<P> Grey matter refers to unmyelinated neurons and other cells of the central nervous system . It is present in the brain, brainstem and cerebellum, and present throughout the spinal cord . </P> <P> Grey matter is distributed at the surface of the cerebral hemispheres (cerebral cortex) and of the cerebellum (cerebellar cortex), as well as in the depths of the cerebrum (thalamus; hypothalamus; subthalamus, basal ganglia--putamen, globus pallidus, nucleus accumbens; septal nuclei), cerebellar (deep cerebellar nuclei--dentate nucleus, globose nucleus, emboliform nucleus, fastigial nucleus), brainstem (substantia nigra, red nucleus, olivary nuclei, cranial nerve nuclei). </P> <P> Grey matter in the spinal cord is known as the grey column which travels down the spinal cord distributed in three grey columns that are presented in an "H" shape . The forward - facing column is the anterior grey column, the rear - facing one is the posterior grey column and the interlinking one is the lateral grey column . The grey matter on the left and right side is connected by the grey commissure . The grey matter in the spinal cord consists of interneurons, as well as the cell bodies of projection neurons . </P> <Ul> <Li> <P> Diagram of a spinal vertebra . The grey matter is in the central part of the spinal cord . </P> </Li> <Li> <P> Cross-section of spinal cord with grey matter labelled . </P> </Li> </Ul>

Which structure links the right and left sides of the gray matter in the spinal cord