Effects of Acute Exposure to Cannabis Smoke on Working Memory in Aged Rats

Alara Guvenli

Authors:  Alara Güvenli, Sabrina Zequeira, Matthew Bruner, Josue Fritz Deslauriers, Marcelo Febo, Jennifer Bizon, Barry Setlow.

Faculty Mentor: Barry Setlow

College:  College of Medicine


Cannabis is the most widely used illicit drug in the United States, and individuals over the age of 65 are the fastest growing demographic of cannabis users. With the number of older adults in the US expected to reach 90 million by 2050, it is imperative to understand the potential cognitive impacts of cannabis consumption in this population. Studies in animal models show that acute administration of delta-9-tetrahydrocannabinol (THC) can impair performance on cognitive tasks dependent upon the hippocampus and prefrontal cortex. The current study assessed the performance of male, fully mature young adult (6 months) and aged (24 months) Fischer 344 x Brown Norway F1 hybrid rats on a delayed response working memory task. The task required rats to remember the location of a visual stimulus over variable delay periods that ranged from 0-24 s. A semi-randomized, within-subjects experimental design was used such that each rat was exposed to smoke from 0, 1, 3, and 5 cannabis cigarettes immediately prior to working memory test sessions. Results indicated that rats with worse baseline performance showed improved task performance following acute exposure to cannabis smoke, suggesting that passive smoke exposure can enhance prefrontal cortex-dependent cognition.

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18 Responses
  1. Barry Setlow

    I just added some references to the message board for this project in basecamp. excited to see where this goes!

  2. Brandon Hellbusch

    Great job presenting your poster. You are confident and direct which is a hard skill. The poster looks great.

  3. Lindsay Altidor

    Solid presentation, proud of you!!! Never in a million years would I imagine your first presentation virtually, but here we are haha.
    Anyways, a few questions

    -Are there any other paths besides PFC that cannabis causes that could have implications of your results?
    -The smoke had a wide exposure, how would you propose testing it targets there?

    -Lindsay Altidor

  4. Madeline Olesky

    Hi Alara, I love your presentation! Were you surprised by any of the results you found?

  5. Alara Guvenli

    Thanks everyone!
    Lindsay to answer your questions –
    -Cannabis is a drug that has a multifaceted effect on the brain and thus on behavior. While our study focused primarily on PFC and HPC dependent tasks, other studies have looked into cannabis’ other effects. An example of an interesting study on this is ”Bruijnzeel -Behavioral Characterization of the Effects of
    Cannabis Smoke and Anandamide in Rats 2016”.
    -By choosing tasks that are known to be dependent on the PFC and HPC, we were able to look more closely at cannabis’ effects on these areas by comparing the rats’ baseline performances (no exposure to cannabis).
    Hi Maddie!
    -The result that surprised me the most was that the aged rats showed increased performance levels after cannabis exposure on the working memory task. Just from prior knowledge and literature I would have expected both groups to have decreased performance, so this is something that we definitely want to look further into with future studies.

  6. Emily Boykin

    Wow! I didn’t know your research focused on the topic of cannabis. I think it’s a super salient topic especially in my field with policy. Looking forward to seeing where this goes, as always

  7. Jada Lewis

    Nice job. Can you comment on the big picture importance of your work given the expansion of both medical and recreational marijuana?

  8. Alara Guvenli

    Thanks again for comments everyone!
    Jada, as the use of medicinal and recreational marijuana use increase, every demographic is going to be quite interested in its effects that are relevant to them specifically. With the eldery population being the current fastet growing demographic in the US for cannabis use, I feel that our research is especially timely. As Emily mentioned, this research is also important to public policy work, so it is quite possible that our research will go further than informing users and even be used for decisions at the political level. While I can’t say that for sure, it is quite interesting to see the overlap in scientific research and political research!