THE ORIENTATIONAL PROJECTIONS OF SENSORY FIBRES OF MEDIAN NERVE TO THE SUBSTANTIA GELATINOSA OF THE SPINAL CORD IN RATS——AN ACID PHOSPHATASE TECHNIQUE / 解剖学报

ABSTRACT

The orientational projections of sensory fibres of median nerve to the Substantia Gelatinosa (SG) of the spinal cord in rats were studied in accordance with the principle of transganglion degeneration by using the acid phosphatase technique. It was found longitudinally that the afferent fibres of the median nerve projected chiefly to SG from the upper part of C_5 to middle part of T_1. In a few rats, projections extended to middle and lower part of C_4 and lower part of T_1. In comparison with the records in anatomy literature and data from researches with HRP technique, a tendency of pre-positioning was noted. The regional projections of the afferent fibres of median nerve were found within the centre line of SG, and mainly in the region of the medial 1/4-1/2 of the medial half. In the segments of C_7-T_1 of a few rats, the whole area of the medial half of SG was projected. In observing the projections of the afferent fibres of median nerve, it was found that they have a tendency of lateralward increase from cranial portion to caudal portion.