Höfundar:
Ebb Mohr Vang
Microglia cells and oligodendrocyte precursor cells (OPCs) are essential cells in the central nervous system, as they ensure that it remains in a healthy condition. Microglia are believed to play a role in synapse development, synapse function and are thought to assume countless states and functions depending on the age, environmental stimulus, and brain region. Additionally, OPCs are important for the maintenance of myelin, as they can differentiate into myelinating oligodendrocytes and therefore help with remyelination.
As the brain ages, microglia appear to become dystrophic or enter an altered state, which may contribute to different neurodegenerative diseases such as Multiple Sclerosis, Alzheimer’s or Parkinson’s. Meanwhile, OPCs seem to proliferate and differentiate at a lower rate in an ageing brain causing difficulties with remyelination. Myelin defects are considered an early pathological hallmark of ageing that occurs in oligodendrocytes before other cells show signs of degeneration. Additionally, microglia are believed to contribute to OPCs development and proliferation and that proinflammatory activation of microglia during demyelination seems to have cytotoxic events on oligodendrocytes, causing a negative loop of demyelination.
To see the effect that ageing has on microglia and OPCs, brains of different ages were sectioned and stained using a free-floating immunohistochemistry with DAPI as a nuclear stain, GFP for OPCs and Iba-1 for microglia. Following this the tissue was imaged using tiling in a confocal microscope, focusing on the motor cortex and the anterior cingulate area. OPCs and microglia were then quantified to calculate their density at various age points.