CELLULAR CORRELATES TO SPATIAL-LEARNING IN THE RAT HIPPOCAMPUS

Learning through exploration gives increased synaptic field potentials in the perforant path/dentate synapses, largely due to an activity-de pendent brain temperature increase. After temperature compensation, sp atial learning was associated with small, but significant, STP-like ch anges of the field potential lasting 20-30 min. A group of spatially t rained adult rats showed faster spatial learning and about 10% higher basal dendritic spine density (LY-filled) compared to two control grou ps. With unchanged dendritic length and branching pattern, the results suggest the formation of new synapses.