Thermosensitivity of dorsal raphe neurons in vitro.

Thermosensitivity of raphe neurons was studied in tissue slices of rat brainstems (400-500 micron). Measurement of activity of single cells in the dorsal raphe region of the slices revealed that the majority of neurons (89%) were sensitive to changes in temperature. Over the range 34 to 42 degrees C, 3 classes of thermosensitive cells were found: warm (61%), cold (15%) and biphasic type cells (13%). Many dorsal raphe neurons may be intrinsically temperature sensitive and may serve as extrahypothalamic thermodetector components in the integrative process of central thermoregulation.