Home ยป The substance that is released at axonal endings to propagate a nervous impulse is called Nervous System MCQs The substance that is released at axonal endings to propagate a nervous impulse is called September 22, 2022 4 Views Q. The substance that is released at axonal endings to propagate a nervous impulse is called: an ionnerve gluea neurotransmitterthe sodium-potassium pumpan action potential Answer: a neurotransmitter