Ed. Deltoro et al., IMMUNOCYTOCHEMICAL LOCALIZATION OF THE ALPHA-7 SUBUNIT OF THE NICOTINIC ACETYLCHOLINE-RECEPTOR IN THE RAT CENTRAL-NERVOUS-SYSTEM, Journal of comparative neurology, 349(3), 1994, pp. 325-342
Previous molecular cloning studies have revealed that alpha-bungarotox
in binding proteins present in the brain are members of the neuronal n
icotinic acetylcholine receptor gene family. The alpha 7 subunit is st
ructurally related to the agonist binding subunits present in the cent
ral and peripheral nervous systems and, when expressed in Xenopus oocy
tes, forms functional channels blockable by a-bungarotoxin. In the pre
sent study, three different monoclonal antibodies raised against the a
lpha 7 subunit were used to map its distribution throughout the centra
l nervous system of the rat. Immunohistochemical localization revealed
that the alpha 7 subunit is expressed in most regions of the brain, b
eing, overall, well correlated with previous ''in situ'' localization
of alpha 7 transcripts and alpha-bungarotoxin autoradiographic binding
studies. Particularly strong immunoreactivity was observed in several
sensory and motor nuclei of the brainstem as well as the red nucleus.
At the cellular level, alpha 7 immunostaining was usually found both
in somata and dendrites, whereas axonal and terminal labeling was not
observed. The widespread distribution of the alpha 7 subunit polypepti
de is consistent with immunoprecipitation data demonstrating that it i
s a component of the predominant subtype of brain alpha-bungarotoxin-s
ensitive nicotinic receptors. (C) 1994 Wiley-Liss, Inc.