Concepedia

Abstract

Norepinephrine (NE) levels were determined in the hypothalamus, midbrain, and medulla oblongata of rats following exposure to cold of 1°C for 1, 15, and 30 days. In comparison to room temperature controls, hypothalamic levels were slightly increased following 15 and 30 days at 1°C, while levels in the medulla and midbrain were slightly increased only after 30 days of cold-exposure. These increases were unrelated to differences in body temperature, body weight and the water content of brain between cold-exposed and room temperature rats. It is suggested that the increases in brain NE derive from a basis similar to the increases in peripheral tissue catecholamines previously observed by others to follow prolonged cold exposure.