title: Immunohistochemical evaluation of cholinergic neurons in the rat superior olivary complex.
abstract: The cholinergic system in the rat superior olivary complex (SOC) was evaluated by immunohistochemistry for choline acetyltransferase (ChAT) and vesicular acetylcholine transporter (VAChT) and histochemistry for acetylcholinesterase (AChE). ChAT-positive somata were found mostly in the lateral superior olive (LSO) and ventral nucleus of the trapezoid body (VNTB). In the LSO, there were both rostral-caudal and medial-lateral gradients in concentration of ChAT-positive somata; the highest concentration was in the middle of the rostral-caudal extent and the most medial part. The estimated total number of ChAT-positive neurons in the LSO was similar to previous estimates of the total number of lateral olivocochlear neurons. Two groups of ChAT-positive somata were found in the VNTB: a dorsolateral group of larger, multipolar, and more darkly labeled neurons and a ventromedial group of smaller, oval, and more lightly labeled neurons, which was about 5 times as numerous. There was a caudal-to-rostral increase in number of neurons in each group. VAChT immunoreactivity, predominantly localized in puncta, was seen in LSO, VNTB, and LNTB, and, to a lesser extent, in other parts of the SOC. VAChT-positive somata were also found in the VNTB and medial LSO. This distribution pattern of VAChT was generally similar to that of ChAT. AChE labeling had a similar appearance to ChAT labeling in the VNTB but differed in the LSO, where AChE labeling was lighter and associated more with neuropil than with somata.
authors.affiliation: Department of Otolaryngology, Medical College of Ohio, Toledo 43699-0008, USA. WYAO@Gemini.MCO.EDU
authors.forename: W
authors.initials: W
authors.lastname: Yao
authors.forename: D A
authors.initials: DA
authors.lastname: Godfrey
mesh_terms: D000110:Acetylcholinesterase / Q000032:analysis*; D000818:Animals; D002352:Carrier Proteins / Q000032:analysis*; D002795:Choline O-Acetyltransferase / Q000032:analysis*; D002799:Cholinergic Fibers / Q000737:chemistry* / Q000201:enzymology; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D026901:Membrane Transport Proteins; D009474:Neurons / Q000737:chemistry* / Q000201:enzymology; D009847:Olivary Nucleus / Q000737:chemistry* / Q000201:enzymology; D010784:Photomicrography / Q000379:methods; D051381:Rats; D050494:Vesicular Acetylcholine Transport Proteins; D033921:Vesicular Transport Proteins
chemical_list: D002352:Carrier Proteins; D026901:Membrane Transport Proteins; C493461:Slc18a3 protein, rat; D050494:Vesicular Acetylcholine Transport Proteins; D033921:Vesicular Transport Proteins; D002795:Choline O-Acetyltransferase; D000110:Acetylcholinesterase