The opioid peptide dynorphin mediates heterosynaptic depression of hippocampal mossy fibre synapses and modulates long-term potentiation

Nature. 1993 Apr 1;362(6419):423-7. doi: 10.1038/362423a0.


The mossy fibre pathway in the hippocampus uses glutamate as a neurotransmitter, but also contains the opioid peptide dynorphin. Synaptic release of dynorphin causes a presynaptic inhibition of neighbouring mossy fibres and inhibits the induction and expression of mossy fibre long-term potentiation. These findings demonstrate a physiological role for a neuropeptide in the central nervous system, provide a functional basis for the coexistence of a neuropeptide with classic neurotransmitters and demonstrate the very different roles played by these two classes of signalling molecules.

Publication types

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

MeSH terms

  • 6-Cyano-7-nitroquinoxaline-2,3-dione
  • Animals
  • Electric Stimulation
  • Evoked Potentials / drug effects
  • Excitatory Amino Acid Antagonists
  • Guinea Pigs
  • Hippocampus / drug effects
  • Hippocampus / physiology*
  • In Vitro Techniques
  • Naloxone / pharmacology
  • Nerve Fibers / drug effects
  • Nerve Fibers / physiology
  • Pyramidal Tracts / drug effects
  • Pyramidal Tracts / physiology*
  • Quinoxalines / pharmacology
  • Receptors, Opioid, kappa / drug effects
  • Receptors, Opioid, kappa / physiology
  • Synapses / drug effects
  • Synapses / physiology*


  • Excitatory Amino Acid Antagonists
  • Quinoxalines
  • Receptors, Opioid, kappa
  • Naloxone
  • 6-Cyano-7-nitroquinoxaline-2,3-dione