Psychological stress increases histone H3 phosphorylation in adult dentate gyrus granule neurons: involvement in a glucocorticoid receptor-dependent behavioural response.

Chromatin remodelling associated with transcriptional activation of silent genes involves phosphorylation at Serine-10 and acetylation at Lysine-14 in the N-terminal tails of the nucleosomal protein histone H3. We have identified neurons predominantly in the dentate gyrus showing a speckled nuclear immunoreactivity pattern for phosphorylated histone H3 [i.e.

The selective glucocorticoid receptor antagonist ORG 34116 decreases immobility time in the forced swim test and affects cAMP-responsive element-binding protein phosphorylation in rat brain.

Glucocorticoid receptor (GR) antagonists can block the retention of the immobility response in the forced swimming test. Recently, we showed that forced swimming evokes a distinct spatiotemporal pattern of cAMP-responsive element-binding protein (CREB) phosphorylation in the dentate gyrus (DG) and neocortex. In the present study, we found that chronic treatment of rats with the selective GR antagonist ORG 34116 decreased the immobility time in the forced swim test, increased baseline levels of phosphorylated CREB (P-CREB) in the DG and neocortex and affected the forced swimming-induced changes in P-CREB levels in a time- and site-specific manner.

Neuronal transfer of the human Cu/Zn superoxide dismutase gene increases the resistance of dopaminergic neurons to 6-hydroxydopamine.

Several mechanisms are thought to be involved in the progressive decline in neurons of the substantia nigra pars compacta (SNpc) that leads to Parkinson's disease (PD). Neurotoxin 6-hydroxydopamine (6-OHDA), which induces parkinsonian symptoms in experimental animals, is thought to be formed endogenously in patients with PD through dopamine (DA) oxidation and may cause dopaminergic cell death via a free radical mechanism. We therefore investigated protection against 6-OHDA by inhibiting oxidative stress using a gene transfer strategy.

Forced swimming evokes a biphasic response in CREB phosphorylation in extrahypothalamic limbic and neocortical brain structures in the rat.

The transcription factor cAMP response element-binding protein (CREB) plays a critical role in plasticity processes underlying learning and memory. We investigated the phosphorylation of CREB in rat brain after forced swimming, a stressor known to impact on higher limbic and neocortical brain areas. As shown by immunohistochemistry, forced swimming increased phosphorylated CREB (P-CREB) levels in the dentate gyrus, all neocortical areas, the medial, lateral and basolateral nuclei of the amygdala, cerebellum but not in the hypothalamic paraventricular nucleus.

Psychological stress increases hippocampal mineralocorticoid receptor levels: involvement of corticotropin-releasing hormone.

We investigated whether acute stressors regulate functional properties of the hippocampal mineralocorticoid receptor (MR), which acts inhibitory on hypothalamic-pituitary-adrenocortical activity. Exposure of rats to forced swimming or novelty evoked a significant rise in density of MR immunoreactivity in all hippocampal subfields after 24 hr, whereas exposure to a cold environment was ineffective. Time course analysis revealed that the effect of forced swimming on MR peaked at 24 hr and returned to control levels between 24 and 48 hr.