Ant Double Bifurcation T

• Introduction
• Apparatus
• Training Protocol
• Data
• Strengths and Limitations
• References

Features

Stem Length: 15 cm

Stem Width: 5cm

Head Length: 22cm

Head Width: 2cm

Communication arm: 6cm length x 5cm width

Buffer: 8cm length; 5cm width

Features

Stem Length: 15 cm

Stem Width: 5cm

Head Length: 22cm

Head Width: 2cm

Communication arm: 6cm length x 5cm width

Buffer: 8cm length; 5cm width

Introduction

The Multiple T-maze is designed for conducting spatial learning and memory studies in rodents. This apparatus consists of several T-mazes joined longitudinally, creating a complex decision-making field for the subjects. It evaluates the subjects' decision-making and memory as they navigate through the mazes and associated paths in search of food. In humans, the hippocampus is crucial for decision making and episodic memory. Damage to this area can significantly affect declarative memory, imagination, and decision-making abilities. Declarative memory, characterized by short temporal specificity, enables tasks like route planning to be executed quickly. The Multiple T-maze simulates an environment where subjects utilize their declarative memory to follow specific routes in pursuit of food. This setup requires subjects to apply their learned information in decision-making tasks within a controlled environment and timeframe. Additionally, the Multiple T-maze can be used to observe neural function in the hippocampus during sequential navigation tasks. The Multiple T-maze features four T-mazes surrounded by a return rail, creating a lap-based task. The return rail includes feeders on both sides to store food rewards, serving as stimuli for the subjects. Other advanced T-mazes for studying learning and memory in rodents include the Two Problem T Maze, Automated T Maze, and Virtual T Maze.

Apparatus and Equipment

The Multiple T-maze measures 165 x 165 cm overall. It includes four T-mazes arranged longitudinally to create a turn sequence. Two return rails are positioned on either side of the T-maze stack. The horizontal arms of the first T-maze connect to the return rail at the top (north end), while the longitudinal arm of the fourth T-maze connects to the return rail at the bottom (south end). Each track is 10 cm wide. Two feeders are installed on each return rail to hold the food rewards.

Training Protocol

Thoroughly clean the apparatus before and after each trial to prevent any residual stimuli from affecting the subjects' behavior. External tracking and recording systems, such as ConductVision, Noldus Ethovision XT, can be used with the Multiple T-Maze to observe and analyze rodent behavior. The Multiple T-Maze task can be used without pretraining the subjects, allowing researchers to observe their foraging behavior in a novel environment. Conduct appropriate habituation sessions based on the specific requirements of your investigation prior to testing. Introduce the subject to the multiple T maze from the south end of the maze. Place food pellets in both feeders present besides the return rail either on the right or the left side of the Multiple T maze. Allow the subject to run through the maze for a 40 min session each day. Change the position of the food pellets to the opposite side after each session. Johnson and Redish (2007) investigated nonlocal representations during navigation in a Multiple T maze task. They recorded neural ensembles in the CA3 hippocampal region of Fisher Brown rats. The subjects were trained on the Multiple T Maze and then implanted with a 14-tetrode microdrive in the CA3 hippocampal region. Following the surgical procedure, the rats were introduced to the Multiple T maze to observe their navigation sequences at critical choice points. The study found that neural ensembles in the CA3 region exhibited transient activity at decision points. Nonlocal representations and extra-field firing were observed at high-cost choice points and during error corrections. Neural ensemble location reconstruction was found to sweep ahead of the animal. Local field potentials showed strong theta and gamma frequencies, but no sharp waves. Prominent neural cell firing activity in the CA3 region was observed at three crucial points: high-cost choice points, error correction points, and reorientation points from the current position. Introduce the subject to the multiple T maze from the south end of the maze. Place food pellets in both feeders present besides the return rail either on the right or the left side of the Multiple T maze. Allow the subject to run through the maze for a 40 min session each day. Change the position of the food pellets to the opposite side after each session. Johnson and Redish (2007) investigated nonlocal representations during navigation in a Multiple T maze task. They recorded neural ensembles in the CA3 hippocampal region of Fisher Brown rats. The subjects were trained on the Multiple T Maze and then implanted with a 14-tetrode microdrive in the CA3 hippocampal region. Following the surgical procedure, the rats were introduced to the Multiple T maze to observe their navigation sequences at critical choice points. The study found that neural ensembles in the CA3 region exhibited transient activity at decision points. Nonlocal representations and extra-field firing were observed at high-cost choice points and during error corrections. Neural ensemble location reconstruction was found to sweep ahead of the animal. Local field potentials showed strong theta and gamma frequencies, but no sharp waves. Prominent neural cell firing activity in the CA3 region was observed at three crucial points: high-cost choice points, error correction points, and reorientation points from the current position.

Data Analysis

The following parameters can be observed in a Multiple T maze:

• Linear velocity
• Angular velocity
• Subject position
• Radial distance
• Orientation of motion
• Time spent at choice point
• Sweep time

Strengths and Limitations

The Multiple T maze provides a complex, multi-choice environment to evaluate both reference memory and working memory in rodents. Unlike the conventional T-maze, the Multiple T-maze offers a more ethologically relevant setup due to its T-turn sequence. The return rails allow for uninterrupted performance, minimizing the need to handle the subjects. The maze can be easily modified for various investigations by adding or removing T-mazes or incorporating guillotine doors to introduce task delays. Training in the Multiple T-maze is efficient, and the results are both rapid and reproducible. This apparatus can also be effectively used for other tasks such as foraging, associative learning, and discrimination tasks, making it a versatile tool for studying different aspects of learning and memory. Operating the Multiple T maze requires a specific skill set due to its complexity. Maintaining the subjects’ exploratory drive is crucial for obtaining accurate results. Performance in the task is influenced by the subjects’ training; those without pretraining exhibit different behaviors compared to habituated subjects. Overtraining or mishandling can induce stress or anxiety, significantly affecting the subjects’ behavior. Factors such as interfering olfactory cues, locomotion biases based on strain, age, and gender are also important considerations. Residual cues left in the maze can impact subject behavior, underscoring the importance of thorough apparatus cleaning. The Multiple T maze provides a complex, multi-choice environment to evaluate both reference memory and working memory in rodents. Unlike the conventional T-maze, the Multiple T-maze offers a more ethologically relevant setup due to its T-turn sequence. The return rails allow for uninterrupted performance, minimizing the need to handle the subjects. The maze can be easily modified for various investigations by adding or removing T-mazes or incorporating guillotine doors to introduce task delays. Training in the Multiple T-maze is efficient, and the results are both rapid and reproducible. This apparatus can also be effectively used for other tasks such as foraging, associative learning, and discrimination tasks, making it a versatile tool for studying different aspects of learning and memory. Operating the Multiple T maze requires a specific skill set due to its complexity. Maintaining the subjects' exploratory drive is crucial for obtaining accurate results. Performance in the task is influenced by the subjects' training; those without pretraining exhibit different behaviors compared to habituated subjects. Overtraining or mishandling can induce stress or anxiety, significantly affecting the subjects' behavior. Factors such as interfering olfactory cues, locomotion biases based on strain, age, and gender are also important considerations. Residual cues left in the maze can impact subject behavior, underscoring the importance of thorough apparatus cleaning.

Summary

• Multiple T-maze is used for the assessment of spatial learning and memory-based behaviors in rodents.
• The presence of T mazes and return rail compose a complicated environment that challenges the decision-making ability of the subject.
• The Multiple T-maze’s return rails form a lap-based task for the subjects.
• Olfactory cues may hinder with results therefore proper cleaning of the track is mandatory.
• The quality and quantity of the food reward should be kept constant during the trial.
• Factors that may affect the subject behavior in a Multiple T-maze include age, sex, strain, and gender of the subject.
• The apparatus produces rapid and reproducible results.

References

Johnson, A., & Redish, D. (2007). Neural Ensembles in CA3 Transiently Encode Paths Forward of the Animal at a Decision Point. The Journal of Neuroscience, 27(45), 12176–12189. doi:10.1523/JNEUROSCI.3761-07.2007