Pain free- Not if you are a mouse?
What causes a relapse, This study says it is Pain
We have had the idea that pressure of the limbs causes a gateway in the 5th Lumbar region of the mouse spine so that white blood cells enter the spine and cause EAE and to demonstrate this they hung mice upside down for months by the tail to show that the gate way could be moved to the front legs.
So in this study they induce EAE in C57BL/6 and they watch them for a year and a half to see if they get EAE. They don't
They then have the idea that pain triggers relapse so they tied facial nerves or injected irritants (Ultra hot chilli pepper type irritants) in the whiskers and feet and relapses occurred. They also sewed the animals together and gave transgenic mice a common blood flow and said monocytes from the blood cause the problem.
The first step is pain-mediated relapse was sensory activation followed by sympathetic activation.
The second step is pain-mediated sympathetic activation.
The third step for EAE relapse is the accumulation of pathogenic CD4+ T cells at the L5 ventral vessels
The fourth and final step is mediated by excessive chemokine expressions and is most likely triggered by the activation of the accumulated pathogenic CD4+ T cells in the third step.
However, the authors state in the discussion there does not seem to be a direct correlation clinically between pain intensity and MS disability or lesional load.
Do you get pain before your lesions start?
Hopefully someone will consider replicating the key experiment, because based on what I have seen, I am not sure the Gateway at L5 holds. If this is wrong maybe the pack of cards collapses.