Presynaptic glycine receptors on hippocampal mossy fibers

Biochem Biophys Res Commun. 2010 Mar 19;393(4):587-91. doi: 10.1016/j.bbrc.2010.02.019. Epub 2010 Feb 10.


Presynaptic glycine receptors (GlyRs) have been implicated in the regulation of glutamatergic synaptic transmission. Here, we characterized presynaptic GlyR-mediated currents by patch-clamp recording from mossy fiber boutons (MFBs) in rat hippocampal slices. In MFBs, focal puff-application of glycine-evoked chloride currents that were blocked by the GlyR antagonist strychnine. Their amplitudes declined substantially during postnatal development, from a mean conductance per MFB of approximately 600 pS in young to approximately 130 pS in adult animals. Single-channel analysis revealed multiple conductance states between approximately 20 and approximately 120 pS, consistent with expression of both homo- and hetero-oligomeric GlyRs. Accordingly, estimated GlyRs densities varied between 8-17 per young, and 1-3 per adult, MFB. Our results demonstrate that functional presynaptic GlyRs are present on hippocampal mossy fiber terminals and suggest a role of these receptors in the regulation of glutamate release during the development of the mossy fiber--CA3 synapse.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Glycine / metabolism
  • Glycine / pharmacology
  • Glycine / physiology
  • Mossy Fibers, Hippocampal / drug effects
  • Mossy Fibers, Hippocampal / growth & development*
  • Patch-Clamp Techniques
  • Rats
  • Rats, Wistar
  • Receptors, Glycine / metabolism
  • Receptors, Glycine / physiology*
  • Receptors, Presynaptic / metabolism
  • Receptors, Presynaptic / physiology*
  • Strychnine / pharmacology


  • Receptors, Glycine
  • Receptors, Presynaptic
  • Strychnine
  • Glycine