Role of cellular prion protein on LTP expression in aged mice

Cellular prion protein (PrPc) has been associated with some physiological functions in the last few years. In a previous paper, we have demonstrated an increased hippocampal synaptic transmission in adult mice lacking this protein. In the present study, we investigate the impact of aging on the generation and maintenance of hippocampal long-term Potentiation (LTP) in 9-month-old mice devoid of PrPc protein (Prnp0/0). We observed a lower threshold for inducing LTP in 9-month-old Prnp0/0 mice compared to wild-type ones at the same age. The maintenance of dentate gyrus LTP was more persistent in hippocampal slices from Prnp0/0 mice. Furthermore, the expression of mRNA for NR2A and NR2B subunits of the NMDA glutamatergic receptor in hippocampus of aged Prnp0/0 animals showed an increase compared to the wild type. We propose that increased hippocampal glutamatergic transmission in Prnp0/0 mice is related to the enhanced plasticity and persistence of the dentate LTP.