library_construction_protocol: Mice were transcardial perfused, dissected out brain and placed in chilled 1xHBSS on ice. Then minced the brain with sterile scapel and disassociated with Papain Dissociation System (Worthington, #LK003150) according to the manufacturer's instructions. Library was performed accoding to the manufacturer's instructions(Chromium Next GEM Single Cell 3' Reagent Kits v3.1(Dual Index)).