Home » Nervous System MCQs » 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 28 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 potentialAnswer: a neurotransmitter