Does the Rodent Cerebellum Play a Role in Cognitive Flexibility?
Conference Year
January 2019
Abstract
Cognitive flexibility is one of the main three executive functions in the brain that allows for an animal to change their behavior in order to adapt to their environment and make goal directed decisions. Executive functions have historically been linked to the prefrontal cortex but recent literature shows that the Crus I/II region of the lateral cerebellum also may play a role in these functions in humans and nonhuman primates. We hypothesize that the inactivation of either the cerebellar projection target of Crus I/II (the dentate nucleus) or Crus I in rodents will impair a form of cognitive flexibility called set shifting. To test this, bilateral guide cannulas were implanted into either the dentate nucleus or Crus I of male Wistar rats and, after recovery, the rats were tested in a T-maze task over two days. This task requires rats to choose the left or right arm of the T in order to receive a food reward. The left and right arms differ in color (black vs. white) and texture (rough vs. smooth). On day one (set 1), the rats learned to discriminate along one dimension, either color or texture, to receive a reward. On the second day (set 2), rats received an infusion of either muscimol (to inactivate either Crus I or the dentate nucleus) or vehicle and then learned to discriminate along the other dimension in order to receive the reward, testing cognitive flexibility. Our results show that neither dentate nucleus nor Crus I inactivation prior to set 2 impaired performance. Overall, we found that inactivation of the dentate nucleus and Crus I in male Wistar rats does not impact cognitive flexibility.
Primary Faculty Mentor Name
John T. Green
Graduate Student Mentors
Megan L. Shipman, Callum M. P. Thomas
Status
Undergraduate
Student College
College of Arts and Sciences
Program/Major
Neuroscience
Primary Research Category
Biological Sciences
Does the Rodent Cerebellum Play a Role in Cognitive Flexibility?
Cognitive flexibility is one of the main three executive functions in the brain that allows for an animal to change their behavior in order to adapt to their environment and make goal directed decisions. Executive functions have historically been linked to the prefrontal cortex but recent literature shows that the Crus I/II region of the lateral cerebellum also may play a role in these functions in humans and nonhuman primates. We hypothesize that the inactivation of either the cerebellar projection target of Crus I/II (the dentate nucleus) or Crus I in rodents will impair a form of cognitive flexibility called set shifting. To test this, bilateral guide cannulas were implanted into either the dentate nucleus or Crus I of male Wistar rats and, after recovery, the rats were tested in a T-maze task over two days. This task requires rats to choose the left or right arm of the T in order to receive a food reward. The left and right arms differ in color (black vs. white) and texture (rough vs. smooth). On day one (set 1), the rats learned to discriminate along one dimension, either color or texture, to receive a reward. On the second day (set 2), rats received an infusion of either muscimol (to inactivate either Crus I or the dentate nucleus) or vehicle and then learned to discriminate along the other dimension in order to receive the reward, testing cognitive flexibility. Our results show that neither dentate nucleus nor Crus I inactivation prior to set 2 impaired performance. Overall, we found that inactivation of the dentate nucleus and Crus I in male Wistar rats does not impact cognitive flexibility.