Abstract
After injection of the HRP to the cervical, thoracic and lumbar spinal cord, the labelled neurons in the pontine and medullary reticular formation were observed.
The reticulospinal tract (RST) which originates in nucleus reticularis magnocellularis descended almost entirely ipsilaterally to the whole spinal cord. The RST which originates in nucleus reticularis gigantocellularis descended bilaterally to the whole spinal cord. The RST which originates in nucleus reticularis pontis caudalis descended bilaterally to the whole spinal cord.
The RST which originates in the nucleus reticularis gigantocellularis is important as a system which relays the information of the labyrinth to both ipsi-and contralateral sites of the whole spinal cord.
