library_construction_protocol: Neurosurgery-obtained fresh human brain specimens were lightly fixed with formalin and broken down to single nuclei with cytoplasmatic fractions. The cell suspensions were next stained cell-type-specific antibodies (NeuN for neurons, Iba1 for microglia, Gfap for astrocytes, Olig2 for oligodendrocytes) and FACS-sorted to distinct cell type populations. RNA from FACS-sorted cell populations was extracted using the RNeasy FFPE kit (Qiagen, 73504), according to the manufacturer's instructions. Libraries were constructed using the D-Plex Small RNA-seq Kit from Illumina (Diagenode, C05030001), using 500 and 1000 pg/sample in Batch 1 and Batch 2, respectively.