Abstract
In preliminary experiments to investigate the influence of masking the eyes of E1-mice on the rate of non-convulsions (RNC), it was suggested that the quantity of light as well as visibility itself played a role in inducing convulsions. The following experiments were thus carried out: (a) Both TSC (the threshold of number of shakings required for induction of convulsions) and RNC increased remarkably on the 5th day after enucleation of bilateral eyeballs from E1-mice, but 15 days later recovery to control level was observed. Moreover, TSC and RNC at 2 p.m. increased considerably compared with the control, however, the increase was rarely observed at 10 a.m.. (b) 2 groups of E1-mice reared intact under radiation of light plus different time schedules were shaken at 10 a.m. and 2 p.m., respectively. Consequently, TSC after radiation for 5 hours was less than that after radiation for 1 hour. When observed 9 hr after radiation, TSC could not be differentiated from TSC at 5 hr after the radiation. (c) E1-mice were reared under continuous lighting, continuous darkness or a normal lighting situation, after which TSC and RNC were examined. From our observations, the intensity of light appears to play a role in inducing convulsions. (d) When mice were shaken immediately after lighting, RNC decreased in inverse proportion to increase in the quantity of light. TSC was not influenced by the luminosity itself. One hour after lighting, however, the influence of lighting had disappeared. The intensity, quantity or irradiation time would not, however, influence the induction of El-mice convulsions so much as the cognizance of light by the individual animals. Such a conception is derived from the “cognitive theory” in psychology.
