Central nervous system circuits that control body temperature

Abstract

Maintenance of mammalian core body temperature within a narrow range is a fundamental homeostatic process to optimize cellular and tissue function, and to improve survival in adverse thermal environments. Body temperature is maintained during a broad range of environmental and physiological challenges by central nervous system circuits that process thermal afferent inputs from the skin and the body core to control the activity of thermoeffectors. These include thermoregulatory behaviors, cutaneous vasomotion (vasoconstriction and, in humans, active vasodilation), thermogenesis (shivering and brown adipose tissue), evaporative heat loss (salivary spreading in rodents, and human sweating). This review provides an overview of the central nervous system circuits for thermoregulatory reflex regulation of thermoeffectors.

Keywords: Brown adipose tissue; Cutaneous vasomotion; Saliva secretion; Shivering; Sweating; Thermoregulation.

Figure 1.

Model for the neuroanatomical pathways and neurotransmitters conveying thermal afferent input from the periphery to the preoptic area. Dashed projections indicate pathways that have not been conclusively demonstrated to function as suggested or that may involve indirect multisynaptic connections. DH, dorsal horn; DRG, dorsal root ganglia; Dyn, dynorphin; GLU, glutamate; LPBd, dorsal lateral parabrachial nucleus; LPBel, external lateral lateral parabrachial nucleus; MnPO, median preoptic nucleus; MPA, medial preoptic area; TRPM8, transient receptor potential subfamily M member 8; TRPV1, transient receptor potential vanilloid 1; NTS, nucleus tractus solitarius; vLPO, ventral portion of the lateral preoptic area.

Figure 2.

Functional neuroanatomical model of the efferent thermoeffector pathways for thermogenesis, vasomotion, and evaporative heat loss. Dashed projections indicate pathways that are unknown and may involve multisynaptic connections. 5HT, 5-hydroxytryptamine (serotonin); α, alpha motor neuron; Ach, acetylcholine; BAT, brown adipose tissue; CAVD, cutaneous active vasodilation; CVC, cutaneous vasoconstriction; DMH, dorsomedial hypothalamus; γ, gamma motor neuron; GABA, gamma aminobutyric acid; GLU, glutamate; IML, intermediolateral cell column; LH, lateral hypothalamus; MnPO, median preoptic nucleus; MPA, medial preoptic area; NE, norepinephrine; NO, nitric oxide; PG, parasympathetic ganglion cell; RPa, raphe pallidus area; RVLM, rostral ventrolateral medulla; SG, sympathetic ganglion cell; SSN, superior salivatory nucleus; VH, ventral horn; VIP, vasoactive intestinal peptide; vLPO, ventral portion of the lateral preoptic area.