Explanation of white matter (noun) form: no plural nerve tissue of the central nervous system that is pale in comparison to the gray matter because it contains more nerve fibers (the myelin covering the nerve fibers is white)
Sample of white matter Most of the cerebrum is made of white matter.
Explanation of electrical synapse (noun) form: no plural a junction between two nerve endings
Sample of electrical synapse At an electrical synapse the action potential passes from one cell to the other without neurotransmitters mediating the process.