Cholinergic and GABAergic afferents to the olfactory bulb in the rat with special emphasis on the projection neurons in the nucleus of the horizontal limb of the diagonal band.

摘要: We have examined the location of cholinergic and GABAergic neurons that project to rat main olfactory bulb by combining choline acetyltransferase (ChAT) glutamic acid decarboxylase (GAD) immunohistochemistry with retrograde fluorescent tracing. Since many projection are located in subcortical basal forebrain structures, where delineation individual regions is difficult, particular care was taken localize respect such landmarks as ventral pallidum (identified on basis GAD immunoreactivity), diagonal band, medial bundle. In addition, sections tracers or immunofluorescence were counterstained for Nissl substance order correlate tracer immunopositive cytoarchitecture forebrain. The majority bulbopetal half nucleus horizontal limb band (HDB), whereas only a few its lateral half. A substantial number cells also found sublenticular substantia innominata. small neurons, finally, ventrolateral portion vertical band. At level crossing anterior commissure, approximately 17% HDB ChAT-positive. The noncholinergic mainly HDB. GAD-containing primarily caudal part HDB, especially part. About 30% GAD-positive. GAD-positive cells, furthermore, pallidum, amygdaloid area, deep cortex, tract, hypothalamic tuberomamillary nucleus. The topography compared other HDB. After multiple injections neocortex, retrogradely labeled concentrated most while projecting entorhinal cortices These results show can be divided into subpopulations based upon target well transmitter content. Furthermore, these correspond, at least considerable extent, areas defined cyto- fibroarchitectural grounds.