the tissue in the bodies of animals

the sensory and control apparatus consisting of a network of nerve cells

a bundle of fibers (especially nerve fibers)

the complex network of unmyelinated axones, dendrites, and glial branches that form the bulk of the central nervous system's grey matter and in which nerve cell bodies are embedded

greyish nervous tissue containing cell bodies as well as fibers; forms the cerebral cortex consisting of unmyelinated neurons

whitish nervous tissue of the CNS consisting of neurons and their myelin sheaths

the sensory and control apparatus consisting of a network of nerve cells