RAT TRAINING PROTOCOL

Version 1.0

Edited & expanded by Ron Cowart

Adapted from an earlier version, author unknown 

 

 

 

Introduction

             The radial maze has been used as a spatial memory test for well over 25 years.   It has been shown that the place cells in the hippocampus are highly involved in mastering the radial maze.   The radial maze learning therefore provides behavioral evidence in a controlled laboratory environment for an experimental effect on place learning.        

There is a pre-training phase and a memory probe phase.   The pre-training phase last 1 week.   The memory probe phase last 40 days or until criterion are met.   Rat training should begin at a similar time every day.   Training will take place five days per week with feeding scheduled on the weekends to maintain food deprivation weight.   Food deprivation weight is 85% of the ad libitum weight of the adult rat or starting weight of young growing rat.   All the rats should be treated the same everyday.   The order of groups and the order of the rats within the groups should be rotated everyday for the injections and then the rats should run on the maze in the same order they were injected everyday.   After the pre-training phase the baited arms of the maze should be in a different randomly selected configuration everyday and be rotated one position everyday.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Tools & Equipment

         rats

           rat cages

           rat food (pellets)

           froot loops (radial arm bate)

           radial arm maze

lab coat

           rubber gloves

           syringes (1mL)

           needles (23 to 27 gage & ½” to 1½” length)

           saline

           experimental drugs

           permanent markers (for color coding)

           plastic tub (to transport cages w/o spillage of rat waste secretions)

            timer

       

Pre-Training :

Time required:   1 hr./ day for pre-training & 1 hr. before the first day of pre-training for identifying the rats & color coding.                      

Purpose:    Pre-training is intended to get the rat accustomed to the injection procedure and being on the maze in order to control for these effects.

Note:    always wear rubber gloves & lab coat.

1.   Prepare saline injection ~ (.2 ml.).

2.   Give the rat an interperitineal injection.

3.   Repeat process for each of the rats in the group.

4.   Take rats to maze room.

5.   Sprinkle broken froot loops on the maze and place 2 rats from the same group     at a time on the maze and leave for 10 minutes. 

6.   After all the rats from that group have spent 10 minutes on the maze return them to their home cage.

7.   Feed rats ( 2 to 3 large food pellets) when they are returned to their home cage and record the amount on their corresponding data sheet.

 

 

 

 

 

 

 

 

 

 

 

 

Memory Trials

Time required:  1 hr.

Purpose:   The memory trial is the learning trial where the rat is exposed to where the food is and this is what the later tested memory is based on.

Note:   Alternate the order of groups and the rats within the groups everyday for the injections and then run them on the maze in the same order they were injected everyday.

             1.   Gather appropriate drug, syringe, & data sheet.

2.   Weigh the rat and record on the appropriate data sheet.

3.   Measure injection (ex. .1 ml. of drug per 100 grams).

4.   Inject the rat and record dosage amount on data sheet.

5.   Wait for drug to take effect (ex. 5 to 10 minutes for an interperitineal injection).

6.   Record rat number, date, and trial type on chalk board.  

7.   Start the video recorder.

8.   Show the chalk board to the video camera.

9.   Place every rat down in the center of the maze facing the same direction on every trial, everyday, one rat at a time.

10.   When a rat’s back feet cross over the line formed by the joining of an arm to the center plate as it moves onto the length of the arm, that arm should be recorded as one trial. 

                11.   Each rat gets 4 trials.

12.   After each rat has run the maze, be sure to replace any empty food troughs on the appropriate arms.

 

 

 

 

 

 

Probe Trials

Time required:   30 min. 

Purpose:    To test the rat’s place finding memory.

1.   Record rat number, date, and trial type on chalk board.

2.   Start the video recorder.

3.   Show the chalk board to the video camera.

4.   Place every rat down in the center of the maze facing the same direction on every trial, everyday, one rat at a time.

5.   When a rat’s back feet cross over the line formed by the joining of an arm to the center plate as it moves onto the length of the arm, that arm should be recorded as one trial. 

    6.   Each rat gets 4 trials or up to 10 minutes on the maze.

7.   After each rat has run the maze be sure to replace any empty food troughs on the appropriate arms.

Criterion :    Graduation is noted when rat gets100% correct on his memory trials and 75% correct on his probe trials 2 days in a row.   When a rat reaches criterion, tell Dr. Thompson in person, e-mail, or phone at 4933  that day   and look for a response.   Usually when a rat reaches criterion you will stop running that rat.   However, sometimes Dr. Thompson will want to pursue another part of the protocol and will ask you to continue to run the rat for another week or two.   Do not announce results with others.   All experimenters should stay blind until the end of the experiment so as to remain unbiased.