trigonum cerebrale, fornix - an arched bundle of white fibers at the base of the brain by which the hippocampus of each hemisphere projects to the contralateral hippocampus and to the thalamus and mamillary bodies

nerve tissue, nervous tissue - tissue composed of neurons

nervous system, systema nervosum - the sensory and control apparatus consisting of a network of nerve cells

nerve, nervus - any bundle of nerve fibers running to various organs and tissues of the body