The development of penile reflexes (erections, cups, and flips) in intact and spinally transected male rats was investigated. Spinal transection on Day 25 advanced the ages of onset of penile erections and flips approximately 10 days relative to control males. There were no differences in the ages of onset of penile cups and preputial separation between transected and control males. In addition to advancing the onset of penile reflexes, spinal transection reduced the latency to first reflex and increased the number of erections and flips. The developmental onset of penile reflexes in intact male rats can not be attributed only to the age at which the spinal mechanisms underlying the reflexes mature, but rather to an age-related reduction in supraspinal inhibition.
Bibliographical noteFunding Information:
We thank Jeffrey Crowell for his invaluable assistance in behav~ total testing. This research was supported by U. S. Public Heallh Service Grant HD-08933 awarded to Benjamin D Sachs,
- Penile reflexes
- Spinal transection