Effect of citalopram, a selective serotonin reuptake inhibitor, on the acquisition of conditioned freezing.
The present study examined the effects of the selective serotonin (5-hydroxytryptamine, 5-HT) reuptake inhibitor citalopram on the acquisition of conditioned freezing, an index of anxiety. Acute treatment with citalopram (1-10 mg/kg) dose dependently prevented the acquisition of conditioned freezing, while acute treatment with noradrenaline or dopamine reuptake inhibitors failed. The acute effect of citalopram was not antagonized by the 5-HT1A receptor antagonist NAN190, 1-(2-methoxyphenyl)-4-[4-(2-phthalimmido)butyl]piperazine or the 5-HT2A/2C receptor antagonist ICI169,369, 2-(2-dimethylaminoethylthio)-3-phenylquinoline hydrochloride. These results indicate that selective 5-HT reuptake inhibitors reduce not only the expression of conditioned freezing as reported previously, but also the acquisition of conditioned freezing. Both these effects of selective 5-HT reuptake inhibitors may be related to their clinical efficacy in the treatment of anxiety disorders.
Inoue
T
T
Department of Psychiatry, Hokkaido University School of Medicine, Sapporo, Japan.
Hashimoto
S
S
Tsuchiya
K
K
Izumi
T
T
Ohmori
T
T
Koyama
T
T
D018759:Adrenergic Uptake Inhibitors / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D015283:Citalopram / Q000494:pharmacology*; D003213:Conditioning, Psychological / Q000187:drug effects*; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004597:Electroshock; D005239:Fear / Q000187:drug effects; D008297:Male; D010879:Piperazines / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology*; D013315:Stress, Psychological / Q000523:psychology
D018759:Adrenergic Uptake Inhibitors; D015283:Citalopram; D018765:Dopamine Uptake Inhibitors; D010879:Piperazines; D011725:Pyridines; D017367:Selective Serotonin Reuptake Inhibitors; C105480:ORG 4428; C043425:vanoxerine