a nerve fiber which loops through the white matter under the cerebral cortex to link one cortical region to another one. U fibers supply the quickest path for cortical conveying of urges; the optional intracortical pathway is made up of extremely thin fibers with slow transmission rates.

U FIBER: "The U fibers are not present in the last few slides."
Cite this page: N., Pam M.S., "U FIBER," in PsychologyDictionary.org, April 29, 2013, https://psychologydictionary.org/u-fiber/ (accessed September 23, 2021).