Description
Automated Zebrafish T-maze |
Acrylic T-maze with walls and translucent base |
Total Length: 38 |
Total Width: 38cm |
Interior Arm Width: 9cm |
Interior wall height: 10cm |
Maze walls are clear; 1/2 inch thick acrylic |
Key Components
- The Zebrafish T-maze Chamber comprises T-maze test areas and returning pathways
- Seven auto doors
- Seven sensor arrays
- Two reward dispensers
- Two auto water stirrers
- Control box and other accessories
Chamber Details
- Chamber partition
- Maze areas (6): S0, S12, A1, A2, P1, P2
- Maze Doors (7): DS0, DS1, DS2, DA1, DA2, DP1, DP2
- Maze Sensors (7): MS0, MS1, MS2, MA1, MA2, MP1, MP2
- The T-maze stem and goal arms dimensions are shown in the picture
- Interior width: 9 cm
- Interior wall height: 10 cm (typical)
- Material: clear acrylic with 1⁄2 inch thick acrylic
Wall Inserts
- Each maze has two green wall inserts and two red wall inserts like the picture below
- Wall insert is removable on the outside of the goal arms
Pellet Dispensers
- The food magazine is equipped with an LED light and has an adjustable slot for food delivery
- The food delivery unit is placed on the outside of the T-Maze goal arms
- The structure is like the picture below and can be mounted on the top of the walls
Software
- The software Conduct T-maze is used to configure and run protocols:
- Protocol and result data are saved
- Implement protocols
- Left free choice
- Right free choice
- Left Forced choice
- Right Forced choice
- Support multiple mazes simultaneously
Sensors
- Seven sensor arrays to detect the fish moving into the areas
- Each door needs a pair of the customized designed sensor array
- The water height is about 10cm so the length of each sensor array is 8 cm
Water Stirrer
- Two automated water stirrers on two-goal arms
- Speed adjustable
- Removable to be positioned in the goal arms used as a positive punishment
Introduction
The Zebrafish Automated T-Maze is designed to explore spatial learning, memory, and conditioned behaviors in zebrafish. This system features a T-shaped maze with designated test areas and return pathways. The return paths enable the zebrafish to swim back to the starting point after reaching the goal area, facilitating rapid trial repetitions without needing to manually reposition the fish.
Equipped with various sensors, the maze automates the control of door operations and the delivery of food rewards in the goal arms. The included software allows for the configuration and execution of different experimental protocols. Protocols such as “left forced choice” and “right forced choice” direct the zebrafish to enter only one specific goal arm, while “left free choice” and “right free choice” protocols enable the zebrafish to choose between goal arms with rewards given in only one arm. Additionally, the “free choice” protocol provides rewards in both goal arms to assess preference and memory retention.
The maze’s sensors are adjusted according to the selected protocol, minimizing manual intervention from the experimenter and streamlining the process. The system also features a water stirrer in the goal arms, which acts as a form of positive punishment if the zebrafish remains in the arm for too long. Colored inserts outside the maze arms can be used to study color preferences in zebrafish.
Apparatus and Equipment
The Zebrafish Automated T-Maze features a testing chamber designed with T-maze test sections and return pathways. The setup includes seven automated doors, seven sensor arrays, two reward dispensers, two automated water stirrers, a control box, and additional accessories.
The maze dimensions are 51 cm in width and 38 cm in length, with the interior width of the maze arms measuring 9 cm and the wall height standing at 10 cm. Constructed from ½ inch thick clear acrylic, the maze can be filled with water up to a height of 10 cm. It also includes two red and two green removable wall inserts that can be placed outside the goal arms.
Movement of the zebrafish is monitored by sensors, with each door equipped with a pair of custom sensor arrays, each 8 cm long. The reward dispensers are located on the exterior of the goal arms, each featuring an LED light and an adjustable slot for dispensing food. Additionally, each goal arm is fitted with a removable water stirrer with adjustable speed settings, used as a form of positive punishment.
The maze is accompanied by software that allows for the configuration and execution of various experimental protocols. Depending on the protocol, the maze doors can be opened or closed to facilitate either free-choice or forced-choice behaviors.
Training Protocol
The Zebrafish Automated T-Maze software manages and executes several protocols, including:
Left Forced Choice: The software keeps the door to the left goal arm open while closing the door to the right goal arm. A food reward is provided at the end of the left goal arm.
Right Forced Choice: In this protocol, the door to the right goal arm is kept open, and the door to the left goal arm is closed. The food reward is delivered at the end of the right goal arm.
Left Free Choice: Both doors to the left and right goal arms are open, but the food reward is given only at the end of the left goal arm.
Right Free Choice: Both goal arm doors are open, with the food reward provided only at the end of the right goal arm.
Free Choice: Both goal arm doors are open, and the food reward is dispensed based on which arm the zebrafish enters.
The software automatically adjusts the maze sensors according to the selected protocol, managing door positions and reward delivery.
Additionally, the water stirrer can be used as a positive punishment if the zebrafish remains in the goal area for too long, encouraging it to exit the area promptly.
Literature Review
Hieu et al. (2020) evaluated the learning and memory of zebrafish using a conditioned place preference test on a T-maze. A green cue card was placed outside the right goal arm, which produced an unfavored stimulus in the zebrafish and caused them to swim to the left goal arm. However, when the subject entered the left goal arm, a mild electric shock was administered for spatial conditioning training or the development of passive avoidance behavior. The subjects’ memory retention was evaluated during testing by analyzing the time they spent in the punished arm and the latency to enter the left goal arm. The results of control fish were compared with ZnCl2-treated fish and genetic mutant zebrafish with a leptin a (lepa) gene deficiency. The results indicated that ZnCl2 exposure did not affect learning behaviors since the number of electric shocks administered was similar to the control group. However, ZnCl2-treated fish spent more time in the punished arm after training and had a shorter latency of swimming to the punished arm. This shows that ZnCl2 exposure affects memory retention in zebrafish. The results from the leptin a fish revealed that learning and memory performance were similar to control fish. However, a greater number of freezing behaviors were observed during training.
Bault, Peterzon, and Freeman (2015) evaluated directional and color preference in zebrafish using a T-maze. During the directional place preference test, the maze was placed in different directions to result in the fish swimming north/south, northeast/southwest, or east/west. The colored preference test utilized a combination of orange, yellow, green, blue, and purple. One colored sleeve was placed outside one goal arm, and another colored sleeve was placed outside the other goal arm during the color preference test. The maze was placed in a direction that was not preferred based on the directional place preference test. The results indicated that rotating the arms pointing west and east reduced the directional preference reported in males. Furthermore, when the directional preference was removed, both male and female zebrafish preferred colors with shorter wavelengths.
Data Analysis
The following parameters can be observed using the Zebrafish Automated T-Maze:
- Number of times the subject chose the right goal arm
- Number of times the subject chose the left goal arm
- Latency to visit the right arm
- Latency to visit the left arm
- Number of times the subject displayed freezing behaviors
- Latency of freezing behaviors
- Time taken to leave the goal arm
- Number of times the correct arm was chosen
- Number of times the incorrect arm was chosen
Strengths
The Zebrafish Automated T-Maze is equipped with sensors and software designed to streamline protocol setup and execution, making experiments quick and efficient. The maze features return pathways that enable zebrafish to swim back to the starting area after each trial, minimizing the need for manual handling. This versatility allows the maze to be utilized for a range of protocols, such as conditioned place preference tests, color discrimination tasks, and assessments of learning and memory.
Summary
- The Zebrafish Automated T-maze is used to study spatial learning and memory and conditioned behaviors in zebrafish.
- It consists of a chamber with test areas, returning pathways, doors, sensors, water stirrers, a colored wall insert, and pellet dispensers in each goal arm.
- The doors placed within the maze testing area form the shape of a “T”.
- The returning pathways are present between the goal areas and the starting area and allow the subject to swim to the starting area after completing a trial.
- The maze is available with software that configures and runs the protocol.
References
Ngoc Hieu, B. T., Ngoc Anh, N. T., Audira, G., Juniardi, S., Liman, R., Villaflores, O. B., Lai, Y. H., Chen, J. R., Liang, S. T., Huang, J. C., & Hsiao, C. D. (2020). Development of a Modified Three-Day T-maze Protocol for Evaluating Learning and Memory Capacity of Adult Zebrafish. International journal of molecular sciences, 21(4), 1464. https://doi.org/10.3390/ijms21041464
Bault, Z. A., Peterson, S. M., & Freeman, J. L. (2015). Directional and color preference in adult zebrafish: Implications in behavioral and learning assays in neurotoxicology studies. Journal of applied toxicology: JAT, 35(12), 1502–1510. https://doi.org/10.1002/jat.3169