How brain immune cells shield injured spinal cords
Researchers at the Hong Kong University of Science and Technology have made significant strides in understanding spinal cord injuries (SCI) by highlighting the role of microglia, the primary immune cells in the central nervous system. These cells have been shown to play a crucial neuroprotective role in preventing axonal degeneration, a common consequence of SCI. An axon is a long, thin extension of a neuron that carries electrical signals away from the cell body.
Traditionally, the study of axonal damage and regeneration has been hindered by the lack of suitable imaging tools. However, a multidisciplinary team led by Professors Jianan Qu and Kai Liu employed advanced multimodal microscopy and optical clearing techniques to observe these processes in vivo. Their research revealed that microglia form direct contacts with myelinated axons at the Nodes of Ranvier—gaps in the myelin sheath that facilitate rapid nerve impulse conduction.
Following an injury, microglia transform their contact into a protective wrapping around the axons. This interaction prevents further degeneration, highlighting a potential therapeutic target for SCI treatment. Additionally, the study found that inhibiting voltage-gated sodium channels can delay axonal degeneration, suggesting another avenue for intervention.
These findings, published in Nature Communications with Wanjie Wu, Yingzhu He, and Yujun Chen as first authors, not only deepen our understanding of neuronal diseases but may open new avenues for developing targeted therapies. The research also underscores the importance of cross-disciplinary collaboration in addressing complex neurological challenges.