RESUMO
Microglia play multiple roles in such processes as brain development, homeostasis, and pathology. Due to their diverse mechanisms of functions, the complex sub-classifications, and the large differences between different species, especially compared with humans, very different or even opposite conclusions can be drawn from studies with different research models. The choice of appropriate research models and the associated tools are thus key ingredients of studies on microglia. Mice are the most commonly used animal models. In this review, we summarize in vitro and in vivo models of mouse and human-derived microglial research models, including microglial cell lines, primary microglia, induced microglia-like cells, transgenic mice, human-mouse chimeric models, and microglial replacement models. We also summarize recent developments in novel single-cell and in vivo imaging technologies. We hope our review can serve as an efficient reference for the future study of microglia.
RESUMO
Different physical and chemical stimuli are detected by the peripheral sensory receptors of dorsal root ganglion (DRG) neurons, and the generated inputs are transmitted via afferent fibers into the central nervous system. The gene expression profiles of DRG neurons contribute to the generation, transmission, and regulation of various somatosensory signals. Recently, the single-cell transcriptomes, cell types, and functional annotations of somatosensory neurons have been studied. In this review, we introduce our classification of DRG neurons based on single-cell RNA-sequencing and functional analyses, and discuss the technical approaches. Moreover, studies on the molecular and cellular mechanisms underlying somatic sensations are discussed.