Biology subjects

Kirstein, C. L.

Publications and source records attributed to Kirstein, C. L..

3 recordsLinked to original sources

bioRxiv2025

Novel reactivity phenotype mediates long-term consequences of cocaine exposure during adolescence and adulthood in male Sprague-Dawley rats.

Individual differences in novelty seeking behavior often predict locomotor responses to psychomotor stimulants, an effect that may have a lasting impact throughout adolescence. The present study examined the role of novel reactivity phenotype on locomotor responses to repeated cocaine exposure during adolescence and adulthood in male rats. Prior to drug exposure, reactivity to a novel object was measured and animals were separated into low responders (LR) and high responders (HR). Cocaine was administered daily (0 or 20 mg/kg, i.p.) for 12 consecutive days, and behavior recorded on days 1, 6, and 12. After 28 days without drug, rats were challenged with cocaine (20 mg/kg) and behavior was assessed. Novel reactivity phenotype had a dramatic role in adolescents acute responsiveness to cocaine. HR adolescents exhibited a robust increase in sensitivity to acute administration of 20 mg/kg cocaine. However, following repeated cocaine exposure, both LR and HR adults displayed a marked increase in cocaine-induced locomotor activity, whereas the change in behavioral responsiveness in LR and HR adolescents was not as dramatic. During the cocaine challenge trial, LR that were exposed to 20 mg/kg cocaine during adolescence showed the highest cocaine-induced responsiveness compared to their saline-exposed and adult-exposed counterparts. Overall, these data indicate that novel reactivity phenotype and age of initial cocaine exposure are intricately involved in the long-term behavioral effects of cocaine. Thus, novel reactivity phenotype may predispose cocaine-using adolescents to continue drug-seeking behavior and potential abuse. HighlightsO_LINovel reactivity is higher in adolescents compared to adults C_LIO_LIAdolescents show greater acute cocaine-induced activity compared to adults C_LIO_LIHigh responding adolescents show robust acute cocaine-induced activity C_LIO_LILow responding adolescents show lasting changes in cocaine activity in adulthood C_LI

neuroscience↗

bioRxiv2025

Developmental Differences in Novelty Reactivity in Adolescent and Adult Male and Female Rats

Adolescence is a time of high-risk behavior and increased exploration. This developmental period is marked by a greater probability of initiating drug use and is associated with an increased risk to develop addiction and dependency in adulthood. Human adolescents are predisposed toward an increased likelihood of risk taking behaviors, including drug use or initiation. The purpose of the study was to examine differences in developmental risk-taking behaviors. Adolescent and adult animals were exposed to a novel stimulus in a familiar environment to assess impulsive behaviors, novelty preference and exploratory behaviors. Adolescent animals had greater novelty-induced locomotor activity, greater novelty preference, and showed higher approach and exploratory behaviors compared to preadolescent and adult animals. These data support the notion that adolescents may be predisposed toward sensation seeking and consequently are more likely to engage in risk taking behaviors, such as drug use initiation.

neuroscience↗

bioRxiv2019

Social interaction with an alcohol-intoxicated or cocaine-injected peer selectively alters social behaviors and drinking in adolescent male and female rats.

BackgroundDrinking alcohol is facilitated by social interactions with peers, especially during adolescence. The importance of peer social influences during adolescence on alcohol and substance use have recently received more attention. We have shown that social interaction with an alcohol-intoxicated peer influences adolescent alcohol drinking differently in male and female rats using the demonstrator-observer paradigm. The present set of experiments analyzed the social interaction session to determine behaviors that influence alcohol drinking in adolescent male and female rats.\n\nMethodsSpecifically, in experiment one we determined which behaviors were altered during social interaction with an alcohol-intoxicated demonstrator and assessed changes in ethanol intake in adolescent observers. Experiment two examined changes in voluntary saccharin consumption to determine if social interaction with an alcohol-intoxicated demonstrator altered consumption of a palatable solution. In experiment three, we administered a low (5 mg/kg) or high (20 mg/kg) dose of cocaine to the demonstrator and assessed changes in the adolescent observers to determine if social interaction with a drugged peer altered social behaviors and voluntary ethanol intake.\n\nResultsWe showed that social interaction with an alcohol-intoxicated demonstrator (1) decreased social play and increased social investigation and social contact in adolescent male and female observers, (2) did not alter non-social behaviors, (3) did not alter saccharin consumption and (4) increased voluntary ethanol intake in adolescent female but not male observers. When the peer was injected with cocaine (1) social play was dose-dependently decreased, (2) there were no changes in other social or non-social behaviors, and (3) voluntary ethanol intake in adolescent male and female observers was unaffected.\n\nConclusionsThe present results are consistent and extend our previous work showing that social interaction with an alcohol-intoxicated peer selectively alters social behaviors and alcohol-drinking in adolescent rats. Females appear to be more sensitive to elevating effects of social interaction on voluntary ethanol consumption.

animal behavior and cognition↗