Figure 4. Temporal rules governing the interactions between of vM1 activation and vibrissa stimulation on the response of vS1 barrel cortex neurons.
(A) The peak of the peri-stimulus histograms (PSTH) recorded from individual vS1 neurons during paired vM1-vibrissa stimulation with different time lags between the vM1 optogenetic activation (20 ms laser pulse) and vibrissa stimulation (−100 ms up to +50 ms). The time lags were calculated by subtracting the onset time of vibrissa stimulation from the onset time of vM1 optogenetic activation. The data are presented for two different individual neurons during passive ramp and hold vibrissa deflection (left panel) and artificial whisking against sandpaper (right panel). (B) The response (mean ± SEM) of two different individual vS1 neurons to paired vM1-vibrissa stimulation applied with different inter-stimuli time lags between the optogenetic and vibrissa deflection. In the left panel, the vibrissa was stimulated with a ramp and hold vibrissa deflection, and in the right panel, the vibrissa was stimulated with artificial whisking against a P320 sand paper. (C) The average (mean ± SEM) response of all recorded vS1 neurons to isolated passive vibrissa stimulation (control) and paired vM1-vibrissa stimulation applied with different inter-stimuli time lags. For both B and C, the data are presented for passive ramp and hold vibrissa deflection (left panels) and artificial whisking against sandpaper (right panels). 238 neurons from six rats for vibrissa deflection experiments; 334 neurons from seven rats in the artificial whisking experiments; *p<0.05, ***p<0.001.