Spatial Delayed Response

Spatial Delayed Response Test

SDR TESTING ROOM SETUP PROCEDURES

1. Fill the SDR tank with 26° C. water. BE CAREFUL NOT TO OVERFILL!!

• To help prevent a flood, set a timer and clip it to your lab coat and check about every 10-min. the beep will serve to remind you that the tank is filling.

2. Add one scoop of dried milk to water and mix well using strainer in SDR room

• (Try not to scratch plexi-glass).

3. Turn on heat lamps and wall lamps, leave overhead light off.

• Remember, CONSISTENCY is the key! Altering the setup of the room will change the spatial cues available to the animals and may possibly corrupt your data. Keep in mind that the room setup includes you! Be sure your dress and manner are as consistent as possible within squads, between squads and among other experimenters.

4. Acclimate subjects to SDR testing room 30 minutes before pretraining begins.

SDR PRE-TRAINING PROCEDURES

1. Using a Sharpie non-toxic pen, mark subjects to be tested with their subject number on their tails, according to squad (back ticks), and wet-cage assignment (1-4 tail ticks, corresponding to mesh-bottom cages 1-4 under heat lamps in test room).

2. After rats have acclimated, place the first squad in appropriate wet-cages.

3. Make sure you have a working stopwatch handy!

4. Ready the SDR tank:

• Check water temperature; adjust to 26° C. if necessary. Check temp before every squad!
• Place ladders on right and left arm of T-maze and make sure they are securely in place.

BEGIN PRETRAINING

1. Block one arm of the T-maze as prescribed by the pretraining worksheet:

• Each trial (1-10) is paired with either “L” or “R”.
• An “L” indicates subjects should be forced to the left arm of the maze; therefore, the right arm must be blocked.
• An “R” indicates subjects should be forced to the right arm, so the left arm must be blocked.

2. Trial 1:

• Starting with subject 1 (should be in wet-cage 1), place subject at the bottom of the starting stem, facing you.
• Record the time it takes for subject to find escape ladder:
• T = 0: Start timing when you release subject into tank
• T = end: Stop timing when subject grasps the escape ladder
• NOTE: 60 SECOND MAX! If subject fails to escape within 60 seconds, guide subject through the maze manually and record “60 +” on the worksheet.
• Return subject to correct wet-cage
• Repeat process for remaining squad members – maintaining a 1 min. interval between each rat
• Make sure ladder is securely in place before placing each subject in maze!

3. Between trials:

• Be sure correct arm block is in place for new trial
• Check to see that escape ladder is intact
• Begin each new trial with subject 1 and test squad in sequence

4. For all subjects/trials, document on worksheet:

• Any abnormal behavior displayed
• Any experimenter error (wrong arm blocked, ladder not in place)
• Any other possible confounding factors

5. When pretraining session is complete (a total of 10 trials for each animal):

• Blot each animal gently to remove excess water and return to wet-cage, allowing squad to dry under heat lamps for NO MORE THAN THIRTY MINUTES!!

SDR TRIALS:

1. Figure out escape arm –

• First day of testing before trial 1 begins, do not block off any arms on the T-maze and do not place any ladder in T-maze.
• Place subject at the bottom of the stem, facing you. Once the subject has gone into one of the escape arms, place the ladder in the opposite arm the subject has chosen.
• This side will now be where the escape ladder will be placed for the first trial.
• Do this procedure for each subject in the squad

2. Once the appropriate escape arm is established for each subject within the squad, trial 1 may begin.

3. Placing the subject at the bottom of the starting stem, facing you.

• Record the arm entries of the subject during the trial.

RULES FOR ARM ENTRIES:

• There is no time limit, keep recording all entries into the wrong arm, entries into the starting stem, and entries into the correct arm without escaping (those that enter correct arm and don’t escape circle the recording).
• If the subject reenters the starting stem before making a choice into one of the arms, it is not recorded
• The whole body of the subject must enter the arm/stem for it to count as an entry
• If the subject was pulled to the stem slightly as it was swimming, but was clearly heading for one of the arms, do not count the slight dip into the stem as an entry.
• If the subject is in the right arm and goes to the middle of the two arms, then goes back to the right arm – it would be recorded as R,R – as two entries to the right arm. Same goes for the left arm.

4. Once the subject successfully escapes, remove the rat from the maze and place in the wet-cage

5. Continue in consecutive order for the rest of the subjects in the squad, maintaining 1 – 2 minute interval before subj.1 begins trial 2 and so on.

6. Once a subject has 6 consecutive successful escapes, the location of the escape ladder is switched to the opposing escape arm.

7. Once the subject has 6 consecutive successful escapes with no errors, the location of the escape ladder is switched again.

8. IF the subject has 4 consecutive successful escapes during the last four trials of the day, the subject is given 1 or 2 more trials to try to complete the 6 consecutive escapes. (so a subj. can have a total of 32 trials in one day)

9. At the end of testing all subj. in one squad for the day, blot each animal gently to remove excess water and return to wet-cage, allowing squad to dry under heat lamps for NO MORE THAN THIRTY MINUTES!!

10. Double check paw codes and return subjects to cages and place back into colony room.

11. Set-up forms for Day 2, the starting place for the ladder on day 2 is the side where the subj. left off on day 1. Day 2 will start with this side for the first 6 trials, no matter if they got three in a row without errors from Day 1, they always will start with an increment of 6 trials.