3. Plasticity in the Cerebellar Cortex
Published Online: 23 AUG 2013
This edition first published 2014 © 2014 John Wiley & Sons, Inc.
The Cerebellum: Learning Movement, Language, and Social Skills
How to Cite
Broussard, D. M. (2013) Plasticity in the Cerebellar Cortex, in The Cerebellum: Learning Movement, Language, and Social Skills, John Wiley & Sons, Inc., Chichester, UK. doi: 10.1002/9781118730133.ch3
- Published Online: 23 AUG 2013
- Published Print: 15 AUG 2013
Print ISBN: 9781118125632
Online ISBN: 9781118730133
- AMPA receptors;
- cerebellar cortex;
- long-term depression (LTD);
- memory trace;
This chapter describes how plasticity works at the cerebellar cortex, and how the different mechanisms may interact to cause learning. The occurrence of long-term depression (LTD) with stimulation of climbing and parallel fibers is actually quite surprising. LTD requires some back-and-forth communication between neurons, analogous to a conversation. This conversation is mediated by at least four substances in the extracellular space: glutamate, gamma-amino-butyric acid (GABA), one or more endocannabinoids, and the gas nitric oxide (NO). LTD requires a complex sequence of molecular signals. Low calcium concentration in the vicinity of the synapse (possibly within the spine) means that no plasticity will occur. More calcium enables LTP, and more still, LTD. If the LTP threshold is not reached, no learning occurs. Two forms of metaplasticity are brought about by repeated activation of the climbing fiber alone, and both make parallel-fiber LTD less likely to happen in the future.