Effects of intrajugular hypertonic saline, vaginal distension and vulvar massage on activity of supraoptic neuroendocrine cells.
Activity of 40 single antidromically identified supraoptic neurons was recorded and evaluated in response to a combination of tactile, vulvar massage, vaginal distension, and slow intrajugular 1.2 M sodium chloride infusion in unanesthetized, randomly hydrated ewes. Estradiol-implanted Southdown ewes were prepared according to techniques described by Jennings et al. Only 4 spontaneous firing patterns were observed in the supraoptic nuclei. Analysis of evoked activity indicated that each stimulus evoked alterations in mean firing rates or increased numbers of short interspike intervals in some cells. The resultant activity of units to sequential vulvar massage and 1.2 M sodium chloride infusion suggests a possibility of separate mechanisms of release of oxytocin and vasopressin.
D000200:Action Potentials; D000818:Animals; D001127:Arginine Vasopressin / Q000378:metabolism; D001931:Brain Mapping; D005260:Female; D006982:Hypertonic Solutions; D010121:Oxytocin / Q000378:metabolism; D012756:Sheep; D012965:Sodium Chloride / Q000494:pharmacology*; D013495:Supraoptic Nucleus / Q000502:physiology*; D014621:Vagina / Q000294:innervation*; D014844:Vulva / Q000294:innervation*
D006982:Hypertonic Solutions; D001127:Arginine Vasopressin; D012965:Sodium Chloride; D010121:Oxytocin