The effects of abused drugs on adolescent development of corticolimbic circuitry and behavior

Abstract

Adolescence is a period of significant neurobiological change that occurs as individuals transition from childhood to adulthood. Because the nervous system is in a relatively labile state during this stage of development, it may be especially sensitive to experience-induced plasticity. One such experience that is relatively common to adolescents is the exposure to drugs of abuse, particularly alcohol and psychostimulants. In this review, we highlight recent findings on the long-lasting effects of exposure to these drugs during adolescence in humans as well as in animal models. Whenever possible, our focus is on studies that use comparison groups of adolescent- and adult-exposed subjects as this is a more direct test of the hypothesis that adolescence represents a period of enhanced vulnerability to the effects of drug-induced plasticity. Lastly, we suggest areas of future investigation that are needed and methodological concerns that should be addressed.

Reinforcing Properties and Neurochemical Response of Ethanol within the Posterior Ventral Tegmental Area Are Enhanced in Adulthood by Periadolescent Ethanol Consumption

“…Similar patterns of growth and pruning are observed in the hippocampus, nucleus accumbens (Acb), amygdala, hypothalamus, ventral tegmental area (VTA), and further cortical regions (c.f., Giedd, 2004;Gulley and Juraska, 2013). It is the interaction between adolescent EtOH drinking and the neurologic flux of adolescence that is thought to produce the enduring deleterious consequences observed in adult alcoholics.…”

High frequency stimulation-induced plasticity in the prelimbic cortex of rats emerges during adolescent development and is associated with an increase in dopamine receptor function

“…Furthermore, the much delayed maturation of dopamine and GABA system revealed in the current study indicates a potential window of vulnerability (Cass et al, 2013;Thomases et al, 2014) in the late-adolescence when humans start to experiment with drugs that have high potential in disrupting the normal development of these neurotransmitter systerms (Gulley and Juraska, 2013). m e a n fE P S P s lo p e (% o f b a s e lin e ) # ** * P 3 5 -P 4 5 P 5 5 -P 6 5 P 6 5 -P 8 0 P 9 5 -P 1 3 5 P 4 5 -P 5 5 P 3 5 -P 4 5 P 4 5 -P 5 5 P 5 5 -P 6 5 P 6 5 -P 8 0 …”

Mechanisms of Action and Persistent Neuroplasticity by Drugs of Abuse

“…Effects of Adolescent Cocaine Exposure. Adolescents are more prone to develop cocaine addiction than adults; they administer cocaine more readily, are more sensitive to lower doses, show increased activation of VTA DA neurons, and show greater escalation of cocaine intake (reviewed in Gulley and Juraska, 2013). Indeed, a significant proportion of studies (specifically, the majority of ex vivo electrophysiology studies) discussed in this review were performed in adolescent animals, because the experiments are less tedious and the results more pronounced.…”