Figure 4

Effect of low Mg²⁺ concentration solution and AP5 on evoked excitation in the Sp5c. a Recording made during superfusion with control mock CSF. b Recording made during superfusion with low Mg²⁺ concentration (0.8 mM) solution. c Recording made during superfusion with low Mg²⁺ solution containing 30 μM AP5. d Peak amplitudes of evoked excitation in the Sp5c (indicated by arrows in the right panels of a–c) were measured during superfusion with control solution, with low Mg²⁺ solution and with low Mg²⁺ solution containing 30 μM AP5. e Fluorescence signal amplitudes at 165 ms after stimulation (indicated by arrows in the right panels of a–c) were measured during superfusion with control solution, with low Mg²⁺ solution, and with low Mg²⁺ solution containing 30 μM AP5. f Fluorescence signal amplitudes at 385 ms after stimulation (indicated by arrows in the right panels of a–c) were measured during superfusion with control solution, with low Mg²⁺ solution, and with low Mg²⁺ solution containing 30 μM AP5. In each graph, fluorescence signal amplitude is indicated as the percent amplitude of the control value during superfusion with control mock CSF. Data were obtained from six preparations and are presented as mean ± SD. Low Mg²⁺ solution induced significant increases in evoked excitation in the Sp5c, but this increase was antagonized by additional administration of 30 μM AP5. *P < 0.05; **P < 0.01; NS not significant.