title: Inhibition by corticosterone of paraventricular nucleus multiple-unit activity responses to sensory stimuli in freely moving rats.
abstract: In order to determine possible electrophysiologic correlates of negative feedback influences of glucocorticoids upon neuroendocrine secretory activity, the effects of various doses of corticosterone on paraventricular nucleus multiple-unit activity responses to neural stimuli were examined in conscious, freely moving male rats. In control animals, photic and acoustic stimulation significantly increased multiple-unit activity of the paraventricular nucleus by increments of 75% and 117% (P less than 0.005), respectively. Doses between 0.1 and 5.0 mg of corticosterone produced a dose-dependent inhibition of responses to photic stimulation with a high correlation coefficient (r = -0.990). Corticosterone also caused an inhibition of paraventricular multiple-unit activity in response to acoustic stimulation, which was more effective than for photic stimulation, with complete blockade of response occurring with a dose of 1 mg corticosterone. These electrophysiologic findings, within a region of the hypothalamus known to contain corticotrophin-releasing factor cell bodies, may be related to reduced secretion of the hormone in response to the neurogenic stimuli employed, following glucocorticoid administration.
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D003345:Corticosterone / Q000494:pharmacology*; D008297:Male; D009474:Neurons / Q000187:drug effects; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects*; D010775:Photic Stimulation; D051381:Rats; D012677:Sensation
chemical_list: D003345:Corticosterone