Masland R H, Rizzo J F, Sandell J H
Program in Neuroscience, Harvard Medical School, Boston, Massachusetts 02114.
J Neurosci. 1993 Dec;13(12):5194-202. doi: 10.1523/JNEUROSCI.13-12-05194.1993.
Events traditionally called "developmental errors" are known to occur in both vertebrate and invertebrate nervous systems. This study was concerned with the frequency and mode of generation of such events in the mammalian retina. We studied three anomalous structures observed in the rabbit's retina after staining of the cell populations that accumulate indoleamines: type 3 cells, stray processes in the optic fiber layer, and displaced cells. They were counted in rabbit retinas prepared as whole-mounts, and in most cases topological maps were made. For comparison, the conventional indoleamine-accumulating amacrine cells and the tyrosine hydroxylase (TH)-positive cells, which are members of the mammalian retina's recognized complement of amacrine cells, were also counted. A further comparison was made with the number and distribution of TH-positive amacrine cells in highly inbred mice. The ordinary amacrine cells did not vary much in number from animal to animal. Especially in inbred mice, the reproducibility was striking: the extreme variation in number of TH amacrine cells between any two of the 14 retinas studied was 22%, and the mean difference between two eyes of individual mice was 2.5 +/- 1.7%. The three anomalous structures were rare and variable. Their numbers varied more than fourfold from animal to animal. However, their numbers in two eyes from the same animal varied by an overall average of only 14 +/- 10%. The anomalous structures were present in all rabbits, and their morphology was the same in all cases: they are under precise control by the developmental program. The anomalous cells share many phenotypic features with the regular amacrine cells of the indoleamine-accumulating class.(ABSTRACT TRUNCATED AT 250 WORDS)
传统上被称为“发育错误”的事件在脊椎动物和无脊椎动物的神经系统中均有发生。本研究关注此类事件在哺乳动物视网膜中的发生频率和产生方式。我们研究了在对积累吲哚胺的细胞群体进行染色后，在兔视网膜中观察到的三种异常结构：3型细胞、视神经纤维层中的游离突起以及移位细胞。我们在制备成整装片的兔视网膜中对它们进行计数，并且在大多数情况下绘制了拓扑图。为作比较，还对传统的积累吲哚胺的无长突细胞以及酪氨酸羟化酶（TH）阳性细胞进行了计数，这两类细胞是哺乳动物视网膜中公认的无长突细胞补体成员。另外还将其与高度近交系小鼠中TH阳性无长突细胞的数量和分布进行了比较。普通无长突细胞在不同动物个体间数量变化不大。特别是在近交系小鼠中，其重复性非常显著：在所研究的14个视网膜中的任意两个之间，TH无长突细胞数量的最大变化为22%，而单个小鼠两只眼睛之间的平均差异为2.5±1.7%。这三种异常结构很少见且具有变异性。它们的数量在不同动物个体间变化超过四倍。然而，同一动物两只眼睛中的它们的数量总体平均仅相差14±10%。这些异常结构在所有兔子中均存在，并且在所有情况下其形态相同：它们受到发育程序的精确控制。这些异常细胞与积累吲哚胺类的正常无长突细胞具有许多表型特征。（摘要截取自250词）
