Figure 1.
Panels A and B illustrate elevation scores (the frequency of receptacle entries during the CS minus the frequency of receptacle entries during the Pre-CS period) over acquisition tests in the receptacles on left (A) and right (B) side of the chamber. Panels C and D illustrate duration scores (duration of entries during the CS minus duration of entries during the PreCS) for the same receptacles and sessions. During the first 10 sessions, both the CS and US were presented in the receptacle on the left side of the chamber and all rats learned to approach the CS, as illustrated by elevation (A) and duration (C) scores above 0. For sessions 11–15, the US was presented in the receptacle on the right side; while all rats learned to approach this receptacle during CS presentations (B, D), rats pretreated with nicotine (NIC group) made more approach responses in the CS receptacle (Left, A). *Indicates a significantly higher elevation score for NIC group relative to SAL group, p<0.01.