A forebrain neural substrate for behavioral thermoregulation.

Thermoregulatory behavior is a basic motivated behavior for body temperature homeostasis. Despite its fundamental importance, a forebrain region or defined neural population required for this process has yet to be established. Here, we show that Vgat-expressing neurons in the lateral hypothalamus (LH neurons) are required for diverse thermoregulatory behaviors. The population activity of LH neurons is increased during thermoregulatory behavior and bidirectionally encodes thermal punishment and reward (P&R). Although this population also regulates feeding and caloric reward, inhibition of parabrachial inputs selectively impaired thermoregulatory behaviors and encoding of thermal stimulus by LH neurons. Furthermore, two-photon calcium imaging revealed a subpopulation of LH neurons bidirectionally encoding thermal P&R, which is engaged during thermoregulatory behavior, but is largely distinct from caloric reward-encoding LH neurons. Our data establish LH neurons as a required neural substrate for behavioral thermoregulation and point to the key role of the thermal P&R-encoding LH subpopulation in thermoregulatory behavior.