Asynchronous light-conditioning during CP impairs OD plasticity and binocular input coincidence. A, Experimental paradigm. Thy1-ChR2 mice were conditioned with blue LED light stimuli at P22–P25, followed by MD at P26–P29. The mice were conditioned for 12 h per day in a dark environment. The light stimuli consisted of trains of five light pulses (5 ms) at 2.5 Hz, with intertrain intervals of 5 s. For the asynchronous conditioning, light pulses to contralateral eye preceded that of the ipsilateral eye by 50 ms (Asyn50), while in the synchronous conditioning, light pulses were simultaneously applied to the two eyes (Syn). B, C, Seven-point histograms and the cumulative percentage distribution (right) of ODI of recorded V1 neurons from Asyn50 (B) or Syn (C) light-conditioned mice (blue), and from mice with succeeding 4 d MD (red). p values are 0.95 and p < 10−7 for B and C, respectively (Kolmogorov–Smirnov test). D, CBI values of the mice treated with the Asyn50 conditioning (AsynNR) or with succeeding MD (AsynMD), and Syn conditioning (SynNR) or with succeeding MD (SynMD). Each circle represents the CBI value calculated from seven-point histograms of ODI of cells in each mouse, and thick horizontal lines represent the mean CBI for total cells in each group. p values were calculated by the t test. E, Summary of the onset latency of contralateral and ipsilateral PSPs evoked by full-field static gratings in Thy1-ChR2 mice before conditioning (P21) and right after the 4 d Asyn50 or Syn conditioning (P26). Data connected with a line are from the same cell. Solid circles with error bars: mean ± SD.
