Figure 5.

AMPH CPP increased other in vivo measures of excitatory synaptic drive. a, The amplitude of measured spontaneous EPSPs was increased by AMPH CPP. There was no difference in the amplitude of measured spontaneous EPSPs between neurons of the delayed-pairing and saline groups. Data are expressed as the mean ± SEM. b, To obtain a measure that is less biased by analysis procedures for identifying synaptic events, the fluctuation of the membrane potential was used as an additional index of the frequency and amplitude of spontaneous synaptic events. The SD of the mean membrane potential was increased in the AMPH CPP group (represented graphically as the distribution of the membrane potential). There was no difference between neurons in the delayed-pairing and saline control groups in the SD of the membrane potential. Data are expressed as the mean ± SEM. c, To further provide evidence for a synaptic change after AMPH CPP, the paired-pulse ratio of a stimulated synaptic input was measured. The paired-pulse ratio, in the presence of DNDS, was increased for the AMPH CPP rats, which is consistent with increased synaptic drive. There was no difference in the paired-pulse ratio between the delayed-pairing and saline groups. Data are expressed as the mean ± SEM. *p < 0.05 versus the delayed-pairing and saline groups.