Chronic cocaine causes age-dependent increases in risky choice in both males and females.

Abstract

Individuals who use cocaine exhibit maladaptive decision-making, overweighting rewards, and underweighting potential risks. We previously showed that chronic cocaine self-administration in young adult male rats causes long-lasting increases in risk taking. The present study expanded upon these findings to determine whether effects of cocaine on risk taking depend on the route of cocaine administration and extend to females. To address the former question, rats in Experiment 1 were trained on the Risky Decision-making Task (RDT), received passively administered cocaine, and were retested in the RDT. Surprisingly, passive cocaine had no effect on risk taking. Experiment 2 determined whether cocaine self-administration increases risk taking in females in a manner comparable to males. Males and females were trained in the RDT, underwent cocaine self-administration, and were retested in the RDT. Unexpectedly, cocaine self-administration had no effect on risk taking in either sex. Because Experiments 1 and 2 involved cocaine exposure at a considerably older age than in previous work, Experiments 3 and 4 determined if cocaine effects on risk taking depend on the age of exposure. Rats began cocaine self-administration at postnatal (PN) day 77 (Experiment 3) or passive cocaine injections starting on PN day 63 (Experiment 4) and were tested in the RDT 3 weeks after cocaine cessation. In these experiments, cocaine increased risk taking in both sexes. These results reveal a limited time window during young adulthood of vulnerability to the effects of chronic cocaine on risk taking. (PsycInfo Database Record (c) 2022 APA, all rights reserved).