Issue Archive

Effects of ACh on the electric activity of rostral ventrolateral medullary neurons of rat in vitro

Chu Xiangping

Department of Physiology, Shanghai Medical University. Shanghai 200032, China

Abstract

Extracellular single-unit discharges were obtained from l65 spontaneously active neurons within the region of the rostral ventrolateral medulla (RVLM) by glass microelectrode from 89 brain slices of the SpragUe-Dawley rats. The units could be divided into three types: regular (61.8%), irregular (24.2%) and silent (14%). Acetylcholine (ACh, 0.1, 0.3 #mu#mol/L) showed four kinds of effects on spontaneous discharges of RVLM neurons: excitatory, inhibitory, biphasic and non-responsive, counting respectively 41.8%, 20%, 3% and 35.2% of the neurons tested. The excitatory effect of ACh was dose-dependent. The effects, either excitatory or inhibitory,of ACh (n=49) were mostly blocked by atropine (0.3 #mu#mol/L, n=42). The excitatory effect of ACh (n=14) could be blocked mainly by selective antagonist of M_(1) receptor,pirenzepine (PZ, 30 nmol/L, n=9), but not by selective antagonist of M_(2) receptor,methoctramine (MT) and AFDX-116.

Key words: Acetylcholine;Brain slices of medulla;Rostral ventrolateral medulla;Spontaneous singleunit discharge;Subtype of muscarinic receptor

Received: 　　Accepted:

Corresponding author: 　　E-mail:

Citing This Article：

Chu Xiangping. Effects of ACh on the electric activity of rostral ventrolateral medullary neurons of rat in vitro. Acta Physiol Sin 1997; 49 (6): (in Chinese with English abstract).