Study: Adolescent Cannabinoid Exposure Doesn’t Harm, Often Improves Adult Working Memory
A new study published in the journal Frontiers in Behavioral Neuroscience, and published online by the U.S. National Institute of Health, has found that cannabinoid exposure as an adolescent doesn’t harm, and often improves working memory as an adult.
“Marijuana is a prevalent illicit substance used by adolescents, and several studies have indicated that adolescent use can lead to long-term cognitive deficits including problems with attention and memory”, begins the study’s abstract. “However, preclinical animal studies that observe cognitive deficits after cannabinoid exposure during adolescence utilize experimenter administration of doses of cannabinoids that may exceed what an organism would choose to take, suggesting that contingency and dose are critical factors that need to be addressed in translational models of consequences of cannabinoid exposure.”
Researchers “recently developed an adolescent cannabinoid self-administration paradigm in male rats, and found that prior adolescent self-administration of the cannabinoid receptor agonist WIN55,212-2 (WIN) [meant to mimic the effects of cannabinoids] resulted in improved working memory performance in adulthood.”
Given “known sex differences in both drug self-administration and learning and memory processes, it is possible that cannabinoid self-administration could have different cognitive consequences in females.” Therefore, this study “aimed to explore the effects of self-administered vs. experimenter-administered WIN in adolescent female rats on adult cognitive function.”
For the study; female rats were trained to self-administer WIN daily throughout adolescence. The acute effects of adolescent WIN self-administration on memory “were determined using a short-term spatial memory test 24 h after final SA session; and the long-term effects on cognitive performance were assessed during protracted abstinence in adulthood using a delayed-match-to-sample working memory task.”
In a separate experiment, females were given “daily intraperitoneal (IP) injections of a low or high dose of WIN, corresponding to self-administered and typical experimenter-administered doses, respectively, or its vehicle during adolescence and working memory was assessed under drug-free conditions in adulthood.”
While self-administration of WIN in adolescence had no significant effects on short-term spatial memory or adult working memory, “experimenter administration of WIN resulted in improved adult working memory performance that was more pronounced in the low dose group.”
Thus, “low-dose adolescent WIN exposure, whether self-administered or experimenter-administered, results in either improvements or no change in adult working memory performance in female rats, similar to previous results found in males.”
The full study, conducted by researchers at the University of Pittsburgh, can be found by clicking here.