Laser (A) and tone-induced (B) responses in each session. The magnitude of neuronal discharge was assessed by Z-scores. The laser-induced response was presented as a time course post laser stimulus and averaged every 1 sec. The tone-elicited response was calculated 0 – 1 s following the onset of the tone. *, # p < 0.05 indicate significantly different from Session 1 and Session 3, respectively.