Dubový P, Svízenská I
Department of Anatomy, Medical Faculty, Purkynĕ University, Brno, Czechoslovakia.
Acta Histochem. 1990;88(1):77-91. doi: 10.1016/S0065-1281(11)80250-3.
Mouse digital corpuscles, located in the dermal papillae of toe pad skin, consist of the sensory axon terminals enveloped by the cytoplasmic processes of Schwann-derived cells forming the so-called inner core. The inner core cells are capable to synthetize nCHE molecules which are released into the interlamellar spaces filled by the basal lamina, collagenous microfibrils, and amorphous matrix. In the present study, the histochemical detection of the nCHE activity was investigated in the sensory corpuscles after sciatic and saphenous nerve transections and subsequent application of irreversible nCHE inhibitor (iso-OMPA) or cryo-treatment of toe pad skin. The recovery of the nCHE reaction product in both intact and denervated corpuscles revealed the resynthesis of the nCHE molecules by the inner core cells without assistance of sensory terminals, as well. The cellular constituents of corpuscles were degraded while extracellular matrix appeared to be undamaged after freezing injury. The molecules of nCHE attached to the extracellular matrix components disappeared in coincidence with the disintegration of Schwann-derived cells. After about 5 d of survival, the Schwann cells exhibiting the nCHE reactivity migrated through the basal lamina tubes as guidance of regrowing axons or alone. After 7 d from the treatment, immature Schwann cells marked by the nCHE reaction product occupied the scaffolds of old damaged sensory corpuscles. During further days of surviving, the Schwann cells entering the extracellular matrix of degraded corpuscles were differentiated to the inner core cells. The re-differentiation of the Schwann cells into the inner core cells was observed not only in the presence but also in the absence of sensory terminals. These findings suggest certain trophic independence of inner core cells upon sensory terminals in the sensory corpuscles of adult animals.
小鼠趾部小体位于趾垫皮肤的真皮乳头内，由感觉轴突终末组成，这些终末被施万细胞衍生的细胞的胞质突起所包裹，形成所谓的内核。内核细胞能够合成nCHE分子，这些分子被释放到由基膜、胶原微纤维和无定形基质填充的层间空间中。在本研究中，在坐骨神经和隐神经横断以及随后应用不可逆的nCHE抑制剂（异-OMPA）或对趾垫皮肤进行冷冻处理后，对感觉小体中nCHE活性进行了组织化学检测。完整和去神经小体中nCHE反应产物的恢复也表明，内核细胞在没有感觉终末协助的情况下也能重新合成nCHE分子。冷冻损伤后，小体的细胞成分降解，而细胞外基质似乎未受损。附着在细胞外基质成分上的nCHE分子随着施万细胞衍生细胞的解体而消失。存活约5天后，表现出nCHE反应性的施万细胞作为再生轴突的引导或单独穿过基膜管迁移。处理7天后，以nCHE反应产物标记的未成熟施万细胞占据了旧的受损感觉小体的支架。在存活的进一步天数中，进入降解小体细胞外基质的施万细胞分化为内核细胞。不仅在有感觉终末的情况下，而且在没有感觉终末的情况下，都观察到施万细胞重新分化为内核细胞。这些发现表明，成年动物感觉小体中的内核细胞在营养方面对感觉终末具有一定的独立性。
