Fig. 1: Oligodendrocytes in spike-timing-dependent plasticity.
From: Oligodendroglia are emerging players in several forms of learning and memory
By altering conduction velocity in afferents converging onto a postsynaptic neuron, myelin plasticity can induce spike-timing-dependent synaptic plasticity by determining the synchrony of spike time arrival with respect to postsynaptic action potential firing. a Effect of action potential latency in spike time arrival on synaptic plasticity. Arrival of synaptic input coincident with or prior to postsynaptic neuron firing, due to rapid conduction velocity or shorter axon path length, will result in long-term potentiation (LTP). Longer latency in spike time arrival, due to slower conduction velocity or longer axon path length, will lead to long-term depression (LTD). b Critical window for synaptic LTP and LTD in Xenopus tectal neurons. The percent change in the EPSC of synaptic inputs after repetitive stimulation (at 1 Hz for 100 s) plotted against the time of action potential input. Open circles represent repetitive spiking induced by injection of depolarizing currents. Impulses arriving within 20 ms before postsynaptic neuron firing become strengthened (i.e., LTP) while impulses arriving 20 ms after postsynaptic neuron firing are weakened (i.e, LTD). Adapted from Zhang et al.94, with permission. c, d Oligodendrocytes modulate conduction velocity. c Dual, whole cell recoding in hippocampal CA1 pyramidal neurons and oligodendrocytes. d Time-course of the latency of action potential arrival after depolarization of an oligodendrocyte forming myelin on that axon. The gray bar indicates time when oligodendrocytes were depolarized. Depolarization of oligodendrocytes increases action potential conduction velocity, and theta burst stimulation of axons depolarizes oligodendrocytes through glutamate receptors and potassium channels. Error bars = SEM. Adapted from Yamazaki et al., (2007)32 with permission.
