Figure 4.
Hippocampal slice methodology. (a) Schematic diagram of a hippocampal slice with a stimulating electrode (Stim) placed in the perforant path fibers (PP) of the dentate gyrus. A recording electrode (Rec) is also pictured in the granular cell layer (GC) of the dentate gyrus. Representative examples of paired pulse stimulus-evoked field EPSPs in the dentate gyrus. (arrows illustrate peak-to-peak measurement of the second population spike amplitude) before (control) and after (FENT) opiate application. (b) Dose-dependent potentiation of dentate gyrus field potential amplitudes by morphine and fentanyl in C57/B6 mice.