Behavioral Inefficiency on a Risky Decision-Making Task in Adulthood after Adolescent Intermittent Ethanol Exposure in Rats

Kelsey M Miller,Nicole Schramm-Sapyta,Matthew Darlow,Shawn K Acheson,Mary-Louise Risher,H S Swartzwelder,Hannah G Sexton

doi:10.1038/s41598-017-04704-7

Abstract

Adolescence is a period of development in neural circuits that are critical for adult functioning. There is a relationship between alcohol exposure and risky decision-making, though the enduring effects of adolescent ethanol exposure on risky decision-making in adulthood have not been fully explored. Studies using positive reinforcement have shown that adolescent intermittent ethanol (AIE) exposure results in higher levels of risky decision-making in adulthood, but the effects of AIE on punishment-mediated decision-making have not been explored. Adolescent rats were exposed to AIE or saline vehicle across a 16-day period, and then allowed to mature into adulthood. They were then trained to lever press for food reward and were assessed for risky decision-making by pairing increased levels of food reward with the probability of footshock punishment. AIE did not alter punishment-mediated risky decision-making. However, it did result in a significant increase in the delay to lever pressing. This finding is consistent with previous reports, using other behavioral tasks, which show decreased behavioral efficiency in adulthood after AIE. These findings indicate that AIE increases behavioral inefficiency, but not punishment-mediated risk-taking, in adulthood. Thus they contribute to a more nuanced understanding of the long-term effects of AIE on adult behavior.

Highlights

Studies in animal models utilize adolescent intermittent ethanol (AIE) exposure to model the pattern and doses associated with binge drinking in human adolescents
The principle findings in this study are that the latency to lever pressing was significantly increased among AIE animals compared to controls, and that AIE did not produce a long term change in punishment-mediated risky decision making
The AIE effect on latency to lever pressing does not appear to be the result of gross motor impairment, as there was no difference in latency to initial nosepoke between AIE animals and controls

Summary

Introduction

Studies in animal models utilize adolescent intermittent ethanol (AIE) exposure to model the pattern and doses associated with binge drinking in human adolescents. Failure to complete the trial’s initial nosepoke or a lever press in the times allotted resulted in both house and trough lights being extinguished, levers retracted (if out), and the trial being terminated, triggering the start of the ITI.

Results

Conclusion