Figure 5. Context-induced drug-seeking in rats self-administering nicotine with an olfactogustatory cue and different concentrations of CS₂.

The nicotine self-administration environment induced strong drug-seeking behavior in all nicotine groups. In rats that received 500 ppm CS₂ during self-administration, the inducing social environment induced a significantly greater amount of drug-seeking behavior compared to the neutral social environment. ***: p<0.001 compared to extinction; ++: p<0.01 compared to the active spouts; +++: p<0.001 compared to the active spouts; #: p<0.05 compared to NSE. NSE: the neutral social environment; ISE: the inducing social environment.