Spinal Cord

Publisher Summary This chapter deals with the gross anatomy, neuronal organization, cyto- and chemoarchitecture of the mouse spinal cord, and refers to the rat, cat and other species where there is no relevant information on the mouse. The spinal cord is the part of the central nervous system that conducts sensory information from the peripheral nervous system to the brain, and motor information from the brain to muscular or glandular tissue. Information regarding the organization of the spinal cord in the mouse is sparse, partly due to the relative difficulties in applying experimental techniques to a very small animal. With the recent advance in molecular biological techniques, genetically-characterized or manipulated inbred strains have been widely used, particularly transgenic mouse lines in which specific proteins or signal transduction components have been altered through genetic knockout technology. Although the general organization of the spinal cord is similar among mammalian species, there are some differences in the connections and neuronal organization that makes the study of the mouse spinal cord necessary. The mouse spinal cord is a slender, almost cylindrical, white structure, which is slightly flattened dorsoventrally. It extends from the caudal end of the hindbrain at the foramen magnum to the lower part of the vertebral column. The most caudal part of the spinal cord reaches the level of the sixth lumbar vertebra, and the spinal dura extends to second caudal vertebra. It also describes the distribution of the major transmitter substances in the spinal cord—acetylcholine, substance P, serotonin (5-hydroxytryptamine), noradrenaline, and dopamine.