The transcriptome of the rat hypothalamic-neurohypophyseal system is highly strain-dependent.

We have used microarrays to comprehensively describe the transcriptomes of the supraoptic nucleus (SON), the paraventricular nucleus (PVN) and the neurointermediate lobe of adult male Sprague-Dawley (SD) and Wistar-Kyoto (WKY) rats, as well as the PVN of Wistar rats. Comparison of these gene lists has enabled us to identify surprisingly large differences in hypothalamic-neurohypophyseal system gene expression patterns in these three strains. We have also shown that different transcript populations are enriched in the PVN and the SON of SD and WKY rats.

Protective effects of endotoxin in a rat model of chronic inflammation are accompanied by suppressed secretion of pro-inflammatory cytokines and biphasic alteration in hypothalamo-pituitary-adrenal axis activity.

We have previously demonstrated that Gram-negative bacterial endotoxin can exert long-term protective effects against the chronic inflammatory disease adjuvant arthritis in rats. The present study was designed to investigate the mechanisms and time-course of hypothalamo-pituitary-adrenocortical (HPA) axis activity and cytokine secretion underlying this phenomenon. Rats were injected with endotoxin (lipopolysaccharide) and blood was collected either 7 or 21 days later.

Stress in autoimmune disease models.

The release of endogenous glucocorticoids is critical in regulating the severity of disease activity in patients with inflammatory conditions such as rheumatoid arthritis (RA). Blocking cortisol production results in a flare-up in disease activity in RA patients, and surgical removal of the adrenals in patients with Cushing's disease has been reported to exacerbate autoimmune disease. In adjuvant-induced arthritis (AA; a rat model of RA), there is an activation of the hypothalamo-pituitary-adrenal (HPA) axis associated with the development of inflammation.

The nociceptin receptor antagonist [Nphe1,Arg14,Lys15]nociceptin/orphanin FQ-NH2 blocks the stimulatory effects of nociceptin/orphanin FQ on the HPA axis in rats.

Nociceptin/orphanin FQ (N/OFQ) is an opioid-related peptide that stimulates corticosterone release after i.c.v.

Differential effects of acute and chronic social defeat stress on hypothalamic-pituitary-adrenal axis function and hippocampal serotonin release in mice.

Hyperactivity of the hypothalamic-pituitary-adrenal (HPA) stress axis and disturbances in serotonin (5-HT) neurotransmission have been implicated in the pathogenesis of depressive disorder. Repeated social defeat of male NMRI mice has been shown to induce increases in core body temperature and corticosterone, indicative of a state of chronic stress in subordinate animals. The present study further characterised the HPA axis response to social defeat stress, and also examined hippocampal extracellular 5-HT release during the stress.