Requirement of protein synthesis for group I mGluR-mediated induction of epileptiform discharges

J Neurophysiol. 1998 Aug;80(2):989-93. doi: 10.1152/jn.1998.80.2.989.


Picrotoxin (50 microM) elicited rhythmic synchronized bursting in CA3 pyramidal cells in guinea pig hippocampal slices. Addition of the selective group I metabotropic glutamate receptor (mGluR) agonist (S)-3,5-dihydroxyphenylglycine (25 microM) elicited an increase in burst frequency. This was soon followed by a slowly progressive increase in burst duration (BD), converting the brief 250-520 ms picrotoxin-induced synchronized bursts into prolonged discharges of 1-5 s in duration. BD was significantly increased within 60 min and reached a maximum after 2-2.5 h of agonist exposure. The protein synthesis inhibitors anisomycin (15 microM) or cycloheximide (25 microM) significantly impeded the mGluR-mediated development of the prolonged bursts; 90-120 min of agonist application failed to elicit the expected burst prolongation. By contrast, the mGluR-mediated enhancement of burst frequency progressed unimpeded. Furthermore, protein synthesis inhibitors had no significant effect on the frequency or duration of fully developed mGluR-induced prolonged discharges. These results suggest that the group I mGluR-mediated prolongation of synchronized bursts has a protein synthesis-dependent mechanism.

Publication types

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

MeSH terms

  • Action Potentials / drug effects
  • Action Potentials / physiology
  • Animals
  • Anisomycin / pharmacology
  • Brain Chemistry / physiology*
  • Convulsants
  • Epilepsy / chemically induced
  • Epilepsy / physiopathology*
  • Excitatory Amino Acid Antagonists / pharmacology
  • Glycine / analogs & derivatives
  • Glycine / pharmacology
  • Guinea Pigs
  • Neurons / chemistry
  • Neurons / physiology
  • Periodicity
  • Picrotoxin
  • Protein Synthesis Inhibitors / pharmacology
  • Receptors, Metabotropic Glutamate / physiology*
  • Resorcinols / pharmacology


  • Convulsants
  • Excitatory Amino Acid Antagonists
  • Protein Synthesis Inhibitors
  • Receptors, Metabotropic Glutamate
  • Resorcinols
  • Picrotoxin
  • 3,5-dihydroxyphenylglycine
  • Anisomycin
  • Glycine