We describe a novel mechanism that is able to synchronize neuronal cell death and glial phagocytosis of dying neurons in the Drosophila embryonic CNS.
The current work shows that dJNK signaling, which is active in certain embryonic neurons, normally dying through apoptosis, is able to synchronize excess neuronal death with upregulation of glial phagocytosis of dying neurons.
To confirm that 4Ig prevented neuronal death, we performed a Fluoro-Jade B staining, which reveals dying neurons.
However, quantification of DAC-labeled neurons showed no significant difference between embryos containing ectopic dJNK signaling in glia and control embryos, indicating that dJNK pathway activation in glia does not affect neuronal death but rather suggests faster elimination of already dying neurons.
Microglia have a critical role in host defense against invading microorganisms and their actions appear to influence neuronal proliferation, as well as contribute to the removal of dying neurons or cellular debris [ 3].
Once activated, the microglia are then able to remove dying neurons and other cells.
The pups had small brains with dying neurons chock-full of the virus; their developing retinas had involuted and shrunk into small gray nubs.
Hume, D.A., Perry, V.H. & Gordon, S. Immunohistochemical localization of a macrophage-specific antigen in developing mouse retina: phagocytosis of dying neurons and differentiation of microglial cells to form a regular array in the plexiform layers.
In all the veterans and athletes, Dr. McKee found the signature evidence of early phase C.T.E.: dead or dying neurons, abnormal clumps of a toxic protein and damaged axons, the fibers that transmit signals between nerve cells.
"Astrocytes can save the dying neurons".
Next, they looked for mutants with shortened life-spans and examined them for signs of dying neurons.
