METAPLASTICITY - THE PLASTICITY OF SYNAPTIC PLASTICITY

In this paper, we review experimental evidence for a novel form of per sistent synaptic plasticity we call metaplasticity. Metaplasticity is induced by synaptic or cellular activity, but it is not necessarily ex pressed as a change in the efficacy of normal synaptic transmission. I nstead, it is manifest as a change in the ability to induce subsequent synaptic plasticity, such as long-term potentiation or depression. Th us, metaplasticity is a higher-order form of synaptic plasticity, Meta plasticity might involve alterations in NMDA-receptor function in some cases, but there are many other candidate mechanisms. The induction o f metaplasticity complicates the interpretation of many commonly studi ed aspects of synaptic plasticity, such as saturation and biochemical correlates.