Neurochemically distinct myenteric neurone populations containing calbindin have specific distribution patterns around the circumference of the gastric corpus.
We recently described calbindin immunoreactivity in the myenteric plexus of the guinea-pig stomach. To study the neurochemical coding of calbindin D28 k (CALB)-containing myenteric neurones, the presence of calretinin (CALRET), choline acetyltransferase (ChAT), enkephalin (ENK), neuropeptide Y, serotonin (5-HT), somatostatin (SOM) and substance P(SP) was investigated immunohistochemically in colchicine-treated preparations. Nitric oxide synthase-containing neurones were detected by NADPH-diaphorase histochemistry. In addition, we investigated the neurone distribution patterns around the gastric corpus. Most CALB neurones were ChAT positive. ChAT/CALB neurones were either CALRET (ca 75%) or 5-HT positive and most contained in addition SP and/or ENK. All 5-HT neurones contained CALB. CALB labelled on average 2.3, 4.8 and 7.5 neurones per ganglion at the lesser curvature, in the central region and the greater curvature, respectively, which indicated a preferential localisation at the greater curvature. Compared to the total number of myenteric neurones, the proportion of CALB neurones increased significantly from the lesser curvature (6%) towards the greater curvature (18%). This shift, although observed for most ChAT/CALB-positive populations, was most prominent for the ChAT/CALB/CALRET/SP/ENK-encoded neurones. SOM-positive and ChAT-only encoded neurones were preferentially located at the lesser curvature. The remaining ten neurochemically defined populations did not exhibit an uneven distribution. The colocalisation of CALB with CALRET or 5-HT is specific for myenteric neurones in the stomach and represents one significant difference to the neurochemical code of CALB neurones in the guinea-pig intestine. The functional significance of the unevenness of neurone distribution along the circumference of the gastric corpus remains to be studied.
Reiche
D
D
Department of Physiology, School of Veterinary Medicine, Bischofsholer Damm 15, 30173 Hannover, Germany.
Huber
K
K
Hoppe
S
S
Schemann
M
M
D000818:Animals; D015153:Blotting, Western; D064032:Calbindin 2; D064026:Calbindins; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D004745:Enkephalins / Q000378:metabolism; D017615:Enteric Nervous System / Q000737:chemistry* / Q000166:cytology; D005260:Female; D006168:Guinea Pigs; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D009197:Myenteric Plexus / Q000737:chemistry* / Q000166:cytology / Q000378:metabolism; D009448:Neurochemistry / Q000379:methods; D009474:Neurons / Q000737:chemistry; D009478:Neuropeptide Y / Q000378:metabolism; D018377:Neurotransmitter Agents / Q000378:metabolism*; D064030:S100 Calcium Binding Protein G / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism; D013004:Somatostatin / Q000378:metabolism; D013270:Stomach / Q000294:innervation*; D013373:Substance P / Q000378:metabolism; D014018:Tissue Distribution
D064032:Calbindin 2; D064026:Calbindins; D004745:Enkephalins; D009478:Neuropeptide Y; D018377:Neurotransmitter Agents; D064030:S100 Calcium Binding Protein G; D012701:Serotonin; D013373:Substance P; D013004:Somatostatin; D002795:Choline O-Acetyltransferase