Dissociating Behavior and Spatial Working Memory Demands Using an H Maze.

Hannah Wirtshafter,Matthew Wilson,Moqing Quan

doi:10.21769/bioprotoc.3947

Abstract

The development of mazes for animal experiments has allowed for the investigation of cognitive maps and place cells, spatial working memory, naturalistic navigation, perseverance, exploration, and choice and motivated behavior. However, many mazes, such as the T maze, currently developed to test learning and memory, do not distinguish temporally and spatially between the encoding and recall periods, which makes it difficult to study these stages separately when analyzing animal behavior and electrophysiology. Other mazes, such as the radial maze, rely on single visits to portions of the maze, making maze coverage sparse for place cell and electrophysiology experiments. In this protocol, we present instructions for building and training an animal on a spatial appetitive choice task on a low-cost double-sided T (or H) maze. This maze has several advantages over the traditional T maze and radial mazes. This maze is unique in that it temporally and directionally dissociates the memory encoding and retrieval periods, while requiring the same behaviors of the animal during both periods. This design allows for independent investigation of brain mechanisms, such as cross-region theta coordination, during memory encoding and retrieval, while at least partially dissociating these stages from behavior. This maze has been previously used in our laboratory to investigate cell firing, single-region local field potential (LFP) patterns, and cross region LFP coherence in the hippocampus, lateral septum, prefrontal cortex, and ventral tegmental area, as well as to investigate the effects of hippocampal theta perturbations on task performance.

Highlights

After early maze experiments established that animals have a proclivity to spontaneously alternate between two spatial choices (Carr, 1917), Tolman became one of the first researchers to use a T-maze
The ability to alternate depends on working memory of the previously made choice, the traditional T maze is limited in that the encoding period, where the animal must form a memory of the current choice, and the recall period, in which the animal must remember the previous choice, overlap both temporally and spatially
Working memory in the radial maze incorporates all previous choices during a session, which means memory errors can compound and a single choice is dependent on all previous choices

Summary

Introduction

After early maze experiments established that animals have a proclivity to spontaneously alternate between two spatial choices (Carr, 1917), Tolman became one of the first researchers to use a T-maze. In order to be rewarded, the animal must visit the arm on the same side of the maze on the choice side of the maze (Figure 2, Video 1).

Results

Conclusion