イヌの骨盤神経膀胱枝, 陰部神経尿道枝の遠心性活動に対する扁桃体刺激の効果

Abstract

Experiments were performed to elucidate the effects of amygdaloid stimulation on the urinary bladder and external sphincter in 38 dogs anesthetized with ketamine and alpha-chloralose and immobilized with gallamine. The hypogastric nerves were severed in all dogs. The bladder was filled with Tyrode's solution under intravesical pressure maintained within a range of 15-20 cmH2O. The outflows of the pelvic vesical branch (PV) and pudendal urethral branch (PU) were recorded simultaneously with isotonic vesical contractions. Stimulation was applied through a unipolar platinum electrode (50 microns, in diameter) inserted into the amygdala from the ventral surface of the exposed pyriform lobe. When bladder contraction was elicited by amygdaloid stimulation, PV excitation and PU inhibition occurred simultaneously, but when the bladder was relaxed, PV inhibition and PU excitation appeared concomitantly. The PV excitation (bladder contraction) was elicited from medial parts of the intermediate and medial principal nuclei and parts of the cortical and pericortical nuclei. Inhibition of PV (bladder relaxation) was induced from the medial nucleus, the central nucleus, lateral parts of the medial principal nucleus and parts of the pericortical nucleus. Electrical stimulation was applied to the excitatory points at varied frequencies (2-100 Hz). PV excitation and bladder contraction were produced at 10, 20 and 50 Hz, but not at 2 Hz. At 5 and 100 Hz, the effects varied with the stimulating points. At the inhibitory points, PV inhibition and bladder relaxation were elicited at 10, 20 and 50 Hz, but not at 2 Hz. (ABSTRACT TRUNCATED AT 250 WORDS)