Fontanesi G, Traina G, Bagnoli P
Department of Physiology and Biochemistry, University of Pisa, Italy.
Vis Neurosci. 1993 Mar-Apr;10(2):271-85. doi: 10.1017/s0952523800003679.
The distribution of somatostatin (SS)-containing neurons was investigated by immunocytochemical methods in the central visual system of adult, developing, and retina-ablated pigeons. In normal adult brains, SS-positive cells and processes were present in the optic tectum, the nucleus of the basal optic root, the visual Wulst, and the ectostriatum. During development, progressive increase or decrease in the numerical density and the total number of SS-containing neurons occurred as determined by quantitative analysis. Changes in SS immunoreactivity also occurred as a consequence of unilateral and bilateral retina removal immediately after hatching, i.e. before retinofugal connections have been established. In spite of the segregation of visual inputs due to the almost completely crossed retinal projections, unilateral and bilateral deafferentation differentially affected SS-containing visual regions. In addition, different effects were observed on the relative packing density of labeled cells as compared to their total number. A possible role of retinal axons in regulating the distribution of SS immunoreactivity was suggested by its altered expression induced by retinal deafferentation. In addition, parallels with the distribution of SS immunoreactivity in the pigeon's visual system were used to suggest possible equivalence between cell populations in the avian and the mammalian brains.
采用免疫细胞化学方法，对成年、发育中和视网膜切除的鸽子的中枢视觉系统中含生长抑素（SS）的神经元分布进行了研究。在正常成年大脑中，视顶盖、基底视根核、视觉顶叶和外纹状体中存在SS阳性细胞和突起。在发育过程中，通过定量分析确定，含SS的神经元的数量密度和总数出现逐渐增加或减少。在孵化后立即（即视网膜离心连接建立之前）进行单侧和双侧视网膜切除后，SS免疫反应性也发生了变化。尽管由于几乎完全交叉的视网膜投射导致视觉输入分离，但单侧和双侧去传入对含SS的视觉区域有不同的影响。此外，与标记细胞总数相比，观察到对标记细胞相对堆积密度的不同影响。视网膜去传入诱导的SS免疫反应性表达改变提示视网膜轴突在调节SS免疫反应性分布中可能发挥作用。此外，通过与鸽子视觉系统中SS免疫反应性分布进行对比，推测鸟类和哺乳动物大脑中的细胞群可能具有等效性。
