Ketamine administration diminishes operant responding but does not impair conditioned fear.

摘要: While not well understood, the NMDA (N-methyl-D-aspartate) antagonist ketamine, a dissociative anesthetic, has been reported to be efficacious in depression and related psychological disorders. Conditioned fear is normal emotional conditioning process that known become dysfunctional individuals suffering from Post-Traumatic Stress Disorder (PTSD) stress We examined effects of ketamine determine potential modulation acquisition extinction conditioned using suppression procedure. Rats were trained on variable interval (VI), food maintained, operant task establish general measure performance. exposed inescapable shock (IES, unconditioned stimulus) paired (×20) with an audio/visual stimulus (CS) conditioning. Conditioning was quantified by measuring response following CS presentation during subsequent trials where alone presented. Ketamine or vehicle administered either after initial each trials. For regimen, series four injections 60 min apart (100, 50, 50 mg/kg, respectively) order sustain effect for minimum 4 h. produced decrease responding VI, relative baseline, as rates slower when tested 24 h later longer. did affect regimen shortly pairings IES CS. alter only Our conclusion these findings while alters behavior appetitively motivated it does not, however, appear directly modulate learning memory processes associated fear.