Sacral spinal cord neurons responsive to bladder pelvic and perineal inputs in cats

In chloralose-anesthetized or decerebrate male cats, 70% of 73 sacral spina l cord neurons activated from the bladder branch of the pelvic nerve also r eceived excitatory inputs from urethra and/or perineal cutaneous nerves (se nsory pudendal in 55% and superficial perineal in 84% of neurons). Only 29% of these neurons were excited by the hindlimb skin and muscle nerves teste d. The pelvic nerve-responsive neurons received monosynaptic urethral/perin eal input in 25% of cases and required temporal summation of this input in 47% of cases. Of 211 neurons responding to superficial perineal nerve stimu lation, 101 were not excited by the other nerves tested. Neurons activated by superficial perineal nerve stimulation were found predominantly in S2. I t is likely that the superficial perineal nerve represents an important pat hway whereby perineal stimulation influences bladder function. (C) 1999 Els evier Science Ireland Ltd. All rights reserved.