Michel Barrot

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Current treatments for depression are inadequate for many individuals, and progress in understanding the neurobiology of depression is slow. Several promising hypotheses of depression and antidepressant action have been formulated recently. These hypotheses are based largely on dysregulation of the hypothalamic-pituitary-adrenal axis and hippocampus and(More)
BACKGROUND Methylphenidate (MPH) is a psychomotor stimulant medication widely used for the treatment of attention-deficit/hyperactivity disorder (ADHD). Given the extent of prescribed use of MPH, and because MPH interacts with the same brain pathways activated by drugs of abuse, most research has focused on assessing MPH's potential to alter an individual's(More)
We previously showed that chronic psychostimulant exposure induces the transcription factor DeltaFosB in gamma-aminobutyric acid (GABA)ergic neurons of the caudal tier of the ventral tegmental area (VTA). This subregion was defined as the tail of the VTA (tVTA). In the present study, we showed that tVTA can also be visualized by analyzing FosB/DeltaFosB(More)
The transcription factor cAMP response element (CRE)-binding protein (CREB) has been shown to regulate neural plasticity. Drugs of abuse activate CREB in the nucleus accumbens, an important part of the brain's reward pathways, and local manipulations of CREB activity have been shown to affect cocaine reward, suggesting an active role of CREB in adaptive(More)
Recent work implicates regulation of neurogenesis as a form of plasticity in the adult rat hippocampus. Given the known effects of opiates such as morphine and heroin on hippocampal function, we examined opiate regulation of neurogenesis in this brain region. Chronic administration of morphine decreased neurogenesis by 42% in the adult rat hippocampal(More)
Brain-derived neurotrophic factor (BDNF) regulates neuronal development and function. However, it has been difficult to discern its role in the adult brain in influencing complex behavior. Here, we use a recently developed inducible knockout system to show that deleting BDNF in broad forebrain regions of adult mice impairs hippocampal-dependent learning and(More)
The longevity of some of the behavioral abnormalities that characterize drug addiction has suggested that regulation of neural gene expression may be involved in the process by which drugs of abuse cause a state of addiction. Increasing evidence suggests that the transcription factor DeltaFosB represents one mechanism by which drugs of abuse produce(More)
Melanin-concentrating hormone (MCH) is a hypothalamic neuropeptide with a prominent role in feeding and energy homeostasis. The rodent MCH receptor (MCH1R) is highly expressed in the nucleus accumbens shell (AcSh), a region that is important in the regulation of appetitive behavior. Here we establish a role for MCH and MCH1R in mediating a(More)
The transcription factor deltaFosB is induced in the nucleus accumbens and dorsal striatum by chronic exposure to several drugs of abuse, and increasing evidence supports the possibility that this induction is involved in the addiction process. However, to date there has been no report of deltaFosB induction by drugs of abuse in the ventral tegmental area(More)
BACKGROUND Indirect evidence suggests that loss of brain-derived neurotrophic factor (BDNF) from forebrain regions contributes to an individual's vulnerability for depression, whereas upregulation of BDNF in these regions is suggested to mediate the therapeutic effect of antidepressants. METHODS We have tested this hypothesis by generating two independent(More)