Spatial and temporal plasticity of synaptic organization in anterior cingulate cortex following peripheral inflammatory pain: multi-electrode array recordings in rats  

作　　者：Yun-Fei Lu Yan Wang Ying He Fu-Kang Zhang Ting He Rui-Rui Wang Xue-Feng Chen Fei Yang Ke-Rui Gong Jun Chen 

机构地区：[1]Institute for Biomedical Sciences of Pain and Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University [2]Key Laboratory of Brain Stress and Behavior,PLA [3]Institute for Biomedical Sciences of Pain, Capital Medical University

出　　处：《Neuroscience Bulletin》2014年第1期1-20,共20页神经科学通报（英文版）

基　　金：supported by grants from the National Basic Research Development Program;Ministry of Science and Technology of China(2013CB835100;2013BAI04B04);the National Natural Science Foundation of China(81070899;81171049);a Military Project of China(AWS12J004)

摘　　要：To explore whether experiencing inflammatory pain has an impact upon intracortical synaptic organization, the planar multi-electrode array （MEA） technique and 2-dimensional current source density （2D-CSD） imaging were used in slice preparations of the anterior cingulate cortex （ACC） from rats. Synaptic activity across different layers of the ACC was evoked by deep layer stimulation through one electrode. The layer-localization of both local field potentials （LFPs） and the spread of current sink calculated by 2D-CSD analysis was characterized pharmacologically. Moreover, the induction of long-term potentiation （LTP） and changes in LTP magnitude were also evaluated. We found that under naive conditions, the current sink was initially generated in layer Ⅵ, then spread to layer Ⅴ and finally confined to layers Ⅱ-Ⅲ. This spatial pattern of current sink movement typically reflected changes in depolarized sites from deep layers （Ⅴ-Ⅵ） to superficial layers （Ⅱ-Ⅲ） where intra- and extra- cortical inputs terminate. In the ACC slices from rats in an inflamed state （for 2 h） caused by intraplantar bee-venom injection, the spatial profile of intra-ACC synaptic organization was significantly changed,showing an enlarged current sink distribution and a leftward shift of the stimulus-response curves relative to the naive and saline controls. The change was more distinct in the superficial layers （Ⅱ-Ⅲ） than in the deep site. In terms of temporal properties, the rate of LTP induction was significantly increased in layers Ⅱ-Ⅲ by inflammatory pain. However, the magnitude of LTP was not significantly enhanced by this treatment. Taken together, these results show that inflammatory pain results in distinct spatial and temporal plasticity of synaptic organization in the ACC, which may lead to altered synaptic transmission and modulation.To explore whether experiencing inflammatory pain has an impact upon intracortical synaptic organization, the planar multi-electrode array （MEA） technique and 2-dimensional current source density （2D-CSD） imaging were used in slice preparations of the anterior cingulate cortex （ACC） from rats. Synaptic activity across different layers of the ACC was evoked by deep layer stimulation through one electrode. The layer-localization of both local field potentials （LFPs） and the spread of current sink calculated by 2D-CSD analysis was characterized pharmacologically. Moreover, the induction of long-term potentiation （LTP） and changes in LTP magnitude were also evaluated. We found that under naive conditions, the current sink was initially generated in layer Ⅵ, then spread to layer Ⅴ and finally confined to layers Ⅱ-Ⅲ. This spatial pattern of current sink movement typically reflected changes in depolarized sites from deep layers （Ⅴ-Ⅵ） to superficial layers （Ⅱ-Ⅲ） where intra- and extra- cortical inputs terminate. In the ACC slices from rats in an inflamed state （for 2 h） caused by intraplantar bee-venom injection, the spatial profile of intra-ACC synaptic organization was significantly changed,showing an enlarged current sink distribution and a leftward shift of the stimulus-response curves relative to the naive and saline controls. The change was more distinct in the superficial layers （Ⅱ-Ⅲ） than in the deep site. In terms of temporal properties, the rate of LTP induction was significantly increased in layers Ⅱ-Ⅲ by inflammatory pain. However, the magnitude of LTP was not significantly enhanced by this treatment. Taken together, these results show that inflammatory pain results in distinct spatial and temporal plasticity of synaptic organization in the ACC, which may lead to altered synaptic transmission and modulation.

关 键 词：anterior cingulate cortex multi-electrodearray synaptic plasticity intracortical synapticorganization PAIN 

分 类 号：R363[医药卫生—病理学]