The neural basis for thermoregulation and the link to obesityNov.11.2017
Speaker：Prof. SHEN Wei
The homeostatic control of body temperature is essential for survival in mammals and is known to be regulated by sophisticated neural circuits in the hypothalamus. However, the specific neural pathways and corresponding neural populations have not been fully elucidated. To identify these pathways, we used whole brain cFos mapping to identify thermo-sensory neurons and their genetic identity. We found induced cFos activity by a thermal challenge in hypothalamic subregions, including the preoptic area (POA) and the dorsomedial hypothalamic nucleus (DMH). We further found optogenetic activation of specific neurons in these regions by ChR2 can induce hyperthermia or hyperthermia, as well as increases or decreases of energy expenditure depending on exact stimulation sites. Accordingly, recording of neural activity in the nerve cell bodies and terminals by fiber photometry showed a specific heat or cold-induced activity. Conversely, genetic deletion of neurotransmitters in the cold activated center resulted in lowered metabolic rate and severe body weight gain. In aggregate, our data indicated that the POA and the DMH serves as a hub in the brain stem to transmit external temperature signals to downstream targets to control thermogenesis and energy expenditure.