Induction of synaptic depression by high-frequency stimulation in area CA1 of the rat hippocampus: Modeling and experimental studies

摘要

It is generally accepted that low-frequency stimulation (LFS) induces long-term depression (LTD), while high-frequency stimulation (HFS) induces long-term potentiation (LTP). We performed modeling and experimental studies to see whether this commonly accepted view is the case for a wide range of stimulation frequencies, and found the induction of LTD by high-frequency stimulation of 300 Hz (HFS-LTD) both in simulation and experiments. HFS-LTD was occluded by standard LFS-LTD induced by 1 Hz-15min stimulation, and blocked by D-AP5, W-7 or FK.-506, but neither by Ni~+ nor nimodipine. The analysis of the model suggested that the crossing of activation curve of CaMKII twice with that of CaN as the increase in [Ca~(2+)]_i was a possible mechanism for the induction of HFS-LTD in our study.