New Insights into Alcohol Addiction in Adolescents is Monthly Publication Highlights
Aug 25, 2014
A research article indicating that developmental differences in neuronal plasticity contribute to the vulnerability of the adolescent hippocampus to alcohol-induced dysfunction and potential susceptibility to addiction is the UK College of Pharmacy Research Publication Highlight for August 2014.
The article was published in Addiction Biology and is entitled, “Ectopic
hippocampal neurogenesis in adolescent rats following alcohol dependence.”
This research was conducted by Kimberly Nixon, Associate Professor and recipient of a Presidential Early Career Award for Scientists and Engineers (PECASE), in the UK College of Pharmacy. The first author on the publication is former Postdoctoral Fellow Justin A. McClain, who won the Enoch Gordis Research Recognition Award at the 2013 Research Society on Alcoholism meeting based on these discoveries. Pharmaceutical Sciences graduate student alumni, Stephanie A. Morris and S. Alex Marshall, are also co-authors on this manuscript.
More than 6 percent of adolescents drink alcohol excessively to the point of meeting the diagnostic criteria for an alcohol use disorder. Excessive alcohol intake in adolescence typical of alcohol use disorders results in impairments in hippocampal structure and function, including reduced hippocampal volume and impaired hippocampal functions such as learning and memory. Dr. Nixon has reported previously that adult neural stem cells and the formation of new neurons, known as neurogenesis, represent an important form of hippocampal plasticity. In rodents, ethanol intoxication dose-dependently interfered with cell proliferation and newborn neuron survival and neurogenesis was altered differentially in adolescent and adult brain.
In this publication highlight, Dr. Nixon and colleagues studied neurogenesis in adolescent male rats during abstinence following a 4-day binge model of alcohol dependence. They found that hippocampal neurogenesis was increased after ethanol dependence similarly in adolescent and adult rats. However, striking ectopic neurogenesis, that is, new neurons appeared in places they should not be, was found in severely withdrawing adolescent rats, an effect not seen in adult hippocampus. The presence of ectopic neuroblasts suggests potential defects in the functional incorporation of new neurons into the existing hippocampal circuitry for the subset of rats undergoing severe alcohol withdrawal. These results could have important implications for how an impairment in hippocampal integrity contributes to the development of alcohol addiction.
“The discovery of the striking pattern of ectopic neuroblasts in hippocampus of alcohol dependence adolescent rats may help to explain the susceptibility of adolescents to developing alcohol use disorders and may lead to new therapeutics aimed at promoting recovery of hippocampal function in adolescents, “ said Linda Dwoskin, Associate Dean for Research.