Intact LTP and fear memory but impaired spatial memory in mice lacking Ca(v)2.3 (alpha(1E)) channel

To investigate the functional roles of the Ca(v)2.3 (alpha (1E)) channel in hippocampal CA1 pyramidal neurons, we studied in vitro synaptic properties and in vivo behaviors of the Ca(v)2.3 gene deficient mice. The Ca(v)2.3 ch annel mRNA was identified in the hippocampal formation of the wild-type mou se by in situ hybridization. The basic excitatory synaptic transmission and long-term potentiation by theta-burst stimulation were intact in CA1 regio n of Ca(v)2.3-/- mice. We performed two forms of behavioral tests to examin e the hippocampus-dependent function, i,e,, emotional and spatial learning tests. The Ca(v)2.3-/- mice were able to establish and maintain fear memori es. Although general improvement in the performance of Morris water maze te st was seen in Ca(v)2.3-/- mice, they displayed an obvious impairment in th e probe test. These results suggest that the Ca(v)2.3 channel plays some ro le in formation of the accurate spatial memory but not of the fear memory. (C) 2001 Academic Press.