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Local and commissural neuropeptide‐containing projections of the nucleus of the solitary tract to the dorsal vagal complex in the pigeon
Author(s) -
Berk Mitchell L.,
Smith Stacy E.
Publication year - 1994
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.903470305
Subject(s) - biology , galanin , bombesin , anatomy , neuropeptide , substance p , solitary tract , neurotensin , cholecystokinin , commissure , dorsal motor nucleus , nucleus , vagus nerve , endocrinology , neuroscience , receptor , biochemistry , stimulation
The neuropeptide content of neurons of the nucleus of the solitary tract (NTS), which have local and commissural projections to the dorsal motor nucleus of the vagus (DMNX) and to NTS, were demonstrated in the pigeon ( Columba livia ) by using a combined fluorescein‐bead retrograde‐transport‐immunofluorescence technique. The specific peptides studied were bombesin, cholecystokinin, enkephalin, galanin, neuropeptide Y, neurotensin, and substance P. Perikarya immunoreactive for bombesin were located in the Medial tier subnuclei of NTS and the caudal NTS. Most galanin‐ and substance P‐immunoreactive cells were found in subnucleus medialis ventralis. Cells immunoreactive for neuropeptide Y were found in the medial tier of NTS and in the lateral tier, especially in subnucleus lateralis dorsalis intermedius. The majority of enkephalin‐ and neurotensin‐immunoreactive cells were found centrally in subnuclei medialis dorsalis and medialis intermedius. Cells immunoreactive for cholecystokinin were located in subnuclei laterolis dorsalis pars anterior, medialis superficialis, and the caudal NTS. Based on the presence of retrogradely labeled cells, numerous neurons of the medial tier of NTS, but extremely few lateral tier NTS neurons, had projections to the ipsilateral and contralateral DMNX and NTS. The number of retrogradely labeled NTS cells was always greater ipsilateral than contralaterally. The percentages of peptide‐immunoreactive NTS cells that projected to the ipsilateral and contralateral DMNX were in the ranges of 29–61% and 10–48%, respectively. The percentages of peptide‐immunoreactive NTS cells that projected to the contralateral NTS ranged from 13 to 60%. Peptide‐immunoreactive NTS cells that have local and commissural projections to DMNX and NTS may act as interneurons in vagovagal reflex pathways and in the integration of visceral sensory and forebrain input to NTS and DMNX. © 1994 Wiley‐Liss, Inc.