Actin is one of the most essential proteins of cells. In the past, super-resolution microscopy technique, such as STORM or STED, was used to visualize the nanoscale details of actin filaments of cultured cells. However, super-resolution of actin in thick tissue slices is still challenging, as actin is highly expressed in almost all cell types, and it forms a very dense network structure. Here, we demonstrate the super-resolution, volumetric, and three-dimensional imaging of actin and associated proteins of the brain via expansion microscopy. Visualization of actin and various associated proteins of the brain would provide us the molecular information on how the mechanical properties of neurons are regulated and how molecular transportation inside neurons are controlled.