A Model of Shivering Thermogenesis Based on the Neurophysiology of Thermoreception

Existing stimulus-response expressions predicting shivering thermogenesis are based on static peripheral, core, and central temperatures. These expressions predict a linear increase in metabolic heat production in response to displacements of either central or core and peripheral temperatures from set-point temperature values. A model of shivering thermogenesis has been developed incorporating the nonlinear static and dynamic characteristics of thermosensitive neural structures in the body. The parameters defining receptor activities, dynamics of response, regional summation, and thermoneutral set points are based on data published in the literature. Predictions of metabolic heat generation (in units of ml O2 ·kg-1 ·min-1) are derived by integrating excitatory and inhibitory thermogenic drives, resulting from thermoreceptor stimulation in various regions of the body. The relative gains of the thermogenic drives were determined by least-squares regression using empirical data from a series of cold water immersions. The present model demonstrated improved simulations of shivering thermogenesis during cooling and rewarming, when compared to existing stimulus-response predictive expressions.