Brain Tissue Temperature: Activation-Induced Changes Determined with a New Multisensor Probe

Abstract

Because of its high oxidative metabolic rate, the brain is a significant heat producer. As with all mammalian tissue, the operating temperature range of the brain must be kept at a nearly constant level for normal function. Brain function is especially sensitive to increases in temperature (Cabanac, 1986). The temperature of the brain tissue is determined by the heat conduction properties of the tissue, the heat produced by metabolism, and the heat and heat-transfer capacity of the blood flowing through the tissue. It has always been thought that one of the functions of the cerebral circulation was to act as a cooler of the brain, and some mammalian species have a carotid rete system to maximize this cooling effect (Baker, 1979; Cabanac, 1986). While there is data on the larger animals such as dog, cat, and primate which indicate that significant cooling of the brain during physical excercise occurs (Baker, 1979; Hayward, 1966), there is only sparse information concerning the relationships of metabolism and blood flew in the CNS of smaller mammals such as rodents.