Adult Neural Stem Cells Show Regional and Sex‐Dependent Responses to Chronic Poly‐Drug Administration

Abstract

Cocaine use disorder (CUD) and alcohol use disorder (AUD) are highly prevalent substance use disorders in the US. Cocaine and alcohol co‐abuse is the third most lethal substance combination and affects 12 million Americans annually. Interestingly, it has been reported that females experience greater euphoria when cocaine and alcohol are combined. Individual use of cocaine and alcohol cause neurodegeneration; however little is known about the combined effects of these substances on the neural stem cell (NSC) population. NSCs are a population of cells in the brain maintained throughout life that are characterized by their ability to self‐renew and give rise to new neurons and astrocytes. Efforts in drug addiction research primarily focus on preventing or stopping abuse, however little work is being done to reverse brain damage incurred by chronic drug abuse. Therefore, the NSC population represents a potential therapeutic target due to their regenerative capabilities. The aim of our study is to evaluate regional and sex differences of endogenous adult neural stem cells to chronic treatment with alcohol and/or cocaine. We sought to elucidate the response of adult endogenous NSCs to chronic alcohol and cocaine treatment using an inducible lineage tracing mouse model. Adult mice were randomly divided into 1 of 4 groups: control, cocaine, ethanol, or combination treatment. Daily i.p. injections of cocaine were administered and ethanol was provided in a complete nutrient liquid diet to appropriate groups. Brain tissue was analyzed for markers of NSC survival and differentiation in two distinct brain regions, the subventricular zone of lateral ventricle (SVZ), and subgranular zone of dentate gyrus (SGZ). The SGZ was also evaluated for changes in metabolic enzymes associated with ethanol and cocaine metabolism. We found that NSCs have a unique response to drug depending on the regional location and sex of the animal. Females had more robust decreases in neural stem cell (NSC) survival in the SVZ compared to males. SGZ neurogenesis was reduced drastically in the combination group. There were significant increases in metabolic enzyme expression in response to drug treatment, with notable differences between sexes. Overall, we show drastic changes to the NSC population following exposure to cocaine and ethanol, as well as alterations in metabolic enzyme expression.Support or Funding InformationJohn S. Dunn Foundation NIDA T32 Award (Grant# 5T32DA007287‐17 and 3T32DA007287‐18S1)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.