Pontine micturition center in the dog

The function and location of the pontine micturition center was studied in ten decerebrate dogs by physiological experiments in which micturition induced by electrical stimulation of the pontine micturition center was compared with reflex micturition in response to bladder filling with physiological saline and by histological studies of the electrolytic lesions made at the stimulated areas. The micturition induced by electrical stimulation of the pontine micturition center showed the same pattern of detrusor contraction, simultaneous urethral relaxation and the elevation of the tail as reflex micturition in response to bladder filling. The peak contraction pressures in both micturitions showed no obvious differences. The electrolytic lesions were histologically identified at the locus coeruleus alpha in six out of 10 dogs, at the locus coeruleus in three and at the peri locus coeruleus alpha in one dog. The coordinated activities of bladder and urethra in the micturition induced by electrical stimulation of locus coeruleus or its subparts suggest that these areas perform an important role in the urine emptying function.