Effects of amygdaloid and olfactory tubercle stimulation on efferent activities of the vesical branch of the pelvic nerve and the urethral branch of the pudendal nerve in dogs.

Abstract

In 69 dogs with divided hypogastric nerves anesthetized with ketamine and chloralose the outflows of the pelvic vesical branch (PV) and pudendal urethral branch (PU) were recorded, and effects of amygdaloid and olfactory tubercle stimulation on them were studied. Stimulation (2-100 Hz, 3 ms, 0.2 mA) was applied to the amygdaloid body and olfactory tubercle. When the bladder contraction was induced by amygdaloid stimulation, the increased PV and decreased PU appeared after latencies of about 115 and 110 ms, respectively. When the bladder relaxation was, oppositely, elicited by stimulation, the decreased PV and enhanced PU occurred after latencies of 110 and 90 ms, respectively. The PV excitation was elicited by medial parts of the intermediate principal nucleus, medial parts of the medial principal nucleus, a part of cortical nucleus and of pericortical nucleus. Inhibition of PV was induced by lateral parts of the medial principal nucleus, medial nucleus, central nucleus and a part of the pericortical nucleus. Olfactory tubercle stimulation elicited PV excitation and PU inhibition with latencies of about 100 ms. The vesicopressor response from the tubercle was not abolished by section of the medial preoptic area, medial hypothalamus and periaqueductal gray, but was abolished by added section of the lateral preoptic area, lateral hypothalamus and lateral mesencephalic tegmentum. At the rostral pontine level, the response was abolished by partial section of the lateral part of the pontine reticular formation ipsilateral to the stimulation.