Methods HE staining was applied on the frozen sections of adult rat heart to identify the sinoatrial node (SAN), atrioventricular node (AVN), and posterior nodal extension (PNE).

• 方法制备成年大鼠心脏冰冻切片，结合大体位置和HE染色结果快速辨认出窦房结、房室结和结后延伸。