Source Paper
Selective Roles for Hippocampal, Prefrontal Cortical, and Ventral Striatal Circuits in Radial-Arm Maze Tasks With or Without a Delay
Stan B. Floresco, Jeremy K. Seamans, Anthony G. Phillips
Journal of Neuroscience • 1997
Delayed Radial-Arm Maze Task
Objective: To investigate functional interactions between hippocampal, prefrontal cortical, and ventral striatal circuits in rats during delayed and nondelayed spatially cued radial-arm maze tasks, examining how different brain regions contribute to spatial memory and goal-directed behavior.
Gather these items before starting the experiment. Check off items as you prepare.
Equipment1
Not specified • Not specified • Not specified • Not specified
Materials2
Software1
Not specified • Not specified
As an Amazon Associate, we earn from qualifying purchases. Product links help support this free resource.
Protocol Steps
Training phase of delayed task
Rats are placed on the radial-arm maze and provided with information about where food will be located. This phase establishes trial-unique, short-term memory of food locations.
Note: This is the first phase of the two-phase delayed task
View evidence from paper
“The two-phase delayed task consisted of a training phase that provided rats with information about where food would be located on the maze 30 min later during a test phase.”
Delay interval
A 30-minute delay period occurs between the training phase and test phase, during which rats must maintain memory of food locations.
Note: This delay tests short-term spatial memory retention
View evidence from paper
“The two-phase delayed task consisted of a training phase that provided rats with information about where food would be located on the maze 30 min later during a test phase.”
Test phase of delayed task
Rats are returned to the maze and must retrieve food from the locations learned during the training phase 30 minutes earlier.
Note: Performance depends on memory of training phase locations
View evidence from paper
“The two-phase delayed task consisted of a training phase that provided rats with information about where food would be located on the maze 30 min later during a test phase.”
Nondelayed task performance
Rats perform a single-phase task identical to the test phase of the delayed task, but without prior training phase. Rats must explore the maze to find food without previous knowledge of food locations.
Note: This task tests goal-directed exploratory behavior without reliance on previously acquired spatial information
View evidence from paper
“The single-phase nondelayed task was identical to the test phase of the delayed task, but in the absence of a training phase rats lacked previous knowledge of the location of food on the maze.”
Bilateral lidocaine injection into ventral CA1/subiculum
Transient inactivation of the ventral CA1/subiculum region via bilateral lidocaine injection to assess its role in maze performance.
Note: This manipulation disrupted performance on both delayed and nondelayed tasks
View evidence from paper
“Transient inactivation of the ventral CA1/subiculum (vSub) by a bilateral injection of lidocaine disrupted performance on both tasks.”
Unilateral disconnection of ventral CA1/subiculum and prefrontal cortex
Lidocaine injection into the ventral CA1/subiculum on one side of the brain combined with injection into the prefrontal cortex on the opposite side to transiently disconnect these two brain regions.
Note: This disconnection significantly impaired performance on the delayed task but not the nondelayed task
View evidence from paper
“Lidocaine injections into the vSub on one side of the brain and the prefrontal cortex on the other transiently disconnected these two brain regions and significantly impaired foraging during the delayed task but not the nondelayed task.”
Unilateral disconnection of ventral CA1/subiculum and nucleus accumbens
Lidocaine injection into the ventral CA1/subiculum on one side of the brain combined with injection into the nucleus accumbens on the opposite side to transiently disconnect these two brain regions.
Note: This disconnection disrupted performance on the nondelayed task but not the delayed task, producing opposite effects compared to vSub-prefrontal cortex disconnection
View evidence from paper
“Transient disconnections between the vSub and the nucleus accumbens produced the opposite effect, disrupting foraging during the nondelayed task but not during the delayed task.”