In ten rats, higher light power gave 0.35 to 0.43 ms earlier callosal P1 peaks under every allowed match of released condition labels

We tested if light power changes a response delay used to link callosal structure to function. Two released tables contain 261 accepted P1 detections and 119 reliable records from 13 rats. The reliable table omits power and pulse duration. We kept every match that agrees with animal, session, and latency multiplicities. The tables allow 1,119,744 joint label assignments. Ten rats have a power pair at fixed duration under every assignment. We averaged highest-minus-lowest power contrasts across durations, then across rats. The mean change lies between -0.430 and -0.347 ms. Each of the ten rat means is negative under every assignment. Conservative 95% animal bootstrap limits are -0.528 to -0.246 ms. A fixed 5 to 10 mW check gives -0.177 to -0.150 ms in seven always-comparable rats. If all P1 delay is treated as conduction time, fixed path length and g-ratio give an apparent diameter rise of 7.71% to 9.03%. No structural change was measured. The result cannot separate activation delay, fiber recruitment, and cortical responses. It applies to selected condition means from one study, not to all fibers or rats. We preserve the small source tables, exact label bounds, code, figures, and repeat instructions. A checked byte-range reader avoids downloading the 28.5 GB trial archive.

corpus callosum · structure and function · optogenetics · P1 latency · axon diameter · condition labels · partial identification · rat · data provenance