Trigeminal deafferentation and hunger in the pigeon (Columba livia).

Abstract

The location and distribution of the pigeon''s trigeminal nerve permitted deafferentation of the oral region without affecting motor functions. Although trigeminal deafferentation did not affect drinking, it reduced the efficiency of the consummatory response of eating and disrupted motivational processes underlying hunger and weight regulation. Although the 2 types of deficit may be experimentally dissociated, trigeminal deafferentation invariably affected both sensorimotor and motivational mechanisms. The deficits in food intake and weight regulation seen after trigeminal deafferentation in the pigeon resembled some components of the lateral hypothalamic syndrome in the rat. The results were related to recent studies of the contribution of peripheral and central oropharyngeal factors to the neural control of food intake in both rat and pigeon.