FIGURE 4.

Responses of freely moving rats to a heat stimulus applied to one of the paws. (A) Averaged ERP (4 central electrodes on the rat head, 12 animals in the experimental group) in response to a heat stimulus to the right forepaw. Two negativity peaks are visible, one at about 149 ms latency after heat onset, the other at about 285 ms latency. (Modified from Peng et al., 2018; their Supplementary Figure 3). (B) EEG group response to a single heat stimulus averaged to display the gamma-band event-related synchronization (γ-ERS) for frequencies of 50–100 Hz. There are two intensity peaks of the gamma-waves, one at about 55 Hz with a 150 ms latency after heat onset, the other at about 65 Hz with a 280 ms latency. The latencies of these peaks in the gamma-band activity correspond closely to the ERP peaks shown in (A). [Modified from Peng et al. (2018); their Figure 2].