Figure 3.

Temperature-responsive raphé-projecting preoptic neurons. A, Representative chart record showing reduced activity of a warm-responsive raphé-projecting preoptic neuron in response to skin cooling, whereas the filtered EEG was unchanged. Traces (from top) show filtered frontal EEG (bandpass, 1–4 Hz), neuron firing rate (10 s counts), and skin and core (rectal) temperatures. B, Plot of the activity of that neuron versus skin temperature (2 cycles, average shown by thick line, sequence indicated by arrows). C, Chart record showing the excitatory response to skin cooling of a cold-responsive raphé-projecting preoptic neuron, whereas the EEG was unchanged. Traces are as in A. D shows the corresponding plot (three cooling cycles) of activity versus skin temperature (details as for B).