European Brain and Behaviour Society Meeting edition:41 location:Rhodes, Greece date:13-18 September 2009
It is well established that the striatum and hippocampus are critically involved in visuo-spatial learning processes. There is evidence that these structures contribute at different phases of learning. Comparing brain activation in a similar spatial learning task between mice and humans will provide more insight into the specific differential and time dependent contributions of striatum and hippocampus. Additionally, we will further assess if there is also overlap in the function of these brain areas. Mice were trained in the Morris water maze task for either 3 days (early learning phase group) or 4 weeks (late learning phase group). Neuronal activity at different phases of spatial learning was determined by a comparison of expression levels of the immediate early genes Arc, Homer1a and Zif268 in hippocampus and striatum between different mouse groups. Data show higher activity of the hippocampus during the early learning phase compared to the late phase, as expected. Upregulation of the ventrolateral striatum was observed during the early learning phase, while activity was higher in dorsal striatum during the late learning phase. We developed a virtual Morris water maze to measure human brain activation during different phases of learning. The task was designed to ensure that specific learning processes observed in both species are comparable. First fMRI data show increased activation of striatum in the late learning phase when compared to the early learning phase of the task (specifically during the initial orientation period of the trial). Using the human virtual Morris water maze allows us to cross-validate learning related plasticity between mouse and human research.