Reaching Chamber/Pellet Retrieval Test
Objective: Assesses skilled forepaw use and motor functioning through pellet retrieval tasks in rodents
Gather these items before starting the experiment. Check off items as you prepare.
Equipment4
Materials2
Software1
Not specified • Not specified
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Protocol Steps
Animal preparation and motivation
Animals are food deprived and maintained at 85-90% of their normal body weight to ensure sufficient motivation to participate in the task
Note: Food deprivation is necessary for animal motivation in the skilled reaching task
View evidence from paper
“In order for animals to be sufficiently motivated to participate in the task, animals are typically food deprived and kept at 85-90% of their normal body weight”
Pre-training and skill acquisition
Animals undergo a long period of pre-training by first shaping them to acquire the skills of the reaching task
Note: Training period is lengthy and requires shaping animals to acquire task skills
View evidence from paper
“Training for the skilled reaching task generally requires a long period of pre-training by first shaping the animals to acquire the skills of the task”
Pellet placement
A pellet is placed in the indention contralateral to the reaching limb in order to evaluate unilateral brain impairments
Note: Pellet placement is contralateral to test the impaired side after stroke
View evidence from paper
“A pellet is placed in the indention contralateral to the reaching limb in order to evaluate unilateral brain impairments”
Reaching and retrieval task execution
Animal must reach through a window, grasp and retract the pellet. Attempts, successes, failures and drops are recorded
Note: Multiple trials are conducted per session
View evidence from paper
“An animal must reach through a window, grasp and retract the pellet. Attempts, successes, failures and drops are recorded in order to determine impairments”
Alternative task variant - overall pellet retrieval
A reaching tray can be used to analyze the overall number of pellets retrieved in a given amount of time
Note: This is an alternative to single pellet retrieval task
View evidence from paper
“A reaching tray can also be used to analyze the overall number of pellets retrieved in a given amount of time”
Forced use variant - restraining unimpaired limb
By restraining the use of the unimpaired limb, researcher can evaluate the effects of forced use of the impaired forelimb
Note: Used to investigate effects of intact forelimb usage on recovery of impaired forelimb
View evidence from paper
“By restraining the use of the unimpaired limb, a researcher can evaluate the effects of forced use of the impaired forelimb”
Height variation for detecting subtle deficits
Altering the height of the single pellet tray has been shown to detect more subtle deficits such as postural adjustments
Note: Height variation increases task difficulty and sensitivity
View evidence from paper
“Altering the height of the single pellet tray has been shown to detect more subtle deficits such as postural adjustments”
Data recording
Time from reaching to eating and paw preference for reaching are measured in addition to attempts, successes, failures and drops
Note: Multiple parameters are recorded to comprehensively assess motor function
View evidence from paper
“In addition, time from reaching to eating and paw preference for reaching can also be measured”