Final answer:
The insulating material found around a neuron is called myelin. Myelin protects the axon and helps to increase the speed and efficiency of electrical impulses.
Step-by-step explanation:
The insulating material found around a neuron is called myelin. Myelin is made up of a lipid substance and is produced by either Schwann cells (in the peripheral nervous system) or oligodendrocytes (in the central nervous system). The myelin sheath protects the axon and helps to increase the speed and efficiency of electrical impulses.