Muscarinic acetylcholine receptors and voltage-gated calcium channels contribute to bidirectional synaptic plasticity at CA1-subiculum synapses

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Item Type:	Article
Title:	Muscarinic acetylcholine receptors and voltage-gated calcium channels contribute to bidirectional synaptic plasticity at CA1-subiculum synapses
Creators Name:	Shor, O.L., Fidzinski, P. and Behr, J.
Abstract:	Hippocampal output is mediated via the subiculum, which is the principal target of CA1 pyramidal cells, and which sends projections to a variety of cortical and subcortical regions. Pyramidal cells in the subiculum display two different firing modes and are classified as being burst-spiking or regular-spiking. In a previous study, we found that low-frequency stimulation induces an NMDA receptor-dependent long-term depression (LTD) in burst-spiking cells and a metabotropic glutamate receptor-dependent long-term potentiation (LTP) in regular-spiking cells [P. Fidzinski, O. Shor, J. Behr, Target-cell-specific bidirectional synaptic plasticity at hippocampal output synapses, Eur. J. Neurosci., 27 (2008) 1111-1118]. Here, we present evidence that this bidirectional plasticity relies upon the co-activation of muscarinic acetylcholine receptors, as scopolamine blocks synaptic plasticity in both cell types. In addition, we demonstrate that the L-type calcium channel inhibitor nifedipine converts LTD to LTP in burst-spiking cells and LTP to LTD in regular-spiking cells, indicating that the polarity of synaptic plasticity is modulated by voltage-gated calcium channels. Bidirectional synaptic plasticity in subicular cells therefore appears to be governed by a complex signaling system, involving cell-specific recruitment of ligand and voltage-gated ion channels as well as metabotropic receptors. This complex regulation might be necessary for fine-tuning of synaptic efficacy at hippocampal output synapses.
Keywords:	Hippocampus, Neuromodulation, Long-term Potentiation, Long-term Depression, Learning and Memory, Animals, Rats
Source:	Neuroscience Letters
ISSN:	0304-3940
Publisher:	Elsevier
Volume:	449
Number:	3
Page Range:	220-223
Date:	16 January 2009
Official Publication:	https://doi.org/10.1016/j.neulet.2008.11.012
PubMed:	View item in PubMed

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