Ca2+ entry via postsynaptic voltage-sensitive Ca2+ channels can transiently potentiate excitatory synaptic transmission in the hippocampus

Neuron. 1992 Dec;9(6):1175-83. doi: 10.1016/0896-6273(92)90075-o.


We have studied the role of Ca2+ entry via voltage-sensitive Ca2+ channels in long-term potentiation (LTP) in the CA1 region of the hippocampus. Repeated depolarizing pulses, in the presence of the NMDA receptor antagonist D-APV and without synaptic stimulation, resulted in a potentiation of excitatory postsynaptic potentials (EPSPs) or currents (EPSCs). This depolarization-induced potentiation was augmented in raised extracellular Ca2+ and was blocked by intracellular BAPTA, a Ca2+ chelator, or by nifedipine, a Ca2+ channel antagonist, indicating that the effect was mediated by Ca2+ entry via voltage-sensitive Ca2+ channels. Although the peak potentiation could be as large as 3-fold, the EPSP(C)s decayed back to baseline values within approximately 30 min. However, synaptic activation paired with depolarizing pulses in the presence of D-APV converted the transient potentiation into a sustained form. These results indicate that a rise in postsynaptic Ca2+ via voltage-sensitive Ca2+ channels can transiently potentiate synaptic transmission, but that another factor associated with synaptic transmission may be required for LTP.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 2-Amino-5-phosphonovalerate / pharmacology
  • 6-Cyano-7-nitroquinoxaline-2,3-dione
  • Animals
  • Calcium / metabolism*
  • Calcium Channels / drug effects
  • Calcium Channels / physiology*
  • Egtazic Acid / analogs & derivatives
  • Egtazic Acid / pharmacology
  • Electric Stimulation
  • Evoked Potentials / drug effects
  • Guinea Pigs
  • Hippocampus / physiology*
  • In Vitro Techniques
  • Kinetics
  • Male
  • Nifedipine / pharmacology
  • Quinoxalines / pharmacology
  • Receptors, N-Methyl-D-Aspartate / antagonists & inhibitors
  • Receptors, N-Methyl-D-Aspartate / physiology
  • Synapses / physiology*
  • Synaptic Transmission*
  • Time Factors


  • Calcium Channels
  • Quinoxalines
  • Receptors, N-Methyl-D-Aspartate
  • Egtazic Acid
  • 6-Cyano-7-nitroquinoxaline-2,3-dione
  • 2-Amino-5-phosphonovalerate
  • Nifedipine
  • 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid
  • Calcium