THE EFFECT OF LESIONS OF THE HIND‐ AND MID‐BRAIN ON MICTURITION IN THE CAT

Abstract

1. Destruction of a small part of the brain just ventral to the internal edge of the superior cerebellar peduncle from the level of the middle of the motor nucleus of the fifth nerve behind to the level of the anterior end of the hind brain in front is followed by a permanent inability to empty the urinary bladder if the lesion is bilateral, but not if it is unilateral. 2. Destruction of the mid‐brain from the ventral half of the side of the posterior end of the aqueduct outwards to just beyond the mesencephalic root of the fifth nerve is followed when the lesion is bilateral by a permanent loss of consciousness of wanting to micturate or defæcate, but does not impair the performance of either of these functions. 3. A lesion in the position of the last, but rather more extensive, produces frequency of micturition as well as the effects observed in 2. I am indebted to Professor J. P. Hill, F.R.S., for allowing the photographs in figs. 3 to 6 to be taken in the Anatomical Department of University College.