Microglia are the first immune responders after injury or impairment of the nervous system. They rush to the site of impact and take up any dying cells or pathogens that might harm the environment. 

Time-lapse video of a microglia response after a neuron degenerates in the zebrafish spinal cord (link to publication).

Microglia are resident immune cells and comprise ~10% of the cells in the CNS. They survey the CNS environment and undergo morphological and biochemical changes in response to disruptions such as injury, pathology, or ageing. This process is termed microglial ‘activation’, describing the rapid proliferation, migration to the region of interest, and biochemical changes such as production of chemokines and cytokines.

Additional detail can be extracted through image processing.

If you are interested in microglia and other glial cells and their role in dementia and MND, please have a closer look at our research publications and/or these two reviews below: