title: Co-localization of vasoactive intestinal polypeptide, gamma-aminobutyric acid and choline acetyltransferase in neocortical interneurons of the adult rat.
abstract: Interneurons immunoreactive for vasoactive intestinal polypeptide (VIP) are integral elements of columnar organization patterns in the rat cerebral cortex. By application of the sensitive mirror technique, the co-localization of VIP with the classical inhibitory neurotransmitter gamma-aminobutyric acid (GABA) and the acetylcholine-synthesizing enzyme, choline acetyltransferase (ChAT), was investigated in neocortical neurons. Furthermore, the frequency of co-localization of ChAT with GABA was determined. In a sample of 118 VIP-immunoreactive neurons, mostly from the primary somatosensory cortex, it was demonstrated that virtually all of them reveal immunoreactivity for GABA and, therefore, are to be GABAergic. Moreover, 34% of mostly bipolar, VIP-positive neurons contained ChAT and are, thus, supposedly cholinergic as well. Co-localization of VIP and ChAT varied according to cortical laminae. Finally, 88% of a total of 60 ChAT-immunoreactive neurons were also immunostained for GABA. It is concluded that almost all VIP-immunoreactive neurons and most of the cholinergic neurons in rat neocortex represent partly overlapping subpopulations of inhibitory interneurons utilizing GABA.
authors.affiliation: C. & O. Vogt-Institute for Brain Research, Heinrich-Heine-University, Düsseldorf, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Bayraktar
authors.forename: J F
authors.initials: JF
authors.lastname: Staiger
authors.forename: L
authors.initials: L
authors.lastname: Acsady
authors.forename: C
authors.initials: C
authors.lastname: Cozzari
authors.forename: T F
authors.initials: TF
authors.lastname: Freund
authors.forename: K
authors.initials: K
authors.lastname: Zilles
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000166:cytology / Q000378:metabolism*; D002795:Choline O-Acetyltransferase / Q000378:metabolism*; D007150:Immunohistochemistry; D007395:Interneurons / Q000378:metabolism*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D014660:Vasoactive Intestinal Peptide; D005680:gamma-Aminobutyric Acid; D002795:Choline O-Acetyltransferase