The medial prefrontal cortex and the amygdala were thought to have similar roles in extinction in juvenile and adult rats. We present findings to show that the two groups of age have distinctive mechanisms of plasticity following stress. The induction of LTP is differentially regulated by the activation of D1 receptors. There is some overlap in the engagement of the NMDA partial agonists. The profile response of the circuit responsible on the regulation of fear in adults and juveniles is different. Developmental differences in the response to stress in juvenile and adults. These differences are critical when pharmacologically treating juveniles with stress disorders.