Mitrofanis J, Maslim J, Stone J
Department of Anatomy, University of Sydney, Australia.
J Comp Neurol. 1988 Oct 15;276(3):343-59. doi: 10.1002/cne.902760303.
We have examined the development of catecholaminergic and cholinergic neurons in the retina of the rat by using antibodies against the enzymes tyrosine hydroxylase (TH) and choline acetyl transferase (ChAT), respectively. TH-immunoreactivity was first detected at P (postnatal day) 3 in somata located in the inner part of the cytoblast layer (CBL) and in fine dendrites extending toward the middle of the inner plexiform layer (IPL). These cells were similar in shape and soma size to the class 2 TH-immunoreactive (TH-IR) cells of the adult rat. At P6, TH-immunoreactivity was expressed by a second population of cells. Their somata were in the inner part of the inner nuclear layer (INL), but were distinctly larger, with short thick dendrites extending into the outer and/or middle parts of the IPL. Over subsequent days, the dendrites of these larger cells spread profusely in the outer part of the IPL, making it likely that they are the class 1 TH-IR cells of the adult. ChAT-immunoreactive (ChAT-IR) cells were not detected until P15, when ChAT-IR somata were observed in the ganglion cell layer (GCL) and INL, and their dendrites were observed already segregated into the distinct strata of the IPL in which they are found in the adult. The subsequent growth of TH-IR somata of both classes was uneven, persisting longer in temporal than in nasal retina. This extended growth of temporal cells establishes the marked nasotemporal differences in soma diameter apparent among TH-IR cells in the adult (Mitrofanis and Stone, '86; Mitrofanis et al., '88b). The growth and adult size of ChAT-IR somata, on the other hand, did not vary with retinal position; their diameters were similar to those of the adult cells from the time they first appeared. The distribution of ChAT-IR cells at P15 shared several features of the distribution of ganglion cells. The density of ChAT-IR cells was greatest at the area of peak ganglion cell density and declined toward the periphery. In contrast, TH-IR cells concentrated from the time they first appeared at the superior temporal margin, peripheral to the area of peak density of ganglion and ChAT-IR cells.
我们分别使用针对酪氨酸羟化酶（TH）和胆碱乙酰转移酶（ChAT）的抗体，研究了大鼠视网膜中儿茶酚胺能神经元和胆碱能神经元的发育情况。TH免疫反应性最早在出生后第3天（P3）在位于成神经细胞层（CBL）内部的胞体以及向内侧网状层（IPL）中部延伸的细树突中检测到。这些细胞在形状和胞体大小上与成年大鼠的2类TH免疫反应性（TH-IR）细胞相似。在P6时，第二批细胞表达了TH免疫反应性。它们的胞体位于内核层（INL）内部，但明显更大，有短而粗的树突延伸到IPL的外侧和/或中部。在随后的几天里，这些较大细胞的树突在IPL外侧大量扩展，这表明它们可能是成年大鼠的1类TH-IR细胞。直到P15才检测到ChAT免疫反应性（ChAT-IR）细胞，此时在神经节细胞层（GCL）和INL中观察到ChAT-IR胞体，并且它们的树突已经分离到成年时所在的IPL的不同层中。这两类TH-IR胞体随后的生长并不均匀，颞侧视网膜中的持续时间比鼻侧视网膜更长。颞侧细胞的这种延长生长导致成年TH-IR细胞之间在胞体直径上出现明显的鼻颞差异（米特罗法尼斯和斯通，'86；米特罗法尼斯等人，'88b）。另一方面，ChAT-IR胞体的生长和成年大小并不随视网膜位置而变化；从它们首次出现时起，其直径就与成年细胞相似。P15时ChAT-IR细胞的分布与神经节细胞的分布有几个共同特征。ChAT-IR细胞密度在神经节细胞密度峰值区域最大，并向周边递减。相比之下，TH-IR细胞从首次出现在颞上缘时就开始集中，位于神经节细胞和ChAT-IR细胞密度峰值区域的周边。
