ON THE INHIBITORY EFFECT UPON THE GROWTH OF INFANT ANIMALS OR ON THE OBESITY IN ADULT CAT INDUCED BY BILATERAL DESTRUCTION OF THE AMYGDALOID NUCLEAR REGION

Abstract

Through bilateral destruction of the amygdaloid nuclear complex in infant and adult animals and through subsequent observations under careful feeding in sxne period of time, following results were obtained: 1) By bilateral amygdalectomy in infant animals, inhibition in the growth was induced in most cases. 2) Histological observations on the brain lesions of these cases reveal that the inhibitory effect upon the growth may be initiated seemingly by destruction of the medial amygdaloid complex such as nuclei B, D or T, or periamygdaloid cortex such as Pam2 and Pam3, or the anterior amygdaloid region, especially at the level of the nucleus of the lateral olfactory trac:. 3) The inhibitory effect upon the growth was exceedingly obvious in those cases, in which the amygdaloid regions or surrounding structures of these most effective parts of the amygdala were extensively damaged on both sides. 4) Somewhat accelerating effect upon the growth was found in some cases, however, no positive evidence could be gained by any means in this series of observation. 5) Unilateral arnygdalar or hypothalamic destruction cannot result in retardation of the growth, even in those highly convincing cases with tissie deterioration in the vicinity of the amygdala. 6) An example of remarkable obesity was found in an adult cat following bilateral destruction of the medial parts of the amygdala and a part of the entorhinal area. Histological alterations of the internal organs of this case were described and a functional relationship of the so-called feeding centre in the hypothalamus was discussed.