Potentiation of synaptic transmission in Rat anterior cingulate cortex by chronic itch.
Ting-Ting Zhang, Feng-Yan Shen, Li-Qing Ma, Wen Wen, Bin Wang, Yuan-Zhi Peng, Zhi-Ru Wang, Xuan Zhao
Author Information
Ting-Ting Zhang: Department of Anesthesiology and Intensive Care Medicine, Xinhua Hospital, College of Medicine, Shanghai Jiaotong University, Shanghai, 200092, China.
Feng-Yan Shen: Department of Anesthesiology, Huashan Hosptital, Fudan University, Shanghai, 200040, China.
Li-Qing Ma: Department of Anesthesiology, Huashan Hosptital, Fudan University, Shanghai, 200040, China.
Wen Wen: Department of Anesthesiology and Intensive Care Medicine, Xinhua Hospital, College of Medicine, Shanghai Jiaotong University, Shanghai, 200092, China.
Bin Wang: Department of Anesthesiology and Intensive Care Medicine, Xinhua Hospital, College of Medicine, Shanghai Jiaotong University, Shanghai, 200092, China.
Yuan-Zhi Peng: Department of Anesthesiology and Intensive Care Medicine, Xinhua Hospital, College of Medicine, Shanghai Jiaotong University, Shanghai, 200092, China.
Zhi-Ru Wang: Institute of Brain Functional Genomics, East China Normal University, Shanghai, 200062, China.
Xuan Zhao: Department of Anesthesiology and Intensive Care Medicine, Xinhua Hospital, College of Medicine, Shanghai Jiaotong University, Shanghai, 200092, China. zhaoxuan0323@hotmail.com.
Itch and pain share similar mechanisms. It has been well documented that the anterior cingulate cortex (ACC) is important for pain-related perception. ACC has also been approved to be a potential pruritus-associated brain region. However, the mechanism of sensitization in pruriceptive neurons in the ACC is not clear. In current study, a chronic itch model was established by diphenylcyclopropenone (DCP) application. We found that both the frequency and amplitude of miniature excitatory postsynaptic currents in the ACC were enhanced after the formation of chronic itch. The paired-pulse ratio in ACC neurons recorded from the DCP group were smaller than those recorded in control group at the 50-ms interval. We also observe a significant increase in the AMPA/NMDA ratio in the DCP group. Moreover, an increased inward rectification of AMPARs in ACC pyramidal neurons was observed in the DCP group. Interestingly, the calculated ratio of silent synapses was significantly reduced in the DCP group compared with controls. Taken together, we conclude that a potentiation of synaptic transmission in the ACC can be induced by chronic itch, and unsilencing silent synapses, which probably involved recruitment of AMPARS, contributed to the potentiation of postsynaptic transmission.
