Criteria for differentiation of brown and white fat in the rat

Abstract

By using a modified method of Falck, the distribution of nerves containing catecholamines in brown and white fat was studied. The brown fat cells had sympathetic nerve fibers with synaptic varicosities running between all cells. White fat had no sympathetic innervation of the parenchymal cells. Both tissues contained a dense network of fibers around the arterial blood vessels.