Journal of Neuroscience, Vol 6, 531-540, Copyright © 1986 by Society for Neuroscience
Localization of muscarinic receptors on cultured myenteric neurons: a combined autoradiographic and immunocytochemical approach
NJ Buckley and G Burnstock
In order to localize the distribution of muscarinic receptors over the
surface of cultured myenteric neurons, an autoradiographic procedure for
detecting muscarinic receptors (using [3H]propylbenzilylcholine mustard;
[3H]PrBCM) has been combined with an immunofluorescence procedure
visualizing neuronal morphology (using an antibody raised against rat brain
synaptosomes; anti-CTX). Using this technique, muscarinic receptors were
localized over discrete areas of the neuronal cell surface. Receptors were
seen to be widely distributed over the somata and neurites of 10-20% of
cultured myenteric neurons. The greatest concentration of receptors
occurred over the cell somata and proximal neurites. Receptors appeared
evenly distributed over labeled cell somata, where their density was
estimated to be between 30 and 100 receptors/micron2. Distal regions of
neurites were labeled intermittently with some varicosities and
intervaricosities being labeled while others were unlabeled. Growth cones
and nerve endings of labeled neurites were consistently labeled. The
ability to localize muscarinic receptors on a subpopulation of
immunocytochemically identified neurons enhances our understanding of
muscarinic neurotransmission in myenteric neurons and provides an
experimental system for the investigation of regulatory influences on
neuronal neurotransmitter receptor expression and distribution.