| |
Abstract:
Multiple systems in the ratÍs brain and periphery
express a left or right dominance, such as amount of dopamine in
the ascending nigro-striatal pathways, paw and whisker domiance.
These asymmetries have been shown to affect behaviors involving
left-right discriminations, and directional biases to turn to the
left or right. The direction rats turn is related to which side of
the brain or body is naturally dominant. Previous research in our
lab established that rats with their left whiskers (LW) numbed
learned to correctly forage for food in a radial-maze better than
rats with their right whiskers (RW) numbed, thereby expressing a RW
dominance for the task. In this study, we sought to test whether or
not intact rats with a natural tendency to turn in the direction of
the task-dominant RW (right-turn) would learn the maze task better
than rats who chose to turn toward the LW (left-turn). 234 intact
albino rats learned which five arms of an eight-arm radial maze had
food in it. As predicted, rats that made predominantly more right
turns in the maze between arms learned the task better than those
that made more left turns. Furthermore, rats that displayed larger
turn biases (independent of direction), made fewer errors during
learning. These results indicate that degree and direction of
naturally occurring asymmetries in the brain and periphery of rats
affect their performance while learning a complex cognitive
task.
|
