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1.
The present study examined the effect of a low-dose of nicotine; below that one expects to be achieved from a single cigarette, on brain regional heterogeneity and sensitivity of catecholaminergic responses. 1 μM nicotine was infused into six brain areas via a microdialysis probe: the dorsal and ventral hippocampus, the medial temporal and prefrontal cortex, the basolateral amygdala, and the ventral tegmental area (VTA). The nicotine concentration in the brain tissue near the probe site was approximately 0.1 μM. Nicotine-induced increases and decreases could be noted in dopamine (DA), norepinephrine (NE), and serotonin (5HT) levels. In particular, DA and 5HT decreased in both hippocampal areas, while NE increased in the dorsal and decreased in the ventral hippocampus. In the cortical areas, DA and NE increased and 5HT was not significantly altered. In the amygdala all three neurotransmitters increased and in the VTA, all three decreased. Many of the nicotine-induced changes in neurotransmitter concentrations were reversed in the presence of atropine. Where nicotine induced decreases in DA and 5HT in the VTA, increases were observed in the presence of atropine. A similar reversal was seen with NE in the VTA and ventral hippocampus. In contrast, the increases in DA observed in the cortex and amygdala and the increases in NE observed in the cortex, amygdala and dorsal hippocampus were inhibited by the presence of atropine. 5HT was also significantly decreased in the amygdala and both cortical areas in the presence of atropine, where nicotine alone had no significant effect. We conclude, that at low doses, nicotine significantly alters the release of DA, NE, and 5HT – in some areas increasing, in others decreasing endogenous neurotransmitter levels. This data, in conjunction with previous experiments, indicates that the effects of nicotine are regionally heterogeneous and arise from both direct and indirect actions on various receptors and neurotransmitter systems and nicotine’s effects at low doses differ from that at higher doses. The changes in effects in the presence of atropine suggest that muscarinic acetylcholine receptors play a major role in nicotine’s actions on neurotransmitter systems.  相似文献   

2.
In a continuing study of nicotine-induced mechanisms in brain areas associated with cognitive processes, the effects of cholinergic and dopaminergic antagonists on nicotine-induced changes in dopamine, norepinephrine, and serotonin were examined. These effects were measured via in vivo microdialysis in the dorsal and ventral hippocampus and in the prefrontal and medial temporal cortex of conscious, freely moving, adult male rats. Nicotine (0.3 mg/kg, free base) was administered subcutaneously and the antagonists were infused locally via the microdialysis probe. Nicotine alone induced an increase of dopamine and its metabolites in all areas, an increase of norepinephrine in the cortex, and an increase of the norepinephrine metabolite 4–hydroxy-3-methoxy-phenylglycol in all areas. Serotonin was decreased in the hippocampus and increased in the cortex. Nicotine-induced dopamine increases were inhibited by nicotinic (mecamylamine 100 μM, methyllycaconitine 500 μM), muscarinic (atropine 100 μM), and dopaminergic D1 (SCH23390 100 μM) and D2 (eticlopride 100 μM) antagonists, in the hippocampal and cortical areas. In the hippocampal areas, these antagonists had less significant effect on norepinephrine and serotonin. However, in the cortical areas, all antagonists inhibited the nicotine-induced increase of serotonin to varying degrees; and some, primarily nicotinic and dopamine D1 antagonists, inhibited the induced increase of norepinephrine. In the hippocampal and cortical areas, the mechanisms of nicotine-induced dopamine increase seem to be similar, but the mechanisms seem to be different for noradrenergic and serotonergic systems, as shown by the fact that nicotine induces no change in norepinephrine and a decrease in serotonin in the hippocampus, while it induces an increase in both in the cortex. Nicotine-induced dopamine release seems to be mediated, in part locally, by nicotinic and muscarinic receptors on dopaminergic cells. In contrast, nicotine’s effect on norepinephrine and serotonin is at least partially mediated by initial changes at other than local sites, and through different receptors. Thus, the effects of nicotine and the mechanisms involved differ for different neurotransmitters and in different brain areas.  相似文献   

3.
Recent evidence indicates that mechanisms involved in reward and mechanisms involved in learning interact, in that reward includes learning processes and learning includes reward processes. In spite of such interactions, reward and learning represent distinct functions. In the present study, as part of an examination of the differences in learning and reward mechanisms, it was assumed that food principally affects reward mechanisms. After a brief period of fasting, we assayed the release of three neurotransmitters and their associated metabolites in eight brain areas associated with learning and memory as a response to feeding. Using microdialysis for the assay, we found changes in the hippocampus, cortex, amygdala, and the thalamic nucleus, (considered cognitive areas), in addition to those in the nucleus accumbens and ventral tegmental area (considered reward areas). Extracellular dopamine levels increased in the nucleus accumbens, ventral tegmental area, amygdala, and thalamic nucleus, while they decreased in the hippocampus and prefrontal cortex. Dopamine metabolites increased in all areas tested (except the dorsal hippocampus); changes in norepinephrine varied with decreases in the accumbens, dorsal hippocampus, amygdala, and thalamic nucleus, and increases in the prefrontal cortex; serotonin levels decreased in all the areas tested; although its metabolite 5HIAA increased in two regions (the medial temporal cortex, and thalamic nucleus). Our assays indicate that in reward activities such as feeding, in addition to areas usually associated with reward such as the mesolimbic dopamine system, other areas associated with cognition also participate. Results also indicate that several transmitter systems play a part, with several neurotransmitters and several receptors involved in the response to food in a number of brain structures, and the changes in transmitter levels may be affected by metabolism and transport in addition to changes in release in a regionally heterogeneous manner. Food reward represents a complex pattern of changes in the brain that involve cognitive processes. Although food reward elements overlap with other reward systems sharing some neurotransmitter compounds, it significantly differs indicating a specific reward to process for food consumption. Like in other rewards, both learning and cognitive areas play a significant part in food reward. Special issue dedicated to Dr. Moussa Youdim.  相似文献   

4.
In the present study, we tested the effects of glutamate and GABA receptor antagonists on nicotine-induced neurotransmitter changes in the hippocampal (dorsal and ventral) and cortical (medial temporal and prefrontal) brain areas of conscious freely moving rats via microdialysis. Both the antagonists and nicotine were administered intracerebrally. The antagonists tested were NMDA, AMPA–kainate, and metabotropic glutamate receptor subtype antagonists (MK801, CNQX, and LY 341495, respectively) and GABAA and GABAB receptor subtype antagonists (bicuculline and hydroxysaclofen, respectively). We assayed nicotine-induced changes in dopamine (DA), norepinephrine (NE), serotonin (5-HT), and their metabolites. We found with the antagonists, both decreases and increases in nicotine-induced neurotransmitter responses. In the presence of nicotine all the antagonists (except LY 341495) caused a decrease in DA levels in the regions tested. NE levels were decreased in the cortex by all antagonists. In the hippocampus, GABA antagonists decreased NE levels, as did the metabotropic glutamate antagonist, LY 341495, while the other glutamate antagonists increased NE levels. The results of the 5-HT assay were more variable and dependent on the region and antagonist examined; increases were found slightly more often than decreases. The changes in metabolites were not often parallel with changes in their associated neurotransmitters, indicating that the antagonists also affect the metabolism of the neurotransmitters. The effect of the antagonists in the absence of nicotine was mostly to decrease the level of neurotransmitters, although increases were seen in a few cases. The results suggest that the excitatory glutamatergic- and inhibitory GABAergic-amino acid receptors are both involved in mediating nicotine-induced neurotransmitter responses, and their inhibitory or stimulatory effects are receptor subtype and brain region dependent. * To John P. Blass, an outstanding scientist, clinician and a great friend.  相似文献   

5.
1. Neurotrophins and serotonin have both been implicated in the pathophysiology of depression and in the mechanisms of antidepressant treatments. 2. Brain-derived neurotrophic factor (BDNF) influences the growth and plasticity of serotonergic (5-HT) neurons via the activation of trkB receptor. 3. Transgenic mice overexpressing the full-length trkB receptor (TrkB.TK+) and showing increased trkB activity in brain, and their wild type (WT) littermates, were injected with the antidepressant fluoxetine or saline, and analyzed behaviorally in the forced swimming test paradigm and biochemically for the concentrations of brain monoamines and their metabolites. 4. The TrkB.TK+ mice displayed increased latency to immobility in the forced swim test, suggesting resistance to behavioral despair. 5. Fluoxetine increased the latency to immobility in wild-type mice to a similar level as seen in the trkB.TK+ mice after saline treatment, but had no further behavioral effect in the swimming behavior of the trkB.TK+ mice. 6. Only minor differences in the levels of brain monoamines and their metabolites were observed between the transgenic and wild-type mice. 7. These data, together with other recent observations, suggest that trkB activation may play a critical role in the behavioral responses to antidepressant drugs in mice.  相似文献   

6.
The effect of castration on the levels of brain monoamines and their metabolites has been investigated in rats which became or did not become muricidal following long-term isolation. Fourteen brain areas were explored: olfactory bulbs (OB), olfactory tubercles (OT), septum (Se), striatum (Sr), amygdala (A), thalamus (Th), hypothalamus (Hy), hippocampus (Hi), superior colliculus (SC), inferior colliculus (IC), raphe (Ra), pons-medulla (PM), frontal cortex (FC), temporal cortex (TC) and parietal cortex (PC). Except in the raphe of non muricidal rats and in the striatum of muricidal animals, all other areas examined demonstrate some changes of monoamines neurotransmitter or their metabolites after castration. The strongest changes, always increases, were found in the thalamus. In several brain areas, the changes occurring after castration, differ quantitatively and qualitatively in muricidal and non-muricidal rats.Special issue dedicated to Dr. Claude Baxter.Prof. P. Mandel passed away on October 6th, 1992.  相似文献   

7.
Functional and behavioral disturbances associated with hydrocephalus may be due in part to altered neurotransmitter function in the brain. Hydrocephalus was induced in adult rabbits by injection of silicone oil into the cisterna magna. These and controls were killed 3 days, 1 and 4 weeks post-injection. Tissue concentrations of norepinephrine, epinephrine, serotonin, dopamine, and the metabolites 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA), and 3,4-dihydroxyphenylacetic acid (DOPAC) levels were determined in fifteen brain regions using HPLC. There were decreases in hypothalamic and medullary dopamine, transient decreases in basal ganglia serotonin, increases in thalamic noradrenaline, and increases in hypothalamic and thalamic epinephrine. Changes in the primary neurotransmitters may be attributable to damage of their axonal projection systems. Metabolite concentrations increased in the cerebrum. Reduced clearance of extracellular fluid which accompanies cerebrospinal fluid stasis may explain the accumulation of metabolites.  相似文献   

8.
Chronic restriction of cerebral blood flow in hypoperfused Wistar rats has been proposed as a new model of cerebrovascular-type dementia. Using this model, we have investigated central monoaminergic neuronal systems that are closely related to higher brain function. Monoamine and monoamine-metabolite levels were determined, as relative monoaminergic markers, at 1 day and 1,3,6 and 12 weeks after the bilateral occlusion of common carotid arteries. Dopaminergic changes in the frontal cortex and striatum were observed in hypoperfused rats at 1–3 weeks following occlusion. Serotonergic changes were recognized at four brain regions examined (frontal cortex, hippocampus, striatum and thalamus+midbrain). In particular, the immediate enhancement of serotonin turnover in the striatum appeared to influence the reaction to the acute ischemic attack such as vasoconstriction produced by hypoperfusion. Our findings suggest that chronic cerebral hypoperfusion induces transient reversible changes in central monoaminergic neuronal function within three weeks of ligation of carotid arteries. This time interval seems to represent a turning point in the process of chronic cerebral hypoperfusion-induced progressive brain injury.  相似文献   

9.
1. The purpose of the present study was to determine the effect of zinc on the status of various neurotransmitters as well as behavioral patterns of lithium-treated rats. The study was designed with a view to find out whether zinc affords protection to brain against lithium toxicity. 2. Animals were segregated into four different groups. Animals in group I were fed with standard laboratory feed and water ad libitum and served as normal controls. Animals in group II and IV were given lithium in the form of lithium carbonate in their diet at a dose level of 1.1 g/Kg diet. Animals in group III and IV were given zinc treatment in the form of zinc sulfate at a dose level of 227 mg/L mixed in drinking water of animals. 3. The effects of all the treatments were studied for a duration of 1, 2, and 4 months with regard to the parameters, which included estimation of serotonin and dopamine concentrations as well as the activity of acetylcholinesterase in cerebral cortex of rat brain. Further, passive avoidance, active avoidance, and behavior despair tests were conducted to assess the short-term memory, cognitive behavior, and psychomotor dysfunction of the animals, respectively. 4. Initially, a decrease in the acetylcholinesterase activity was reported in cerebral cortex followed by an increase in the enzyme activity after 2 and 4 months of lithium treatment. Serotonin concentration significantly decreased after 2 and 4 months of lithium treatment, whereas dopamine concentration increased significantly after 4 months of lithium treatment. Zinc administration to the lithium-treated group significantly improved the acetylcholinesterase activity as well as the concentration of dopamine and serotonin. Further, lithium-treated rats showed an increase in depression time as compared to normal controls both after 1 and 4 months of treatment. Short-term memory significantly improved in lithium-treated rats in all treatment groups. However, no change in the cognitive behavior of the animals was reported after lithium treatment. Zinc co-administration with lithium significantly improved the short-term memory and cognitive functions of the animals. From the above results it can be concluded that zinc proved beneficial in altering the status of neurotransmitters as well as the behavior patters of the animals treated with both short and long-term lithium therapy.  相似文献   

10.
It is believed that drug-induced behavioral sensitization is an important process in the development of substance dependence. In order to explore mechanisms of sensitization, a mouse model of nicotine-induced locomotor sensitization was established, and effects of the sensitization process on mesencepahlic gene expression were examined. A schedule, which included 3 weeks of intermittent nicotine exposure (0.5 mg/kg, s.c.) and 3 weeks of withdrawal, resulted in locomotor sensitization. Effects of sensitization on mesencephalic expression of approximately 14,000 genes were assessed using oligonucleotide microarrays. Signal intensity differences in samples obtained from repeated nicotine- and saline-exposed animals were analyzed with z-test after False Discovery Rate (FDR) multiple test correction. Genes related to GABA-A receptors and protein phosphatases were among 68 genes showing significantly different expression levels between the saline and the nicotine groups. We hypothesize that some of the gene expression changes in the mesencephalon are involved in pathways leading to nicotine-induced sensitization. Down-regulation of GABA-A receptors induced by repeated nicotine exposure may facilitate dopaminergic neuronal transmission and may contribute to increased locomotor activity.  相似文献   

11.
摘要 目的:探讨抑郁症患者的脑CT灌注成像特征与认知功能的相关性。方法:选取我院2020年1月到2023年1月收治的90例抑郁症患者作为研究对象,将其分为观察组,另选取同期来我院体检的90名健康志愿者作为对照组。收集所有受检者脑CT灌注成像检查数据,分析抑郁症患者的脑CT灌注成像特征,并建立受试者工作特征(ROC)曲线分析脑CT灌注成像对抑郁症的诊断效能。随后对观察组和对照组受检者均进行认知功能评估,其中包括连线检测(TMT)、视觉再生测验(VRT)、言语流畅性测验(VF)、数字广度测验(DST)以及数字符号测验(SDMT),并分析脑CT灌注成像与抑郁症认知功能的相关性。结果:观察组与对照组受检者rCBV、rCBF、MTT、TIP、右枕叶、左枕叶、右颞叶、左颞叶、右顶叶、左顶叶CT值对比无明显差异(P>0.05),观察组与对照组受检者右额叶、左额叶CT值对比差异显著,观察组明显低于对照组(P<0.05);90例抑郁症患者经过汉密尔顿抑郁量表(HAMD)评估后分数均>20分,确定存在抑郁症状,脑CT灌注成像与HAMD评分诊断抑郁症的准确性、灵敏度、特异性、阳性预测值和阴性预测值对比无明显差异(P>0.05),脑CT灌注成像的曲线下面积为83.89,最佳诊断着色界限值为82.53%,HAMD评分的曲线下面积为84.26,最佳诊断着色界限值为87.57%;观察组与对照组受检者连线提笔数、连线错误数、视觉再生检测结果对比无明显差异(P>0.05),观察组与对照组受检者连线、言语流畅性、数字广度、数字符号检测结果对比差异显著(P<0.05);Spearman相关分析结果表明:连线提笔数、连线错误数、视觉再生与脑CT灌注参数均无明显相关性(P>0.05),连线、言语流畅性、数字广度、数字符号与rCBV、rCBF、MTT、TIP、右枕叶、左枕叶、右颞叶、左颞叶、右顶叶、左顶叶CT值无明显相关性(P>0.05),连线与右额叶、左额叶CT值呈负相关(P<0.05),言语流畅性、数字广度、数字符号与右额叶、左额叶CT值呈正相关(P<0.05)。结论:抑郁症患者的脑CT灌注成像与健康群体呈现差异,其中右额叶、左额叶差异情况最为显著,提示抑郁症患者可能存在大脑额叶功能改变,另外,抑郁症患者的大脑额叶功能与认知功能变化具有明显相关性。  相似文献   

12.
Levels of brain neurotransmitters and their metabolites, as well as concentrations of enzymes associated with their synthesis and metabolism, fluctuate during the day in patterns defined as circadian. The present study examined these rhythms in albino rats exposed to 60-Hz electric fields. Thirty-six animals were exposed to a 39 kV/m field for 4 weeks, 20 h/day, in a parallel-plate electrode system. A group of 36 sham animals was similarly handled and housed in a nonenergized exposure system. On the sampling day, animals were sacrificed at 4-h intervals throughout the 24-h day. Brains were removed, dissected, and kept frozen until chemically analyzed. The levels of biogenic amines and their acidic metabolites in the striatum, hypothalamus, and hippocampus were determined by high-performance liquid chromatography with electrochemical detection (HPLC-ECD) methods. Repeated exposure to 60-Hz electric fields produced significant alterations in the diurnal rhythms of several biogenic amines: dihydroxyphenylacetic acid (DOPAC, the primary metabolite of dopamine in the rat) in the striatum, and norepinephrine, dopamine, and 5-hydroxyindoleacetic acid (5-HIAA; serotonin metabolite) in the hypothalamus. Levels of serotonin in the striatum and hypothalamus showed clear circadian patterns that was not affected by the field. No diurnal or field-related changes were observed in the hippocampal amines.  相似文献   

13.
Numerous recent studies found that proteases play a major role in brain function. In addition to their role in protein turnover, they have modulatory functions and an important role in apoptosis, pathological changes, and other mechanisms. To explore possible differences in brain protein metabolism of suicide victims, we examined the activity of two proteases, cathepsin D and calpain (I and II combined), in eleven discrete areas of postmortem brain tissue of 21 victims of suicide and of 31 age- and sex-matched control subjects without a history of psychiatric or neurological disease. The levels of functionally important amino acids in five of these areas were also measured. Cathepsin D activity was found to be lower in two of eleven regions of brains of suicide victims, the parahippocampal cortex and the medial hypothalamus, by 26% and 27%, respectively. Calpain activity was lower in two different areas tested, 29% in the medulla oblongata and 26% in the lateral prefrontal cortex, and was 18% higher in the midbrain. There were no significant differences in the other areas (globus pallidus, hippocampus, amygdala, caudate nucleus, ventral tegmental area, and nucleus accumbens). Protease distribution was regionally heterogeneous—the levels in the globus pallidus were low, and in the hippocampus high, with about a two-fold difference. The length of the postmortem period for obtaining tissue, the storage time of the frozen tissue, and the age of the subject had no apparent influence on the results obtained. Although there was a tendency toward higher levels of aspartate and glycine in brain areas from suicide victims, the difference was not significant. The variations among individual brains were greater in amino acid levels than in protease levels. The findings indicate the possible role of protein metabolism in depressive or suicidal behavior.  相似文献   

14.
15.
The effects of the organophosphate acetylcholinesterase (AChE) inhibitor soman (31.2 micrograms/kg s.c.) on guinea-pig brain AChE, transmitter, and metabolite levels were investigated. Concentrations of acetylcholine (ACh) and choline (Ch), noradrenaline (NA), dopamine (DA), 5-hydroxytryptamine (5-HT), and their metabolites, and six putative amino acid transmitters were determined concurrently in six brain regions. The brain AChE activity was maximally inhibited by 90%. The ACh content was elevated in most brain areas by 15 min, remaining at this level throughout the study. This increase reached statistical significance in the cortex, hippocampus, and striatum. The Ch level was significantly elevated in most areas by 60-120 min. In all regions, levels of NA were reduced, and levels of DA were maintained, but those of its metabolites increased. 5-HT levels were unchanged, but those of its metabolites showed a small increase. Changes in levels of amino acids were restricted to those areas where ACh levels were significantly raised: Aspartate levels fell, whereas gamma-aminobutyric acid levels rose. These findings are consistent with an initial increase in ACh content, resulting in secondary changes in DA and 5-HT turnover and release of NA and excitatory and inhibitory amino acid transmitters. This study can be used as a basis to investigate the effect of toxic agents and their treatments on the different transmitter systems.  相似文献   

16.
目的:探讨血浆超敏C反应蛋白(hs-CRP)和同型半胱氨酸(Hcy)水平与血管性痴呆(VD)患者认知功能的相关性。方法:回顾性分析2011年12月-2014年7月间我院100例脑梗死住院患者的临床资料,按诊断结果,将患者分为VD组55例和非VD组45例,另选取同期50例健康体检者为对照组。检测并比较3组血浆hs-CRP和Hcy水平,采用简易精神状态速检表(MMSE)对VD组进行痴呆程度分类,分析其与血浆hs-CRP和Hcy的相关性。结果:血浆Hcy与hs-CRP在3组间差异有统计学意义(P0.05),且VD组、非VD组均显著高于对照组,VD组显著高于非VD组,差异均有统计学意义(P0.05)。随着痴呆程度的加重,MMSE评分逐渐降低,血浆hs-CRP与Hcy水平则逐渐升高,差异有统计学意义(P0.05)。经相关性分析发现,MMSE评分和血浆hs-CRP与Hcy水平均呈负相关(r=-0.672,-0.703,P0.05)。结论:血浆hs-CRP与Hcy水平与VD患者的认知功能负相关,临床加强对两指标的检测对VD的诊断及防治有着重要的临床意义。  相似文献   

17.
目的:探讨缺血性脑血管病患者认知功能。方法:将60例缺血性脑血管病患者依据卒中风险评分量表评分,分为轻危组20例、中危组22例、高危组18例;应用蒙特利尔量表进行认知功能评定。结果:(1)高危组与低危组在视空间和执行功能、注意力、计算力、抽象概括能力、命名、记忆、时间定向方面有显著性差异(P<0.05);中危组与低危组比较在视空间和执行功能、注意力、计算力、抽象概括能力、记忆各方面有显著性差异(P<0.05);视空间、命名、计算、语言、时间定向各方面中危组较高危组有显著性差异(P<0.05)。(2)各项认知功能评分与血管因素进行相关分析,年龄、TIA或脑卒中、高血压与MOCA各项评分呈负相关。结论:缺血性脑血管病患者随着危险因素增多,其认知功能障碍越显著。  相似文献   

18.
目的:探讨缺血性脑血管病患者认知功能。方法:将60例缺血性脑血管病患者依据卒中风险评分量表评分,分为轻危组20例、中危组22例、高危组18例;应用蒙特利尔量表进行认知功能评定。结果:(1)高危组与低危组在视空间和执行功能、注意力、计算力、抽象概括能力、命名、记忆、时间定向方面有显著性差异(P〈0.05);中危组与低危组比较在视空间和执行功能、注意力、计算力、抽象概括能力、记忆各方面有显著性差异(P〈0.05);视空间、命名、计算、语言、时间定向各方面中危组较高危组有显著性差异(P〈O.05)。(2)各项认知功能评分与血管因素进行相关分析,年龄、TIA或脑卒中、高血压与MOCA各项评分呈负相关。结论:缺血性脑血管病患者随着危险因素增多,其认知功能障碍越显著。  相似文献   

19.
This research was initiated to assess the turnover rates (TORs) of dopamine (DA), norepinephrine (NA), serotonin (5-HT), aspartate, glutamate, and GABA in brain regions during rodent ethanol/sucrose (EtOH) and sucrose (SUC) drinking and in animals with a history of EtOH or SUC drinking to further characterize the neuronal systems that underlie compulsive consumption. Groups of five male rats were used, with two trained to drink EtOH solutions, two to drink SUC and one to serve as a non-drinking control. When stable drinking patterns were obtained, rats were pulse labeled intravenously and killed 60 or 90 min later and the TORs of DA, norepinephrine, 5-HT, aspartate, glutamate, and GABA determined in brain regions. Changes in the TOR of 5-HT, DA, and NA were detected specific to EtOH drinking, SUC drinking or a history of EtOH or SUC drinking. An acute EtOH deprivation effect was detected that was mostly reversed with EtOH drinking. These results suggest that binge-like drinking of moderate amounts of EtOH produces a deficit in neuronal function that could set the stage for the alleviation of anhedonic stimuli with further EtOH intake that strengthen EtOH seeking behaviors which may contribute to increased EtOH use in at risk individuals.  相似文献   

20.
Monoaminergic systems are important modulators of the responses to stress. Stress may influence feeding behavior, and the involvement of monoamines in the control of food intake is well recognized. We investigated the effects induced by chronic-restraint stress, 1 h a day, for 40 days, on eating behavior and on monoamines in distinct brain structures. Increased consumption of sweet pellets, and not of peanuts, was observed. Dopamine (DA), serotonin (5–HT), and their metabolites were measured by HPLC-EC. After chronic restraint, the results observed were decreased 5–HT in hippocampus, with increased 5–HIAA/5–HT; decreased 5–HIAA levels in cortex; reduction in DA in hippocampus, and increased levels in amygdala and hypothalamus; HVA increased in cortex, as well as HVA/DA ratio, while DOPAC/DA decreased. HVA decreased in hypothalamus, as well as HVA/DA, and DOPAC/DA and HVA/DA decreased in the amygdala. These results suggest that restraint stress differentially affects the activity of central dopaminergic and serotonergic neurons, and this may be related to the effects observed in eating behavior.  相似文献   

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