Alimentary behavior in cats following lesions of the ventromedial hypothalamus.

The problem of the role of various parts of the hypothalamus in the regulation of food intake in animals is still not clear in spite of numerous studies concerning this subject. It is generally accepted that lesions in the ventromedial nucleus of the hypothalamus (VMH) produce hyper-phagia leading to obesity However, the extent and localization of lesions in particular papers are far from being uniform. Some authors doubt the possibility of obtaining hyperphagia as a result of ventromedial hypothalamic lesions (Holmes and Fraser 1965, Rosen 1968). In some cases a slight increase in food intake was produced by these lesions but it failed to lead to obesity (Lewinska 1964, 1967). Less numerous are the papers concerned with stimulation of this region which give the opposite effect-inhibition of the food intake (Wyrwicka and Dobrzecka 1960). In recent years strong criticism was put forward to the VMH nucleus lesions technique arguing that anodal coagulation of the VMH nucleus causes an irritating effect upon the hunger center situated in the lateral hypothalamus (Reynolds 1963, 1965, Rabin and Smith 1968). On the other hand Hoebel's opinion (1965) is different because he did succed in obtaining hyperphagia by electrocauterization with radio-frequency current. To our konwledge there are few papers which clearly confirm the hyperphagic symptoms after injuries of entire VMH nucleus in cats. Such lesions are performed by Morgane and Kosman (1960) but according to their data the increase of food intake is not convincing.