Bi-directional alterations of LTP after acute homocysteine exposure

Homocysteine (HCY) is a known risk factor for neuronal diseases. We here report that HCY (10-1000 μM) interfered bi-directionally with long-term potentiation (LTP) in hippocampal slices, causing an impairment at concentrations <100 μM, and enhancement ≥500 μM. By comparison, NMDA unidirectionally reduced LTP, whereas l-cysteine led to facilitated LTP. Such HCY-induced alterations in neuronal communication may contribute to cognitive failure in dementia.