Biomaterial Database

The NMDA antagonist MK-801 blocks the extinction of Pavlovian fear conditioning. 1996

J D Baker, and J L Azorlosa

Department of Psychology, Southeastern Louisiana University, Hammond 70402, USA.

Five groups of rats were given Pavlovian fear conditioning. Four groups were then given extinction training. Prior to extinction these groups received an injection of either the noncompetitive NMDA antagonist MK-801 (0.025, 0.05, or 0.1 mg/kg) or saline. The 5th group received saline but no extinction. During testing, the extinction groups given saline or 0.025 mg/kg of MK-801 showed reduced fear, but the groups that had received the higher doses exhibited as much conditioned fear as the saline group, which had not received extinction. This study showed that MK-801 blocked extinction in a dose-dependent manner. The design of the study ruled out the possibility that the effect was due to state-dependency or to MK-801 interfering with the processing of the conditioned stimulus.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D003214	Conditioning, Classical	Learning that takes place when a conditioned stimulus is paired with an unconditioned stimulus.	Reflex, Conditioned,Classical Conditioning,Classical Conditionings,Conditioned Reflex,Conditionings, Classical
D005108	Extinction, Psychological	The procedure of presenting the conditioned stimulus without REINFORCEMENT to an organism previously conditioned. It refers also to the diminution of a conditioned response resulting from this procedure.	Psychological Extinction,Extinction (Psychology),Extinctions (Psychology),Extinctions, Psychological,Psychological Extinctions
D005239	Fear	The affective response to an actual current external danger which subsides with the elimination of the threatening condition.	Threat Cues,Threat Sensitivity,Cue, Threat,Fears,Sensitivity, Threat,Threat Cue,Threat Sensitivities
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001362	Avoidance Learning	A response to a cue that is instrumental in avoiding a noxious experience.	Aversion Behavior,Aversion Learning,Aversive Behavior,Aversive Learning,Avoidance Behavior,Aversion Behaviors,Aversive Behaviors,Avoidance Behaviors,Behavior, Aversion,Behavior, Aversive,Behavior, Avoidance,Behaviors, Aversion,Behaviors, Aversive,Behaviors, Avoidance,Learning, Aversion,Learning, Aversive,Learning, Avoidance
D016202	N-Methylaspartate	An amino acid that, as the D-isomer, is the defining agonist for the NMDA receptor subtype of glutamate receptors (RECEPTORS, NMDA).	N-Methyl-D-aspartate,NMDA,N-Methyl-D-aspartic Acid,Acid, N-Methyl-D-aspartic,N Methyl D aspartate,N Methyl D aspartic Acid,N Methylaspartate
D016291	Dizocilpine Maleate	A potent noncompetitive antagonist of the NMDA receptor (RECEPTORS, N-METHYL-D-ASPARTATE) used mainly as a research tool. The drug has been considered for the wide variety of neurodegenerative conditions or disorders in which NMDA receptors may play an important role. Its use has been primarily limited to animal and tissue experiments because of its psychotropic effects.	Dizocilpine,MK-801,MK 801,MK801
D017207	Rats, Sprague-Dawley	A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.	Holtzman Rat,Rats, Holtzman,Sprague-Dawley Rat,Rats, Sprague Dawley,Holtzman Rats,Rat, Holtzman,Rat, Sprague-Dawley,Sprague Dawley Rat,Sprague Dawley Rats,Sprague-Dawley Rats
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus