THE SOMATOTOPICAL PATTERN OF THE SPINAL PROJECTION TO THE LATERAL RETICULAR NUCLEUS OF THE RABBIT. AN ANTEROGRADE HRP STUDY / 解剖学报

ABSTRACT

The somatotopical pattern of the spinal projection to the lateral reticular nucleus (LRN) was examined in 16 rabbits. The anterograde transport of HRP method were used.1. Cervical, thoracic and lumbar segments all gave rise to small numbers of fibers projecting to bilateral lateral reticular subtrigeminal subnucleus (Lrs).2. Cervical, thoracic and lumbar projections to the LRN were bilateral but the cervical ascending fibers terminated predominately on the ipsilateral side. The lumbar ascending fibers projected chiefly to the contralateral side. The thoracic cord gave fibers to bilateral LRN. No significant difference could be seen between the two sides. There were certain overlapping among the distribution areas of the terminal branches from different parts of the cord.3. The spinal projections of the rabbit were predominately terminated in the caudal half of the LRN. It showed a somatotopical pattern. The cervical cord projected to the lateral 3/5 of the lateral reticular magnocellular subnucleus (Lrm) and its neighbouring part of the lateral reticular parvocellular subnucleus (Lrp). The thoracic cord projected to the medial 3/5 of the Lrm and its neighbouring part of Lrp. The lumbar cord gave afferents to the Lrp and its neighbouring part of Lrm.