The Experimental Study of Repetitive Transcranial Magnetic Stimulation in Prevention of Posttraumatic Stress Disorder
|School||Fourth Military Medical University|
|Keywords||posttraumatic stress disorder prepulse inhibition repetitivetranscranial magnetic stimulation|
ObjectivesPosttraumatic stress disorder (PTSD) refers to a series ofpsychophysiological syndrome caused by severely traumatic events，whose coresymptom is intrusive memories. At present, diagnosis of PTSD is based onsemeiological criterion，because the appearance of core symptom of PTSDpostpones after the stress, chronic course of disease, high relapse rate, whichmakes it difficult to identify and treat it early. Therefore, how to effectivelyprevent PTSD has become a point in psychiatrical field.At present, post-stress crisis intervention and drugs are mainly introducedin treating PTSD, while, neither of them is satisfying methods toward improvingthe clinical symptom. Repetitive transcranial magnetic stimulation (rTMS), anew, noninvasive and safe physiotherapy, is widely used in treatment of PTSD.Nevertheless, rTMS has been treated as therapeutic measure in clinical studies,few studies have used rTMS as preventive measure.Single prolonged stress (SPS) is a prevalent animal model of PTSD, whicheffectively imitate neuroendocrine change and clinical symptoms. There are many methods including Open Field, Elevated Plus Maze, Morris Water Puzzlein order to investigate the level of anxiety and impaired cognition with stressfulanimals. However, they could not reflect and explain the core symptom ofPTSD-Intrusive memories.Intrusive memories indicate that patients with PTSD could not effectivelyinhibit traumatic events and negative emotions. Some related researches haveimplied that patients may fail to filter negative experience, which suggesteddysfunction of sensorimotor gating (SG) and a new criterion to appraise PTSD.Therefore, we will adopt rTMS as early preventive measure and OF, EPM,PPI as appraise criterions to identify preventive effects of rTMS.Methods1.48male SD rats were randomly divided into4groups: control group,SPS&S1d group, SPS&S7d group, SPS&S14d group (n=12per group).Control rats were left in their home cage for7days then received OF, EPM andPPI paradigms. SPS&S rats were left in their home cage for7days and thenreceived SPS&S, OF, EPM and PPI paradigms were carried out on day1,7,14after stress, respectively.2.40male SD rats were randomly divided into4groups: control group,SPS&S group, rTMS group and SPS&S+rTMS group. All rats were left in theirhome cage for7days. Besides administration of isoflurane, control rats were leftin their home cage for other7days, SPS&S rats received SPS&S and then left intheir home cage for other7days, rTMS rats received rTMS for7days, whileSPS&S+rTMS rats received both SPS&S and administration of rTMS for other7days. Behavioral changes in these rats were analyzed in OF, EPM and PPIparadigms.Results 1. There was no significant difference of locomotoractivity among fourgroups (P>0.05). Distance of central movement, time of central movement,distance of central movement (%) in SPS&S1d group were lower than those incontrol group (P<0.05). While, distance of central movement, time of centralmovement, distance of central movement (%), time of central movement (%) inSPS&S7d group were lower than those in control group (P<0.05). Comparedwith control group, time of central movement and time of central movement (%)were reduced in SPS&S14d group (P<0.05). Each SPS&S group has reductionof time spent in open arms, time spent in open arms (%) and No. of entry intoopen arms (%) compared to control group (P<0.05). Average%PPI in anySPS&S groups were lower than that in control group (P<0.05).2. There was no significant difference of locomotoractivity among fourgroups (P>0.05). Distance of central movement, time of central movement,distance of central movement (%), time of central movement (%) in SPS&Sgroup were lower than those in the rest of three groups (P<0.05). SPS&S grouphas reduction of time spent in open arms and time spent in open arms (%)compared to other three groups (P<0.05). Average%PPI in SPS&S group waslower than that in the rest of three groups (P<0.05).ConclusionsSPS&S rats develop persistent anxiety-like behavior and impaired PPI afterstress, which provide basic theory for eatly prevention. rTMS has no effects onhealthy rats, but early treatment can alter the damage of PPI caused by stress,which imply rTMS is a effective measure in protection of PTSD.