NEURONAL SUBPOPULATIONS IN AUTONOMIC GANGLIA ASSOCIATED WITH THE CHICKEN URETER - AN IMMUNOHISTOCHEMICAL STUDY

The neurochemical coding of neurones located in ganglia of the nerve t runk accompanying the chicken ureter was analysed and quantified using NADPH-diaphorase reactivity and immunohistochemistry against tyrosine hydroxylase (TH), nitric oxide synthase (NOS), calbindin (CAL), vasoa ctive intestinal polypeptide (VIP), neuropeptide Y (NPY), somatostatin (SOM), substance P (SP) and calcitonin gene-related peptide (CGRP) in untreated or colchicine-treated preparation. Almost all neurones were either positive for TH (38%) or for SOM (60%). Only 4% of the neurone s were both TH-and SOM-positive and 3% of the neurones exhibited neith er TH nor SOM immunoreactivity. The relative numbers of NPY-, NOS-, GA L-and VIP-positive neurones were 57%, 28%, 14% and 7%, respectively. N o SP-or CGRP-positive neurones were observed. All NADPH-diaphorase-pos itive neurones expressed NOS immunoreactivity. Only in some TH-positiv e neurones was NPY and/or NOS found. Four major subpopulations were fo und in the ureteric ganglia. The SOM-positive neurones were subdivided into SOM/NPY/NOS-(28% of all neurones), SOM/NPY-(18%) and SOM/CAL/NPY -positive neurones (14%). A subpopulation of these peptidergic neurone s also contained VIP. About 35% of the neurones contained TH only. Neu rones of all subpopulations (72% of the neurones), except most of the GAL-positive neurones, were encircled by dense plexus of varicose SP/C GRP-positive, presumably sensory nerve fibres. Dense plexus of VIP-pos itive fibres were observed around 89% of the neurones. The chemical co ding of the neuronal subpopulations identified in the ganglia accompan ying the chicken ureter resembled that observed in the ganglia of Rema k's nerve but was remarkably different from that of the autonomic neur ones described in mammalian species.