Abstract: ObjectiveTo investigate the expression of synaptotagmin 1 (Syt 1) in the anterior cingulate cortex of mice with neuropathic pain and its relationship with pain behavior. MethodsA total of mice weighting 20-25 g were randomly divided into four groups: Group Sham+Syt antibody (Syt-Ab), Group Sham+Control-IgG (Con-IgG), Group chronic constriction injury (CCI)+Syt-Ab and Group CCI+Con-IgG. Corresponding drugs (0.1 μg/0.5 μl) were stereotaxically injected into the anterior cingulate cortex of mice in each group on Day 7 of CCI. The changes of thermal hyperalgesia were measured by the Hargreaves method. The changes of mechanical paw withdrawal threshold were determined by an electronic dolorimeter. The level of Syt 1 in the anterior cingulate cortex of each group was detected by Western blotting. ResultsThe amount of Syt 1 was remarkably increased in the anterior cingulate cortex of mice with neuropathic pain. Stereotactic injection of Syt 1 Ab could significantly improve pain behavior. ConclusionsThe expression of Syt 1 is significantly increased in the anterior cingulate cortex of mice with neuropathic pain. The pain can be relieved by stereotaxic injection of Syt 1 Ab in the anterior cingulate cortex.