Chronic pretrigeminal kitten.

In two kittens the brainstem was transected at the pretrigeminal level at the age of 11 days. The kittens were then observed for 79 and 51 days. As compared with control littermates, the weight of the transected brains was reduced by about 25 percent. As compared with the controls transected at the age of 2 or 3 months, as well as with previously described cats transected at adult age, the function of the caudal part of the kittens was much better. They showed some locomotion, drank and ate when the mouth was placed in contact with the milk or meat, rejected untasty food and showed satiation. On the other hand, the function of the isolated cerebrum was reduced as shown by only abortive ocular and EEG responses to visual stimuli. Thus, the pretrigeminal transection performed at an early period of life improves the development of the caudal part of preparation, but impairs that of the isolated cerebrum.