title: GABA(A) receptor activation is involved in noncontingent shock inhibition of instrumental conditioning in spinal rats.
abstract: Previous work has demonstrated that the spinal cord, isolated from higher neural structures, can support a simple form of instrumental learning. Furthermore, preexposure to uncontrollable (noncontingent) shock to the leg or tail inhibits this form of learning. The present study explores the role of GABA(A) receptor modulation on this inhibitory effect in spinal cord-transected rats. Intrathecal administration of the GABA(A) receptor antagonist bicuculline blocked induction and expression of the inhibition. The GABA(A) receptor agonist muscimol inhibited learning in a dose-dependent manner. However, this effect was transient and showed no additivity with shock. The findings suggest that GABA(A) receptor activation may work like a pharmacological switch that is activated by noncontingent shock to inhibit instrumental conditioning within the spinal cord.
authors.affiliation: Department of Psychology, Texas A&M University, College Station 77843-4235, USA. arf7646@neo.tamu.edu
authors.forename: Adam R
authors.initials: AR
authors.lastname: Ferguson
authors.forename: Stephanie N
authors.initials: SN
authors.lastname: Washburn
authors.forename: Eric D
authors.initials: ED
authors.lastname: Crown
authors.forename: James W
authors.initials: JW
authors.lastname: Grau
mesh_terms: D000818:Animals; D001640:Bicuculline / Q000008:administration & dosage / Q000494:pharmacology; D003216:Conditioning, Operant; D004558:Electric Stimulation; D018755:GABA Agonists / Q000008:administration & dosage / Q000494:pharmacology; D018756:GABA Antagonists / Q000008:administration & dosage / Q000494:pharmacology; D009118:Muscimol / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011963:Receptors, GABA-A / Q000502:physiology*; D012054:Reinforcement, Psychology; D013116:Spinal Cord / Q000502:physiology* / Q000601:surgery
chemical_list: D018755:GABA Agonists; D018756:GABA Antagonists; D011963:Receptors, GABA-A; D009118:Muscimol; D001640:Bicuculline