Diencephalic projections from the superficial and deep laminae of the medullary dorsal horn in the rat.

摘要: An important function of the medullary dorsal horn (MDH) is relay nociceptive information from face and mouth to higher centers central nervous system. We studied projection pattern axons arising MDH by examining axonal transport Phaseolus vulgaris-leucoagglutinin (PHA-L). Labeled axon terminal distributions were analyzed at light microscopic level. After large injections PHA-L into both superficial deep laminae in rat, labeled observed nucleus submedius thalamus (SUB), ventroposterior thalamic medialis (VPM), parvicellularis (VPPC), posterior nuclei (PO), zona incerta (ZI), lateral hypothalamic (LH), (PH). Restriction only resulted heavy varicosity labeling SUB, VPM, PO, VPPC LH. In contrast, after laminae, mainly distributed ZI PH; some also VPM LH, fewer still PO SUB. Varicosities significantly larger than those VPPC, ZI, PH. Varicosity density was highest SUB lowest VPPC. We concluded that there are two distinct pathways, one originating terminating primarily diencephalon second ventral diencephalon. propose input deeper involved motivational-affective component pain, whereas related sensory-discriminative pain. Published 1992 Wiley-Liss, Inc.