title: Benzodiazepine antagonist flumazenil reduces bicuculline-induced enhancement of neuronal activity in the spinal cord.
abstract: The interaction between the GABAA receptor antagonist bicuculline and the benzodiazepine receptor (BR) antagonist flumazenil was studied in the lumbosacral cord of spinal cats. Bicuculline (0.8 mg/kg i.v.) evoked epileptiform bursting of motoneurons in parallel with a depression of peripherally elicited dorsal root potentials (DRP) and dorsal root reflexes (DDR). A low dose of flumazenil (0.03 mg/kg i.v.) reduced the bursting activity of motoneurons as well as partially reversed the depression of DRP and DRR induced by bicuculline. It is suggested that an endogenous BR ligand down-regulating GABAA receptors is released during the bicuculline-evoked enhancement of neuronal activity and may contribute to the epileptiform discharge of motoneurons in the spinal cord.
authors.affiliation: Pharma Research Department, F. Hoffmann-La Roche Ltd, Basel, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Polc
authors.forename: I
authors.initials: I
authors.lastname: Ducić
mesh_terms: D000818:Animals; D001640:Bicuculline / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D002415:Cats; D004827:Epilepsy / Q000503:physiopathology; D005071:Evoked Potentials / Q000187:drug effects; D005442:Flumazenil / Q000494:pharmacology*; D008297:Male; D009046:Motor Neurons / Q000187:drug effects / Q000502:physiology*; D011963:Receptors, GABA-A / Q000187:drug effects / Q000502:physiology*; D013116:Spinal Cord / Q000187:drug effects / Q000502:physiology* / Q000503:physiopathology
chemical_list: D011963:Receptors, GABA-A; D005442:Flumazenil; D001640:Bicuculline