Phelps P E, Brady D R, Vaughn J E
Division of Neurosciences, Beckman Research Institute of the City of Hope, Duarte, CA 91010.
Brain Res Dev Brain Res. 1989 Mar 1;46(1):47-60. doi: 10.1016/0165-3806(89)90142-9.
By combining [3H]thymidine autoradiography with choline acetyltransferase (ChAT) immunocytochemistry, we have determined the generation pattern of the large cholinergic neurons in the neostriatum. All of these neurons are produced between embryonic days 12 and 17 (E12-E17), with 75% of them being born between E13 and 15. Cholinergic neurons appeared to be among the earliest cells produced in the neostriatum when compared with previous generation studies of all neurons in the rat caudate-putamen. The caudal-to-rostral neurogenic gradient reported in previous investigations of all neurons was the only spatiotemporal gradient observed for cholinergic neurons. The generation peak for these cells was E13 caudally, and E15 rostrally. Additional immunocytochemical studies detected ChAT immunoreactivity within somata and primary dendrites of 1 day postnatal (1 dpn) rat neostriatum, and subsequently demonstrated a dramatic increase in the intensity of reaction product and the complexity of dendritic arborizations by 14 dpn. Large ChAT-positive neurons of the basal forebrain contained within the same specimens appeared to differentiate their cholinergic phenotype earlier than those in the neostriatum. However, recent generation studies of basal forebrain neurons combined with the present results have demonstrated that both cholinergic populations are produced simultaneously along the same neurogenic gradients. This then represents an example of cholinergic projection (basal forebrain system) and local circuit (neostriatum) neurons that share similar generation patterns but differ with respect to sequences of transmitter phenotype expression. Thus, for cholinergic forebrain neurons, a cell's position along the neurogenic gradient and its transmitter phenotype appear to be more closely associated with its birth date than its ultimate projection or rate of differentiation.
通过将[3H]胸腺嘧啶核苷放射自显影术与胆碱乙酰转移酶（ChAT）免疫细胞化学相结合，我们确定了新纹状体中大胆碱能神经元的生成模式。所有这些神经元均在胚胎第12至17天（E12 - E17）产生，其中75%在E13至15天出生。与先前对大鼠尾状核 - 壳核中所有神经元的生成研究相比，胆碱能神经元似乎是新纹状体中最早产生的细胞之一。先前对所有神经元的研究中报道的从尾侧向头侧的神经发生梯度是胆碱能神经元观察到的唯一时空梯度。这些细胞的生成高峰在尾侧是E13，在头侧是E15。额外的免疫细胞化学研究在出生后1天（1 dpn）大鼠新纹状体的胞体和初级树突内检测到ChAT免疫反应性，随后证明到14 dpn时反应产物强度和树突分支复杂性显著增加。同一标本中包含的基底前脑的大型ChAT阳性神经元似乎比新纹状体中的那些神经元更早分化出其胆碱能表型。然而，最近对基底前脑神经元的生成研究与当前结果表明，这两个胆碱能群体是沿着相同的神经发生梯度同时产生的。这代表了胆碱能投射（基底前脑系统）和局部回路（新纹状体）神经元的一个例子，它们具有相似的生成模式，但在神经递质表型表达顺序方面有所不同。因此，对于胆碱能前脑神经元来说，细胞在神经发生梯度上的位置及其神经递质表型似乎与其出生日期比与其最终投射或分化速率更密切相关。
