Fig. 1.

Acute administration of ARI reduced DA neuron activity in the VTA in MAM but not SAL rats in a manner distinct from D₂ receptor antagonist antipsychotic drugs [35]. a At 2 h following oral ARI administration of 3 mg/kg and 10 mg/kg, MAM rats displayed a reduced number of spontaneously active DA neurons in the VTA compared to MAM rats that received VEH administration, which was not observed in SAL rats. There were no significant differences in the firing rate (b, c) or percentage of spikes in bursts (d, e) between ARI and VEH administration in MAM or SAL rats. f An example trace of a DA neuron recorded before and 5 min after APO, which was administered i.p. following six tracks, 10 min prior to recording an additional six tracks. APO reduced the firing rate and bursting activity of the DA neuron. g APO administration did not significantly reduce DA neuron population activity in the VTA of ARI-treated MAM rats, although there was a trend toward reduced spontaneous activity and a leftward shift in the distribution of firing rate (h) and percent of spikes in bursts (i) in neurons recorded after APO compared to tracks recorded before APO. *p < 0.05