Facilitatory effect of antidromic stimulation on milk ejection-related activation of oxytocin neurons during suckling in the rat.
Oxytocin neurons of the paraventricular nucleus were identified by their antidromic response to stimulation of the neurohypophysis and a short high-frequency burst of spikes displayed before reflex milk ejection in the urethane-anesthetized lactating rat. During suckling, the milk ejection-related bursts recurred at regular intervals. Stimulation of the neurohypophysis at 50-300 pulses/s for 0.5-6 s (current 1 mA) evoked additional burst(s) with the amplitude higher than those of spontaneously occurring ones. Stimulation with subthreshold current for antidromic response or constant-collision test could also facilitate the neurosecretory bursts. Possibly, oxytocin released within the magnocellular nuclei is responsible for these effects.
D000818:Animals; D005071:Evoked Potentials; D005260:Female; D007774:Lactation; D008893:Milk Ejection; D010121:Oxytocin / Q000502:physiology*; D010286:Paraventricular Hypothalamic Nucleus / Q000502:physiology*; D010904:Pituitary Gland, Posterior / Q000502:physiology*; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains; D011930:Reaction Time / Q000502:physiology
D010121:Oxytocin