Electrophysiological Techniques to Study Activity in Rat Hippocampus
Publication Date
July 2019
Location
LSU Health Medical Education Building
Document Type
Abstract
Start Date
26-7-2019 9:00 AM
End Date
26-7-2019 12:00 PM
Description
Electrophysiological techniques are adept at investigating neuroanatomical functions and mapping brain activity to behavior. In this study, we use electrophysiology to study how the hippocampus contributes to associative learning, which is the ability to learn and remember relationships between arbitrary stimuli. Previous research has shown that the hippocampus is involved in interpreting context and environmental cues, which is a key component of associative learning. Rats were trained to perform a visuomotor conditional association task in which they were presented with a visual stimulus and required to nose-poke a left or right port depending on the pattern of the stimulus. Correct choices were reinforced with chocolate milk, and incorrect trials were repeated until the correct action was made. Once the behavior was learned to 70% accuracy, the rats underwent a craniotomy where handmade electrodes were inserted into the CA1 area of the hippocampus. Postmortem histology confirmed placement in desired structures. After recovery, the rats performed the same task while the electrodes recorded their neural activity for analysis. Spikes were detected by an algorithm which isolated the downward deflections greater than three times the standard deviation using custom MATLAB programing. Inspection of spiking activity one second before and after the nose poke showed evident correlation between the task and the neural activity. Results demonstrate that electrophysiological techniques are effective at evaluating neurological activity in vivo and further suggest that there is a correlation between hippocampal activity and associative learning.
Recommended Citation
Morin, Samantha D., "Electrophysiological Techniques to Study Activity in Rat Hippocampus" (2019). Summer Research Internship Program. 25.
https://digitalscholar.lsuhsc.edu/srip/2019/undergrad/25
Electrophysiological Techniques to Study Activity in Rat Hippocampus
LSU Health Medical Education Building
Electrophysiological techniques are adept at investigating neuroanatomical functions and mapping brain activity to behavior. In this study, we use electrophysiology to study how the hippocampus contributes to associative learning, which is the ability to learn and remember relationships between arbitrary stimuli. Previous research has shown that the hippocampus is involved in interpreting context and environmental cues, which is a key component of associative learning. Rats were trained to perform a visuomotor conditional association task in which they were presented with a visual stimulus and required to nose-poke a left or right port depending on the pattern of the stimulus. Correct choices were reinforced with chocolate milk, and incorrect trials were repeated until the correct action was made. Once the behavior was learned to 70% accuracy, the rats underwent a craniotomy where handmade electrodes were inserted into the CA1 area of the hippocampus. Postmortem histology confirmed placement in desired structures. After recovery, the rats performed the same task while the electrodes recorded their neural activity for analysis. Spikes were detected by an algorithm which isolated the downward deflections greater than three times the standard deviation using custom MATLAB programing. Inspection of spiking activity one second before and after the nose poke showed evident correlation between the task and the neural activity. Results demonstrate that electrophysiological techniques are effective at evaluating neurological activity in vivo and further suggest that there is a correlation between hippocampal activity and associative learning.
Comments
Mentor: Theodore Weyand, Department of Cell Biology and Anatomy