SOMATOTOPIC PROJECTION OF THE RAPHE NUCLEI TO THE SPINAL DORSAL HORN IN THE CAT. A HORSERADISH PEROXIDASE STUDY
- VernacularTitle:猫中缝核至脊髓后角之体部定位投射——辣根过氧化物酶法研究
- Author:
Gong JU
;
Siyun SHU
- Publication Type:Journal Article
- From:
Acta Anatomica Sinica
1953;0(01):-
- CountryChina
- Language:Chinese
-
Abstract:
It is well known anatomically and physiologically that the raphe nuclei project to the spinal cord. No definite data on somatotopic raphe-spinal relationship, however, are available. The raphe nuclei, especially the nucleus raphe magnus, were found to inhibit nociceptive transmission and pain reflexes in the spinal cord, and they presumably play an important role in acupuncture analgesia. Thus, the question on whether there is a somatotopic raphe-spinal projection has much to do with the analysis of the function of the raphe nuclei and the evaluation of their possible role in acupuncture analgesia. 11 cats were used in the present study. Horseradish peroxidase (HRP) was injected into the dorsal horn of the 7th cervical or 4,5th lumbar spinal cord and labelled cells were traced in the raphe nuclei. In the cases of cervical cord injection, labelled cells were found in the nucleus raphe magnus, nucleus raphe pallidus and nucleus raphe obscurus. In the lumbar injections only the nucleus raphe. magnus and nucleus raphe pallidus were labelled. The labellcd cells were distributed over relatively wide areas in the raphe nuclei after HRP injection into single spinal segments. Nevertheless, a certain degree of somatotopic relationship existed. In the nucleus raphe magnus cells projecting to G7 were distributed more rostrally and those projecting to L4,5, more caudally. In the nucleus raphe pallidus, on the contrary, cells to C7 were located more caudally while those to L4,5 more rostrally. A definite, though diffuse to a certain degree, somatotopie raphe-spinal projection is consistent with the extent of analgesia during acupuncture or electrical stimulation of the nucleus raphe magnus, thus favours the hypothsis of the role of descending inhibition from the raphe nuclei in acupuncture analgesia, and provides a possible explanation for the relative specificity of acupuncture points in their fields of analgesia.
