Figure 1

Diagram of the hippocampal slice and presynaptic zinc signals and field potentials obtained in the presence of DCG-IV. a. Hippocampal slice scheme representing different hippocampal areas, CA1, CA3 and dentate gyrus (DG), and the mossy fiber tract (mf). It also shows the location of the injection site (I) of the calcium indicator Fura-2, the stimulation electrode (S) and the recording electrode (R). The dark squared area represents the region from where the optical signals were detected. b. Presynaptic zinc signals evoked by single stimuli are significantly and reversibly reduced by the application of DCG-IV. Normalized amplitude of zinc signals from experiments with (closed circles) and without (open circles) the mGlu receptor agonist DCG-IV (left side), and sample zinc transients (n = 5), (right side). c. Normalized amplitude of the population spikes (left) and sample field potentials (right) from the same experiments. The sample traces A–C were recorded at the times indicated by the letters in the graphs. The bars represent the period of application of the solutions containing DCG-IV. The slices were stimulated at the control frequency (16 mHz). The points in the graphs represent the mean value ± S.E.M. All stimuli were delivered at baseline stimulus strength.