Utilizing the Modified T-Maze to Assess Functional Memory Outcomes After Cardiac Arrest

Celeste Y. C. Wu; Francesca M. Lerner; Alexandre Couto e Silva; Harlee E. Possoit; Tsung-Han Hsieh; Jake T. Neumann; Alireza Minagar; Hung Wen Lin; Reggie H. C. Lee

doi:10.3791/56694

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Method Article

Utilizing the Modified T-Maze to Assess Functional Memory Outcomes After Cardiac Arrest

11.9K views

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DOI:

10.3791/56694

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January 5th, 2018

Celeste Y. C. Wu¹^,² , Francesca M. Lerner⁴ , Alexandre Couto e Silva³ , Harlee E. Possoit¹^,² , Tsung-Han Hsieh¹^,² , Jake T. Neumann⁵ , Alireza Minagar¹ , Hung Wen Lin¹^,²^,³ , Reggie H. C. Lee¹^,²

¹Department of Neurology, Louisiana State University Health Science Center, ²Center for Brain Health, Louisiana State University Health Science Center, ³Department of Cellular Biology and Anatomy, Louisiana State University Health Science Center, ⁴Department of Neurology, Cerebral Vascular Disease Research Laboratories, University of Miami Miller School of Medicine, ⁵Department of Biomedical Sciences, West Virginia School of Osteopathic Medicine

Summary

This protocol describes the use of a modified T-maze to evaluate functional learning/memory in asphyxia cardiac arrest-induced cerebral ischemia.

Abstract

Background: Evaluating mild to moderate cognitive impairment in a global cerebral ischemia (i.e. cardiac arrest) model can be difficult due to poor locomotion after surgery. For example, rats who undergo surgical procedures and are subjected to the Morris water maze may not be able to swim, thus voiding the experiment.

New Method: We established a modified behavioral spontaneous alternation T-maze test. The major advantage of the modified T-maze protocol is its relatively simple design that is powerful enough to assess functional learning/memory after ischemia. Additionally, the data analysis is simple and straightforward. We used the T-maze to determine the rats' learning/memory deficits both in the presence or absence of mild to moderate (6 min) asphyxial cardiac arrest (ACA). Rats have a natural tendency for exploration and will explore the alternate arms in the T-maze, whereas hippocampal-lesioned rats tend to adopt a side-preference resulting in decreased spontaneous alternation ratios, revealing the hippocampal-related functional learning/memory in the presence or absence of ACA.

Results: ACA groups have higher side-preference ratios and lower alternations as compared to control.

Comparison with Existing Method(s): The Morris water and Barnes maze are more prominent for assessing learning/memory function. However, the Morris water maze is more stressful than other mazes. The Barnes maze is widely used to measure reference (long-term) memory, while ACA-induced neurocognitive deficits are more closely related to working (short-term) memory.

Conclusions: We have developed a simple, yet effective strategy to delineate working (short-term) memory via the T-maze in our global cerebral ischemia model (ACA).

Introduction

According to the American Heart Association (2017), cardiac arrest (CA)-induced mortality occurs every four minutes, and affects over 400,000 people per year in the United States¹. It is well-documented that CA can cause neuronal brain injury as a result of insufficient blood perfusion²^,³^,⁴. CA-induced brain injury occurs in the ischemia-sensitive CA1 region of the hippocampus⁵^,⁶^,⁷, affecting neurons that are critical to learning and memory^8<....