Lesions of Cholinergic Pedunculopontine Tegmental Nucleus Neurons Fail to Affect Cocaine or Heroin Self-Administration or Conditioned Place Preference in Rats
Figure 4
Intravenous self-administration of heroin is not altered by bilateral pedunculopontine tegmental nucleus (PPTg) cholinergic cell loss.
Bilateral PPTg cholinergic cell lesions (solid circles; n = 4) did not significantly affect heroin self-administration relative to sham lesions (open squares; n = 4), either in terms of the number of heroin infusions in daily sessions (top) or the number of active lever presses to attain those infusions (bottom panel). All rats showed a slight increase in heroin intake across the post-lesion testing period. The ability to distinguish between the retractable heroin and stationary levers was not compromised by PPTg cholinergic cell loss. Error bars represent ± SEM.