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

Neurosci Lett. 2009 Jan 16;449(3):220-3. doi: 10.1016/j.neulet.2008.11.012. Epub 2008 Nov 11.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium Channel Blockers / pharmacology
  • Calcium Channels / physiology*
  • Electric Stimulation
  • Female
  • Hippocampus / cytology*
  • In Vitro Techniques
  • Male
  • Muscarinic Antagonists / pharmacology
  • Neuronal Plasticity / drug effects
  • Neuronal Plasticity / physiology*
  • Nifedipine / pharmacology
  • Patch-Clamp Techniques / methods
  • Rats
  • Rats, Wistar
  • Receptors, Muscarinic / physiology*
  • Scopolamine / pharmacology
  • Synapses / drug effects
  • Synapses / physiology*


  • Calcium Channel Blockers
  • Calcium Channels
  • Muscarinic Antagonists
  • Receptors, Muscarinic
  • Scopolamine
  • Nifedipine