Habituation to novel food and eating environment differs in early and mid-adolescence

Novel foods and feeding environments suppress feeding behavior in adults. The aim of the current study was to determine if adolescents respond to food and context novelty similarly to adults. In three experiments, male and female adults and early (P33) and middle (P42) stage adolescents were tested for consumption of a novel compared to familiar food in a novel or familiar environment across eight habituation sessions. The novel food was palatable due to high-sucrose context, in order to facilitate habituation. Habituation sessions occurred on separate days, and rats were food deprived prior to each session. Both groups of adolescents, like adults, suppressed consumption of the novel food during first exposure. All rats increased consumption of the novel food across sessions, indicating habituation to the novel taste. Adults and P42 adolescents in the novel context condition ate less food overall compared to their counterparts of the same age in the familiar environment condition, indicating that both ages suppressed feeding behavior due to context unfamiliarity. For rats tested during early adolescence, the reduction of overall consumption in the novel environment did not occur until the eighth session. Adult and P42 females in the familiar context condition developed preference for the novel food faster than males and consumed more of it compare to familiar food during third exposure. Adult females tested in the novel context also developed preference for the novel food, while adult males did not. There were no systematic differences in preference for the novel food between P33 males and females. These results indicate that responses to novelty differ across adolescence. During early adolescence rats showed mature responses to novel taste but not to novel feeding environment, while by mid-adolescence rats showed mature responses to both.