I just read something in a book, written in the 1940s by a doctor of, shall we say, questionable repute:
Now, I learned in my high school biology class that nerve cells send signals to the muscles they’re connected to, which cause the muscle cells to contract. But the way this author describes it, it sounds like the nerve cells – or at least the glial cells that accompany the nerve cells – are themselves contracting and expanding.
Do nerves actually move when they fire impulses? Or was this doctor merely seeing the movements of the muscles in the the immediate vicinity of the nerves, which were pulling the nerves along with them?
The technical name for a neuron firing is an “action potential”. In short, the doctor is full of it. Neurons communicate with each other by releasing neurotransmitter across a synapse when an action potential is generated. The size of the synapse is very important in how effective this communication is. If neurons were moving around at all, it would wreak havoc with the delicate balance of the system. Not true at all.
The technical name for a neuron firing is an “action potential”. In short, the doctor is full of it. Neurons communicate with each other by releasing neurotransmitter across a synapse when an action potential is generated. The size of the synapse is very important in how effective this communication is. If neurons were moving around at all, it would wreak havoc with the delicate balance of the system. Not true at all.
Okay, neurons don’t budge when they release neurotransmitters in their end-buttons, or when they receive neurotransmitters at the “starting points” (whatever they’re called) of their dendrites.
But do neurons move when an electrical impulse conducts down their length? (Not necessarily in such a way that the synaptic gap changes; the neurons might be waving sideways and carrying their neighbors with them. After all, the nerves in my arm have to move when I bend my elbow or my wrist, just to keep up with the rest of my arm (even though it’s my muscles that are actually contracting and causing my arm to move), so obviously it’s possible for neurons to move around without wreaking havok with their synaptic-system balance.)
And if not, do the rest of the cells making up the nerve (the glial cells) move in response to this impulse travelling down the neuron or in response to the release of neurotransmitters?