Midbrain periaqueductal gray projections to the dorsomedial medulla in the rabbit.
The present study sought to determine the existence of projections from the midbrain periaqueductal gray (PAG) to the nucleus of the solitary tract (NTS) and dorsal motor nucleus of the vagus nerve (DMN) in the rabbit. Fast Blue injections into the NTS/DMN complex revealed a population of retrogradely labeled cells within the ventrolateral PAG. Deposits of wheat germ agglutinin/horseradish peroxidase (WGA/HRP) into the ventrolateral PAG revealed terminal label within the dorsomedial, lateral, ventrolateral, intermediate, and commissural subnuclei of the NTS. Label was also observed within the DMN and a heavy concentration encapsulated this nucleus. These data suggest that the projection from the PAG to the NTS/DMN complex may represent a substrate by which the PAG may influence autonomic and cardiovascular regulation, particularly during emotional arousal.
Wilson
A
A
University of Vermont, Department of Psychology, Burlington 05405.
Kapp
B S
BS
D000578:Amidines; D000818:Animals; D001370:Axonal Transport; D005456:Fluorescent Dyes; D006735:Horseradish Peroxidase; D008526:Medulla Oblongata / Q000033:anatomy & histology* / Q000166:cytology; D010487:Periaqueductal Gray / Q000033:anatomy & histology* / Q000166:cytology; D011817:Rabbits / Q000033:anatomy & histology*; D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014909:Wheat Germ Agglutinins
D000578:Amidines; D005456:Fluorescent Dyes; D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014909:Wheat Germ Agglutinins; C031455:diamidino compound 253-50; D006735:Horseradish Peroxidase