Figure 10.

Effects of CNQX infusions on CR performance parallels depression of field potentials in periocular microzones. A and D summarize behavioral data from two different experiments. Each point represents the mean NMR amplitude and SE for a block of 10 consecutive CS presentations. A shows the effect of two 0.8 μl infusions, the first centered as close as possible to the target periocular microzone area and the second infusion centered in a control non-periocular microzone area 4.8 mm dorsally (dotted lines). The on-target infusion transiently and completely abolishes the behavior, whereas the control infusion has no significant effect on NMR amplitude. The raw NMRs for these infusions are illustrated in Figure 9. D shows the effect of smaller infusions of 0.2 μl in a different animal; the on-target infusion transiently reduces NMR amplitude significantly, whereas the control infusion made 3 mm dorsally has no effect (unmatched, one-tailed Wilcoxon's rank-sum test, *p < 0.05, **p < 0.01, ***p < 0.001.) B and E illustrate the averaged periocular-evoked LFPs within periocular microzones on which the on-target injections in A and D, respectively, were centered (calibration: 20 ms, 100 μV). Two pairs of low-intensity periocular stimuli were delivered 40 ms apart (arrowheads). Times at which the recordings were made are expressed relative to the time axes in A (for B) and D (for E). The preinfusion field potentials have discernible early mossy fiber (MF) and later climbing fiber (CF) components. Grouped data showing mean CR and evoked LFP amplitudes for all infusions, both on-target and control, are illustrated in C (larger infusions) and F (smaller infusions); all amplitudes are normalized relative to preinfusion values, and error bars represent SEM. Amplitudes before the infusion, at maximum behavioral effect within at most 20 min of the infusion (<20 min), and at 40–45 min after infusion (on-target infusions only) are presented. There is a statistically significant reduction in both CR and evoked LFP amplitudes within 20 min of on-target infusions relative to the preinfusion baseline, but no effect is seen after control infusions (one-sample t test, *p < 0.05; NS, not significant).