Prenatal Heavy Cannabis Exposure May Diminish Cognitive Functioning Into Adulthood

MedicalResearch.com Interview with:

Ryan J. McLaughlin, PhD Assistant Professor Department of Integrative Physiology & Neuroscience College of Veterinary Medicine Washington State University Pullman, WA 99164-7620

Dr. McLaughlin

Ryan J. McLaughlin, PhD
Assistant Professor
Department of Integrative Physiology & Neuroscience
College of Veterinary Medicine
Washington State University
Pullman, WA 99164-7620

MedicalResearch.com: What is the background for this study? What are the main findings? 

Response: The use of cannabis during pregnancy is a growing health concern, yet the long-term cognitive ramifications for developing offspring remain largely unknown. Human studies exploring the long-term effects of maternal cannabis use have been sparse for several reasons, including the length and cost of such studies, as well as the fact that experimentally assigning mothers to smoke cannabis during pregnancy is obviously ethically impractical. Animal models of maternal cannabis use have been advantageous in this respect, but they have been limited by the drugs used (synthetic cannabinoids vs. THC vs. cannabis plant) and the way that they are administered. In our study, we used a more translationally relevant animal model of maternal cannabis use that exposes pregnant rat dams to whole plant cannabis extracts using the intra-pulmonary route of administration that is most common to human users. Our preliminary data indicate that twice-daily exposure to a high-dose cannabis extract during pregnancy may produce deficits in cognitive flexibility in adult rat offspring. Importantly, these rats did not experience general learning deficits, as they performed comparably to non-exposed offspring when required to follow a cue in their environment that dictate reinforcer delivery. Instead, deficits were observed only when rats were required to disregard this previous cue-based strategy and adopt a new egocentric spatial strategy in order to continue receiving the sugar reinforcers.

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