Figure 2.
The priming effect of nicotine on cocaine is unidirectional. (A) One-day nicotine exposure did not alter LTP. (Open circles) control, (closed circles) nicotine. (B) One-day nicotine exposure followed by cocaine injection produces a short-lasting enhancement of LTP. (Open squares) cocaine, (closed circles) nicotine + cocaine. (C) Cocaine injection followed by 1-d nicotine exposure (reverse sequence) did not produce any enhancement of LTP. (Open squares) control, (closed circles) nicotine + cocaine. (D) Seven-day cocaine followed by 1-d nicotine did not produce significant enhancement of LTP.
