Belgian Society for Neuroscience edition:10 location:Campus Jette, Brussels, Belgium date:31 May 2013
One of the most important and fascinating abilities of the human brain is to learn and memorize complex tasks. The hidden-platform Morris water maze is a robust visually guided spatial navigation task for rodents in which the platform location relative to distal environmental cues is learned. The task is quickly apprehended during the early learning phase where navigation is driven by flexible goal-directed actions. In later training sessions further improvements in the task are rather small and execution of the task becomes a rigid automated habit. Previous results from an immediate early gene expression study demonstrated the differential involvement of distinct subregions of the dorsal striatum to the navigation strategies guiding early and late learning. To unravel the underlying molecular mechanisms driving the switch from early to late learning in the dorsal striatum we employed MALDI-TOF MS imaging. A pilot study that screened for learning phase-related changes in the expression of small proteins in the dorsal striatum revealed one m/z of 6724 Da in the dorsolateral striatum which was detected at a relatively higher intensity in the late compared to the early learning group. The MALDI-TOF MS imaging results suggest the involvement of this target ion in the transition from early to late learning during the acquisition of the spatial learning task.