Varying Levels of Impulsivity in an ADHD Rodent Model Influences Behavioral Accuracy

March 28, 2021   /  

Name: Sydney Schultz
Major: Neuroscience
Minor: Biology
Advisor: Amy Jo Stavnezer

Attention Deficit Hyperactivity Disorder (ADHD) is a neuropsychiatric condition that typically arises in childhood, and is often characterized by varying intensities of traits such as impulsivity, attentiveness, and hyperactivity. While research has been done to examine the combined effects of these traits on a range of behaviors in both human and rodent models of ADHD, little research has been done only on the influence of impulsivity on these behaviors. Additionally, little research has been conducted examining the ways in which spaced training โ€“which is the process of practicing a task for short periods of time each day over a longer span of time โ€“would help to mitigate the effects of impulsive tendencies. The present study examined how the level of impulsivity observed in the SHR rodent model of ADHD would influence behavioral performance in the 5-CSRTT mechanism. Alongside examining the effect of impulsivity, whether or not the rodents were in the spaced training group was also analyzed to determine ifthe type of training received mitigated the influence of impulsive tendencies on the rodentsโ€™ behavior. It was found that impulsivity level had a significant effect on the percentage of correct responses obtained in a majority of the training levels, as well as that spaced training actively decreased the levels of impulsivity measured across all training phases. Future research areas could examine the relationship between sex differences and impulsivity, as well as utilizing additional behavioral tasks like the Morris Water Maze to test the potential of impulsive behaviors to carry over into other areas of learning and memory research.

Sydney will be online to field comments on April 16:
10am-noon pm EDT (Asia: late evening; PST 6am-8am, Africa/Europe: late afternoon)

30 thoughts on “Varying Levels of Impulsivity in an ADHD Rodent Model Influences Behavioral Accuracy”

  1. Thanks for sharing your work Sydney. If you hypothesized on your future direction of testing the animals in a different learning task, do you think the impact of having decreased impulsivity would improve their learning, or, more like human “cognitive training” do you think it only works in the same sort of task?

    1. Thank you for the question! When testing the animals in a different learning task, it is likely that there would be some effect of the decreased level of impulsivity on learning ability. While there may not be as large of an impact of lowered impulsivity on learning in a novel task (especially when compared to the familiar task), being less impulsive overall definitely can’t hurt the animals’ learning ability!

  2. Sydney, We are so proud of all of your hard work on your IS! It is so interesting how impulsivity can impact so many aspects of our behavior and responses. Awesome job!

  3. Sydney, this is so very impressive! I can’t wait to see how your future in science unfolds!!! Congratulations!!!!!!!!!!!!!!

  4. Wow, Syd!! I am so impressed. I need you help in redirecting my own impulsivity. ๐Ÿ˜ฌ I look forward to having you help me better understand your research in person which i hope we can do in Boise. Great job!

  5. Hi Sydney,
    Nice work! Could you please describe the effect of impulsivity you found? Just curious why you chose a the task you did over a something like a visual singleton countermanding/ stop signal task?

    Polly

    1. Thank you for your question! I ended up choosing to use the 5-Choice Serial Reaction Time Task (5-CSRTT) for the experiment because it most easily allows for measuring multiple facets of ADHD, including impulsivity, as well as that it was the primary/best experimental tool available for students that could be used to study what I wanted to examine. Additionally, I used this task because it provided an easier method for measuring the defining factors of impulsivity, which was the combined effect of the number of premature responses and the number of perseverating responses. The main effect of impulsivity that I found was that there was a significant relationship between lower levels of impulsivity and higher correct response accuracy. This was important because it confirmed that rats expressing more impulsivity had more difficulty with learning processes.

      1. Cool. How do you know it was due to impulsivity and not just a speed-accuracy trade off? Thanks for putting up with my questions!

        1. I don’t mind answering questions at all! When working with the rats, it can be difficult sometimes to fully understand all aspects of their behavior. However, for this experiment, as well as with many other studies examining ADHD symptoms in animals, a particular genetic strain of rats are used, specifically the Spontaneously Hypertensive Rats (SHRs). These rats are specifically bred to express ADHD neurochemistry and behavior, so for the sake of this experiment, it is useful to infer that the rats’ behaviors and the results found are primarily due to their innate impulsive tendencies.

  6. Impressive Sidney! And such an important area of study, especially for the well-being of kids in an increasingly difficult world.

    Thanks for what you are doing.

  7. Congratulations, Sydney! This looks like a fascinating study. I am so impressed. I’m going to miss seeing you in classes–please stay in touch.

  8. Hi Sydney! I worked on the basis for this project for my Independent Study last year and I am so happy to see what you have done with it! It is so interesting to me that impulsivity decreased over training levels and how it related to correct responses. Especially interesting is that spaced training decreased impulsivity levels! You write in your abstract that the Morris Water Maze could test for impulsivity (or lack thereof) that carries over after training. I was wondering how you decided to pick that test and why you think it would be the best one? Thank you for your work!

    1. Thank you so much, and I loved getting to continue what you worked on for your IS! I decided to pick the Morris Water Maze because after reading through your work where you examined the rats’ behavior in the Open Field Maze and in the Object Displacement, I wanted to see if there were any other behavioral testing mechanisms in which the effects of the ADHD behaviors could be examined. Also, I found a couple of interesting prior research studying the SHRs using the Morris Water Maze, and I thought it could be a neat way to expand upon the research!

      1. That’s so awesome! I think since the MWM is also more restrictive (swimming is a lot of work) than Object Displacement or Open Field, the SHRs may act less hyperactive and allow for a better examination of impulsivity. Just speculation though! I hope this test is utilized in the future!

  9. Congratulations, Sydney! It’s awesome to see how you overcame the challenge COVID and turned this remote project into something important, unique, and impressive! Wishing you all the best!

  10. Hi Sydney:
    This work is very cool in that you chose to explore a question that previous researchers have only danced around, re: impulsiveness and ADHD. I enjoyed reading about your experimental design and the fabric of your analytical method to do behavior testing. Thank you for sharing, and best wishes in your future endeavors!

  11. Fantastic project Syd!! This is an impressive thesis, and I am so happy to see you succeed. You’re going to do amazing things after Wooster!

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