sentence: This , alongside the remarkable persistence of LTP at hippocampal perforant path-dentate gyrus synapses , provides compelling evidence for the involvement of LTP-type plasticity in memory function.Long-term potentiation induced at perforant path synapses in awake freely moving animals consists of three temporally and mechanistically distinct canonical phases : LTP1 , LTP2 , and LTP3 ( Abraham and Otani , 1991 ) .