Co-localization of N-acetyl-aspartyl-glutamate in central cholinergic, noradrenergic, and serotonergic neurons.
An immunohistochemical technique for simultaneously visualizing two different antigens has been used to investigate the presence of the acidic dipeptide, N-acetyl-aspartyl-glutamate (NAAG), in cholinergic, noradrenergic-adrenergic, and serotonergic neurons within CNS. The brain slices were processed sequentially with purified antisera against NAAG and then monoclonal antibody against choline acetyltransferase (ChAT), a marker for cholinergic neurons, or antiserum against dopamine-beta-hydroxylase (DBH), a marker of noradrenergic-adrenergic neurons, or antiserum against serotonin (5HT). Both antigens were revealed by the peroxidase reaction but with different chromogens, which are easily distinguishable. An intense double staining of NAAG-like immunoreactivity (NAAG-LI) and ChAT was observed in the motoneurons of the spinal cord as well as in the several motor components of cranial nerve nuclei including facial, ambiguus, and trigeminal nuclei. A partial colocalization of NAAG-LI and ChAT was evident in the perikarya of the basal forebrain cholinergic system, whereas cholinergic neurons of the medial septum exhibited only sporadic staining for NAAG-LI. A complete coexistence of NAAG-LI and DBH was observed in the locus coeruleus. Most of the other noradrenergic and adrenergic cell groups of the medulla region exhibited substantial co-localization with the exception of the A2 cell group, which was virtually devoid of NAAG-LI. In the dorsal raphe, only a low percentage of serotonergic neurons stained for NAAG-LI. The co-existence of NAAG-LI and serotonin was more evident in the neurons of the median raphe, although the majority of cells failed to show double staining.(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D001921:Brain / Q000166:cytology* / Q000201:enzymology; D002795:Choline O-Acetyltransferase / Q000378:metabolism*; D004151:Dipeptides / Q000032:analysis*; D004299:Dopamine beta-Hydroxylase / Q000378:metabolism*; D006651:Histocytochemistry; D007150:Immunohistochemistry; D008297:Male; D009928:Organ Specificity; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000032:analysis*; D013116:Spinal Cord / Q000166:cytology
D004151:Dipeptides; C027172:isospaglumic acid; D012701:Serotonin; D004299:Dopamine beta-Hydroxylase; D002795:Choline O-Acetyltransferase