Mohammad Alzoubani
Research Mentor(s): Joanna Spencer Segal
Mentor Department:
Authors: Mohammad Alzoubani, Jennifer Meng, Shany Yang, Joanna Spencer-Segal, MD, PhD
Session: Session 2 (10:00am – 10:50am)
Presentation Type: Poster 4
Abstract
Memory is a critical cognitive function that can be assessed in mice through behavioral paradigms such as the Object Recognition (OR) and Object Placement (OP) tests. The OR and OP are widely used to assess spatial and pattern recognition forms of memory, respectively, in rodents, by leveraging their natural exploratory behavior. However, variations in protocol design can influence data reliability leading to a lack reproducibility. In this study, we aimed to establish a reliable experimental protocol for the OR and OP that could be widely used to pro- duce a discrimination index (DI; novelfamiliar + novel) of above 0.5 baseline (chance). Adult male and female mice (n=6-11) were subjected to the OR and OP paradigms, consisting of a habituation, a familiarization phase, and a testing phase. In the testing phase of the OR, a familiar and a novel object were resented, while in the OP, one of the objects was relocated to a new position. Behavioral data, including object exploration time and DI, were recorded and analyzed to assess memory performance. Protocol variations, such as object type and interaction duration determine their effects on DI. A set yellow bottles were used for the OP which produced a DI that was higher than 0.5, indicating that mice seemed to prefer the relocated object. However, OR results varied depending on object type. When using yellow and blue bottles, these mice showed a clear preference for the yellow bottle regardless of whether it was a familiar or novel object. Using Lego objects showed no significant preference towards the novel object with a DI of 0.5. Interestingly, decreasing the time between the familiarization phase and the testing phase from 1.5 hours to 30 minutes yielded a higher discrimination index when using the same object set consisting of a Celsius can and a Lego tower. Lastly, we used objects such as an amber glass bottle and a 50-mL conical tube as testing objects and mice showed a preference for the novel object. Our findings suggest that the OP has the potential to provide a robust measure of spatial memory although a bigger sample size is needed. However, OR results indicate that object characteristics and minor protocol adjustments can significantly influence recognition memory outcomes. While some object combinations failed to elicit a clear preference for the novel object, others, particularly those incorporating a bottle of Celsius and a Lego tower, successfully produced a DI above 0.5. These results underscore the importance of standardizing object selection and protocol conditions to enhance the reliability of OR. Further adjustments are necessary to establish a standardized and applicable protocol for assessing recognition memory.
