Although neuronal activity was not altered by the conditioned cues in the central or medial amygdala, there was a 60% increase in c-Fos positive neurons in the basolateral amygdala in the rats who smelled the odor associated with alcohol. Because the basolateral amygdala was only activated through the excitatory conditioned cue, the researchers hypothesized that activation of the basolateral amygdala enhanced alcohol-seeking behavior. Subsequent pharmacologic silencing of the basolateral amygdala did not affect baseline alcohol seeking or the inhibitory effect of the odor associated with the absence of alcohol, but it did prevent enhancement of alcohol seeking invoked by the odor associated with alcohol.
The researchers concluded that the basolateral amygdala may mediate the ability of conditioned cues to enhance drug-seeking behavior. This region of the brain could serve as a target for intervention to reduce drug craving and relapse, they concluded.