PNS

This shows the outline of two bodies. One has the head highlighted red, the other has the gut highlighted red

Where does Parkinson’s disease start? In the brain or gut? Or both?

Lewy body disorders, including Parkinson's disease and Lewy body dementia, comprise of two distinct subtypes. One subtype originates in the peripheral nervous system (PNS) of the gut and spreads to the brain. The other originates in the brain, or enters the brain via the olfactory system, before spreading to the brainstem and PNS.... Read More...
This image shows microglia passing from the CNS to PNS

Microglia, cells thought restricted to central nervous system, are redefined in new study

In response to injury, microglia cross the spinal boundary from the central nervous system to the peripheral nervous system. While in the PNS, microglia provide the function of clearing cellular debris at the point of injury, then return to the CNS in an altered state. Researchers propose this could account for some damage associated with neurodegenerative diseases.... Read More...