Morphofunctional studies on the neuropeptide Y/adrenaline costoring terminal systems in the dorsal cardiovascular region of the medulla oblongata. Focus on receptor-receptor interactions in cotransmission

The morphological studies in the past have been performed by means of computer-assisted morphometry and microdensitometry to give an objective representation of the central adrenaline (A) nerve cell groups in the medulla oblongata. The functional and biochemical studies of the A neurons within the medulla oblongata, especially within the dorsal cardiovascular region, have given evidence that the adrenergic neurons have an important vasodepressor function in the central nervous system (CNS). The existence of neuropeptide Y–like immunoreactivity in the A cell groups C1, C2, and C3 in the medulla oblongata has been demonstrated by studies in the past. Based on these observations, the effects of centrally administered neuropeptide Y (NPY) on cardiovascular and respiratory parameters and on pre- and postsynaptic mechanisms in central A nerve terminal networks in the dorsal cardiovascular region of the medulla oblongata of the rat have been analyzed. These studies have shown that NPY given intracutaneously in the α-chloralose anesthetized rat can reduce arterial blood pressure and heart rate. These actions have been observed in the presence of α-adrenergic receptor blockade. © 1986, Academic Press Inc. All rights reserved.