of endoplasmic reticulum Ca2+ ATPase, or the inositol 1,4,5-triphosphate (IP3 receptor antagonists 2-aminoethoxydiphenyl borate and xestospongin C, but not by extracellular Cd2+, the dihydropyridine antagonist nifedipine, or by ryanodine at concentrations that caused depletion of ryanodine-sensitive Ca2+ stores. These results support the notion that postganglionic sympathetic neurons possess the ability to release Ca2+ from IP3-sensitive internal stores in response to membrane depolarization, independent of Ca2+ influx.

Neuronal Rac1 Is Required for Learning-Evoked Neurogenesis

Science.gov (United States)

Anderson, Matthew P.; Freewoman, Julia; Cord, Branden; Babu, Harish; Brakebusch, Cord

2013-01-01

Hippocampus-dependent learning and memory relies on synaptic plasticity as well as network adaptations provided by the addition of adult-born neurons. We have previously shown that activity-induced intracellular signaling through the Rho family small GTPase Rac1 is necessary in forebrain projection neurons for normal synaptic plasticity in vivo, and here we show that selective loss of neuronal Rac1 also impairs the learning-evoked increase in neurogenesis in the adult mouse hippocampus. Earlier work has indicated that experience elevates the abundance of adult-born neurons in the hippocampus primarily by enhancing the survival of neurons produced just before the learning event. Loss of Rac1 in mature projection neurons did reduce learning-evoked neurogenesis but, contrary to our expectations, these effects were not mediated by altering the survival of young neurons in the hippocampus. Instead, loss of neuronal Rac1 activation selectively impaired a learning-evoked increase in the proliferation and accumulation of neural precursors generated during the learning event itself. This indicates that experience-induced alterations in neurogenesis can be mechanistically resolved into two effects: (1) the well documented but Rac1-independent signaling cascade that enhances the survival of young postmitotic neurons; and (2) a previously unrecognized Rac1-dependent signaling cascade that stimulates the proliferative production and retention of new neurons generated during learning itself. PMID:23884931

The modulatory action of harmane on serotonergic neurotransmission in rat brain.

Science.gov (United States)

Abu Ghazaleh, Haya; Lalies, Maggie D; Nutt, David J; Hudson, Alan L

2015-02-09

The naturally occurring β-carboline, harmane, has been implicated in various physiological and psychological conditions. Some of these effects are attributed to its interaction with monoaminergic systems. Previous literature indicates that certain β-carbolines including harmane modulate central monoamine levels partly through monoamine oxidase (MAO) inhibition. However, this is not always the case and thus additional mechanisms may be involved. This study set to assess the potential modulatory role of harmane on the basal or K(+) stimulated release of preloaded radiolabelled noradrenaline (NA), dopamine (DA) and serotonin (5-HT) in rat brain cortex in vitro in the presence of the MAO inhibitor pargyline. Harmane displayed an overt elevation in K(+) -evoked [(3)H]5-HT release; whilst little and no effect was reported with [(3)H]DA and [(3)H]NA respectively. The effect of harmane on [(3)H]5-HT efflux was partially compensated in K(+)-free medium. Further analyses demonstrated that removal of Ca(2+) ions and addition of 1.2mM EGTA did not alter the action of harmane on [(3)H]5-HT release from rat brain cortex. The precise mechanism of action however remains unclear but is unlikely to reflect an involvement of MAO inhibition. The current finding aids our understanding on the modulatory action of harmane on monoamine levels and could potentially be of therapeutic use in psychiatric conditions such as depression and anxiety. Copyright © 2014 Elsevier B.V. All rights reserved.

Water - The radiological health of rivers: releases are very much controlled downstream power plants. What do hospital releases represent? The Seine reserves a surprise

International Nuclear Information System (INIS)

Anon.

2015-01-01

After a brief presentation of the role of the IRSN in the control of the radioactivity present in waters and in the control and follow-up of all sources of radioactivity, a first article briefly present the hydro-collector network, indicates that some point samplings of sediment and aquatic species are performed, that a national network of beacons for a continuous radioactivity measurement is installed in the main French rivers, downstream nuclear installations, and that advanced measurement techniques are used to detect very small level of tritium. Maps giving a brief indication of the radiological condition of the Loire and Rhone are provided. A second article addresses the control of releases downstream power plants, and evokes the legal context and the associated objectives and produced documents. The third article discusses the risk associated with hospital wastes and releases (liquid and solid effluents), how radioactivity is controlled between the hospital and tap water distribution. The last article reports and comments the results obtained by an analysis of historical pollutions trapped in the sediments of the Seine: 40 year-old traces of plutonium have been discovered, due to an accidental release from a CEA installation in Fontenay-aux-Roses, with no detrimental impact on population or on sewer workers

Musical Brains. A study of evoked musical sensations without external auditory stimuli. Preliminary report of three cases

International Nuclear Information System (INIS)

Goycoolea, Marcos V; Mena, Ismael; Neubauer, Sonia G; Levy, Raquel G.; Fernandez Grez, Margarita; Berger, Claudia G

2006-01-01

Background: There are individuals, usually musicians, who are seemingly able to evoke musical sensations without external auditory stimuli. However, to date there is no available evidence to determine if it is feasible to have musical sensations without using external sensory receptors nor if there is a biological substrate to these sensations. Study design: Two single photon emission computerized tomography (SPECT) evaluations with [99mTc]-HMPAO were conducted in each of three female musicians. One was done under basal conditions (without evoking) and the other one while evoking these sensations. Results: In the NeuroSPECT studies of the musicians who were tested while evoking a musical composition, there was a significant increase in perfusion above the normal mean in the right and left hemispheres in Brodmann's areas 9 and 8 (frontal executive area) and in areas 40 on the left side (auditory center). However, under basal conditions there was no hyper perfusion of areas 9, 8, 39 and 40. In one case hyper perfusion was found under basal conditions in area 45, however it was less than when she was evoking. Conclusions: These findings are suggestive of a biological substrate to the process of evoking musical sensations (au)

Genesis and Maintenance of Attentional Biases: The Role of the Locus Coeruleus-Noradrenaline System

Directory of Open Access Journals (Sweden)

Mana R. Ehlers

2017-01-01

Full Text Available Emotionally arousing events are typically better remembered than mundane ones, in part because emotionally relevant aspects of our environment are prioritized in attention. Such biased attentional tuning is itself the result of associative processes through which we learn affective and motivational relevance of cues. We propose that the locus coeruleus-noradrenaline (LC-NA system plays an important role in the genesis of attentional biases through associative learning processes as well as their maintenance. We further propose that individual differences in and disruptions of the LC-NA system underlie the development of maladaptive biases linked to psychopathology. We provide support for the proposed role of the LC-NA system by first reviewing work on attentional biases in development and its link to psychopathology in relation to alterations and individual differences in NA availability. We focus on pharmacological manipulations to demonstrate the effect of a disrupted system as well as the ADRA2b polymorphism as a tool to investigate naturally occurring differences in NA availability. We next review associative learning processes that—modulated by the LC-NA system—result in such implicit attentional biases. Further, we demonstrate how NA may influence aversive and appetitive conditioning linked to anxiety disorders as well as addiction and depression.

Purines released from astrocytes inhibit excitatory synaptic transmission in the ventral horn of the spinal cord

DEFF Research Database (Denmark)

Carlsen, Eva Maria Meier; Perrier, Jean-Francois Marie

2014-01-01

by different neuromodulators. These substances are usually thought of being released by dedicated neurons. However, in other networks from the central nervous system synaptic transmission is also modulated by transmitters released from astrocytes. The star-shaped glial cell responds to neurotransmitters....... Neurons responded to electrical stimulation by monosynaptic EPSCs (excitatory monosynaptic postsynaptic currents). We used mice expressing the enhanced green fluorescent protein under the promoter of the glial fibrillary acidic protein to identify astrocytes. Chelating calcium with BAPTA in a single...... neighboring astrocyte increased the amplitude of synaptic currents. In contrast, when we selectively stimulated astrocytes by activating PAR-1 receptors with the peptide TFLLR, the amplitude of EPSCs evoked by a paired stimulation protocol was reduced. The paired-pulse ratio was increased, suggesting...

Nitric oxide-induced calcium release: activation of type 1 ryanodine receptor by endogenous nitric oxide.

Science.gov (United States)

Kakizawa, Sho; Yamazawa, Toshiko; Iino, Masamitsu

2013-01-01

Ryanodine receptors (RyRs), located in the sarcoplasmic/endoplasmic reticulum (SR/ER) membrane, are required for intracellular Ca2+ release that is involved in a wide range of cellular functions. In addition to Ca2+-induced Ca2+ release in cardiac cells and voltage-induced Ca2+ release in skeletal muscle cells, we recently identified another mode of intracellular Ca2+ mobilization mediated by RyR, i.e., nitric oxide-induced Ca2+ release (NICR), in cerebellar Purkinje cells. NICR is evoked by neuronal activity, is dependent on S-nitrosylation of type 1 RyR (RyR1) and is involved in the induction of long-term potentiation (LTP) of cerebellar synapses. In this addendum, we examined whether peroxynitrite, which is produced by the reaction of nitric oxide with superoxide, may also have an effect on the Ca2+ release via RyR1 and the cerebellar LTP. We found that scavengers of peroxynitrite have no significant effect either on the Ca2+ release via RyR1 or on the cerebellar LTP. We also found that an application of a high concentration of peroxynitrite does not reproduce neuronal activity-dependent Ca2+ release in Purkinje cells. These results support that NICR is induced by endogenous nitric oxide produced by neuronal activity through S-nitrosylation of RyR1.

Nostalgia-Evoked Inspiration: Mediating Mechanisms and Motivational Implications.

Science.gov (United States)

Stephan, Elena; Sedikides, Constantine; Wildschut, Tim; Cheung, Wing-Yee; Routledge, Clay; Arndt, Jamie

2015-10-01

Six studies examined the nostalgia-inspiration link and its motivational implications. In Study 1, nostalgia proneness was positively associated with inspiration frequency and intensity. In Studies 2 and 3, the recollection of nostalgic (vs. ordinary) experiences increased both general inspiration and specific inspiration to engage in exploratory activities. In Study 4, serial mediational analyses supported a model in which nostalgia increases social connectedness, which subsequently fosters self-esteem, which then boosts inspiration. In Study 5, a rigorous evaluation of this serial mediational model (with a novel nostalgia induction controlling for positive affect) reinforced the idea that nostalgia-elicited social connectedness increases self-esteem, which then heightens inspiration. Study 6 extended the serial mediational model by demonstrating that nostalgia-evoked inspiration predicts goal pursuit (intentions to pursue an important goal). Nostalgia spawns inspiration via social connectedness and attendant self-esteem. In turn, nostalgia-evoked inspiration bolsters motivation. © 2015 by the Society for Personality and Social Psychology, Inc.

Distinct presynaptic control of dopamine release in striosomal and matrix areas of the cat caudate nucleus

International Nuclear Information System (INIS)

Kemel, M.L.; Desban, M.; Glowinski, J.; Gauchy, C.

1989-01-01

By use of a sensitive in vitro microsuperfusion method, the cholinergic presynaptic control of dopamine release was investigated in a prominent striosome (areas poor in acetylcholinesterase activity) located within the core of cat caudate nucleus and also in adjacent matrix area. The spontaneous release of [ 3 H]dopamine continuously synthesized from [ 3 H]tyrosine in the matrix area was found to be twice that in the striosomal area; the spontaneous and potassium-evoked releases of [ 3 H]dopamine were calcium-dependent in both compartments. With 10 -6 M tetrodotoxin, 5 x 10 -5 M acetylcholine stimulated [ 3 H]dopamine release in both striosomal and matrix areas, effects completely antagonized by atropine, thus showing the involvement of muscarinic receptors located on dopaminergic nerve terminals. Experiments without tetrodotoxin revealed a more complex regulation of dopamine release in the matrix: (i) in contrast to results seen in the striosome, acetylcholine induced only a transient stimulatory effect on matrix dopamine release. (ii) Although 10 -6 M atropine completely abolished the cholinergic stimulatory effect on [ 3 H]dopamine release in striosomal area, delayed and prolonged stimulation of [ 3 H] dopamine release was seen with atropine in the matrix. The latter effect was completely abolished by the nicotinic antagonist pempidine. Therefore, in the matrix, in addition to its direct (tetrodotoxin-insensitive) facilitatory action on [ 3 H]dopamine release, acetylcholine exerts two indirect (tetrodotoxin-sensitive) opposing effects: an inhibition and a stimulation of [ 3 H]dopamine release mediated by muscarinic and nicotinic receptors, respectively

In vitro release of arachidonic acid and in vivo responses to respirable fractions of cotton dust

International Nuclear Information System (INIS)

Thomson, T.A.; Edwards, J.H.; Al-Zubaidy, T.S.; Brown, R.C.; Poole, A.; Nicholls, P.J.

1986-01-01

It was considered that the fall in lung function seen after exposure to cotton dust may be attributable in part to the activity of arachidonic acid metabolites, such as leucotrienes as well as to the more established release of histamine by cotton dust. However, we found that cotton and barley dusts elicited poor release of arachidonic acid from an established macrophage like cell line compared with that observed with other organic dusts. In the experimental animal, pulmonary cellular responses to both cotton and barley dust were similar to those evoked by moldy hay and pigeon dropping dusts, although after multiple doses a more severe response was seen to cotton and barley. Since both moldy hay and pigeon droppings elicit a greater arachidonic acid release than cotton or barley, a role for arachidonic acid in inducing the cellular response is less likely than other factors. There are limitations to our conclusions using this system, i.e., the arachidonic acid may be released in a nonmetabolized form, although it is noted that the two dusts with the greatest arachidonic acid release produce their clinical responses in humans largely by hypersensitivity mechanisms

Fetal MEG evoked response latency from beamformer with random field theory.

Science.gov (United States)

McCubbin, J; Vrba, J; Murphy, P; Temple, J; Eswaran, H; Lowery, C L; Preissl, H

2010-01-01

Analysis of fetal magnetoencephalographic brain recordings is restricted by low signal to noise ratio (SNR) and non-stationarity of the sources. Beamformer techniques have been applied to improve SNR of fetal evoked responses. However, until now the effect of non-stationarity was not taken into account in detail, because the detection of evoked responses is in most cases determined by averaging a large number of trials. We applied a windowing technique to improve the stationarity of the data by using short time segments recorded during a flash-evoked study. In addition, we implemented a random field theory approach for more stringent control of false-positives in the statistical parametric map of the search volume for the beamformer. The search volume was based on detailed individual fetal/maternal biometrics from ultrasound scans and fetal heart localization. Average power over a sliding window within the averaged evoked response against a randomized average background power was used as the test z-statistic. The significance threshold was set at 10% over all members of a contiguous cluster of voxels. There was at least one significant response for 62% of fetal and 95% of newborn recordings with gestational age (GA) between 28 and 45 weeks from 29 subjects. We found that the latency was either substantially unchanged or decreased with increasing GA for most subjects, with a nominal rate of about -11 ms/week. These findings support the anticipated neurophysiological development, provide validation for the beamformer model search as a methodology, and may lead to a clinical test for fetal cognitive development.

Influence of detomidine and buprenorphine on motor-evoked potentials in horses.

Science.gov (United States)

Nollet, H; Van Ham, L; Gasthuys, F; Dewulf, J; Vanderstraeten, G; Deprez, P

2003-04-26

Horses need to be sedated before they are investigated by transcranial magnetic stimulation because of the mild discomfort induced by the evoked muscle contraction and the noise of stimulation. This paper describes the influence of a combination of detomidine (10 microg/kg bodyweight) and a low dose of buprenorphine (2.4 microg/kg) on the onset latency and peak-to-peak amplitude of magnetic motor-evoked potentials in normal horses. There were no significant differences between measurements of these parameters made before the horses were sedated and measurements made 10 and 30 minutes after the drugs were administered.

From Nose to Memory: The Involuntary Nature of Odor-evoked Autobiographical Memories in Alzheimer's Disease.

Science.gov (United States)

El Haj, Mohamad; Gandolphe, Marie Charlotte; Gallouj, Karim; Kapogiannis, Dimitrios; Antoine, Pascal

2017-12-25

Research suggests that odors may serve as a potent cue for autobiographical retrieval. We tested this hypothesis in Alzheimer's disease (AD) and investigated whether odor-evoked autobiographical memory is an involuntary process that shares similarities with music-evoked autobiographical memory. Participants with mild AD and controls were asked to retrieve 2 personal memories after odor exposure, after music exposure, and in an odor-and music-free condition. AD participants showed better specificity, emotional experience, mental time travel, and retrieval time after odor and music exposure than in the control condition. Similar beneficial effects of odor and music exposure were observed for autobiographical characteristics (i.e., specificity, emotional experience, and mental time travel), except for retrieval time which was more improved after odor than after music exposure. Interestingly, regression analyses suggested executive involvement in memories evoked in the control condition but not in those evoked after music or odor exposure. These findings suggest the involuntary nature of odor-evoked autobiographical memory in AD. They also suggest that olfactory cuing could serve as a useful and ecologically valid tool to stimulate autobiographical memory, at least in the mild stage of the disease. © The Author(s) 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Newborn hearing screening with transient evoked otoacoustic emissions and automatic auditory brainstem response

OpenAIRE

Renata Mota Mamede de Carvallo; Carla Gentile Matas; Isabela de Souza Jardim

2008-01-01

Objective: The aim of the present investigation was to check Transient Evoked Otoacoustic Emissions and Automatic Auditory Brainstem Response tests applied together in regular nurseries and Newborn Intensive Care Units (NICU), as well as to describe and compare the results obtained in both groups. Methods: We tested 150 newborns from regular nurseries and 70 from NICU. Rresults: The newborn hearing screening results using Transient Evoked Otoacoustic Emissions and Automatic Auditory Brainstem...

Effects of minoxidil and nitroprusside on reflex increases in myocardial contractility.

Science.gov (United States)

Robie, N W

1978-01-01

1 The effects of nitroprusside and minoxidil on increases in myocardial contractility resulting from carotid artery occlusion were investigated in anaesthetized dogs. The results were compared with those produced by intravenous influsion of noradrenaline. 2 Nitroprusside and minoxidil attenuated the pressor responses produced by carotid artery occlusion. 3 Nitroprusside, but not minoxidil, attenuated the maximal myocardial contractility resulting from carotid occlusion. 4 The pressor and contractility responses to noradrenaline infusion were unaffected by either agent. 5 Nitroprusside failed to alter the myocardial responses produced by dimethylphenylpiperazinium. 6 These results, in conjunction with those of other investigators who have demonstrated that nitroprusside does not affect the release of noradrenaline from adrenergic neurons, suggest that nitroprusside may inhibit sympathetic nervous system reflex activity via an afferent and/or central component. PMID:620094

Speech Evoked Auditory Brainstem Response in Stuttering

Directory of Open Access Journals (Sweden)

Ali Akbar Tahaei

2014-01-01

Full Text Available Auditory processing deficits have been hypothesized as an underlying mechanism for stuttering. Previous studies have demonstrated abnormal responses in subjects with persistent developmental stuttering (PDS at the higher level of the central auditory system using speech stimuli. Recently, the potential usefulness of speech evoked auditory brainstem responses in central auditory processing disorders has been emphasized. The current study used the speech evoked ABR to investigate the hypothesis that subjects with PDS have specific auditory perceptual dysfunction. Objectives. To determine whether brainstem responses to speech stimuli differ between PDS subjects and normal fluent speakers. Methods. Twenty-five subjects with PDS participated in this study. The speech-ABRs were elicited by the 5-formant synthesized syllable/da/, with duration of 40 ms. Results. There were significant group differences for the onset and offset transient peaks. Subjects with PDS had longer latencies for the onset and offset peaks relative to the control group. Conclusions. Subjects with PDS showed a deficient neural timing in the early stages of the auditory pathway consistent with temporal processing deficits and their abnormal timing may underlie to their disfluency.

Visual Evoked Response in Children Subjected to Prenatal Maternal ...

African Journals Online (AJOL)

neural conduction, or arousal level. S. Afr. Med. J., 48 ... pression treatment in either development or IQ, whether ... children in brain function at an electrophysiological level, ..... Perry, N. W. and Childers, D. G. (1969): The Human Visual Evoked.

Gender differences in rival characteristics that evoke jealousy in response to emotional versus sexual infidelity

NARCIS (Netherlands)

Buunk, Abraham (Bram); Dijkstra, Pieternel

2004-01-01

Previous research has shown that in men jealousy is evoked more by a rival's status-related characteristics than in women, whereas in women jealousy is evoked more by a rival's physical attractiveness than in men. The present study examined whether the occurrence of this gender difference depends

Abdominal acupuncture reduces laser-evoked potentials in healthy subjects

DEFF Research Database (Denmark)

Pazzaglia, C.; Liguori, S.; Minciotti, I.

2015-01-01

Objective: Acupuncture is known to reduce clinical pain, although the exact mechanism is unknown. The aim of the current study was to investigate the effect of acupuncture on laser-evoked potential amplitudes and laser pain perception. Methods: In order to evaluate whether abdominal acupuncture...... is able to modify pain perception, 10 healthy subjects underwent a protocol in which laser-evoked potentials (LEPs) and laser pain perception were collected before the test (baseline), during abdominal acupuncture, and 15. min after needle removal. The same subjects also underwent a similar protocol...... in which, however, sham acupuncture without any needle penetration was used. Results: During real acupuncture, both N1 and N2/P2 amplitudes were reduced, as compared to baseline (p . < 0.01). The reduction lasted up to 15. min after needle removal. Furthermore, laser pain perception was reduced during...

Coordination of eye and head components of movements evoked by stimulation of the paramedian pontine reticular formation

Science.gov (United States)

Barton, Ellen J.; Sparks, David L.

2013-01-01

Constant frequency microstimulation of the paramedian pontine reticular formation (PPRF) in head-restrained monkeys evokes a constant velocity eye movement. Since the PPRF receives significant projections from structures that control coordinated eye-head movements, we asked whether stimulation of the pontine reticular formation in the head-unrestrained animal generates a combined eye-head movement or only an eye movement. Microstimulation of most sites yielded a constant-velocity gaze shift executed as a coordinated eye-head movement, although eye-only movements were evoked from some sites. The eye and head contributions to the stimulation-evoked movements varied across stimulation sites and were drastically different from the lawful relationship observed for visually-guided gaze shifts. These results indicate that the microstimulation activated elements that issued movement commands to the extraocular and, for most sites, neck motoneurons. In addition, the stimulation-evoked changes in gaze were similar in the head-restrained and head-unrestrained conditions despite the assortment of eye and head contributions, suggesting that the vestibuloocular reflex (VOR) gain must be near unity during the coordinated eye-head movements evoked by stimulation of the PPRF. These findings contrast the attenuation of VOR gain associated with visually-guided gaze shifts and suggest that the vestibulo-ocular pathway processes volitional and PPRF stimulation-evoked gaze shifts differently. PMID:18458891

Absence of both auditory evoked potentials and auditory percepts dependent on timing cues.

Science.gov (United States)

Starr, A; McPherson, D; Patterson, J; Don, M; Luxford, W; Shannon, R; Sininger, Y; Tonakawa, L; Waring, M

1991-06-01

An 11-yr-old girl had an absence of sensory components of auditory evoked potentials (brainstem, middle and long-latency) to click and tone burst stimuli that she could clearly hear. Psychoacoustic tests revealed a marked impairment of those auditory perceptions dependent on temporal cues, that is, lateralization of binaural clicks, change of binaural masked threshold with changes in signal phase, binaural beats, detection of paired monaural clicks, monaural detection of a silent gap in a sound, and monaural threshold elevation for short duration tones. In contrast, auditory functions reflecting intensity or frequency discriminations (difference limens) were only minimally impaired. Pure tone audiometry showed a moderate (50 dB) bilateral hearing loss with a disproportionate severe loss of word intelligibility. Those auditory evoked potentials that were preserved included (1) cochlear microphonics reflecting hair cell activity; (2) cortical sustained potentials reflecting processing of slowly changing signals; and (3) long-latency cognitive components (P300, processing negativity) reflecting endogenous auditory cognitive processes. Both the evoked potential and perceptual deficits are attributed to changes in temporal encoding of acoustic signals perhaps occurring at the synapse between hair cell and eighth nerve dendrites. The results from this patient are discussed in relation to previously published cases with absent auditory evoked potentials and preserved hearing.

Methodologic aspects of acetylcholine-evoked relaxation of rabbit aorta

DEFF Research Database (Denmark)

Larsen, Kirsten Vendelbo; Nedergaard, Ove A.

1999-01-01

The acetylcholine-evoked relaxation of rabbit isolated thoracic aorta precontracted by phenylephrine was studied. Phenylephrine caused a steady contraction that was maintained for 6 h. In the presence of calcium disodium ethylenediaminetetraacetate (EDTA) and ascorbic acid the contraction decreased...

Measures of spontaneous and movement-evoked pain are associated with disability in patients with whiplash injuries.

Science.gov (United States)

Mankovsky-Arnold, Tsipora; Wideman, Timothy H; Larivière, Christian; Sullivan, Michael J L

2014-09-01

This study examined the degree to which measures of spontaneous and movement-evoked pain accounted for shared or unique variance in functional disability associated with whiplash injury. The study also addressed the role of fear of movement as a mediator or moderator of the relation between different indices of pain and functional disability. Measures of spontaneous pain, single-point movement-evoked pain, repetition-induced summation of activity-related pain (RISP), and fear of movement and disability were obtained on a sample of 142 individuals who had sustained whiplash injuries. Participants' pain ratings, provided after lifting a weighted canister, were used as the index of single-point movement-evoked pain. RISP was computed as the increase in pain reported by participants over successive lifts of 18 weighted canisters. Measures of functional disability included physical lift tolerance and self-reported disability. Hierarchical regression analyses revealed that measures of single-point movement-evoked pain and RISP accounted for significant unique variance in self-reported disability, beyond the variance accounted for by the measure of spontaneous pain. Only RISP accounted for significant unique variance in lift tolerance. The results suggest that measures of movement-evoked pain represent a disability-relevant dimension of pain that is not captured by measures of spontaneous pain. The clinical and conceptual implications of the findings are discussed. This study examined the degree to which measures of spontaneous and movement-evoked pain accounted for shared or unique variance in functional disability associated with whiplash injury. The findings suggest that approaches to the clinical evaluation of pain would benefit from the inclusion of measures of movement-evoked pain. Copyright © 2014 American Pain Society. Published by Elsevier Inc. All rights reserved.

Torque decrease during submaximal evoked contractions of the quadriceps muscle is linked not only to muscle fatigue.

Science.gov (United States)

Matkowski, Boris; Lepers, Romuald; Martin, Alain

2015-05-01

The aim of this study was to analyze the neuromuscular mechanisms involved in the torque decrease induced by submaximal electromyostimulation (EMS) of the quadriceps muscle. It was hypothesized that torque decrease after EMS would reflect the fatigability of the activated motor units (MUs), but also a reduction in the number of MUs recruited as a result of changes in axonal excitability threshold. Two experiments were performed on 20 men to analyze 1) the supramaximal twitch superimposed and evoked at rest during EMS (Experiment 1, n = 9) and 2) the twitch response and torque-frequency relation of the MUs activated by EMS (Experiment 2, n = 11). Torque loss was assessed by 15 EMS-evoked contractions (50 Hz; 6 s on/6 s off), elicited at a constant intensity that evoked 20% of the maximal voluntary contraction (MVC) torque. The same stimulation intensity delivered over the muscles was used to induce the torque-frequency relation and the single electrical pulse evoked after each EMS contraction (Experiment 2). In Experiment 1, supramaximal twitch was induced by femoral nerve stimulation. Torque decreased by ~60% during EMS-evoked contractions and by only ~18% during MVCs. This was accompanied by a rightward shift of the torque-frequency relation of MUs activated and an increase of the ratio between the superimposed and posttetanic maximal twitch evoked during EMS contraction. These findings suggest that the torque decrease observed during submaximal EMS-evoked contractions involved muscular mechanisms but also a reduction in the number of MUs recruited due to changes in axonal excitability. Copyright © 2015 the American Physiological Society.

Influence of exercise on NA- and Hsp72-induced release of IFNγ by the peritoneal suspension of macrophages and lymphocytes from genetically obese Zucker rats.

Science.gov (United States)

Martín-Cordero, L; García, J J; Hinchado, M D; Bote, E; Ortega, E

2013-03-01

Regular physical exercise is recognized as a nonpharmacological therapeutic strategy in the treatment of metabolic syndrome, and has been proposed for improving obesity, diabetic status, insulin resistance, and immune response. The aim of the present study was to evaluate the effect of a regular exercise program (treadmill running, 5 days/week for 14 weeks at 35 cm/s for 35 min in the last month) on the release of the pro-inflammatory cytokine interferon gamma (IFNγ) by peritoneal cells (macrophages and lymphocytes) from obese Zucker rats (fa/fa) in response to noradrenaline (NA) and heat shock proteins of 72 kDa (Hsp72), and the possible adaptation due to training for a bout acute exercise (a single session of 25-35 min at 35 cm/s). In healthy (lean Fa/fa) and obese animals, peritoneal cells released greater concentrations of IFNγ in response to Hsp72 and lower concentrations in response to NA. The regular exercise training protocol, evaluated in the obese animals, produced a clear change in the regulation of the release of IFNγ. Peritoneal immune cells from trained animals released more IFNγ in response to NA, but there was a reduction in the release of IFNγ in response to Hsp72. In the obese animals, regular exercise caused a change in the inhibitory effect of NA (which now becomes stimulatory) and the stimulatory effect of Hsp72e (which now becomes inhibitory) in relation to the release of IFNγ. This reflects that Hsp72, induced by the prior release of NA following exercise-induced stress, plays a role in the homeostatic balance of release of IFNγ by peritoneal immune cells in obese animals during exercise.

Regulation of dopamine synthesis and release in striatal and prefrontal cortical brain slices

International Nuclear Information System (INIS)

Wolf, M.E.

1986-01-01

Brain slices were used to investigate the role of nerve terminal autoreceptors in modulating dopamine (DA) synthesis and release in striatum and prefrontal cortex. Accumulation of dihydroxyphenylalanine (DOPA) was used as an index of tyrosine hydroxylation in vitro. Nomifensine, a DA uptake blocker, inhibited DOPA synthesis in striatal but not prefrontal slices. This effect was reversed by the DA antagonist sulpiride, suggesting it involved activation of DA receptors by elevated synaptic levels of DA. The autoreceptor-selective agonist EMD-23-448 also inhibited striatal but not prefrontal DOPA synthesis. DOPA synthesis was stimulated in both brain regions by elevated K + , however only striatal synthesis could be further enhanced by sulpiride. DA release was measured by following the efflux of radioactivity from brain slices prelabeled with [ 3 H]-DA. EMD-23-448 and apomorphine inhibited, while sulpiride enhanced, the K + -evoked overflow of radioactivity from both striatal and prefrontal cortical slices. These findings suggest that striatal DA nerve terminals possess autoreceptors which modulate tyrosine hydroxylation as well as autoreceptors which modulate release. Alternatively, one site may be coupled to both functions through distinct transduction mechanisms. In contrast, autoreceptors on prefrontal cortical terminals appear to regulate DA release but not DA synthesis

Evoked responses to sinusoidally modulated sound in unanaesthetized dogs

NARCIS (Netherlands)

Tielen, A.M.; Kamp, A.; Lopes da Silva, F.H.; Reneau, J.P.; Storm van Leeuwen, W.

1. 1. Responses evoked by sinusoidally amplitude-modulated sound in unanaesthetized dogs have been recorded from inferior colliculus and from auditory cortex structures by means of chronically indwelling stainless steel wire electrodes. 2. 2. Harmonic analysis of the average responses demonstrated

Multi-channel motor evoked potential monitoring during anterior cervical discectomy and fusion

Directory of Open Access Journals (Sweden)

Dong-Gun Kim

Full Text Available Objectives: Anterior cervical discectomy and fusion (ACDF surgery is the most common surgical procedure for the cervical spine with low complication rate. Despite the potential prognostic benefit, intraoperative neurophysiological monitoring (IONM, a method for detecting impending neurological compromise, is not routinely used in ACDF surgery. The present study aimed to identify the potential benefits of monitoring multi-channel motor evoked potentials (MEPs during ACDF surgery. Methods: We retrospectively reviewed 200 consecutive patients who received IONM with multi-channel MEPs and somatosensory evoked potentials (SSEPs. On average, 9.2 muscles per patient were evaluated under MEP monitoring. Results: The rate of MEP change during surgery in the multi-level ACDF group was significantly higher than the single-level group. Two patients from the single-level ACDF group (1.7% and four patients from the multi-level ACDF group (4.9% experienced post-operative motor deficits. Multi-channel MEPs monitoring during single and multi-level ACDF surgery demonstrated higher sensitivity, specificity, positive predictive and negative predictive value than SSEP monitoring. Conclusions: Multi-channel MEP monitoring might be beneficial for the detection of segmental injury as well as long tract injury during single- and multi-level ACDF surgery. Significance: This is first large scale study to identify the usefulness of multi-channel MEPs in monitoring ACDF surgery. Keywords: Disc disease, Somatosensory evoked potentials, Intraoperative neurophysiological monitoring, Motor evoked potentials, Anterior cervical discectomy and fusion

The interaction between tropomyosin-related kinase B receptors and presynaptic muscarinic receptors modulates transmitter release in adult rodent motor nerve terminals.

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Garcia, Neus; Tomàs, Marta; Santafé, Manel M; Besalduch, Nuria; Lanuza, Maria A; Tomàs, Josep

2010-12-08

The neurotrophin brain-derived neurotrophic factor (BDNF), neurotrophin-4 (NT-4) and the receptors tropomyosin-related kinase B (trkB) and p75(NTR) are present in the nerve terminals on the neuromuscular junctions (NMJs) of the levator auris longus muscle of the adult mouse. Exogenously added BDNF or NT-4 increased evoked ACh release after 3 h. This presynaptic effect (the size of the spontaneous potentials is not affected) is specific because it is not produced by neurotrophin-3 (NT-3) and is prevented by preincubation with trkB-IgG chimera or by pharmacological block of trkB [K-252a (C₂₇H₂₁N₃O₅)] or p75(NTR) [Pep5 (C₈₆H₁₁₁N₂₅O₁₉S₂] signaling. The effect of BDNF depends on the M₁ and M₂ muscarinic acetylcholine autoreceptors (mAChRs) because it is prevented by atropine, pirenzepine and methoctramine. We found that K-252a incubation reduces ACh release (~50%) in a short time (1 h), but the p75(NTR) signaling inhibitor Pep5 does not have this effect. The specificity of the K-252a blocking effect on trkB was confirmed with the anti-trkB antibody 47/trkB, which reduces evoked ACh release, like K-252a, whereas the nonpermeant tyrosine kinase blocker K-252b does not. Neither does incubation with the fusion protein trkB-IgG (to chelate endogenous BDNF/NT-4), anti-BDNF or anti-NT-4 change ACh release. Thus, the trkB receptor normally seems to be coupled to ACh release when there is no short-term local effect of neurotrophins at the NMJ. The normal function of the mAChR mechanism is a permissive prerequisite for the trkB pathway to couple to ACh release. Reciprocally, the normal function of trkB modulates M₁- and M₂-subtype muscarinic pathways.

Guanfacine potentiates the activation of prefrontal cortex evoked by warning signals.

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Clerkin, Suzanne M; Schulz, Kurt P; Halperin, Jeffrey M; Newcorn, Jeffrey H; Ivanov, Iliyan; Tang, Cheuk Y; Fan, Jin

2009-08-15

Warning signals evoke an alert state of readiness that prepares for a rapid response by priming a thalamo-frontal-striatal network that includes the dorsolateral prefrontal cortex (DLPFC). Animal models indicate that noradrenergic input is essential for this stimulus-driven activation of DLPFC, but the precise mechanisms involved have not been determined. We tested the role that postsynaptic alpha(2A) adrenoceptors play in the activation of DLPFC evoked by warning cues using a placebo-controlled challenge with the alpha(2A) agonist guanfacine. Sixteen healthy young adults were scanned twice with event-related functional magnetic resonance imaging (fMRI), while performing a simple cued reaction time (RT) task following administration of a single dose of oral guanfacine (1 mg) and placebo in counterbalanced order. The RT task temporally segregates the neural effects of warning cues and motor responses and minimizes mnemonic demands. Warning cues produced a marked reduction in RT accompanied by significant activation in a distributed thalamo-frontal-striatal network, including bilateral DLPFC. Guanfacine selectively increased the cue-evoked activation of the left DLPFC and right anterior cerebellum, although this increase was not accompanied by further reductions in RT. The effects of guanfacine on DLPFC activation were specifically associated with the warning cue and were not seen for visual- or target-related activation. Guanfacine produced marked increases in the cue-evoked activation of DLPFC that correspond to the well-described actions of postsynaptic alpha(2) adrenoceptor stimulation. The current procedures provide an opportunity to test postsynaptic alpha(2A) adrenoceptor function in the prefrontal cortex in the pathophysiology of several psychiatric disorders.

[Effects of sevoflurane and propofol on evoked potentials during neurosurgical anesthesia].

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Nakagawa, Itsuo; Hidaka, Syozo; Okada, Hironori; Kubo, Takashi; Okamura, Kenta; Kato, Takahiro

2006-06-01

The effect of anesthetics on somatosensory evoked potential (SEP) and auditory brain stem response (ABR) has been a subject of intense reseach over the last two decades. In fact, volatile anesthetics have been repeatedly shown to decrease cortical amplitude in a dose-dependent fashion but the information regarding the effect of propofol is incomplete. The purpose of this study was to compare the effects of sevoflurane and propofol on evoked potentials during comparable depth of anesthesia guided by bispectral index (BIS). Forty four patients scheduled for neurosurgery were studied. Anesthesia was maintained with intravenous propofol using target controlled infusion (TCI). We measured the change of amplitude and latency of SEP(N20-P25), ABR (V wave) and visual evoked potential (VEP: P100) at three sets of sevoflurane (0%, 1%, 2%) or propofol concentrations (effect site concentration of 1.5, 2.0, 3.0 microug x ml(-1)). BIS monitor was used to measure relative depth of hypnosis. With increasing concentrations of sevoflurane (0, 1% and 2%), SEP showed dose-related reduction in its amplitude, ABR produced less marked changes and VEP showed a significant reduction at 1%. VEP at the propofol concentration of 3.0 microg x ml(-1) was decreased significantly compared with the amplitude at 1.5 microg x ml(-1) concentration. No significant change was observed with SEP and ABR during the change of propofol dosages. BIS values were almost the same with each anesthetics. VEP was most strongly affected with anesthetics, and ABR showed less marked influence of sevoflurane and propofol. Propofol based TIVA technique would induce less change in evoked potentials than sevoflurane.

pKI values of prazosin and idazoxan for receptors stimulated by neuronally released transmitter in the epididymal portion of rat isolated vas deferens.

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Mackay, D; Kengatharan, M

1994-01-01

1. A new method has been used to measure pKI values of prazosin and idazoxan against neuronally-released transmitter in the epididymal portion of the rat isolated vas deferens. The most reproducible results were obtained with a prolonged antagonist equilibration time (1 h). 2. Under these conditions the pKI of prazosin was practically unaffected by addition of alpha, beta-methylene-adenosine-5'-triphosphate (10 microM) to desensitize purinoceptors. Addition of desmethylimipramine (DMI) (0.3 microM) produced a small, but statistically non-significant, reduction. 3. The same method has been used to measure the pKI of prazosin against exogenous noradrenaline. In the latter case addition of DMI (0.3 microM) and corticosterone (30 microM) together produced a statistically significant reduction in the apparent pKI of prazosin. 4. The new method for estimating pKI values shows that DMI itself acts either pseudo-irreversibly or non-competitively and may be reducing the apparent pKI of prazosin. 5. The pKI values obtained for prazosin and idazoxan against neuronally-released transmitter are in good agreement with those obtained by other workers for the actions of these drugs on alpha-adrenoceptors.

Cortical modulation of short-latency TMS-evoked potentials

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Domenica eVeniero

2013-01-01

Full Text Available Transcranial magnetic stimulation - electroencephalogram (TMS-EEG co-registration offers the opportunity to test reactivity of brain areas across distinct conditions through TMS-evoked potentials (TEPs. Several TEPs have been described, their functional meaning being largely unknown. In particular, short-latency potentials peaking at 5 (P5 and 8 (N8 ms after the TMS pulse have been recently described, but because of their huge amplitude, the problem of whether their origin is cortical or not has been opened. To gain information about these components, we employed a protocol that modulates primary motor cortex excitability (MI through an exclusively cortical phenomena: low frequency stimulation of premotor area (PMC. TMS was applied simultaneously with EEG recording from 70 electrodes. Amplitude of TEPs evoked by 200 single-pulses TMS delivered over MI at 110% of resting motor threshold was measured before and after applying 900 TMS conditioning stimuli to left premotor cortex with 1 Hz repetition rate. Single subject analyses showed reduction in TEPs amplitude after PMC conditioning in a sample of participants and increase in TEPs amplitude in two subjects. No effects were found on corticospinal excitability as recorded by motor evoked potentials (MEPs. Furthermore, correlation analysis showed an inverse relation between the effects of the conditioning protocol on P5-N8 complex amplitude and MEPs amplitude. Because the effects of the used protocol have been ascribed to a cortical interaction between premotor area and MI, we suggest that despite the sign of P5-N8 amplitude modulation is not consistent across participant, this modulation could indicate, at least in part, their cortical origin. We conclude that with an accurate experimental procedure early-latency components can be used to evaluate the reactivity of the stimulated cortex.

Single-sweep spectral analysis of contact heat evoked potentials

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Hansen, Tine M; Graversen, Carina; Frøkjaer, Jens B

2015-01-01

AIMS: The cortical response to nociceptive thermal stimuli recorded as contact heat evoked potentials (CHEPs) may be altered by morphine. However, previous studies have averaged CHEPs over multiple stimuli, which are confounded by jitter between sweeps. Thus, the aim was to assess single-sweep ch......AIMS: The cortical response to nociceptive thermal stimuli recorded as contact heat evoked potentials (CHEPs) may be altered by morphine. However, previous studies have averaged CHEPs over multiple stimuli, which are confounded by jitter between sweeps. Thus, the aim was to assess single...... by 13% (P = 0.04) and 9% (P = 0.007), while the beta and gamma bands were increased by 10% (P = 0.006) and 24% (P = 0.04). CONCLUSION: The decreases in the delta and theta band are suggested to represent a decrease in the pain specific morphology of the CHEPs, which indicates a diminished pain response...

The roles of superficial amygdala and auditory cortex in music-evoked fear and joy.

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Koelsch, Stefan; Skouras, Stavros; Fritz, Thomas; Herrera, Perfecto; Bonhage, Corinna; Küssner, Mats B; Jacobs, Arthur M

2013-11-01

This study investigates neural correlates of music-evoked fear and joy with fMRI. Studies on neural correlates of music-evoked fear are scant, and there are only a few studies on neural correlates of joy in general. Eighteen individuals listened to excerpts of fear-evoking, joy-evoking, as well as neutral music and rated their own emotional state in terms of valence, arousal, fear, and joy. Results show that BOLD signal intensity increased during joy, and decreased during fear (compared to the neutral condition) in bilateral auditory cortex (AC) and bilateral superficial amygdala (SF). In the right primary somatosensory cortex (area 3b) BOLD signals increased during exposure to fear-evoking music. While emotion-specific activity in AC increased with increasing duration of each trial, SF responded phasically in the beginning of the stimulus, and then SF activity declined. Psychophysiological Interaction (PPI) analysis revealed extensive emotion-specific functional connectivity of AC with insula, cingulate cortex, as well as with visual, and parietal attentional structures. These findings show that the auditory cortex functions as a central hub of an affective-attentional network that is more extensive than previously believed. PPI analyses also showed functional connectivity of SF with AC during the joy condition, taken to reflect that SF is sensitive to social signals with positive valence. During fear music, SF showed functional connectivity with visual cortex and area 7 of the superior parietal lobule, taken to reflect increased visual alertness and an involuntary shift of attention during the perception of auditory signals of danger. Copyright © 2013 Elsevier Inc. All rights reserved.

The effect of digital signage on shoppers’ behavior: the role of the evoked experience

OpenAIRE

Dennis, Charles; Brakus, J. Joško; Gupta, Suraksha; Alamanos, Eleftherios

2014-01-01

This paper investigates the role of digital signage as experience provider in retail spaces. The findings of a survey-based field experiment demonstrate that digital signage content high on sensory cues evokes affective experience and strengthens customers' experiential processing route. In contrast, digital signage messages high on “features and benefits” information evoke intellectual experience and strengthen customers' deliberative processing route. The affective experience is more strong...

Perceptual learning of acoustic noise generates memory-evoked potentials.

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Andrillon, Thomas; Kouider, Sid; Agus, Trevor; Pressnitzer, Daniel

2015-11-02

Experience continuously imprints on the brain at all stages of life. The traces it leaves behind can produce perceptual learning [1], which drives adaptive behavior to previously encountered stimuli. Recently, it has been shown that even random noise, a type of sound devoid of acoustic structure, can trigger fast and robust perceptual learning after repeated exposure [2]. Here, by combining psychophysics, electroencephalography (EEG), and modeling, we show that the perceptual learning of noise is associated with evoked potentials, without any salient physical discontinuity or obvious acoustic landmark in the sound. Rather, the potentials appeared whenever a memory trace was observed behaviorally. Such memory-evoked potentials were characterized by early latencies and auditory topographies, consistent with a sensory origin. Furthermore, they were generated even on conditions of diverted attention. The EEG waveforms could be modeled as standard evoked responses to auditory events (N1-P2) [3], triggered by idiosyncratic perceptual features acquired through learning. Thus, we argue that the learning of noise is accompanied by the rapid formation of sharp neural selectivity to arbitrary and complex acoustic patterns, within sensory regions. Such a mechanism bridges the gap between the short-term and longer-term plasticity observed in the learning of noise [2, 4-6]. It could also be key to the processing of natural sounds within auditory cortices [7], suggesting that the neural code for sound source identification will be shaped by experience as well as by acoustics. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of methylmercury on histamine release from rat mast cells

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Graevskaya, Elizabeth E.; Rubin, Andrew B. [Moscow State University, Biological Faculty, Department of Biophysics, 119899, Vorobjovy Gory, Moscow (Russian Federation); Yasutake, Akira; Aramaki, Ryoji [National Institute for Minamata Disease, 4058-18 Hama, Minamata, Kumamoto 867-0008 (Japan)

2003-01-01

Methylmercury chloride (MeHgCl) is well known as a significant environmental hazard, particularly as a modulator of the immune system. As it is acknowledged that the critical effector cells in the host response participating in various biological responses are mast cells, we tried to define the possible contribution of mast cells in the development of methylmercury-evoked effects. We investigated the effects of methylmercury on the rat mast cell degranulation induced by non-immunological stimuli (the selective liberator of histamine, compound 48/80, and calcium ionophore A23187) both in vivo and in vitro. Using the cells prepared from methylmercury-intoxicated rats through a 5-day treatment of MeHgCl (10 mg/kg/day), we observed the suppression of calcium ionophore A23187- and 48/80-induced histamine release, which was enhanced with time after treatment. Similar suppression was observed in the ionophore-stimulated release, when cells were prepared from rat with a single treatment of MeHgCl (20 mg/kg). It should be noted that when cells from the control rat were pre-incubated with methylmercury in vitro at a 10{sup -8} M concentration for 10 min, A23187 and compound 48/80-stimulated histamine release was significantly enhanced. However, when the pre-incubation period was prolonged to 30 min, the release was suppressed. An increase in the methylmercury concentration to 10{sup -6} M also suppressed the histamine release. These results show that methylmercury treatment can modify mast cell function depending on concentration and time, and might provide an insight into the role of mast cells in the development of methylmercury-stimulated effects. (orig.)

A Parallel World for the World Bank: A Case Study of Urgent: Evoke, An Educational Alternate Reality Game

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David I. Waddington

2013-01-01

Full Text Available In 2010, the World Bank launched Urgent: Evoke, an alternate reality game. Conceived in response to the demands of African universities, the game was designed to promote the World Bank Institute’s vision of positive global change through social innovation, and made substantial use of Web 2.0 tools such as blogs, personal profiles, and social networks. This article offers a case study of Urgent: Evoke, divided into four sections: first, the potential to use video games as citizenship education tools is discussed; second, the unique game genre (alternate reality games into which Evoke falls is explained and some possible uses of this genre in higher education are examined; third, the functioning of the Evoke game world is explained; and fourth, the results of the Evoke educational project are assessed. The case study concludes with some commentary on Evoke’s ideological message, which those less sympathetic to capitalism may view as problematic.

Effect of naftopidil on brain noradrenaline-induced decrease in arginine-vasopressin secretion in rats

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Masaki Yamamoto

2016-09-01

Full Text Available Naftopidil, an α1-adrenoceptor antagonist, has been shown to inhibit nocturnal polyuria in patients with lower urinary tract symptom. However, it remains unclear how naftopidil decreases nocturnal urine production. Here, we investigated the effects of naftopidil on arginine-vasopressin (AVP plasma level and urine production and osmolality in rats centrally administered with noradrenaline (NA. NA (3 or 30 μg/kg was administered into the left ventricle (i.c.v. of male Wistar rats 3 h after naftopidil pretreatment (10 or 30 mg/kg, i.p.. Blood samples were collected from the inferior vena cava 1 h after NA administration or 4 h after peritoneal administration of naftopidil; plasma levels of AVP were assessed by ELISA. Voiding behaviors of naftopidil (30 mg/kg, i.p.-administered male Wistar rats were observed during separate light- and dark cycles. Administration of NA decreased plasma AVP levels and elevated urine volume, which were suppressed by systemic pretreatment with naftopidil (30 mg/kg, i.p.. Urine osmolality decreased 1 h after NA administration. However, naftopidil by itself had no effect on plasma AVP levels or urodynamic parameters during light- and dark cycles. Our findings suggest that systemic administration of naftopidil could prevent central noradrenergic nervous system-mediated decline in AVP secretion and increase in urine production in rats.

Changes in acetylcholine release from the chick retina are not associated with myopia development

International Nuclear Information System (INIS)

Vessey, K.A.; Cotriall, C.L.; McBrien, N.A.

2002-01-01

Full text: The effectiveness of muscarinic receptor antagonists in inhibiting myopia progression in animal models and humans implicates cholinergic signalling in ocular growth regulation. Therefore to determine if changes in the release of acetylcholine from the retina are involved in myopia development, the efflux of acetylcholine from the in vitro retina of normal and myopic chick eyes was investigated. Chicks were monocularly deprived (MD) of pattern vision with translucent occluders for 2 or 7 days and refractive error of MD groups and age matched normals was monitored using retinoscopy (n=6 each group). 3 H-choline-Cl (1 Ci in 7μL) was injected into the vitreous of each eye under 2.5% halothane anaesthesia. After 1hr, the eyes were enucleated, under terminal anaesthesia (sodium pentobarbital, 120 mg/kg, im). Retinas were flat-mounted on acetate filter discs and superfused with oxygenated physiological saline solution (PSS) for 30min at 0.4mL/min. Five baseline fractions were collected (B1-B5), then three stimulated fractions were collected in the presence of PSS containing 50mM KCl (K1-K3) at 2min intervals. 3 H-acetylcholine ( 3 H-ACh) in each fraction was quantified by liquid scintillation counting. Significant amounts of myopia were induced in MD eyes after 2 (-5.1±0.8D) and 7 days (-18.8±2.4D) relative to control eyes (paired t-test p 3 H-ACh release was 146±15% above basal levels (K2/B1%) from retinas of normal animals. After 2 days MD, there was no significant difference between KCl-evoked release of 3 H-ACh from deprived eyes (147 39%) compared to control eyes (198±61%, paired t-test, p=0.27) or the eyes of normal animals (ANOVA, p>0.5). Similar results were obtained following 7 days MD. The results demonstrate that evoked acetylcholine release from the chick retina of myopic eyes is unaltered relative to control or normal eyes using an in vitro approach. Copyright (2002) Australian Neuroscience Society

Sexual side effects of serotonergic antidepressants: mediated by inhibition of serotonin on central dopamine release?

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Bijlsma, Elisabeth Y; Chan, Johnny S W; Olivier, Berend; Veening, Jan G; Millan, Mark J; Waldinger, Marcel D; Oosting, Ronald S

2014-06-01

Antidepressant-induced sexual dysfunction adversely affects the quality of life of antidepressant users and reduces compliance with treatment. Animal models provide an instructive approach for examining potential sexual side effects of novel drugs. This review discusses the stability and reproducibility of our standardized test procedure that assesses the acute, subchronic and chronic effects of psychoactive compounds in a 30 minute mating test. In addition, we present an overview of the effects of several different (putative) antidepressants on male rat sexual behavior, as tested in our standardized test procedure. By comparing the effects of these mechanistically distinct antidepressants (paroxetine, venlafaxine, bupropion, buspirone, DOV 216,303 and S32006), this review discusses the putative mechanism underlying sexual side effects of antidepressants and their normalization. This review shows that sexual behavior is mainly inhibited by antidepressants that increase serotonin neurotransmission via blockade of serotonin transporters, while those that mainly increase the levels of dopamine and noradrenaline are devoid of sexual side effects. Those sexual disturbances cannot be normalized by simultaneously increasing noradrenaline neurotransmission, but are normalized by increasing both noradrenaline and dopamine neurotransmission. Therefore, it is hypothesized that the sexual side effects of selective serotonin reuptake inhibitors may be mediated by their inhibitory effects on dopamine signaling in sex brain circuits. Clinical development of novel antidepressants should therefore focus on compounds that simultaneously increase both serotonin and dopamine signaling. © 2013 Elsevier Inc. All rights reserved.

Dynamic properties of sensory stimulation evoked responses in mouse cerebellar granule cell layer and molecular layer.

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Bing, Yan-Hua; Zhang, Guang-Jian; Sun, Lei; Chu, Chun-Ping; Qiu, De-Lai

2015-01-12

Sensory information coming from climbing fiber and mossy fiber-granule cell pathways, generates motor-related outputs according to internal rules of integration and computation in the cerebellar cortex. However, the dynamic properties of sensory information processing in mouse cerebellar cortex are less understood. Here, we studied the dynamic properties of sensory stimulation-evoked responses in the cerebellar granule cell layer (GCL) and molecular layer (ML) by electrophysiological recordings method. Our data showed that air-puff stimulation (5-10 ms in duration) of the ipsilateral whisker pad evoked single-peak responses in the GCL and ML; whereas a duration of stimulation ≥30 ms in GCL and ≥60 ms in ML, evoked double-peak responses that corresponded with stimulation-on and -off responses via mossy fiber pathway. The highest frequency of stimulation train for evoking GCL responses was 33 Hz. In contrast, the highest frequency of stimulation train for evoking ML responses was 4 Hz. These results indicate that the cerebellar granule cells transfer the high-fidelity sensory information from mossy fibers, which is cut-off by molecular layer interneurons (MLIs). Our results suggest that the MLIs network acts as a low-pass filter during the processing of high-frequency sensory information. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

The glial cell line-derived neurotrophic factor (GDNF) does not acutely change acetylcholine release in developing and adult neuromuscular junction.

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Garcia, Neus; Santafé, Manel M; Tomàs, Marta; Lanuza, Maria A; Besalduch, Nuria; Priego, Merche; Tomàs, Josep

2010-08-16

We use immunocytochemistry to show that the trophic molecule glial cell line-derived neurotrophic factor (GDNF) and its receptor GDNF family receptor alpha-1 (GFRalpha-1) are present in both neonatal (P6) and adult (P45) rodent neuromuscular junctions (NMJ) colocalized with several synaptic markers. However, incubation with exogenous GDNF (10-200ng/ml, 1-3h), does not affect spontaneous ACh release. Moreover, GDNF does not change the size of the evoked ACh release from the weak and the strong axonal inputs on dually innervated postnatal endplates nor in the most developed singly-innervated synapses at P6 and P45. Our findings indicate that GDNF (unlike neurotrophins) does not acutely modulate transmitter release during the developmental process of synapse elimination nor as the NMJ matures. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

A comparison of auditory evoked potentials to acoustic beats and to binaural beats

OpenAIRE

Pratt, H; Starr, A; Michalewski, HJ; Dimitrijevic, A; Bleich, N; Mittelman, N

2010-01-01

The purpose of this study was to compare cortical brain responses evoked by amplitude modulated acoustic beats of 3 and 6 Hz in tones of 250 and 1000 Hz with those evoked by their binaural beats counterparts in unmodulated tones to indicate whether the cortical processes involved differ. Event-related potentials (ERPs) were recorded to 3- and 6-Hz acoustic and binaural beats in 2000 ms duration 250 and 1000 Hz tones presented with approximately 1 s intervals. Latency, amplitude and source cur...

Evaluation of the influence of UV/IR radiation on iron release from ferritin

International Nuclear Information System (INIS)

Gritzkov, M.; Kochev, V.; Vladimirova, L

2010-01-01

In the present work the influence of UV/IR radiation on the iron-releasing process from ferritin is investigated. The ferritins are a family of iron-storing proteins playing a key role in the biochemical reactions between iron and oxygen-processes of exclusive importance for the existence of all living organisms. The iron is stored within the ferritin core in the form of insoluble crystals containing Fe(III). Therefore for its release, the mineral matrix has to be decomposed, usually through a reduction of Fe(III) to Fe(II). Our study considers the action of UV/IR radiation on the structure of the protein molecule. Eventual changes in the ferritin conformation under the irradiation could result in the change of channel forming regions responsible for the iron efflux. This can be assess by the quantity of Fe (II) obtained in a subsequent mobilization procedure evoked by exogenous reducing agents. In our case the content of the reduced iron is determined electrochemically by the method of potentiometric titration. As already was shown, this method promises to become highly useful for quantitative evaluation of released Fe 2+ . (Author)

[In vitro release of [5Met]- and [5Leu]-enkephalins from the rat brain crude synaptosomal (P2) fraction: Ca2+-dependency of K+-stimulation and effects of various drugs].

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Koida, M; Takahashi, M; Takenaga, K

1983-01-01

The rat brain P2 fraction was suspended in Krebs Ringer bicarbonate buffer containing 20 microM bacitracin and incubated at 37 degrees C for 10 min under an atmosphere of 95% O2-5% CO2. Incubation was terminated by centrifugation at 4 degrees C and 10,000 X g for 10 min. The supernatant was designated as the S1 fraction, and from the pellet, the S2 to S4 fractions were collected by repeated suspension, incubation, and centrifugation. The radioimmunoassays of each S fraction revealed the spontaneous release of [5Met]- and [5Leu]-enkephalins at the ratio of 2 to 1. The peptide contents gradually decreased from S1 to S4, but the release tended to become constant in S3 and S4. Thus, the effects of some ions and drugs on the release were compared at the stage of obtaining the S3 fraction. The release of both peptides were significantly stimulated in 50 mM KCl buffer, and the stimulatory effect appears to be dependent on Ca2+ concentration. Veratrine and A23187 were also effective stimulants of the release. On the other hand, neither spontaneous nor K+-stimulated release of enkephalins was affected by morphine (1 microM), naloxone (1 microM), kyotorphin (1 or 10 microM), and Li+ (50 mM). Similar results were obtained with the release of 3H-noradrenaline taken up in vitro by the P2 fraction. The usability of the P2 fraction as an in vitro model for the study of stimulus-coupled release of enkephalins was discussed with some limitations found herein.

Loss of nitric oxide-mediated inhibition of purine neurotransmitter release in the colon in the absence of interstitial cells of Cajal.

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Durnin, Leonie; Lees, Andrea; Manzoor, Sheerien; Sasse, Kent C; Sanders, Kenton M; Mutafova-Yambolieva, Violeta N

2017-11-01

Regulation of colonic motility depends on the integrity of enteric inhibitory neurotransmission mediated by nitric oxide (NO), purine neurotransmitters, and neuropeptides. Intramuscular interstitial cells of Cajal (ICC-IM) and platelet-derived growth factor receptor-α-positive (PDGFRα + ) cells are involved in generating responses to NO and purine neurotransmitters, respectively. Previous studies have suggested a decreased nitrergic and increased purinergic neurotransmission in Kit W /Kit W-v ( W/W v ) mice that display lesions in ICC-IM along the gastrointestinal tract. However, contributions of NO to these phenotypes have not been evaluated. We used small-chamber superfusion assays and HPLC to measure the spontaneous and electrical field stimulation (EFS)-evoked release of nicotinamide adenine dinucleotide (NAD + )/ADP-ribose, uridine adenosine tetraphosphate (Up4A), adenosine 5'-triphosphate (ATP), and metabolites from the tunica muscularis of human, monkey, and murine colons and circular muscle of monkey colon, and we tested drugs that modulate NO levels or blocked NO receptors. NO inhibited EFS-evoked release of purines in the colon via presynaptic neuromodulation. Colons from W/W v , Nos1 -/- , and Prkg1 -/- mice displayed augmented neural release of purines that was likely due to altered nitrergic neuromodulation. Colons from W/W v mice demonstrated decreased nitrergic and increased purinergic relaxations in response to nerve stimulation. W/W v mouse colons demonstrated reduced Nos1 expression and reduced NO release. Our results suggest that enhanced purinergic neurotransmission may compensate for the loss of nitrergic neurotransmission in muscles with partial loss of ICC. The interactions between nitrergic and purinergic neurotransmission in the colon provide novel insight into the role of neurotransmitters and effector cells in the neural regulation of gastrointestinal motility. NEW & NOTEWORTHY This is the first study investigating the role of nitric

Occipital lobe lesions result in a displacement of magnetoencephalography visual evoked field dipoles.

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Pang, Elizabeth W; Chu, Bill H W; Otsubo, Hiroshi

2014-10-01

The pattern-reversal visual evoked potential measured electrically from scalp electrodes is known to be decreased, or absent, in patients with occipital lobe lesions. We questioned whether the measurement and source analysis of the neuromagnetic visual evoked field (VEF) might offer additional information regarding visual cortex relative to the occipital lesion. We retrospectively examined 12 children (6-18 years) with occipital lesions on MRI, who underwent magnetoencephalography and ophthalmology as part of their presurgical assessment. Binocular half-field pattern-reversal VEFs were obtained in a 151-channel whole-head magnetoencephalography. Data were averaged and dipole source analyses were performed for each half-field stimulation. A significant lateral shift (P occipital lesions. Magnetoencephalography may be useful as a screening test of visual function in young patients. We discuss potential explanations for this lateral shift and emphasize the utility of adding the magnetoencephalography pattern-reversal visual evoked field protocol to the neurologic work-up.

Prejunctional inhibition of norepinephrine release caused by acetylcholine in the human saphenous vein

International Nuclear Information System (INIS)

Rorie, D.K.; Rusch, N.J.; Shepherd, J.T.; Vanhoutte, P.M.; Tyce, G.M.

1981-01-01

We performed experiments to determine whether or not acetylcholine exerts a prejunctional inhibitory effect on adrenergic neurotransmission in the human blood vessel wall. Rings of human greater saphenous veins were prepared 2 to 15 hours after death and mounted for isometric tension recording in organ chambers filled with Krebs-Ringer solution. Acetylcholine depressed contractile responses to electric activation of the sympathetic nerve endings significantly more than those to exogenous norepinephrine; the relaxations caused by the cholinergic transmitter were antagonized by atropine. Helical strips were incubated with [/sub 3/H]norepinephrine and mounted for superfusion. Electric stimulation augmented the fractional release of labeled norepinephrine. Acetylcholine caused a depression of the evoked /sub 3/H release which was antagonized by atropine but not by hexamethonium. These experiments demonstrate that, as in animal cutaneous veins, there are prejunctional inhibitory muscarinic receptors on the adrenergic nerve endings in the human saphenous vein. By contrast, the human vein also contains postjunctional inhibitory muscarinic receptors

Evoked traveling alpha waves predict visual-semantic categorization-speed

Science.gov (United States)

Fellinger, Robert; Gruber, Walter; Zauner, Andrea; Freunberger, Roman; Klimesch, Wolfgang

2012-01-01

In the present study we have tested the hypothesis that evoked traveling alpha waves are behaviorally significant. The results of a visual-semantic categorization task show that three early ERP components including the P1–N1 complex had a dominant frequency characteristic in the alpha range and behaved like traveling waves do. They exhibited a traveling direction from midline occipital to right lateral parietal sites. Phase analyses revealed that this traveling behavior of ERP components could be explained by phase-delays in the alpha but not theta and beta frequency range. Most importantly, we found that the speed of the traveling alpha wave was significantly and negatively correlated with reaction time indicating that slow traveling speed was associated with fast picture-categorization. We conclude that evoked alpha oscillations are functionally associated with early access to visual-semantic information and generate – or at least modulate – the early waveforms of the visual ERP. PMID:22100769

Analysis of Spontaneous and Nerve-Evoked Calcium Transients in Intact Extraocular Muscles in Vitro

Science.gov (United States)

Feng, Cheng-Yuan; Hennig, Grant W.; Corrigan, Robert D.; Smith, Terence K.; von Bartheld, Christopher S.

2012-01-01

Extraocular muscles (EOMs) have unique calcium handling properties, yet little is known about the dynamics of calcium events underlying ultrafast and tonic contractions in myofibers of intact EOMs. Superior oblique EOMs of juvenile chickens were dissected with their nerve attached, maintained in oxygenated Krebs buffer, and loaded with fluo-4. Spontaneous and nerve stimulation-evoked calcium transients were recorded and, following calcium imaging, some EOMs were double-labeled with rhodamine-conjugated alpha-bungarotoxin (rhBTX) to identify EOM myofiber types. EOMs showed two main types of spontaneous calcium transients, one slow type (calcium waves with 1/2max duration of 2–12 s, velocity of 25–50 μm/s) and two fast “flash-like” types (Type 1, 30–90 ms; Type 2, 90–150 ms 1/2max duration). Single pulse nerve stimulation evoked fast calcium transients identical to the fast (Type 1) calcium transients. Calcium waves were accompanied by a local myofiber contraction that followed the calcium transient wavefront. The magnitude of calcium-wave induced myofiber contraction far exceeded those of movement induced by nerve stimulation and associated fast calcium transients. Tetrodotoxin eliminated nerve-evoked transients, but not spontaneous transients. Alpha-bungarotoxin eliminated both spontaneous and nerve-evoked fast calcium transients, but not calcium waves, and caffeine increased wave activity. Calcium waves were observed in myofibers lacking spontaneous or evoked fast transients, suggestive of multiply-innervated myofibers, and this was confirmed by double-labeling with rhBTX. We propose that the abundant spontaneous calcium transients and calcium waves with localized contractions that do not depend on innervation may contribute to intrinsic generation of tonic functions of EOMs. PMID:22579493

Thermoreceptive innervation of human glabrous and hairy skin: a contact heat evoked potential analysis.

Science.gov (United States)

Granovsky, Yelena; Matre, Dagfinn; Sokolik, Alexander; Lorenz, Jürgen; Casey, Kenneth L

2005-06-01

The human palm has a lower heat detection threshold and a higher heat pain threshold than hairy skin. Neurophysiological studies of monkeys suggest that glabrous skin has fewer low threshold heat nociceptors (AMH type 2) than hairy skin. Accordingly, we used a temperature-controlled contact heat evoked potential (CHEP) stimulator to excite selectively heat receptors with C fibers or Adelta-innervated AMH type 2 receptors in humans. On the dorsal hand, 51 degrees C stimulation produced painful pinprick sensations and 41 degrees C stimuli evoked warmth. On the glabrous thenar, 41 degrees C stimulation produced mild warmth and 51 degrees C evoked strong but painless heat sensations. We used CHEP responses to estimate the conduction velocities (CV) of peripheral fibers mediating these sensations. On hairy skin, 41 degrees C stimuli evoked an ultra-late potential (mean, SD; N wave latency: 455 (118) ms) mediated by C fibers (CV by regression analysis: 1.28 m/s, N=15) whereas 51 degrees C stimuli evoked a late potential (N latency: 267 (33) ms) mediated by Adelta afferents (CV by within-subject analysis: 12.9 m/s, N=6). In contrast, thenar responses to 41 and 51 degrees C were mediated by C fibers (average N wave latencies 485 (100) and 433 (73) ms, respectively; CVs 0.95-1.35 m/s by regression analysis, N=15; average CV=1.7 (0.41) m/s calculated from distal glabrous and proximal hairy skin stimulation, N=6). The exploratory range of the human and monkey palm is enhanced by the abundance of low threshold, C-innervated heat receptors and the paucity of low threshold AMH type 2 heat nociceptors.

Long-term culture of astrocytes attenuates the readily releasable pool of synaptic vesicles.

Directory of Open Access Journals (Sweden)

Hiroyuki Kawano

Full Text Available The astrocyte is a major glial cell type of the brain, and plays key roles in the formation, maturation, stabilization and elimination of synapses. Thus, changes in astrocyte condition and age can influence information processing at synapses. However, whether and how aging astrocytes affect synaptic function and maturation have not yet been thoroughly investigated. Here, we show the effects of prolonged culture on the ability of astrocytes to induce synapse formation and to modify synaptic transmission, using cultured autaptic neurons. By 9 weeks in culture, astrocytes derived from the mouse cerebral cortex demonstrated increases in β-galactosidase activity and glial fibrillary acidic protein (GFAP expression, both of which are characteristic of aging and glial activation in vitro. Autaptic hippocampal neurons plated on these aging astrocytes showed a smaller amount of evoked release of the excitatory neurotransmitter glutamate, and a lower frequency of miniature release of glutamate, both of which were attributable to a reduction in the pool of readily releasable synaptic vesicles. Other features of synaptogenesis and synaptic transmission were retained, for example the ability to induce structural synapses, the presynaptic release probability, the fraction of functional presynaptic nerve terminals, and the ability to recruit functional AMPA and NMDA glutamate receptors to synapses. Thus the presence of aging astrocytes affects the efficiency of synaptic transmission. Given that the pool of readily releasable vesicles is also small at immature synapses, our results are consistent with astrocytic aging leading to retarded synapse maturation.

Cannabinoid signalling inhibits sarcoplasmic Ca2+ release and regulates excitation–contraction coupling in mammalian skeletal muscle

Science.gov (United States)

Oláh, Tamás; Bodnár, Dóra; Tóth, Adrienn; Vincze, János; Fodor, János; Reischl, Barbara; Kovács, Adrienn; Ruzsnavszky, Olga; Dienes, Beatrix; Szentesi, Péter; Friedrich, Oliver

2016-01-01

Key points Marijuana was found to cause muscle weakness, although the exact regulatory role of its receptors (CB1 cannabinoid receptor; CB1R) in the excitation–contraction coupling (ECC) of mammalian skeletal muscle remains unknown.We found that CB1R activation or its knockout did not affect muscle force directly, whereas its activation decreased the Ca2+‐sensitivity of the contractile apparatus and made the muscle fibres more prone to fatigue.We demonstrate that CB1Rs are not connected to the inositol 1,4,5‐trisphosphate pathway either in myotubes or in adult muscle fibres.By contrast, CB1Rs constitutively inhibit sarcoplasmic Ca2+ release and sarcoplasmic reticulum Ca2+ ATPase during ECC in a Gi/o protein‐mediated way in adult skeletal muscle fibres but not in myotubes.These results help with our understanding of the physiological effects and pathological consequences of CB1R activation in skeletal muscle and may be useful in the development of new cannabinoid drugs. Abstract Marijuana was found to cause muscle weakness, although it is unknown whether it affects the muscles directly or modulates only the motor control of the central nervous system. Although the presence of CB1 cannabinoid receptors (CB1R), which are responsible for the psychoactive effects of the drug in the brain, have recently been demonstrated in skeletal muscle, it is unclear how CB1R‐mediated signalling affects the contraction and Ca²⁺ homeostasis of mammalian skeletal muscle. In the present study, we demonstrate that in vitro CB1R activation increased muscle fatigability and decreased the Ca2+‐sensitivity of the contractile apparatus, whereas it did not alter the amplitude of single twitch contractions. In myotubes, CB1R agonists neither evoked, nor influenced inositol 1,4,5‐trisphosphate (IP3)‐mediated Ca2+ transients, nor did they alter excitation–contraction coupling. By contrast, in isolated muscle fibres of wild‐type mice, although CB1R agonists did not evoke IP3

Cannabinoid signalling inhibits sarcoplasmic Ca2+ release and regulates excitation-contraction coupling in mammalian skeletal muscle.

Science.gov (United States)

Oláh, Tamás; Bodnár, Dóra; Tóth, Adrienn; Vincze, János; Fodor, János; Reischl, Barbara; Kovács, Adrienn; Ruzsnavszky, Olga; Dienes, Beatrix; Szentesi, Péter; Friedrich, Oliver; Csernoch, László

2016-12-15

Marijuana was found to cause muscle weakness, although the exact regulatory role of its receptors (CB1 cannabinoid receptor; CB1R) in the excitation-contraction coupling (ECC) of mammalian skeletal muscle remains unknown. We found that CB1R activation or its knockout did not affect muscle force directly, whereas its activation decreased the Ca 2+ -sensitivity of the contractile apparatus and made the muscle fibres more prone to fatigue. We demonstrate that CB1Rs are not connected to the inositol 1,4,5-trisphosphate pathway either in myotubes or in adult muscle fibres. By contrast, CB1Rs constitutively inhibit sarcoplasmic Ca 2+ release and sarcoplasmic reticulum Ca 2+ ATPase during ECC in a G i/o protein-mediated way in adult skeletal muscle fibres but not in myotubes. These results help with our understanding of the physiological effects and pathological consequences of CB1R activation in skeletal muscle and may be useful in the development of new cannabinoid drugs. Marijuana was found to cause muscle weakness, although it is unknown whether it affects the muscles directly or modulates only the motor control of the central nervous system. Although the presence of CB1 cannabinoid receptors (CB1R), which are responsible for the psychoactive effects of the drug in the brain, have recently been demonstrated in skeletal muscle, it is unclear how CB1R-mediated signalling affects the contraction and Ca²⁺ homeostasis of mammalian skeletal muscle. In the present study, we demonstrate that in vitro CB1R activation increased muscle fatigability and decreased the Ca 2+ -sensitivity of the contractile apparatus, whereas it did not alter the amplitude of single twitch contractions. In myotubes, CB1R agonists neither evoked, nor influenced inositol 1,4,5-trisphosphate (IP 3 )-mediated Ca 2+ transients, nor did they alter excitation-contraction coupling. By contrast, in isolated muscle fibres of wild-type mice, although CB1R agonists did not evoke IP 3 -mediated Ca 2

Toxicity of noradrenaline, a novel anti-biofouling component, to two non-target zooplankton species, Daphnia magna and Ceriodaphnia dubia.

Science.gov (United States)

Overturf, C L; Wormington, A M; Blythe, K N; Gohad, N V; Mount, A S; Roberts, A P

2015-05-01

Noradrenaline (NA) is the active component of novel antifouling agents and acts by preventing attachment of fouling organisms. The goal of this study was to examine the toxicity of NA to the non-target zooplankton D. magna and C. dubia. Neonates were exposed to one of five concentrations of NA and effects on survival, reproduction and molting were determined. Calculated LC50 values were determined to be 46 and 38 μM in C. dubia and D. magna, respectively. A 10-day C. dubia study found that reproduction metrics were significantly impacted at non-lethal concentrations. In D. magna, concentrations greater than 40 μM significantly impacted molting. A toxicity test was conducted with D. magna using oxidized NA, which yielded similar results. These data indicate that both NA and oxidized NA are toxic to non-target zooplankton. Results obtained from this study can be used to guide future ecological risk assessments of catecholamine-based antifouling agents. Copyright © 2015. Published by Elsevier Inc.

Direct electrical stimulation of human cortex evokes high gamma activity that predicts conscious somatosensory perception

Science.gov (United States)

Muller, Leah; Rolston, John D.; Fox, Neal P.; Knowlton, Robert; Rao, Vikram R.; Chang, Edward F.

2018-04-01

Objective. Direct electrical stimulation (DES) is a clinical gold standard for human brain mapping and readily evokes conscious percepts, yet the neurophysiological changes underlying these percepts are not well understood. Approach. To determine the neural correlates of DES, we stimulated the somatosensory cortex of ten human participants at frequency-amplitude combinations that both elicited and failed to elicit conscious percepts, meanwhile recording neural activity directly surrounding the stimulation site. We then compared the neural activity of perceived trials to that of non-perceived trials. Main results. We found that stimulation evokes distributed high gamma activity, which correlates with conscious perception better than stimulation parameters themselves. Significance. Our findings suggest that high gamma activity is a reliable biomarker for perception evoked by both natural and electrical stimuli.

Normalization reduces intersubject variability in cervical vestibular evoked myogenic potentials.

Science.gov (United States)

van Tilburg, Mark J; Herrmann, Barbara S; Guinan, John J; Rauch, Steven D

2014-09-01

Cervical vestibular evoked myogenic potentials are used to assess saccular and inferior vestibular nerve function. Normalization of the VEMP waveform has been proposed to reduce the variability in vestibular evoked myogenic potentials by correcting for muscle activation. In this study, we test the hypothesis that normalization of the raw cervical VEMP waveform causes a significant decrease in the intersubject variability. Prospective cohort study. Large specialty hospital, department of otolaryngology. Twenty healthy subjects were used in this study. All subjects underwent cervical vestibular evoked myogenic potential testing using short tone bursts at 250, 500, 750, and 1,000 Hz. Both intersubject and intrasubject variability was assessed. Variability between raw and normalized peak-to-peak amplitudes was compared using the coefficient of variation. Intrasubject variability was assessed using the intraclass correlation coefficient and interaural asymmetry ratio. cVEMPs were present in most ears. Highest peak-to-peak amplitudes were recorded at 750 Hz. Normalization did not alter cVEMP tuning characteristics. Normalization of the cVEMP response caused a significant reduction in intersubject variability of the peak-to-peak amplitude. No significant change was seen in the intrasubject variability. Normalization significantly reduces cVEMP intersubject variability in healthy subjects without altering cVEMP characteristics. By reducing cVEMP amplitude variation due to nonsaccular, muscle-related factors, cVEMP normalization is expected to improve the ability to distinguish between healthy and pathologic responses in the clinical application of cVEMP testing.

Evoked responses of the superior olive to amplitude-modulated signals.

Science.gov (United States)

Andreeva, N G; Lang, T T

1977-01-01

Evoked potentials of some auditory centers of Rhinolophidae bats to amplitude-modulated signals were studied. A synchronization response was found in the cochlear nuclei (with respect to the fast component of the response) and in the superior olivary complex (with respect to both fast and slow components of the response) within the range of frequency modulation from 50 to 2000 Hz. In the inferior colliculus a synchronized response was recorded at modulation frequencies below 150 Hz, but in the medial geniculate bodies no such response was found. Evoked responses of the superior olivary complex were investigated in detail. The lowest frequencies of synchronization were recorded within the carrier frequency range of 15-30 and 80-86 kHz. The amplitude of the synchronized response is a function of the frequency and coefficient of modulation and also of the angle of stimulus presentation.

Role played by acid-sensitive ion channels in evoking the exercise pressor reflex.

Science.gov (United States)

Hayes, Shawn G; McCord, Jennifer L; Rainier, Jon; Liu, Zhuqing; Kaufman, Marc P

2008-10-01

The exercise pressor reflex arises from contracting skeletal muscle and is believed to play a role in evoking the cardiovascular responses to static exercise, effects that include increases in arterial pressure and heart rate. This reflex is believed to be evoked by the metabolic and mechanical stimulation of thin fiber muscle afferents. Lactic acid is known to be an important metabolic stimulus evoking the reflex. Until recently, the only antagonist for acid-sensitive ion channels (ASICs), the receptors to lactic acid, was amiloride, a substance that is also a potent antagonist for both epithelial sodium channels as well as voltage-gated sodium channels. Recently, a second compound, A-317567, has been shown to be an effective and selective antagonist to ASICs in vitro. Consequently, we measured the pressor responses to the static contraction of the triceps surae muscles in decerebrate cats before and after a popliteal arterial injection of A-317567 (10 mM solution; 0.5 ml). We found that this ASIC antagonist significantly attenuated by half (Pacid injection into the popliteal artery. In contrast, A-317567 had no effect on the pressor responses to tendon stretch, a pure mechanical stimulus, and to a popliteal arterial injection of capsaicin, which stimulated transient receptor potential vanilloid type 1 channels. We conclude that ASICs on thin fiber muscle afferents play a substantial role in evoking the metabolic component of the exercise pressor reflex.

Intrasexual competition at work : Sex differences in the jealousy-evoking effect of rival characteristics in work settings

NARCIS (Netherlands)

Buunk, Abraham P.; 't Goor, Joel Aan; Solano, Alejandro C.

Sex differences in jealousy-evoking rival characteristics in the relationship with a supervisor at work were examined in a community sample of 188 individuals from Argentina. Among men, the rivals' social dominance and communal attributes evoked the most jealousy, followed by physical dominance.

Adrenergic receptors inhibit TRPV1 activity in the dorsal root ganglion neurons of rats.

Science.gov (United States)

Matsushita, Yumi; Manabe, Miki; Kitamura, Naoki; Shibuya, Izumi

2018-01-01

Transient receptor potential vanilloid type 1 (TRPV1) is a polymodal receptor channel that responds to multiple types of stimuli, such as heat, acid, mechanical pressure and some vanilloids. Capsaicin is the most commonly used vanilloid to stimulate TRPV1. TRPV1 channels are expressed in dorsal root ganglion neurons that extend to Aδ- and C-fibers and have a role in the transduction of noxious inputs to the skin into the electrical signals of the sensory nerve. Although noradrenergic nervous systems, including the descending antinociceptive system and the sympathetic nervous system, are known to modulate pain sensation, the functional association between TRPV1 and noradrenaline in primary sensory neurons has rarely been examined. In the present study, we examined the effects of noradrenaline on capsaicin-evoked currents in cultured dorsal root ganglion neurons of the rat by the whole-cell voltage clamp method. Noradrenaline at concentrations higher than 0.1 pM significantly reduced the amplitudes of the inward capsaicin currents recorded at -60 mV holding potential. This inhibitory action was reversed by either yohimbine (an α2 antagonist, 10 nM) or propranolol (a β antagonist, 10 nM). The α2 agonists, clonidine (1 pM) and dexmedetomidine (1 pM) inhibited capsaicin currents, and yohimbine (1 nM) reversed the effects of clonidine. The inhibitory action of noradrenaline was not seen in the neurons pretreated with pertussis toxin (100 μg/ml for 24 h) and the neurons dialyzed intracellularly with guanosine 5'- [β-thio] diphosphate (GDPβS, 200 μM), the catalytic subunit of protein kinase A (250 U/ml) or okadaic acid (1 μM). These results suggest that noradrenaline directly acts on dorsal root ganglion neurons to inhibit the activity of TRPV1 depending on the activation of α2-adrenoceptors followed by the inhibition of the adenylate cyclase/cAMP/protein kinase A pathway.

The role of Magnetic Resonance Imaging and Visual Evoked ...

African Journals Online (AJOL)

Introduction: To report our experience in management of patients with optic neuritis. The effects of brain magnetic resonance imaging and visual evoked potential on management were investigated. Methods: This is a four years clinical trial that included patients presenting with first attack of optic neuritis older than 16 years ...

Role of connexin 32 hemichannels in the release of ATP from peripheral nerves.

Science.gov (United States)

Nualart-Marti, Anna; del Molino, Ezequiel Mas; Grandes, Xènia; Bahima, Laia; Martin-Satué, Mireia; Puchal, Rafel; Fasciani, Ilaria; González-Nieto, Daniel; Ziganshin, Bulat; Llobet, Artur; Barrio, Luis C; Solsona, Carles

2013-12-01

Extracellular purines elicit strong signals in the nervous system. Adenosine-5'-triphosphate (ATP) does not spontaneously cross the plasma membrane, and nervous cells secrete ATP by exocytosis or through plasma membrane proteins such as connexin hemichannels. Using a combination of imaging, luminescence and electrophysiological techniques, we explored the possibility that Connexin 32 (Cx32), expressed in Schwann cells (SCs) myelinating the peripheral nervous system could be an important source of ATP in peripheral nerves. We triggered the release of ATP in vivo from mice sciatic nerves by electrical stimulation and from cultured SCs by high extracellular potassium concentration-evoked depolarization. No ATP was detected in the extracellular media after treatment of the sciatic nerve with Octanol or Carbenoxolone, and ATP release was significantly inhibited after silencing Cx32 from SCs cultures. We investigated the permeability of Cx32 to ATP by expressing Cx32 hemichannels in Xenopus laevis oocytes. We found that ATP release is coupled to the inward tail current generated after the activation of Cx32 hemichannels by depolarization pulses, and it is sensitive to low extracellular calcium concentrations. Moreover, we found altered ATP release in mutated Cx32 hemichannels related to the X-linked form of Charcot-Marie-Tooth disease, suggesting that purinergic-mediated signaling in peripheral nerves could underlie the physiopathology of this neuropathy. Copyright © 2013 Wiley Periodicals, Inc.

Serotonin and noradrenaline reuptake inhibitors (SNRIs) for fibromyalgia.

Science.gov (United States)

Welsch, Patrick; Üçeyler, Nurcan; Klose, Petra; Walitt, Brian; Häuser, Winfried

2018-02-28

Fibromyalgia is a clinically defined chronic condition of unknown etiology characterized by chronic widespread pain that often co-exists with sleep disturbances, cognitive dysfunction and fatigue. People with fibromyalgia often report high disability levels and poor quality of life. Drug therapy, for example, with serotonin and noradrenaline reuptake inhibitors (SNRIs), focuses on reducing key symptoms and improving quality of life. This review updates and extends the 2013 version of this systematic review. To assess the efficacy, tolerability and safety of serotonin and noradrenaline reuptake inhibitors (SNRIs) compared with placebo or other active drug(s) in the treatment of fibromyalgia in adults. For this update we searched CENTRAL, MEDLINE, Embase, the US National Institutes of Health and the World Health Organization (WHO) International Clinical Trials Registry Platform for published and ongoing trials and examined the reference lists of reviewed articles, to 8 August 2017. We selected randomized, controlled trials of any formulation of SNRIs against placebo or any other active treatment of fibromyalgia in adults. Three review authors independently extracted data, examined study quality, and assessed risk of bias. For efficacy, we calculated the number needed to treat for an additional beneficial outcome (NNTB) for pain relief of 50% or greater and of 30% or greater, patient's global impression to be much or very much improved, dropout rates due to lack of efficacy, and the standardized mean differences (SMD) for fatigue, sleep problems, health-related quality of life, mean pain intensity, depression, anxiety, disability, sexual function, cognitive disturbances and tenderness. For tolerability we calculated number needed to treat for an additional harmful outcome (NNTH) for withdrawals due to adverse events and for nausea, insomnia and somnolence as specific adverse events. For safety we calculated NNTH for serious adverse events. We undertook meta

Prior Expectations Evoke Stimulus Templates in the Primary Visual Cortex

NARCIS (Netherlands)

Kok, P.; Failing, F.M.; de Lange, F.P.

2014-01-01

Exposure to rhythmic stimulation results in facilitated responses to events that appear in-phase with the rhythm and modulation of anticipatory and target-evoked brain activity, presumably reflecting "exogenous," unintentional temporal expectations. However, the extent to which this effect is

Multimodal evoked potentials follow up in multiple sclerosis patients under fingolimod therapy

DEFF Research Database (Denmark)

Iodice, R; Carotenuto, A; Dubbioso, R

2016-01-01

related to EDSS at baseline (t=-1), while MEP and total EP sum score were related to EDSS at all time points. CONCLUSION: Fingolimod is able to improve visual and somatosensory evoked potential in RR-MS patients even if clinical disability scale remains stable. VEP and SEP could give eloquent information...... patients examined 12months prior to initiation of fingolimod (t=-1), at treatment initiation (t=0) and 1year later (t=+1) were compared. Each EP (VEP, MEP, SEP) and EP sum score, a global evoked potential score as the sum score of the each EP score was evaluated and correlated with Expanded Disability...

Effect of mechanical tactile noise on amplitude of visual evoked potentials: multisensory stochastic resonance.

Science.gov (United States)

Méndez-Balbuena, Ignacio; Huidobro, Nayeli; Silva, Mayte; Flores, Amira; Trenado, Carlos; Quintanar, Luis; Arias-Carrión, Oscar; Kristeva, Rumyana; Manjarrez, Elias

2015-10-01

The present investigation documents the electrophysiological occurrence of multisensory stochastic resonance in the human visual pathway elicited by tactile noise. We define multisensory stochastic resonance of brain evoked potentials as the phenomenon in which an intermediate level of input noise of one sensory modality enhances the brain evoked response of another sensory modality. Here we examined this phenomenon in visual evoked potentials (VEPs) modulated by the addition of tactile noise. Specifically, we examined whether a particular level of mechanical Gaussian noise applied to the index finger can improve the amplitude of the VEP. We compared the amplitude of the positive P100 VEP component between zero noise (ZN), optimal noise (ON), and high mechanical noise (HN). The data disclosed an inverted U-like graph for all the subjects, thus demonstrating the occurrence of a multisensory stochastic resonance in the P100 VEP. Copyright © 2015 the American Physiological Society.

Releasing stimuli and aggression in crickets: octopamine promotes escalation and maintenance but not initiation

Directory of Open Access Journals (Sweden)

Jan eRillich

2015-04-01

Full Text Available Biogenic amines have widespread effects on numerous behaviors, but their natural functions are often unclear. We investigated the role of octopamine (OA, the invertebrate analogue of noradrenaline, on initiation and maintenance of aggression in male crickets of different social status. The key-releasing stimulus for aggression is antennal fencing between males, a behavior occurring naturally on initial contact. We show that mechanical antennal stimulation (AS alone is sufficient to initiate an aggressive response (mandible threat display. The efficacy of AS was augmented in winners of a previous fight, but unaffected in losers. The efficacy of AS was not, however, influenced by OA receptor (OAR agonists or antagonists, regardless of social status. Additional experiments indicate that the efficacy of AS is also not influenced by dopamine (DA or serotonin (5HT. In addition to initiating an aggressive response, prior AS enhanced aggression exhibited in subsequent fights, whereby AS with a male antenna was now necessary, indicating a role for male contact pheromones. This priming effect of male-AS on subsequent aggression was dependent on OA since it was blocked by OAR-antagonists, and enhanced by OAR-agonists. Together our data reveal that neither OA, DA nor 5HT are required for initiating aggression in crickets, nor do these amines influence the efficacy of the natural releasing stimulus to initiate aggression. OA’s natural function is restricted to promoting escalation and maintenance of aggression once initiated, and this can be invoked by numerous experiences, including prior contact with a male antenna as shown here.

DC-Evoked Modulation of Excitability of Myelinated Nerve Fibers and Their Terminal Branches; Differences in Sustained Effects of DC.

Science.gov (United States)

Kaczmarek, Dominik; Jankowska, Elzbieta

2018-03-15

Direct current (DC) evokes long-lasting changes in neuronal networks both presynaptically and postsynaptically and different mechanisms were proposed to be involved in them. Different mechanisms were also suggested to account for the different dynamics of presynaptic DC actions on myelinated nerve fibers stimulated before they entered the spinal gray matter and on their terminal branches. The aim of the present study was to examine whether these different dynamics might be related to differences in the involvement of K + channels. To this end, we compared effects of the K + channel blocker 4-amino-pyridine (4-AP) on DC-evoked changes in the excitability of afferent fibers stimulated within the dorsal columns (epidurally) and within their projection areas in the dorsal horn and motor nuclei (intraspinally). 4-AP was applied systemically in deeply anesthetized rats. DC-evoked increases in the excitability of epidurally stimulated afferent nerve fibers, and increases in field potentials evoked by these fibers, were not affected by 4-AP. In contrast, sustained decreases rather than increases in the excitability of intraspinally stimulated terminal nerve branches were evoked by local application of DC in conjunction with 4-AP. The study leads to the conclusion that 4-AP-sensitive K + channels contribute to the sustained DC-evoked post-polarization increases in the excitability at the level of terminal branches of nerve fibers but not of the nodes of Ranvier nor within the juxta-paranodal regions where other mechanisms would be involved in inducing the sustained DC-evoked changes. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

Amperometric Microsensors Monitoring Glutamate-Evoked In Situ Responses of Nitric Oxide and Carbon Monoxide from Live Human Neuroblastoma Cells

Directory of Open Access Journals (Sweden)

Yejin Ha

2017-07-01

Full Text Available In the brain, nitric oxide (NO and carbon monoxide (CO are important signaling gases which have multifaceted roles, such as neurotransmitters, neuromodulators, and vasodilators. Even though it is difficult to measure NO and CO in a living system due to their high diffusibility and extremely low release levels, electrochemical sensors are promising tools to measure in vivo and in vitro NO and CO gases. In this paper, using amperometric dual and septuple NO/CO microsensors, real-time NO and CO changes evoked by glutamate were monitored simultaneously for human neuroblastoma (SH-SY5Y cells. In cultures, the cells were differentiated and matured into functional neurons by retinoic acid and brain-derived neurotrophic factor. When glutamate was administrated to the cells, both NO and CO increases and subsequent decreases returning to the basal levels were observed with a dual NO/CO microsensor. In order to facilitate sensor’s measurement, a flower-type septuple NO/CO microsensor was newly developed and confirmed in terms of the sensitivity and selectivity. The septuple microsensor was employed for the measurements of NO and CO changes as a function of distances from the position of glutamate injection. Our sensor measurements revealed that only functionally differentiated cells responded to glutamate and released NO and CO.

Torque and mechanomyogram relationships during electrically-evoked isometric quadriceps contractions in persons with spinal cord injury.

Science.gov (United States)

Ibitoye, Morufu Olusola; Hamzaid, Nur Azah; Hasnan, Nazirah; Abdul Wahab, Ahmad Khairi; Islam, Md Anamul; Kean, Victor S P; Davis, Glen M

2016-08-01

The interaction between muscle contractions and joint loading produces torques necessary for movements during activities of daily living. However, during neuromuscular electrical stimulation (NMES)-evoked contractions in persons with spinal cord injury (SCI), a simple and reliable proxy of torque at the muscle level has been minimally investigated. Thus, the purpose of this study was to investigate the relationships between muscle mechanomyographic (MMG) characteristics and NMES-evoked isometric quadriceps torques in persons with motor complete SCI. Six SCI participants with lesion levels below C4 [(mean (SD) age, 39.2 (7.9) year; stature, 1.71 (0.05) m; and body mass, 69.3 (12.9) kg)] performed randomly ordered NMES-evoked isometric leg muscle contractions at 30°, 60° and 90° knee flexion angles on an isokinetic dynamometer. MMG signals were detected by an accelerometer-based vibromyographic sensor placed over the belly of rectus femoris muscle. The relationship between MMG root mean square (MMG-RMS) and NMES-evoked torque revealed a very high association (R(2)=0.91 at 30°; R(2)=0.98 at 60°; and R(2)=0.97 at 90° knee angles; Ptorque, between 0.65 and 0.79 for MMG-RMS, and from 0.67 to 0.73 for MMG-PTP. Their standard error of measurements (SEM) ranged between 10.1% and 31.6% (of mean values) for torque, MMG-RMS and MMG-PTP. The MMG peak frequency (MMG-PF) of 30Hz approximated the stimulation frequency, indicating NMES-evoked motor unit firing rate. The results demonstrated knee angle differences in the MMG-RMS versus NMES-isometric torque relationship, but a similar torque related pattern for MMG-PF. These findings suggested that MMG was well associated with torque production, reliably tracking the motor unit recruitment pattern during NMES-evoked muscle contractions. The strong positive relationship between MMG signal and NMES-evoked torque production suggested that the MMG might be deployed as a direct proxy for muscle torque or fatigue measurement during

Effects of chlordiazepoxide and buspirone on plasma catecholamine and corticosterone levels in rats under basal and stress conditions

NARCIS (Netherlands)

de Boer, S.F.; Slangen, J L; van der Gugten, J

The effects of the classical benzodiazepine (BDZ) anxiolytic drug chlordiazepoxide (CDP) and the non-BDZ anxiolytic agent buspirone (BUSP) on basal and stress-induced plasma noradrenaline (NA), adrenaline (A) and corticosterone (CS) release were investigated. Male Wistar rats provided with a

The cAMP cascade modulates the neuroinformative impact of quantal release at cholinergic synapse

Czech Academy of Sciences Publication Activity Database

Vyskočil, František; Bukcharaeva, E.; Samigullin, D. V.; Nikolsky, E. E.

2001-01-01

Roč. 2, č. 2 (2001), s. 317-323 ISSN 1539-2791 R&D Projects: GA AV ČR IAA7011902 Grant - others:EU(XX) Nesting; RFBR(RU) 99-04-48286 Institutional research plan: CEZ:AV0Z5011922 Keywords : frog neuromuscular synapse * noradrenaline Subject RIV: ED - Physiology

Honour and debt release in the parable of the Unmerciful Servant (Mt 18:23–33: A social-scientific and realistic reading

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Ernest van Eck

2015-06-01

Full Text Available This article presents a social-scientific and realistic reading of the parable of the Unmerciful Servant. The parables of Jesus are realistic stories about everyday events in 1st-century Palestine that evoke specific social realia and practices known to its first hearers. As recent studies on the parables have shown, papyri from early Roman Egypt provide detailed information on the implied social realities and practices assumed in the parables. In reading the parable through the lens of patronage and clientism and against the background of the relationship between royal ideology and debt release attested in documented papyri, it is argued that the parable suggests that in the basileia of God debt should be released in terms of general reciprocity, emulating the way in which patrons release debt for the sake of honour.

Intermediate Latency-Evoked Potentials of Multimodal Cortical Vestibular Areas: Galvanic Stimulation

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Stefan Kammermeier

2017-11-01

Full Text Available IntroductionHuman multimodal vestibular cortical regions are bilaterally anterior insulae and posterior opercula, where characteristic vestibular-related cortical potentials were previously reported under acoustic otolith stimulation. Galvanic vestibular stimulation likely influences semicircular canals preferentially. Galvanic stimulation was compared to previously established data under acoustic stimulation.Methods14 healthy right-handed subjects, who were also included in the previous acoustic potential study, showed normal acoustic and galvanic vestibular-evoked myogenic potentials. They received 2,000 galvanic binaural bipolar stimuli for each side during EEG recording.ResultsVestibular cortical potentials were found in all 14 subjects and in the pooled data of all subjects (“grand average” bilaterally. Anterior insula and posterior operculum were activated exclusively under galvanic stimulation at 25, 35, 50, and 80 ms; frontal regions at 30 and 45 ms. Potentials at 70 ms in frontal regions and at 110 ms at all of the involved regions could also be recorded; these events were also found using acoustic stimulation in our previous study.ConclusionGalvanic semicircular canal stimulation evokes specific potentials in addition to those also found with acoustic otolith stimulation in identically located regions of the vestibular cortex. Vestibular cortical regions activate differently by galvanic and acoustic input at the peripheral sensory level.SignificanceDifferential effects in vestibular cortical-evoked potentials may see clinical use in specific vertigo disorders.

Apigenin inhibits TNFα/IL-1α-induced CCL2 release through IKBK-epsilon signaling in MDA-MB-231 human breast cancer cells.

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David Bauer

Full Text Available Mortality associated with breast cancer is attributable to aggressive metastasis, to which TNFα plays a central orchestrating role. TNFα acts on breast tumor TNF receptors evoking the release of chemotactic proteins (e.g. MCP-1/CCL2. These proteins direct inward infiltration/migration of tumor-associated macrophages (TAMs, tumor-associated neutrophils (TANs, myeloid-derived suppressor cells (MDSCs, T-regulatory cells (Tregs, T helper IL-17-producing cells (Th17s, metastasis-associated macrophages (MAMs and cancer-associated fibroblasts (CAFs. Tumor embedded infiltrates collectively enable immune evasion, tumor growth, angiogenesis, and metastasis. In the current study, we investigate the potential of apigenin, a known anti-inflammatory constituent of parsley, to downregulate TNFα mediated release of chemokines from human triple-negative cells (MDA-MB-231 cells. The results show that TNFα stimulation leads to large rise of CCL2, granulocyte macrophage colony-stimulating factor (GMCSF, IL-1α and IL-6, all suppressed by apigenin. While many aspects of the transcriptome for NFkB signaling were evaluated, the data show signaling patterns associated with CCL2 were blocked by apigenin and mediated through suppressed mRNA and protein synthesis of IKBKe. Moreover, the data show that the attenuation of CCL2 by apigenin in the presence TNFα paralleled the suppression of phosphorylated extracellular signal-regulated kinase 1 (ERK 1/ 2. In summary, the obtained findings suggest that there exists a TNFα evoked release of CCL2 and other LSP recruiting cytokines from human breast cancer cells, which can be attenuated by apigenin.

Quantified distribution of the noradrenaline innervation in the hippocampus of adult rat

International Nuclear Information System (INIS)

Oleskevich, S.; Descarries, L.; Lacaille, J.C.

1989-01-01

A recently developed radioautographic technique, based on the uptake labeling of monoamine terminals in vitro, was used to quantify the noradrenaline (NA) innervation in adult rat hippocampus. After incubation of brain slices with 1 microM 3H-NA, the NA varicosities were visualized as small aggregates of silver grains, in light microscope radioautographs prepared at 3 equidistant horizontal levels across the ventral 2/3 of the hippocampus. Using a computer-assisted image analyzer, counts were obtained from the subiculum (SUB), 3 sectors of Ammon's horn (CA1, CA3-a, CA3-b) and 3 sectors of the dentate gyrus (DG-medial blade, crest, and lateral blade), every lamina being sampled in each region. After a double correction for duration of radioautographic exposure and section thickness, and following measurement of varicosity diameter in electron microscope radioautographs, it was possible to express these results in number of terminals per volumetric unit of tissue. It was thus found that the overall density of hippocampal NA innervation averages 2.1 million varicosities/mm3 of tissue, a value almost twice as high as that in cerebral cortex. This innervation is 20% denser ventrally than dorsally and is heterogeneous both in terms of regional and laminar distribution. SUB and DG are more strongly innervated than Ammon's horn, wherein CA1 has the lowest overall density. In SUB and CA1, there is a clear predilection of NA varicosities for the stratum moleculare. In CA3, there is a narrow band of even stronger innervation in the stratum radiatum, near the apical border of the stratum pyramidale, contrasting with a 3 times lower density in this cell layer and the stratum oriens. In DG, the NA innervation is again the weakest in the cell body layer and exhibits an almost 3-fold greater density in the polymorph layer, the highest of all hippocampus

Automatic classification of visual evoked potentials based on wavelet decomposition

Science.gov (United States)

Stasiakiewicz, Paweł; Dobrowolski, Andrzej P.; Tomczykiewicz, Kazimierz

2017-04-01

Diagnosis of part of the visual system, that is responsible for conducting compound action potential, is generally based on visual evoked potentials generated as a result of stimulation of the eye by external light source. The condition of patient's visual path is assessed by set of parameters that describe the time domain characteristic extremes called waves. The decision process is compound therefore diagnosis significantly depends on experience of a doctor. The authors developed a procedure - based on wavelet decomposition and linear discriminant analysis - that ensures automatic classification of visual evoked potentials. The algorithm enables to assign individual case to normal or pathological class. The proposed classifier has a 96,4% sensitivity at 10,4% probability of false alarm in a group of 220 cases and area under curve ROC equals to 0,96 which, from the medical point of view, is a very good result.

Increase in serum noradrenaline concentration by short dives with bradycardia in Indo-Pacific bottlenose dolphin Tursiops aduncus.

Science.gov (United States)

Suzuki, Miwa; Tomoshige, Mika; Ito, Miki; Koga, Sotaro; Yanagisawa, Makio; Bungo, Takashi; Makiguchi, Yuya

2017-07-01

In cetaceans, diving behavior immediately induces a change in blood circulation to favor flow to the brain and heart; this is achieved by intense vasoconstriction of the blood vessels that serve other organs. This blood circulation response is allied to a decrease in heart rate in order to optimize oxygen usage during diving. Vasoconstrictors are present in all mammals and stimulate the contraction of the smooth muscle in the walls of blood vessels. The most important of these vasoconstrictors are the hormones adrenaline (A), noradrenaline (NA), and angiotensin II (ANG II). At present, the contribution of these hormones to vasoconstriction during diving in cetaceans is unclear. To elucidate their possible roles, changes in serum levels of A, NA and ANG II were monitored together with heart rate in the Indo-Pacific bottlenose dolphin Tursiops aduncus during 90 and 180s dives. Both brief diving periods induced an increase in serum NA concentration and a decrease in heart rate; however, no changes were detected in serum levels of A or ANG II. These data indicate that NA may play a role in diving-induced vasoconstriction. Copyright © 2017 Elsevier Inc. All rights reserved.

Thermal grill-evoked sensations of heat correlate with cold pain threshold and are enhanced by menthol and cinnamaldehyde.

Science.gov (United States)

Averbeck, B; Rucker, F; Laubender, R P; Carr, R W

2013-05-01

Thunberg's thermal grill produces a sensation of strong heat upon skin contact with spatially interlaced innocuous warm and cool stimuli. To examine the classes of peripheral axons that might contribute to this illusion, the effects of topical l-menthol, an activator of TRPM8, and cinnamaldehyde, a TRPA1 agonist, on the magnitude of thermal sensations were examined during grill stimulation in healthy volunteers. Under control conditions, cutaneous grill stimulation (interlaced 20/40 °C) evoked a sensation of heat, and for individual subjects, the magnitude of this heat sensation was positively correlated with cold pain threshold (CPT). Menthol increased the CPT and enhanced the magnitude of grill-evoked heat. Cinnamaldehyde intensified warm sensations, reduced heat pain threshold and also enhanced grill-evoked heat. Both TRPM8-expressing and TRPA1-expressing afferent axons can affect grill-evoked thermal sensations. The enhancement of grill-evoked sensations of temperature with menthol and cinnamaldehyde may provide an additional clinically relevant means of testing altered thermal sensitivity, which is often affected in neuropathic patient groups. © 2012 European Federation of International Association for the Study of Pain Chapters.

Free amino acids exhibit anthozoan "host factor" activity: they induce the release of photosynthate from symbiotic dinoflagellates in vitro.

Science.gov (United States)

Gates, R D; Hoegh-Guldberg, O; McFall-Ngai, M J; Bil, K Y; Muscatine, L

1995-08-01

Reef-building corals and other tropical anthozoans harbor endosymbiotic dinoflagellates. It is now recognized that the dinoflagellates are fundamental to the biology of their hosts, and their carbon and nitrogen metabolisms are linked in important ways. Unlike free living species, growth of symbiotic dinoflagellates is unbalanced and a substantial fraction of the carbon fixed daily by symbiont photosynthesis is released and used by the host for respiration and growth. Release of fixed carbon as low molecular weight compounds by freshly isolated symbiotic dinoflagellates is evoked by a factor (i.e., a chemical agent) present in a homogenate of host tissue. We have identified this "host factor" in the Hawaiian coral Pocillopora damicornis as a set of free amino acids. Synthetic amino acid mixtures, based on the measured free amino acid pools of P. damicornis tissues, not only elicit the selective release of 14C-labeled photosynthetic products from isolated symbiotic dinoflagellates but also enhance total 14CO2 fixation.

In vivo microdialysis studies on the effects of decortication and excitotoxic lesions on kainic acid-induced calcium fluxes, and endogenous amino acid release, in the rat striatum

Energy Technology Data Exchange (ETDEWEB)

Butcher, S.P.; Lazarewicz, J.W.; Hamberger, A.

1987-11-01

The in vivo effects of kainate (1 mM) on fluxes of /sup 45/Ca2+, and endogenous amino acids, were examined in the rat striatum using the brain microdialysis technique. Kainate evoked a rapid decrease in dialysate /sup 45/Ca2+, and an increase in the concentration of amino acids in dialysates in Ca2+-free dialysates. Taurine was elevated six- to 10-fold, glutamate two- to threefold, and aspartate 1.5- to twofold. There was also a delayed increase in phosphoethanolamine, whereas nonneuroactive amino acids were increased only slightly. The kainic acid-evoked reduction in dialysate /sup 45/Ca2+ activity was attenuated in striata lesioned previously with kainate, suggesting the involvement of intrinsic striatal neurons in this response. The increase in taurine concentration induced by kainate was slightly smaller under these conditions. Decortication did not affect the kainate-evoked alterations in either dialysate /sup 45/Ca2+ or amino acids. These data suggest that kainate does not release acidic amino acids from their transmitter pools located in corticostriatal terminals.

Neurophysiological mechanisms of bradykinin-evoked mucosal chloride secretion in guinea pig small intestine.

Science.gov (United States)

Qu, Mei-Hua; Ji, Wan-Sheng; Zhao, Ting-Kun; Fang, Chun-Yan; Mao, Shu-Mei; Gao, Zhi-Qin

2016-02-15

To investigate the mechanism for bradykinin (BK) to stimulate intestinal secretomotor neurons and intestinal chloride secretion. Muscle-stripped guinea pig ileal preparations were mounted in Ussing flux chambers for the recording of short-circuit current (Isc). Basal Isc and Isc stimulated by BK when preincubated with the BK receptors antagonist and other chemicals were recorded using the Ussing chamber system. Prostaglandin E2 (PGE2) production in the intestine was determined by enzyme immunologic assay (EIA). Application of BK or B2 receptor (B2R) agonist significantly increased the baseline Isc compared to the control. B2R antagonist, tetrodotoxin and scopolamine (blockade of muscarinic receptors) significantly suppressed the increase in Isc evoked by BK. The BK-evoked Isc was suppressed by cyclooxygenase (COX)-1 or COX-2 specific inhibitor as well as nonselective COX inhibitors. Preincubation of submucosa/mucosa preparations with BK for 10 min significantly increased PGE2 production and this was abolished by the COX-1 and COX-2 inhibitors. The BK-evoked Isc was suppressed by nonselective EP receptors and EP4 receptor antagonists, but selective EP1 receptor antagonist did not have a significant effect on the BK-evoked Isc. Inhibitors of PLC, PKC, calmodulin or CaMKII failed to suppress BK-induced PGE2 production. The results suggest that BK stimulates neurogenic chloride secretion in the guinea pig ileum by activating B2R, through COX increasing PGE2 production. The post-receptor transduction cascade includes activation of PLC, PKC, CaMK, IP3 and MAPK.

Is the auditory evoked P2 response a biomarker of learning?

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Kelly eTremblay

2014-02-01

Full Text Available Even though auditory training exercises for humans have been shown to improve certain perceptual skills of individuals with and without hearing loss, there is a lack of knowledge pertaining to which aspects of training are responsible for the perceptual gains, and which aspects of perception are changed. To better define how auditory training impacts brain and behavior, electroencephalography and magnetoencephalography have been used to determine the time course and coincidence of cortical modulations associated with different types of training. Here we focus on P1-N1-P2 auditory evoked responses (AEP, as there are consistent reports of gains in P2 amplitude following various types of auditory training experiences; including music and speech-sound training. The purpose of this experiment was to determine if the auditory evoked P2 response is a biomarker of learning. To do this, we taught native English speakers to identify a new pre-voiced temporal cue that is not used phonemically in the English language so that coinciding changes in evoked neural activity could be characterized. To differentiate possible effects of repeated stimulus exposure and a button-pushing task from learning itself, we examined modulations in brain activity in a group of participants who learned to identify the pre-voicing contrast and compared it to participants, matched in time, and stimulus exposure, that did not. The main finding was that the amplitude of the P2 auditory evoked response increased across repeated EEG sessions for all groups, regardless of any change in perceptual performance. What’s more, these effects were retained for months. Changes in P2 amplitude were attributed to changes in neural activity associated with the acquisition process and not the learned outcome itself. A further finding was the expression of a late negativity (LN wave 600-900 ms post-stimulus onset, post-training, exclusively for the group that learned to identify the pre

A comparison of myogenic motor evoked responses to electrical and magnetic transcranial stimulation during nitrous oxide/opioid anesthesia

NARCIS (Netherlands)

Ubags, L. H.; Kalkman, C. J.; Been, H. D.; Koelman, J. H.; Ongerboer de Visser, B. W.

1999-01-01

Transcranial motor evoked potentials (tc-MEPs) are used to monitor spinal cord integrity intraoperatively. We compared myogenic motor evoked responses with electrical and magnetic transcranial stimuli during nitrous oxide/opioid anesthesia. In 11 patients undergoing spinal surgery, anesthesia was

Lifting the veil on the dynamics of neuronal activities evoked by transcranial magnetic stimulation.

Science.gov (United States)

Li, Bingshuo; Virtanen, Juha P; Oeltermann, Axel; Schwarz, Cornelius; Giese, Martin A; Ziemann, Ulf; Benali, Alia

2017-11-22

Transcranial magnetic stimulation (TMS) is a widely used non-invasive tool to study and modulate human brain functions. However, TMS-evoked activity of individual neurons has remained largely inaccessible due to the large TMS-induced electromagnetic fields. Here, we present a general method providing direct in vivo electrophysiological access to TMS-evoked neuronal activity 0.8-1 ms after TMS onset. We translated human single-pulse TMS to rodents and unveiled time-grained evoked activities of motor cortex layer V neurons that show high-frequency spiking within the first 6 ms depending on TMS-induced current orientation and a multiphasic spike-rhythm alternating between excitation and inhibition in the 6-300 ms epoch, all of which can be linked to various human TMS responses recorded at the level of spinal cord and muscles. The advance here facilitates a new level of insight into the TMS-brain interaction that is vital for developing this non-invasive tool to purposefully explore and effectively treat the human brain.

Head movements evoked in alert rhesus monkey by vestibular prosthesis stimulation: implications for postural and gaze stabilization.

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Diana E Mitchell

Full Text Available The vestibular system detects motion of the head in space and in turn generates reflexes that are vital for our daily activities. The eye movements produced by the vestibulo-ocular reflex (VOR play an essential role in stabilizing the visual axis (gaze, while vestibulo-spinal reflexes ensure the maintenance of head and body posture. The neuronal pathways from the vestibular periphery to the cervical spinal cord potentially serve a dual role, since they function to stabilize the head relative to inertial space and could thus contribute to gaze (eye-in-head + head-in-space and posture stabilization. To date, however, the functional significance of vestibular-neck pathways in alert primates remains a matter of debate. Here we used a vestibular prosthesis to 1 quantify vestibularly-driven head movements in primates, and 2 assess whether these evoked head movements make a significant contribution to gaze as well as postural stabilization. We stimulated electrodes implanted in the horizontal semicircular canal of alert rhesus monkeys, and measured the head and eye movements evoked during a 100 ms time period for which the contribution of longer latency voluntary inputs to the neck would be minimal. Our results show that prosthetic stimulation evoked significant head movements with latencies consistent with known vestibulo-spinal pathways. Furthermore, while the evoked head movements were substantially smaller than the coincidently evoked eye movements, they made a significant contribution to gaze stabilization, complementing the VOR to ensure that the appropriate gaze response is achieved. We speculate that analogous compensatory head movements will be evoked when implanted prosthetic devices are transitioned to human patients.

Biomarkers of neuropathic pain in skin nerve degeneration neuropathy: contact heat-evoked potentials as a physiological signature.

Science.gov (United States)

Wu, Shao-Wei; Wang, Yi-Chia; Hsieh, Paul-Chen; Tseng, Ming-Tsung; Chiang, Ming-Chang; Chu, Chih-Pang; Feng, Fang-Ping; Lin, Yea-Huey; Hsieh, Sung-Tsang; Chao, Chi-Chao

2017-03-01

Contact heat-evoked potentials (CHEPs) have become an established method of assessing small-fiber sensory nerves; however, their potential as a physiological signature of neuropathic pain symptoms has not been fully explored. To investigate the diagnostic efficacy in examining small-fiber sensory nerve degeneration, the relationship with skin innervations, and clinical correlates with sensory symptoms, we recruited 188 patients (115 men) with length-dependent sensory symptoms and reduced intraepidermal nerve fiber (IENF) density at the distal leg to perform CHEP, quantitative sensory testing, and nerve conduction study. Fifty-seven age- and sex-matched controls were enrolled for comparison of CHEP and skin innervation. Among patients with neuropathy, 144 patients had neuropathic pain and 64 cases had evoked pain. Compared with quantitative sensory testing and nerve conduction study parameters, CHEP amplitudes showed the highest sensitivity for diagnosing small-fiber sensory nerve degeneration and exhibited the strongest correlation with IENF density in multiple linear regression. Contact heat-evoked potential amplitudes were strongly correlated with the degree of skin innervation in both patients with neuropathy and controls, and the slope of the regression line between CHEP amplitude and IENF density was higher in patients with neuropathy than in controls. Patients with evoked pain had higher CHEP amplitude than those without evoked pain, independent of IENF density. Receiver operating characteristic analysis showed that CHEP had better performance in diagnosing small-fiber sensory nerve degeneration than thermal thresholds. Furthermore, CHEPs showed superior classification accuracy with respect to evoked pain. In conclusion, CHEP is a sensitive tool to evaluate pathophysiology of small-fiber sensory nerve and serves as a physiological signature of neuropathic pain symptoms.

Short-interval and long-interval intracortical inhibition of TMS-evoked EEG potentials.

Science.gov (United States)

Premoli, Isabella; Király, Julia; Müller-Dahlhaus, Florian; Zipser, Carl M; Rossini, Pierre; Zrenner, Christoph; Ziemann, Ulf; Belardinelli, Paolo

2018-03-15

Inhibition in the human motor cortex can be probed by means of paired-pulse transcranial magnetic stimulation (ppTMS) at interstimulus intervals of 2-3 ms (short-interval intracortical inhibition, SICI) or ∼100 ms (long-interval intracortical inhibition, LICI). Conventionally, SICI and LICI are recorded as motor evoked potential (MEP) inhibition in the hand muscle. Pharmacological experiments indicate that they are mediated by GABAA and GABAB receptors, respectively. SICI and LICI of TMS-evoked EEG potentials (TEPs) and their pharmacological properties have not been systematically studied. Here, we sought to examine SICI by ppTMS-evoked compared to single-pulse TMS-evoked TEPs, to investigate its pharmacological manipulation and to compare SICI with our previous results on LICI. PpTMS-EEG was applied to the left motor cortex in 16 healthy subjects in a randomized, double-blind placebo-controlled crossover design, testing the effects of a single oral dose 20 mg of diazepam, a positive modulator at the GABAA receptor, vs. 50 mg of the GABAB receptor agonist baclofen on SICI of TEPs. We found significant SICI of the N100 and P180 TEPs prior to drug intake. Diazepam reduced SICI of the N100 TEP, while baclofen enhanced it. Compared to our previous ppTMS-EEG results on LICI, the SICI effects on TEPs, including their drug modulation, were largely analogous. Findings suggest a similar interaction of paired-pulse effects on TEPs irrespective of the interstimulus interval. Therefore, SICI and LICI as measured with TEPs cannot be directly derived from SICI and LICI measured with MEPs, but may offer novel insight into paired-pulse responses recorded directly from the brain rather than muscle. Copyright © 2018 Elsevier Inc. All rights reserved.

Sex differences in the jealousy-evoking effect of rival characteristics

NARCIS (Netherlands)

Dijkstra, P; Buunk, BP; Buunk, Abraham (Bram)

2002-01-01