Hypothalamic obesity following knife cuts that minimize arterial damage

Parasagittal knife cuts that separate the medial hypothalamus from the lateral hypothalamus produce obesity. It has been assumed that the obesity results from the cutting of axons. However, these cuts also appear to sever arteries. The present study demonstrates that the severing of arteries is not necessary for the production of obesity. Knife cuts were placed at an angle so as to separate the medial hypothalamus from the lateral hypothalamus with minimal damage to arteries. These rats overate and became obese just as rapidly as rats with parasagittal cuts.