Figure 8.

Rats readily choose cocaine but high responders prefer saccharin. The overall population of rat preferred cocaine over a sweet solution of saccharin (a). (b) Nevertheless, high responders (HR, n=11) progressively lost their interest for cocaine whereas low responders (LR, n=12) did not. (c) Sign- (ST, n=12) and goal-trackers (GT, n=10) exhibited similar and constant cocaine preference as well as (d) low (LA, n=12) and high anxious animals (HA, n=12). The dashed line at 50% of choice toward cocaine represents no preference between cocaine and saccharin.