Griffiths I R, McCulloch M C, Barrie J A, Kyriakides E
Applied Neurobiology Group, University of Glasgow, Bearsden, UK.
J Neurocytol. 1991 May;20(5):396-403. doi: 10.1007/BF01355536.
This study examines whether there is a relationship between the abundance of expression for P0 mRNA in myelinated Schwann cells and fibre diameter. Individual teased sciatic nerve fibres from young adult rats were hybridized with radiolabelled probe for P0 mRNA which is expressed in the perinuclear cytoplasm of the mid-internode. Signal intensity was measured as optical density of the developed autoradiograms. A highly significant positive linear correlation was present between signal intensity and fibre diameter. In a companion study, individual fibres were mounted in Araldite resin and transversely serially sectioned at 4 microns for autoradiography. Grain densities were determined for fibres of different diameters. Again, larger diameter fibres were associated with higher grain densities. The results indicate that the abundance of P0 mRNA expressed by a myelin-producing Schwann cell is related to fibre diameter with axonal size probably being the critical determinant. Axons may regulate P0 expression through the number of signalling molecules exposed on or released from the axolemma.
本研究探讨有髓雪旺细胞中P0 mRNA的表达丰度与纤维直径之间是否存在关联。从年轻成年大鼠分离出的单根坐骨神经纤维，与用于标记P0 mRNA的放射性探针杂交，P0 mRNA在节间中部的核周细胞质中表达。信号强度通过显影后的放射自显影片的光密度来测量。信号强度与纤维直径之间存在高度显著的正线性相关。在一项配套研究中，将单根纤维嵌入环氧树脂中，以4微米的厚度进行横向连续切片用于放射自显影。测定不同直径纤维的颗粒密度。同样，较大直径的纤维与较高的颗粒密度相关。结果表明，产生髓鞘的雪旺细胞表达的P0 mRNA丰度与纤维直径有关，轴突大小可能是关键决定因素。轴突可能通过暴露在轴膜上或从轴膜释放的信号分子数量来调节P0的表达。
