ERIC Number: EJ827485
Record Type: Journal
Publication Date: 2009-Feb
Abstractor: As Provided
Activity-Dependent Calpain Activation Plays a Critical Role in Synaptic Facilitation and Post-Tetanic Potentiation
Khoutorsky, Arkady; Spira, Micha E.
Learning & Memory, v16 n2 p129-141 Feb 2009
Synaptic facilitation and post-tetanic potentiation (PTP) are believed to necessitate active regeneration of the release machinery and supply of synaptic vesicles to a ready-releasable site. The prevailing hypothesis assumes that synapsins play pivotal roles in these processes. Using a cholinergic synapse formed between cultured "Aplysia" neurons (B2 and MCn), we demonstrate here that the calcium-activated protease-calpain serves as a major regulating element in the cascade that links electrical activity, elevation of the free intracellular calcium concentration, and short-term synaptic enhancements such as facilitation and PTP. Our study revealed that calpain inhibitors (calpeptin and MG132) transform a facilitating synapse into a depressing one, and reduce its PTP by 80.6%. Inhibition of CaM kinases, PKA, and MAPK also reduced PTP at this synapse. When inhibitors of these kinases were applied together with calpeptin, tetanic stimuli led to synaptic depression. We concluded that at this synapse facilitation and PTP are mediated mainly by the calpain-dependent processes and to a smaller extent by the CaMKs/PKA/MAPK-dependent cascades.
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Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Authoring Institution: N/A