[The delayed sensitization of CRH response developed after chronic variable stress on the acoustic startle reflex].

Substantial evidence indicates that brain neurons containing and secreting norepinephrine (NE) and corticotrophin-releasing hormone (CRH) are activated during stress. The acoustic startle reflex (ASR) can be enhanced by CRH neuronal activity in the central nucleus of the amygdala. Our previous study demonstrates an augmentation of the footshock-induced ASR (f-ASR) 1 day after chronic variable stress (CVS) for 13 days.

Fluvoxamine and sigma-1 receptor agonists dehydroepiandrosterone (DHEA)-sulfate induces the Ser473-phosphorylation of Akt-1 in PC12 cells.

Aims: The expression of brain-derived neurotrophic factor (BDNF) may be a downstream target of a variety of antidepressant treatments, and selective serotonin reuptake inhibitors (SSRIs) are used clinically for the treatment of depression. BDNF binds to and activates tyrosine kinases receptor (TrkB) to exert its effects. TrkB, after activation by ligands, stimulates phosphoinositide 3-kinase (PI3K).

[Long-lasting sensitization to footshock after chronic variable stress on the acoustic startle reflex].

Corticotropin releasing hormone (CRH)--and norepinephrine (NE) -containing neurons in the brain are activated during stress. We previously reported a decrease in the basal level of CRH immunoreactivity in the central nucleus of the amygdala and the tyrosine hydroxylase immunoreactivity in the locus coeruleus after chronic variable stress (CVS), whereas both responses were augmented by a novel stress (footshock). Since the acoustic startle reflex (ASR) can be enhanced by the CRH neuronal activity in the central nucleus of the amygdala, we examined the influence of footshock on ASR in rats exposed to CVS.

[Effect of chronic variable stress on limbic corticotrapin-releasing hormone receptor].

The Corticotropin-releasing hormone (CRH) is a key mediator in the stress response. Two CRH-receptor subtypes have been identified in the brain, CRH-receptor 1 (CRH-R1) and CRH-receptor 2, and stress responses are mediated by the CRH-R1. In this study we have examined the effect of chronic variable stress (CVS) on the CRH-R1 immunoreactivity in the hypothalamic and limbic brain regions of the rat.

[Regulation of TH activity by GAD immunoreactivity in rat peri-LC after chronic variable stress].

Locus coeruleus (LC) is the major component of noradrenergic neurons in the brain. The corticotropin-releasing hormone (CRH) and norepinephrine (NE) are suggested to play a role in modulating the central stress response. In a previous study we observed a decrease of the basal level of tyrosine hydroxylase (TH) immunoreactivity (-ir) in the LC of rats treated with chronic variable stress (CVS) for 14 days.

[Effect of concurrent treatment of SSRI on the tyrosine hydroxylase immunoreactivity in the rat locus coeruleus treated with chronic variable stress].

Locus coeruleus (LC) is the major component of noradrenergic neurons in the brain. corticotropine-releasing hormone (CRH) and norepinephrine (NE) are suggested to play significant roles in the pathophysiology of depression, although the involvement of the serotonergic system in the CRH-NE systems is not elucidated. Chronic inescapable and unpredictable stress can result in a sustained dysregulation of both of CRH and NE systems.

Chronic carbamazepine treatment increases myristoylated alanine-rich C kinase substrate phosphorylation in the rat cerebral cortex via down-regulation of calcineurin A alpha.

Carbamazepine (CBZ) is generally used as a mood-stabilizing drug for the treatment of bipolar disorders. However, little is known about the molecular mechanisms of CBZ actions in the brain, which account for this therapeutic profile. In the present study, we examined the effects of chronic CBZ treatment on the protein kinase C (PKC) pathway.

[Reduction and sensitization of CRH neuron in rat hypothalamic and extrahypothalamic regions after chronic variable stress].

The hyperactivity of corticotropin-releasing hormone (CRH) neurons of the hypothalamic and/or extrahypothalamic regions is believed to contribute to the pathophysiology of major depression in an experimental animal chronically exposed to stress. In the present study, we examined the effects of chronic variable stress (CVS) and novel stress (footshock) on the CRH immunoreactivity in the hypothalamic paraventricular nucleus (PVN) and subdivision of PVN, and the extrahypothalamic bed nucleus of the stria terminalis (BNST) and the central nucleus of the amygdala (CeA). We observed a significant reduction in CRH levels in the whole PVN, lateral parvocellular part of PVN, BNST and CeA 24 hours after the last stressor of CVS for 13 days.