Effects of physiological manipulations on locus coeruleus neuronal activity in freely moving cats. I. Thermoregulatory challenge

摘要: Insulin-induced hypoglycemia and the subsequent administration of glucose were examined for their effects on single unit activity locus coeruleus noradrenergic (LC-NE) neurons in unanesthetized, unrestrained cats. LC-NE neuronal showed an inverse relationship to blood levels. The most cells increased during sustained hypoglycemia, then decreased following administration. Some unaffected by but inhibited glucose. activation response insulin generally paralleled increase plasma epinephrine, although adrenal was more sensitive. These data, together with those reported preceding papers, suggest general conclusions: (1) physiological stimuli can influence unanesthetized subjects (although they do so less strongly than environmental stimuli); (2) these upon be exerted independent changes behavioral state; (3) not appear play a specific role regulation any systems examined, may instead global challenges general; (4) are co-activated both neural hormonal components sympatho-adrenal system, sympathetic occur absence activity. A previously hypothesized facilitating stressors thus extended include challenges, perhaps facilitation as well stress response.