DESCENDING FIBERS OF LATERAL FUNICULUS OF AMPHIBIAN SPINAL-CORD - THEIR COURSE AND TERMINAL DISTRIBUTION

  • 1 January 1978
    • journal article
    • research article
    • Vol. 125  (JAN) , 1-9
Abstract
The origin, course and termination of descending fibers of the lateral funiculus (LF) were investigated in the frog, Rana catesbeiana. Following unilateral transections of cervical LF fibers in 20 adult animals and survival periods of 3-28 days at room temperature, Nauta stained material revealed a massive projection to the central gray of the spinal cord. Some of these descending fibers were shown to decussate in the thoracic region and to terminate primarily in the intermediate gray of the lumbar cord. Terminal fields of ipsilateral fibers included areas of the motoneuron pool more often than did those of contralateral fibers. Although internuncial cells probably are involved in ipsilateral and contralateral fiber projections, these findings may also be interpreted in terms of a preference of the 2 fiber groups for different sites of the motoneuron cell membrane.