Projections from the ventrolateral periaqueductal gray to endocrine regulatory subdivisions of the paraventricular nucleus of the hypothalamus in the rat.
The ventrolateral periaqueductal gray (vlPAG) mediates quiescence, hyporeactivity, hypotension and bradycardia, a pattern of response evoked by injury or social defeat. These stimuli also evoke increased levels of vasopressin (VP) and adrenocorticotrophic hormone (ACTH). A key central nervous system (CNS) locus mediating endocrine changes is the paraventricular nucleus of the hypothalamus (PVH). We investigated the extent of vlPAG projections to PVH. Anterograde tracer injections into the vlPAG, revealed 'terminal' label in: (1) the medial, dorsal, anterior and lateral parvicellular divisions, and (2) lateral and medial posterior magnocellular divisions of the PVH. Deposits of the retrograde tracer Fast Blue, verified the projection to the PVH arising from the vlPAG.
Floyd
N S
NS
Department of Anatomy and Histology, University of Sydney, NSW, Australia.
Keay
K A
KA
Arias
C M
CM
Sawchenko
P E
PE
Bandler
R
R
D000818:Animals; D001522:Behavior, Animal; D006339:Heart Rate; D008297:Male; D009434:Neural Pathways; D010286:Paraventricular Hypothalamic Nucleus / Q000166:cytology* / Q000502:physiology; D010487:Periaqueductal Gray / Q000166:cytology*; D051381:Rats; D017207:Rats, Sprague-Dawley