Figure 4.

The expression of meth-induced CPP was inhibited by fendiline only in rats with a treatment history of 10 fendiline injections, or two injections corresponding to the last two treatments of the 10 day treatment protocol (Timeline in Fig. 1B, Experiment 3). All “re-conditioned” rats demonstrated preference for the meth-paired chamber during CPP Test 3. In contrast, fendiline given immediately prior to CPP Test 4, had a treatment history-dependent effect on the preference expression during this test. (A) Rats with a treatment history of 10 fendiline vehicle injections expressed CPP following the vehicle challenge (CPP Test 4). (C) CPP was also retained when the fendiline challenge was given to rats with a treatment history of two fendiline injections during the first two treatment protocol days (Early Fendiline History). (B & D) Fendiline challenge immediately prior to CPP Test 4 blocked preference in rats with a treatment history of 10 once daily fendiline injections (B) or two fendiline injections on the last two days of the 10 day protocol (D). Newman Keuls test; ** p<0.01. Filled diamond, time spent in meth-paired chamber; open square, time spent in saline-paired chamber; filled triangle, time spent in center chamber.