Figure 4.
Intrahippocampal METH self administration is modulated via local D1/D5 receptors. (A) Average lever presses on the active and inactive levers during the 30-min test sessions across 7 days. Rats in the Ringer's (n = 12) and METH 10 μg/μl (n = 17) groups were co-treated with 250 μM SCH 23390 during days 5–7 (black bars). METH group active lever presses were significantly greater than Ringer's group active lever presses. Local application of SCH 23390 impairs (black bars) impairs METH lever pressing behavior. (B) METH only induces lever-pressing in the hippocampus and not the cortex (CTX). All groups were co-treated with 100 μM SCH 23390 during days 5–7. Intrahippocampal METH group active lever presses were significantly greater than CTX METH and Ringer's vehicle groups from day 2 onward. The symbol * represents a difference from all other groups (P < 0.05).