Fig. 3. Effects of varying L-glutamate (L-Glu) iontophoretic current magnitudes on electromotor neuron (EMN) intervals in the dorsal posterior (DP), precommand (PCN) and ventroposterior nuclei (VP). (A) One example from each nucleus in a single fish. EMN intervals are plotted against time. The timing of L-Glu iontophoresis is indicated by the horizontal bars beneath the plots, with the current magnitude increasing from –100 nA to –900 nA in steps of –200 nA. (B) Dose–response curves of the effects of varying current magnitude on median EMN intervals. Values shown are means ± S.E.M.