<p>Diabetic cardiac autonomic neuropathy (DCAN) represents a significant and prevalent complication of diabetes. Further research is required to ascertain the role of the P2Y12 receptor, which is expressed on macrophages and satellite glial cells (SGCs), in the pathophysiology of DCAN. The objective of this study was to ascertain whether resident macrophages in the superior cervical ganglion (SCG) are involved in the pathological changes associated with DCAN, which are mediated by the P2Y12 receptor in satellite glial cells (SGCs). The findings showed that DCAN rats had higher sympathetic nerve discharge activity than the control group. Furthermore, the expression of P2Y12 receptor, glial fibrillary acidic protein (GFAP), macrophage-like targets (colony-stimulating factor 1 receptor (CSF1R), colony-stimulating factor 1 (CSF1)), and interleukin-34 (IL-34) in SCG among DCAN rats was clearly elevated. Moreover, co-expression levels of NeuN and CSF1 in neurons, P2Y12 and GFAP as well as P2Y12 and IBA-1 in SCGs were increased. However, treatment with P2Y12 shRNA led to significant reductions in all above parameters. The action mechanism may involve reducing the expression of P2Y12 receptors in macrophages and SGCs, decreasing the expression of CSF1 in SCG neurons to weaken the CSF1-CSF1R signal, inhibiting the activation of macrophages and SGCs, and reducing the release of inflammatory factors. This ultimately alleviated abnormal neuronal excitation in SCG and maintaining balance in cardiac autonomic nervous activity. Therefore, targeting the P2Y12 receptor to disrupt the resident macrophages participate in pathological changes, may be an effective approach for improving DCAN.</p> Graphical Abstract <p></p>