Another useful approach for examining neural activity changes through adolescence is with in vivo electrophysiological recording from implanted electrode arrays in awake behaving animals. This technique enables one to record the activity of individual neurons as well as larger-scale field potentials. We recently carried out such a study, in which adolescent and adult rats performed a simple goal-directed behavior (Figure 1a) as recordings were taken from orbitofrontal cortex. While adolescents and adults performed the same behavior, striking age-related neural encoding differences were observed, especially to reward (Sturman and Moghaddam, 2011). This indicates that even when behavior may appear similar, the adolescent prefrontal cortex is in a different state than that of adults. Specifically, adolescent orbitofrontal cortex neurons became far more excited to the reward, while the proportion of adolescent inhibited neurons was substantially smaller at that time and at other points in the task (Figure 1b). As neural inhibition is critical for the controlling the precise timing of spikes and entraining synchronized oscillatory activity (Cardin et al., 2009; Fries et al., 2007; Sohal et al., 2009), reduced task-related adolescent orbitofrontal
