Prepulse inhibition(PPI) refers to a decreased response to a startling stimulus when another weaker stimulus precedes it. Most PPI studies have focused on the physiological startle reflex and fewer have reported the P...Prepulse inhibition(PPI) refers to a decreased response to a startling stimulus when another weaker stimulus precedes it. Most PPI studies have focused on the physiological startle reflex and fewer have reported the PPI of cortical responses. We recorded local field potentials(LFPs) in four monkeys and investigated whether the PPI of auditory cortical responses(alpha, beta, and gamma oscillations and evoked potentials) can be demonstrated in the caudolateral belt of the superior temporal gyrus(STGcb). We also investigated whether the presence of a conspecific, which draws attention away from the auditory stimuli, affects the PPI of auditory cortical responses. The PPI paradigm consisted of Pulse-only and Prepulse + Pulse trials that were presented randomly while the monkey was alone(ALONE) and while another monkey was present in the same room(ACCOMP). The LFPs to the Pulse were significantly suppressed by the Prepulse thus, demonstrating PPI of cortical responses in the STGcb. The PPI-related inhibition of the N1 amplitude of the evoked responses and cortical oscillations to the Pulse were not affected by the presence of a conspecific. In contrast, gamma oscillations and the amplitude of the N1 response to Pulse-only were suppressed in the ACCOMP condition compared to the ALONE condition. Thesefindings demonstrate PPI in the monkey STGcb and suggest that the PPI of auditory cortical responses in the monkey STGcb is a pre-attentive inhibitory process that is independent of attentional modulation.展开更多
目的采用低频振幅(amplitude of low frequency fluctuation,ALFF)初步探索轻度认知障碍(mild cognitive impairment,MCI)患者言语流畅性下降的脑机制。材料与方法前瞻性纳入20例MCI患者(MCI组)及16例性别、年龄、受教育程度相匹配的健...目的采用低频振幅(amplitude of low frequency fluctuation,ALFF)初步探索轻度认知障碍(mild cognitive impairment,MCI)患者言语流畅性下降的脑机制。材料与方法前瞻性纳入20例MCI患者(MCI组)及16例性别、年龄、受教育程度相匹配的健康人作为对照组(健康对照组),入组前分别采集两组临床资料、神经心理学量表和静息态功能磁共振(resting-state functional magnetic resonance,rs-fMRI)数据。采取ALFF分析方法,比较MCI组与健康对照组静息态脑功能差异,并进一步采用Spearman相关分析分别观察ALFF变化的脑区与言语流畅性测试量表的相关性。结果与健康对照组比较,MCI组患者右侧岛叶/颞上回ALFF降低(高斯随机场校正,voxel P<0.005,cluster P<0.05)。未发现ALFF升高脑区。降低的ALFF值与蒙特利尔认知量表基础版的流畅性测试有显著的正相关性(r_(s)=0.500,P=0.025)。结论MCI存在右侧岛叶/颞上回大脑活动降低,可能是患者言语流畅性下降的原因。展开更多
基金supported by the aivo AALTO Project of Aalto Universitythe Academy of Finland(a grant No.P273147,a Project No.T31116,and the International Program/ChinaFinland 2014-2016)the National Natural Science Foundation of China(31271168)
文摘Prepulse inhibition(PPI) refers to a decreased response to a startling stimulus when another weaker stimulus precedes it. Most PPI studies have focused on the physiological startle reflex and fewer have reported the PPI of cortical responses. We recorded local field potentials(LFPs) in four monkeys and investigated whether the PPI of auditory cortical responses(alpha, beta, and gamma oscillations and evoked potentials) can be demonstrated in the caudolateral belt of the superior temporal gyrus(STGcb). We also investigated whether the presence of a conspecific, which draws attention away from the auditory stimuli, affects the PPI of auditory cortical responses. The PPI paradigm consisted of Pulse-only and Prepulse + Pulse trials that were presented randomly while the monkey was alone(ALONE) and while another monkey was present in the same room(ACCOMP). The LFPs to the Pulse were significantly suppressed by the Prepulse thus, demonstrating PPI of cortical responses in the STGcb. The PPI-related inhibition of the N1 amplitude of the evoked responses and cortical oscillations to the Pulse were not affected by the presence of a conspecific. In contrast, gamma oscillations and the amplitude of the N1 response to Pulse-only were suppressed in the ACCOMP condition compared to the ALONE condition. Thesefindings demonstrate PPI in the monkey STGcb and suggest that the PPI of auditory cortical responses in the monkey STGcb is a pre-attentive inhibitory process that is independent of attentional modulation.
文摘目的采用低频振幅(amplitude of low frequency fluctuation,ALFF)初步探索轻度认知障碍(mild cognitive impairment,MCI)患者言语流畅性下降的脑机制。材料与方法前瞻性纳入20例MCI患者(MCI组)及16例性别、年龄、受教育程度相匹配的健康人作为对照组(健康对照组),入组前分别采集两组临床资料、神经心理学量表和静息态功能磁共振(resting-state functional magnetic resonance,rs-fMRI)数据。采取ALFF分析方法,比较MCI组与健康对照组静息态脑功能差异,并进一步采用Spearman相关分析分别观察ALFF变化的脑区与言语流畅性测试量表的相关性。结果与健康对照组比较,MCI组患者右侧岛叶/颞上回ALFF降低(高斯随机场校正,voxel P<0.005,cluster P<0.05)。未发现ALFF升高脑区。降低的ALFF值与蒙特利尔认知量表基础版的流畅性测试有显著的正相关性(r_(s)=0.500,P=0.025)。结论MCI存在右侧岛叶/颞上回大脑活动降低,可能是患者言语流畅性下降的原因。
