Question: why do you still feel pain if your motor neurons stop working probably?

Martha Havenith answered on 18 Jun 2015:

Hi Aria, the reason is that the brain generally tends to divide tasks so that they get done by different groups of neurons. So there is a bunch of pain sensors all along your skin (and in your bones, gut etc.). Their signals get passed on in a bundle along the spine into the brain, and in the brain there is a specific group of neurons that only deals with feeling pain. It’s even separate from other neurons that deal with feeling normal touch. So if you lost all your pain neurons you could touch a hot stove, feel its surface on your skin, but not notice any pain. Anyways, those pain neurons communicate with a lot of other neuron groups in the brain, and the motor neurons are definitely one of the biggest connections – after all you want to be able to move away from something harmful as quickly as possible. That’s why some connections between pain and motor neurons even happen in the spine without going to the brain at all. Those connections make you have reflexes like jumping when you tread on something sharp – you don’t even have to think about it. So it makes sense that the feeling of pain and the motor response feels super-connected to us (they are), but they are not done by the same neurons – that’s why you can still feel pain even if your motor neurons are messed up!