The effect of long standing hippocampal lesions on the crypt cell kinetics of isolated colon

Using a stathmokinetic technique, the crypt cell mitotic rate was determined in segments of rat colon isolated by colostomy, 6 months after bilateral hippocampal lesions. For the first time, it was found that the expected hypoproliferation in the isolated colonic segments was largely overridden by the hyperproliferative effects following bilateral hippocampal and neocortical lesions (the neocortical lesions being control lesions), with a resulting increased crypt cell mitotic rate in the isolated segments. It is suggested that the hippocampus can exert a suppressant effect to modulate the usual mechanism of crypt cell mitosis control, which depends largely on intraluminal influences, and may possibly prevent excessive mitotic proliferative response to intraluminal factors.