File Name : 16-0221-suppmat - _spikes per div-final-17cm.eps Caption : supplemental fig. 1 statistical analyses for spike number and median interspike interval (isi) between devices and days in vitro (div). (a) comparisons for spike number for each challenge chemical over days in vitro for each device. (b) comparison of spike number for each chemical between devices. (c) comparison of median isi between div for each challenge chemical on each device. (d) median isi comparisons between devices for each chemical. n.s. = no significance, n.a. = not applicable.