Hypogastric nerve activity to the feline bladder during slow filling

Hypogastric efferent nerve activity was measured in cats anaesthetised with a continuous pentobarbitone infusion while the bladder was filled at a physiological rate. Pelvic efferent nerve recording was used to determine the end of the continence process. The point in the continence process at which non-micturating contractions commenced was usually the point at which sympathetic nerve activity began to increase. By the time the continence process was half over, sympathetic nerve activity had increased from the resting level by 21%. There is disagreement about the role of the sympathetic innervation in the process of urine storage. In the present study, there appears to be significant sympathetic drive to the bladder for much of the continence process.