The "hyperphagic syndrome" consists of a number of behavioral changes which normally occur along with the increased weight gain following VMH lesions in the rat. The present study explored the possibility of separating these behavioral changes from the increased weight gain. The behavioral dimensions sampled were activity, tendency to work for food and reactivity to diet adulteration. Three different methods were employed to produce the increased weight gain: electrolytic VMH lesions, cuts lateral to the VMH, and cuts anterior to the VMH. The results confirmed the decreased activity, decreased tendency to work for food, and increased reactivity to taste manipulation previously reported for VMH-lesioned animals. Cuts lateral to the VMH were indistinguishable from lesions on each of these measures. Cuts anterior to the VMH resulted in no change in normal activity level or in the tendency to work for food but did result in increased reactivity to taste manipulation. The results are consistent with the notion of a medial-lateral system controlling some facit of energy balance and of an anterior system underlying a sex dependent part of the weight gain in female rats. / Arts, Faculty of / Psychology, Department of / Graduate