Funding for this research was provided by:
National Natural Science Foundation of China (No. 81271173)
Article History
Received: 8 November 2017
Accepted: 9 April 2018
First Online: 20 April 2018
Ethics approval
: The experimental protocols were approved by the Animal Use and Care Committee of Peking University, China, and were consistent with the Ethical Guidelines of the International Association for the Study of Pain. All efforts were made to minimize the number of animals used and their suffering.
: The authors declare that they have no competing interests.
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