Figure 2.

Role of local D₁/D₅ receptors in the acquisition and expression of intrahippocampal METH CPP. (A) The effects of intrahippocampal METH μg/μl (n = 6) or Ringer's (n = 5) on CPP Test 1 and the effects of local SCH 23390 on CPP acquisition (Test 1) and CPP expression (Test 2) of intrahippocampal METH CPP (n = 6) or Ringer's vehicle (n = 6). (B) METH only induces CPP in the hippocampus and not the cortex (CTX). The effects of intracranial METH (hippocampus n = 13 or CTX n = 10) or Ringer's (hippocampus n = 11 or CTX n = 10) on CPP and local SCH 23390 on CPP acquisition (Test 1) and expression (Test 2) of intrahippocampal METH CPP. The symbol * represents a difference from all other groups (P < 0.05). (C) Local hippocampal D₁/D₅ antagonism does not affect locomotor activity. White bar represents crosses during pre conditioning test. The gray bar is activity during the first drug-free test while the black bar is activity in the presence of the D₁/D₅ antagonist (100 μM).