 |
|||||
|
|||||
|
|||||
|
|||||
|
|||||
The Journal of Neuroscience, April 25, 2007, 27(17):4747-4755; doi:10.1523/JNEUROSCI.0369-07.2007
Previous Article | Next Article
Behavioral/Systems/Cognitive
Prelimbic/Infralimbic Inactivation Impairs Memory for Multiple Task Switches, But Not Flexible Selection of Familiar Tasks
Erin L. Rich andMatthew L. Shapiro Fishberg Department of Neuroscience and Alfred B. and Gudrun J. Kastor Neurobiology of Aging Laboratories, Mount Sinai School of Medicine, New York, New York 10029-6574
Correspondence should be addressed to Dr. Matthew L. Shapiro, Mount Sinai School of Medicine, One Gustave Levy Place, Box 1065, New York, NY 10029. Email: Matthew.Shapiro{at}mssm.edu
Behavioral flexibility, in the form of strategy switching or set shifting, helps animals cope with changing contingencies in familiar environments. The prelimbic (PL) and infralimbic (IL) regions of the rat prefrontal cortex (PFC) contribute to this ability so that rats trained to use one strategy have difficulty learning a new one if the PL/IL is inactivated. Thus, the PL/IL mediates learning new tasks in place of old ones, but it may also be required to switch between familiar tasks. To test this hypothesis, we trained rats to perform multiple task switches on a plus-shaped maze, alternating between two familiar tasks. Muscimol inactivation of the PL/IL never impaired switch acquisition, but did impair memory for the recently acquired switch 24 h later. Additional experiments determined that control rats continued to perform the new task 24 h after a switch, but rats with PL/IL inactivation had impaired memory and performed the same task that was learned before inactivation. This impairment was observed in multiple switches, demonstrating that PL/IL activity was required to remember which of two familiar tasks was most recently successful. After many switches, however, muscimol no longer impaired performance, and both saline- and muscimol-infused rats appeared to use immediate task contingencies rather than memory to select among familiar tasks. This strategy may account for the decreased effect of PL/IL inactivation observed after extensive training. Thus, although PL/IL activity contributed to memory for multiple task switches, it was not required for flexibly selecting among highly familiar tasks.
Key words: prefrontal cortex; prelimbic; infralimbic; muscimol; task switch; strategy
Received Jan. 26, 2007; revised March 2, 2007; accepted March 21, 2007.
Correspondence should be addressed to Dr. Matthew L. Shapiro, Mount Sinai School of Medicine, One Gustave Levy Place, Box 1065, New York, NY 10029. Email: Matthew.Shapiro{at}mssm.edu
This article has been cited by other articles:
E. L. Rich and M. Shapiro
Rat Prefrontal Cortical Neurons Selectively Code Strategy Switches
J. Neurosci., June 3, 2009; 29(22): 7208 - 7219.
[Abstract] [Full Text] [PDF]
A. Farovik, L. M. Dupont, M. Arce, and H. Eichenbaum
Medial Prefrontal Cortex Supports Recollection, But Not Familiarity, in the Rat
J. Neurosci., December 10, 2008; 28(50): 13428 - 13434.
[Abstract] [Full Text] [PDF]
I. Lee and F. Solivan
The roles of the medial prefrontal cortex and hippocampus in a spatial paired-association task
Learn. Mem., May 5, 2008; 15(5): 357 - 367.
[Abstract] [Full Text] [PDF]
M. G. Baxter, D. Gaffan, D. A. Kyriazis, and A. S. Mitchell
Orbital Prefrontal Cortex Is Required for Object-in-Place Scene Memory But Not Performance of a Strategy Implementation Task
J. Neurosci., October 17, 2007; 27(42): 11327 - 11333.
[Abstract] [Full Text] [PDF]
|
|
|
|
 |
|