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Effects of intracerebroventricular administration of norepinephrine on paraventricular neurosecretory cells

Ji Yaping, Mei Jun, Tang Bin

Deartment of Brain and Nerve, Xi^an Medical University. Xi^an 710061, Shaanxi

Abstract

Extracellular electrical activities of paraventricular nucleus (PVN) cells were recorded in anaesthetized adult rats by using glass microelectrodes. After antidromical identification of the magnocellular neurosecretory cells, the effects of intracere broventricular (i. c. v.) injection of norepinephrine (NE) on such cells were observed. Of 49 neurons of antidromic stimulation, phasic, fast continuous and slowly irregularly firing units constituted 42.9%, 36.7%, and 20.4% of the total population respectively. With i.c.v. injection, NE inhibited the activity of most phasically firing units, but enhanced that of most fast continuous and slowly irregular firing units. The inhibition effect of NE could be partially antagonized by i.c.v. injection of phentolamine (2#mu#g/#mu#l), showing that the effect is possibly mediated by #alpha#--receptor. The above findings indicate that NE plays different roles in different PVN magnocellular neurons having different patterns of firing activity.

Key words: Hypothalamus;Paraventricular nucleus;Neurosecretory;Antidromical identification;Norepinephrine phentolamine;

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Citing This Article：

Ji Yaping, Mei Jun, Tang Bin. Effects of intracerebroventricular administration of norepinephrine on paraventricular neurosecretory cells. Acta Physiol Sin 1995; 47 (2): (in Chinese with English abstract).