Spontaneous multiple unit activity from the preoptic nucleus and changes in blood pressure in the rainbow trout Salmo gairdneri under acute experimental conditions.
Multiple unit activity (MUA) from the preoptic nucleus (NPO) blood pressure and heart rate were recorded in 41 anaesthetized and curarized rainbow trout. Mayer waves were frequently observed in blood pressure recordings (83%). Rhythmic MUA from the NPO, recorded in 46% of the experimented trout, occurred preferentially during Mayer waves. The initiation of the period of MUA occurred during low pressure vasomotor tone and large vasomotor pulse pressure inhibited MUA. Sustained decrease in blood pressure induced proportional rise in MUA. These results suggest that cardiovascular inputs influence the electrical activity of neurosecretory cells within the NPO and so may modulate the neurohypophysial hormones secretion.
Le Mevel
J C
JC
Mabin
D
D
D000818:Animals; D001794:Blood Pressure; D004027:Diencephalon / Q000166:cytology; D004553:Electric Conductivity; D006339:Heart Rate; D011301:Preoptic Area / Q000502:physiology*; D013997:Time Factors; D014337:Trout