The priming effect is impaired in CBP+/− mice. (A) There are no significant differences in the input–output curves between WT and CBP+/− mice. (B) LTP induced by a single train of tetanus (1 × 100 Hz) is normal in CBP+/− mice. (C) A single injection of cocaine did not alter LTP either in WT or CBP+/− mice. (D) Seven days’ exposure of nicotine did not alter LTP either in WT or CBP+/− mice. (E) The pretreatment with nicotine (7-d) prior to cocaine produced a significant enhancement of LTP in the WT but not the CBP+/− mice. (Open circles) 7-d nicotine+cocaine in CBP+/− mice, (closed circles) 7-d nicotine+cocaine in WT mice. (F) A histogram comparing the effect of nicotine, cocaine, and nicotine plus cocaine on LTP in WT and CBP+/− mice. Top panel shows the representative field EPSPs in WT and CBP+/− mice. Calibration: 10 msec, 1 mV.
