Abstract:

he dorsal column nuclei consist of gracile, cuneate and external cuneate nuclei. The fiber projections from the spinal cord to the dorsal column nuclei were studied with anterograde transported phaseolus vulgaris leucoagglutinin (PHA-L ) in rat. In case of injections into the cervical enlargement the labeled fibers were seen in the lateral region of the dorsal part of the dorsal column (corticospinal tract in the ventral.part of the dorsal column) and labeled terminations were distributed in the cuneate and the external cuneate nuclei. In case of injections into the thoracic cord the labeled fibers could be found in the median region and labeledterminations in the medial part of cuneate nucleus and lateral part of gracile nudeus. In case of injections into the lumbar enlargement the labeled fibers were in the medial region and labeled terminations in most of the gracile nucleus. In case of injections into the sacral cord the labeled fibers were in the most medial region and labeled terminations in the most medial part of gracile nucleus. Experimental results showed that the fiber projections from the spinal cord to the dorsal column nuclei have distinct topographical distributions.

Key words: dorsal column nuclei, spinal dorsal column, PHA-L, anterograde tract tracing, rat