Heat-induced neuronal injury: A review of cellular and animal models

The increasing incidence and lack of effective therapeutic approaches for heat-related illnesses have attracted much research attention. Hyperthermia occurs along a continuum of heat-related conditions, starting with heat stress, progressing to heat exhaustion, heat stroke and culminating in multiorgan dysfunction and death in some instances. Neuronal injury is a major concern to clinicians because of the permanent neurological sequelae in patients who survive heat illness. Despite extensive studies in this field, the mechanisms underlying heat-induced neuronal injuries remain unclear. Many experimental models using animals or cell cultures exposed to heating conditions have been employed to study heat-induced neuronal injury. The heating conditions vary with intensity, duration of exposure and application of anesthetics, leading to variations in stress responses. In this review we extend from clinical findings to animal and cell culture models in which neurons have been injured by heat exposure. We compare the advantages and disadvantages of these models and propose a possible mechanism for the pathogenesis of heat-induced neuronal injury.