Vasodilator mechanism of the intracerebral (non-sympathetic) adrenergic pathway.
Stimulation of the intracerebral noradrenergic pathway causes a vasodilatation in the hypothalamus. We have investigated whether this vasodilatation is caused by a direct vascular innervation or whether it is secondary to an activation of hypothalamic neurons. Non-specific neuronal activation using glutamate increased the mean hypothalamic blood flow. Depression of neuronal activity using barbiturate reduced hypothalamic blood flow and blocked the glutamate and the intracerebral noradrenergic pathway-induced vasodilatation. These results suggest that stimulation of the intracerebral noradrenergic pathway increases hypothalamic neuronal activity which indirectly causes a vasodilatation.
D000818:Animals; D001341:Autonomic Nervous System / Q000187:drug effects / Q000502:physiology*; D001463:Barbiturates / Q000494:pharmacology; D002560:Cerebrovascular Circulation / Q000187:drug effects; D005260:Female; D005971:Glutamates / Q000494:pharmacology; D007031:Hypothalamus / Q000098:blood supply* / Q000187:drug effects; D008297:Male; D009638:Norepinephrine; D011817:Rabbits; D014664:Vasodilation / Q000187:drug effects
D001463:Barbiturates; D005971:Glutamates; D009638:Norepinephrine