Sex is a primary reward and it is the basis of pair-bond formation in voles. The striatum is part of the neuronal circuitry underlying a remarkable pair-bond formation in which both partners remain monogamous. It is important to note that the role of the striatum extends beyond that of movement and reward.
in human nervous system: The spinal cord. Associated with local regions of the spinal cord and imposing on it an external segmentation are 31 pairs of spinal nerves, each of which receives and furnishes one dorsal and one ventral root.
Spinal Nerve Cross-Section. Spinal nerves are the peripheral nerves that connect the spinal cord to the diverse tissues of the body. Thirty-one pairs of spinal nerves extend from the spinal cord in the neck and back to supply the skin, muscles, and organs of the neck, trunk, and limbs. The 31 pairs of spinal nerves are named for the region of the vertebral column from which they exit the spinal cord.