Graduation Year


Document Type




Degree Granting Department


Major Professor

Cheryl Kirstein, Ph.D

Committee Member

Cynthia Cimino, Ph.D

Committee Member

Toru Shimizu, Ph.D


Development, Adolescent, Dopamine, Novelty-seeking, Impulsivity, Neurochemistry, Nucleus accumbens


Adolescence is a time of high risk behavior and increased exploration. This developmental period is marked by a greater probability to initiate drug use and is associated with an increased risk to develop addiction and dependency in adulthood. Human adolescents are predisposed toward an increased likelihood of risk taking behaviors (Zuckerman M, 1986), including drug use or initiation. The purpose of this study was to examine differences in developmental risk taking behaviors and neurochemical responsivity to cocaine based on these behavioral characteristics. Adolescent and adult animals were exposed to a novel stimulus in a familiar environment to assess impulsivity, novelty preference and exploratory behaviors, subsequently, in vivo microdialysis was performed to assess dopaminergic responsivity to cocaine. Adolescent animals had greater novelty-induced locomotor activity, greater novelty preference, were more impulsive and showed higher exploratory behaviors compared to adult animals.

Furthermore, the results demonstrate neurochemical differences between adolescent and adult animals in novel environment exploratory behavior, novel object preference, novelty-induced impulsivity and novelty-induced exploration. These data support the notion that adolescents may be predisposed toward sensation seeking and consequently are more likely to engage in risk taking behaviors, such as drug use initiation.