Preoptic EP3R neurons constitute a two-way switch for fever and torpor

Area of Science:

• Neuroscience
• Physiology
• Molecular Biology

Background:

• Torpor, a state of decreased body temperature and metabolism, is a survival strategy for many species facing food scarcity.
• Preoptic neurons regulate torpor, but a specific genetic marker for these neurons has been elusive.
• The median preoptic nucleus (MnPO) is implicated in thermoregulation.

Purpose of the Study:

• To identify a specific genetic marker for neurons involved in regulating torpor and fever.
• To investigate the role of identified neurons in controlling body temperature responses.
• To elucidate the mechanism behind prolonged thermoregulatory responses.

Main Methods:

• Utilized genetic markers to identify specific neuronal populations in the MnPO.
• Employed chemogenetics and optogenetics to manipulate neuronal activity.
• Measured intracellular cAMP and calcium levels to understand response mechanisms.

Main Results:

• Prostaglandin EP3 receptor (EP3R) expression marks a unique population of MnPO neurons essential for torpor and fever.
• Inhibition of MnPO-EP3R neurons induced persistent fever, while activation caused prolonged hypothermia.
• Prolonged responses are linked to sustained increases in intracellular cAMP and calcium.

Conclusions:

• MnPO-EP3R neurons serve as a critical two-way switch for hypothermic and hyperthermic responses.
• These neurons play a vital role in survival by enabling adaptable thermoregulation.
• The findings provide a molecular target for understanding and potentially manipulating thermoregulatory behaviors.