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OBJECTIVE To investigate the relationship between the anti-post-traumatic stress disorder(PTSD)effect of sertraline and nitric oxide in fear conditioning rats. METHODS Conditioned fear stress was established by electric shock with a cue tone,and fear extinction training was carried out by giving the rats only tone signals the next day. The rats were treated with sertraline(15 mg · kg-1) intragastrically within 1 h before the experiment for 8 d. Freezing time was tested at the 1st,4th and 7th day after the extinction training in rats. The NO contents were detected by Griess method and the nNOS and iNOS level on amygdala was detected by Western blotting. RESULTS The behavior tests showed that compared with normal control group ,the freezing time was significantly increased in extinction control group and extinction training group(P<0.01),indicating that the conditioned fear model of rats was successfully established. At the 1st and 4th day after conditioned fear extinction training in the rats,freezing time in sertraline(15 mg·kg-1)group was decreased compared with extinction training group (P<0.05). At the 7th day,the freezing time was significantly decreased(P<0.01),indicating that ser?traline reversed the fear response. At the same time,the contents of NO,nNOS and iNOS on amygdala of rats in sertraline group were lower than that in extinction training group(P<0.01). CONCLUSION Sertraline can promote extinction of conditioned fear memory,suggesting that sertraline has anti-PTSD effects on the model of fear condition in rats. The underlying mechanisms may be connected with NO.
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Objective To identify the role of the IKK / NF-kappa B signaling pathways in the acquisition and consolidation of extinction memory in conditioning fear.Methods Aduh SD rats were treated with nuclei buried surgery.After a week recovery from nuclei buried surgery,adult SD rats accepted auditory fear conditioning training.Before the extinction training,bilateral intra-BLA infusion of sulfasalazine(SSZ),an inhibitor of IKK/NFκ B,and Vehicle were done.The freezing time were tested on the 24h and 1w after the extinction.Results After training,all the rats showed higher percentage of freezing time than the baseline(Vehicle:pre-CS 21.16％,post-CS 71.23％,P＜0.01 ; SSZ:pre-CS 22.23％,post-CS 72.14％,P＜0.01).The percentage of freezing time had no significant difference(SSZ 47.52％,Vehicle 46.20％,P＞0.05)between Vehicle and SSZ at the end of extinction training.However,SSZ groups showed significantly higher percentage of freezing time than the control group on the 24h(Vehicle 41.03％,SSZ 60.51％,P＜0.01) and the same was found on 1 weck test(Vehicle 34.17％,SSZ 57.21％,P＜ 0.01).The rats injection with SSZ showed significant fear response for the auditory fear condition.Conclusion All above results suggest that interference of IKK/NF-κ B signaling pathway impaire the consolida tion but have no effect on the acquisition of fear extinction memory in conditioning fear.The available date could provide us some clinical guidance in the treatment of post-traumatic stress disorder and panic disorder.