Pituitary stalk section transiently impairs the acquisition of shuttle box avoidance behavior

Three days after stalk section, rats displayed a marked deficit in acquiring a shuttle box avoidance response. The performance of stalk sectioned rats was similar to that of 3-day hypophysectomized rats. At eighteen days after stalk section acquisition of the avoidance response was, however, not different from that of sham-operated controls. Stalk sectioned rats that showed poor performance at three days and that were tested again at eighteen days displayed similar avoidance behavior at eighteen days as their sham-operated controls. The results suggest that pituitary stalk section impairs performance of an active avoidance response. The transient nature of this effect may be due to disruption and subsequent regeneration of vascular contact between pituitary and brain.