Electrical properties of paraventricular neurosecretory neurons with and without recurrent inhibition.

Twelve out of 32 neurosecretory neurons in the paraventricular nucleus of rats showed a silent phase following subthreshold stimulation to the posterior pituitary gland. After suprathreshold stimulation, the duration of the silent phase was significantly longer than that of the remaining 20 neurons, which did not show the silent phase at subthreshold stimulation. The latency and threshold in the former neurons were significantly longer and higher than those of the latter neurons. These data indicate a relationship between the recurrent inhibitory system and other electrical properties in the paraventricular neurons.