Study of paired-pulse inhibition of transcallosal response in the pyramidal tract neuron in vivo.
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.
Chowdhury
S A
SA
Department of Neurophysiology, Gifu University, School of Medicine, Japan.
Kawashima
T
T
Konishi
T
T
Niwa
M
M
Matsunami
K
K
D000818:Animals; D002415:Cats; D003337:Corpus Callosum / Q000187:drug effects; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000187:drug effects; D005260:Female; D018756:GABA Antagonists / Q000494:pharmacology*; D058788:GABA-B Receptor Antagonists; D008297:Male; D009433:Neural Inhibition / Q000187:drug effects*; D009474:Neurons / Q000187:drug effects*; D009943:Organophosphorus Compounds / Q000494:pharmacology*; D011712:Pyramidal Tracts / Q000166:cytology / Q000187:drug effects*; D011930:Reaction Time / Q000187:drug effects
D018756:GABA Antagonists; D058788:GABA-B Receptor Antagonists; D009943:Organophosphorus Compounds; C066430:CGP 35348