Coulombe J, Bronner-Fraser M
Development Biology Center, University of California, Irvine 92717.
Neuroscience. 1990;37(1):259-70. doi: 10.1016/0306-4522(90)90212-m.
The avian ciliary ganglion is a parasympathetic ganglion derived from the neural crest whose neurons provide cholinergic innervation to the eye. Here, we describe the time course of appearance and the morphology of cholinergic cells in the ciliary ganglion, as assessed by antibodies against choline acetyltransferase. Choline acetyltransferase immunoreactivity was first observed in 5.5-day-old quail embryos, 1 day after condensation of the ciliary ganglion. Both the intensity of choline acetyltransferase immunoreactivity and size of the choline acetyltransferase-immunoreactive cells increased with ganglionic age. By 12 days, a second population of choline acetyltransferase-immunoreactive cells, possibly corresponding to choroid neurons, was observed whose cells were smaller and less intensely stained than earlier differentiating choline acetyltransferase-immunoreactive cells. The percentage of choline acetyltransferase-immunoreactive cells was initially high, constituting approximately 50% of the total cell population. As a function of time, the proportion of cholinergic cells decreased, probably due to proliferation of non-neuronal cells and naturally-occurring cell death. Our results confirm the existence of two morphologically distinct populations of cholinergic neurons in the avian ciliary ganglion and demonstrate that these neuronal subpopulations express choline acetyltransferase immunoreactivity at different times in development. Because choroid neurons innervate their targets later than ciliary neurons, this finding is consistent with the hypothesis that target interactions regulate expression of choline acetyltransferase.
禽睫状神经节是一个源自神经嵴的副交感神经节，其神经元为眼睛提供胆碱能神经支配。在此，我们描述了睫状神经节中胆碱能细胞的出现时间进程和形态，这是通过针对胆碱乙酰转移酶的抗体进行评估的。胆碱乙酰转移酶免疫反应性首先在5.5日龄的鹌鹑胚胎中观察到，此时距睫状神经节形成已有1天。胆碱乙酰转移酶免疫反应性的强度和胆碱乙酰转移酶免疫反应性细胞的大小均随神经节年龄的增长而增加。到12天时，观察到第二批胆碱乙酰转移酶免疫反应性细胞，可能对应脉络膜神经元，其细胞比早期分化的胆碱乙酰转移酶免疫反应性细胞更小且染色更浅。胆碱乙酰转移酶免疫反应性细胞的百分比最初很高，约占细胞总数的50%。随着时间的推移，胆碱能细胞的比例下降，这可能是由于非神经元细胞的增殖和自然发生的细胞死亡所致。我们的结果证实了禽睫状神经节中存在两种形态不同的胆碱能神经元群体，并表明这些神经元亚群在发育的不同时间表达胆碱乙酰转移酶免疫反应性。由于脉络膜神经元比睫状神经元更晚支配其靶标，这一发现与靶标相互作用调节胆碱乙酰转移酶表达的假设一致。
