Study of paired-pulse inhibition of transcallosal response in the pyramidal tract neuron in vivo

Eur J Pharmacol. 1996 Oct 31;314(3):313-7. doi: 10.1016/s0014-2999(96)00659-0.


The effects of a specific GABAB receptor antagonist, p-(3-aminopropyl)-p-diethoxymethyl-phosphonic acid (CGP 35348), on pyramidal tract neuron responses to transcallosal stimulation were investigated in the cat motor cortex in vivo. The paired-pulse method was used to obtain more insight into the role of GABAB receptors. At a 200-ms inter-stimulus interval the spike response was inhibited in 75% of the neurons. There was an approximately 40% depression of the mean spike value in the control. CGp 35348 reduced paired-pulse inhibition, while (-)-baclofen increased it. Stronger drug effects on the second stimulation-induced response possibly indicate their presynaptic action on GABAB receptors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cats
  • Corpus Callosum / drug effects
  • Electric Stimulation
  • Evoked Potentials / drug effects
  • Female
  • GABA Antagonists / pharmacology*
  • GABA-B Receptor Antagonists*
  • Male
  • Neural Inhibition / drug effects*
  • Neurons / drug effects*
  • Organophosphorus Compounds / pharmacology*
  • Pyramidal Tracts / cytology
  • Pyramidal Tracts / drug effects*
  • Reaction Time / drug effects


  • GABA Antagonists
  • GABA-B Receptor Antagonists
  • Organophosphorus Compounds
  • CGP 35348