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