neurofibril

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of the long, thin, microscopic fibrils that run through the body of a neuron and extend into the axon and dendrites.

from The Century Dictionary.

• noun Same as neurofibrilla.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun anatomy Any of a group of microscopic fibrils through the body of a neuron that extend into the axon and dendrites