The mechanisms and functions of activity-dependent long-term potentiation of intrinsic excitability.

The efficiency of neural circuits can be enhanced not only by increasing synaptic strength but also by increasing neuronal intrinsic excitability. Three major types of activity-dependent long-term potentiation of intrinsic excitability (LTP-IE) have been well defined: decreased action potential (AP) threshold, reduced afterhyperpolarization (AHP), and attenuated dendritic propagation. The ionic basis and induction pathways for these three types of LTP-IE have been largely revealed recently. These intrinsic plasticities and their cooperation enrich the functions fulfilled by neurons, and may serve as a supplementary mechanism for learning and memory.