Kittens were decerebrated within 1 wk after birth and the subsequent development of functional capacity of these mesencephalic animals was observed for up to 2 mo. The only detectable immediate deficit was that sucking behavior was abolished. Ingestion of solid foods and lapping of milk, however, developed at weaning age. These were reflex in nature and and required contact of the lips with the food. Development of temperature regulation was impaired only slightly. Auditory reflexes, placing reactions, defense reactions, and many other types of behavior except visual recognition and socialization developed in nearly normal chronological order. In most animals some aspects of behavior were exaggerated. Hyperkinesis, hypermetria, compulsive climbing, and exaggerated prey behavior were frequently observed. The findings suggest that many aspects of behavior and regulatory processes generally thought to be organized primarily in the prosencephalon originate instead in the mesencephalon and more caudal structures and, during ontogeny, become increasingly dependent upon subsequently developing descending synaptic inputs.
ASJC Scopus subject areas
- Developmental Neuroscience