Chapter 6 - Spinal Cord Cyto- and Chemoarchitecture

Abstract

The gray matter of the spinal cord comprises 10 laminae (layers) and a number of spinal cord nuclei. These laminae were first described by Rexed in transverse sections of the spinal cord of the cat on the basis of neuronal size, shape, cytological features and density. Neurons within a lamina show distinct dendritic architecture, chemoarchitecture and patterns of connection as well as function. A number of neurons in the spinal cord are organized as spinal cord nuclei. Of these, the lateral spinal and the lateral cervical nuclei are located in the white matter, and the remaining such as the central cervical nucleus, the intermediomedial nucleus, the internal basilar nucleus, the dorsal nucleus, and the intermediolateral and sacral parasympathetic nuclei are located in the gray matter. A large variety of neurochemical substances are found in neurons of Rexed’s laminae and spinal cord nuclei including acetylcholine, calbindin, calcitonin gene-related peptide, glutamate, nitric oxide and substance P.