Differential Projection of cholinergic and nitroxergic neurons in
The Myenteric plexus of the guinea-pig stomach.
Schemann, M., and C. Schaaf.
Max-Planck-Institute for Physiological and Clinical Research, 61231
Bad Nauheim, and Department of Physiology, School of Veterinary
Medicine, 30173 Hannover, Germany
APStracts 2:0053G, 1995.
The aim of this study was to investigate the organization of myenteric
circuits in the guinea-pig stomach. Intracellular Neurobiotin
-injections followed by choline acetyltransferase (ChAT)
immunohistochemistry and NADPH-diaphorase reaction were used to
identify projections of cholinergic and nitroxergic neurons. Neurons
were classified as motor neurons based on varicose endings in the
muscle or the occurrence of retraction bulbs, as non-motor neurons if
varicose endings terminated onto other ganglion cells or as multi
-targeted neurons. ChAT-positive cells comprised of 64% motor-, 27%
non-motor-, and 9% multi-targeted neurons. The percentages for NADPH
-reactive motor-, non-motor neurons, and multi-targeted neurons were
57%, 39% and 4%, respectively. The majority of ChAT-positive motor-
(81%) and non-motor neurons (85%) had ascending projections. In
contrast, the majority of NADPH-reactive motor- (86%) and non-motor
neurons (86%) had descending projections. Cell bodies of ascending
neurons were smaller in size than the descending neurons. The results
indicate that ChAT- and NADPH-neurons in the stomach have preferred
projections, the former being primarily ascending, the latter mainly
descending neurons. This suggests the existence of a basic circuit
for polarized reflexes in the myenteric plexus of the stomach which
might mediate descending relaxation and ascending excitation.
Received 8 November 1994; accepted in final form 24 February
1995.
APS Manuscript Number G445-4.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 4 April 1995.