创伤后应激障碍大鼠心血管功能变化及相关心理生理学通路

Changes in cardiovascular function and related psychophysiological pathways in a rat model of post-traumatic stress disorder

本研究旨在探究创伤后应激障碍(post-traumatic stress disorder,PTSD)模型大鼠心血管功能以及延髓头端腹外侧(rostral ventrolateral medulla,RVLM)区和内侧缰核(medial habenular nucleus,MHb)神经元活动间的可能性联系。运用在体多通道同步记录技术结合荧光金(FluoroGold,FG)逆向示踪等技术,同步记录神经元自发放电和多项外周生理指标,并观察荧光金逆行标记神经元分布。结果显示,PTSD组大鼠RVLM、MHb神经元放电频率及收缩压和平均动脉压均显著高于正常对照组(P<0.05)。微量注射0.5μL 4%FG至RVLM区,MHb区神经元被逆行标记;电刺激MHb后,正常对照组大鼠RVLM神经元放电频率在100~500μA下较刺激前明显升高(P<0.05或P<0.01),心率在100~300μA下较刺激前显著加快(P<0.05),收缩压和平均动脉压在200~300μA下较刺激前显著上升(P<0.05);相比之下,PTSD组大鼠仅RVLM放电频率在100~300μA下较刺激前明显升高(P<0.05)。以上结果提示,PTSD模型大鼠的心血管功能活动增强,该变化可能与RVLM、MHb神经元活动以及二者之间潜在的神经通路联系有关。

This study was aimed to investigate the cardiovascular function in rats with post-traumatic stress disorder(PTSD)and the potential association with the activities of the rostral ventrolateral medulla(RVLM)and the medial habenular nucleus(MHb).Multi-channel in vivo recordings were used to simultaneously acquire spontaneous neuronal firing and peripheral physiological indices,and FluoroGold(FG)retrograde tracing technique was used to observe the projections of labeled neurons in the MHb.The results showed that the discharge frequency of RVLM and MHb neurons,the systolic blood pressure(SBP),and the mean arterial pressure(MAP)in the PTSD group were all increased significantly compared with those in control group(P<0.05).MHb neurons were retrogradely labeled by FG through microinjection(4%FG,0.5μL)into the RVLM.In the control group,electrical stimulation in the MHb increased heart rate(HR)at 100–300μA(P<0.05),elevated SBP and MAP at 200–300μA(P<0.05),and remarkably increased the RVLM neuronal discharge frequency at 100–500μA(P<0.05 or P<0.01).In the PTSD group,however,only the discharge frequency of RVLM neurons was increased by the electrical stimulation at 100–300μA(P<0.05).These results suggest that cardiovascular activities of the PTSD model rat are enhanced,and this change may be related to the activity changes of RVLM and MHb and the potential connection between the two nuclei.