role of brain nicotinic acetylcholine receptor in centrally administered corticotropinreleasing factorinduced elevation of plasma corticosterone in rats the present study was undertaken to clarify the central mechanisms involved in the intracerebroventricularly administered corticotropinreleasing factorinduced elevation of plasma corticosterone in urethane and alphachloraloseanesthetized rats using microdialysis and immunohistochemical techniques when corticotropinreleasing factor was given at 05 15 and 30 nmolanimal intracerebroventricularly it dosedependently increased noradrenaline release but not adrenaline release in the hypothalamic paraventricular nucleus the 15 nmolanimal dose of corticotropinreleasing factorinduced noradrenaline release was attenuated by cp154526 butylethyl25dimethyl7246 trimethylphenyl7hpyrrolo23dpyrimidin4ylamine a selective corticotropinreleasing factor receptor 1 antagonist at 13 micromolanimal intracerebroventricularly and was also abolished by phentolamine at 066 micromolanimal intracerebroventricularly in addition the corticotropinreleasing factorinduced elevation of noradrenaline release in the hypothalamic paraventricular nucleus and plasma corticosterone were abolished by hexamethonium a nonselective nicotinic acetylcholine receptor antagonist at 18 micromolanimal intracerebroventricularly and alphaconotoxin mii a potent alpha3beta2 nicotinic acetylcholine receptor antagonist at 30 nmolanimal icv corticotropinreleasing factor at 15 nmolanimal icv evoked a significant expression of fos an immediateearly transcription factor in neurons on the dopaminebetahydroxylasecontaining neurons and alpha3 nicotinic acetylcholine receptor subunitexpressing neurons in the locus coeruleus but not in the medullary a1 and a2 regions containing noradrenergic neurons these results suggest that centrally administered corticotrophinreleasing factor elevates plasma corticosterone by the corticotropinreleasing factor 1 receptor and alpha3 subunitcontaining nicotinic acetylcholine receptor probably alpha3beta2 nicotinic acetylcholine receptor mediated activation of the locus coeruleus noradrenergic neurons projecting to the paraventricular nucleus in rats