Bagnoli P, Fontanesi G, Alesci R, Erichsen J T
Department of Environmental Sciences, University of Tuscia, Viterbo, Italy.
J Comp Neurol. 1992 Apr 22;318(4):392-414. doi: 10.1002/cne.903180405.
The distribution of three neuroactive substances, neuropeptide Y, substance P, and choline acetyltransferase, was studied by immunocytochemical methods in central visual regions of adult, developing, and ablated pigeon brains. In normal adult brains, neuropeptide Y-positive cells and processes were present in the nucleus pretectalis, the nucleus of the basal optic root, the nucleus of the marginal optic tract, and the visual Wulst. Substance P-positive cells and processes were found in the optic tectum and in the visual Wulst. Stained fibers and terminal-like processes, but no cells, were also observed in several visual thalamic nuclei. Choline acetyltransferase-positive cells and processes were located in the optic tectum, visual Wulst, the nucleus isthmo opticus, nucleus isthmi and certain visual thalamic nuclei. Cholinergic fibers and processes, but no cells, were present in the nucleus principalis precommissuralis, the supraoptic decussation, and the nucleus lentiformis mesencephali, pars magnocellularis. In the course of development, the distribution of immunoreactivity for all three substances was found to vary. These changes often involved either progressive increases or decreases in the density of labeled cells, neuropil and/or terminal-like profiles. Experiments with retina ablated pigeons clearly demonstrated that changes in the normal pattern of immunoreactivity distribution only occurred if the retina was removed immediately after hatching, i.e., before retinofugal connections have been established. The adult pattern of immunoreactivity for all three substances appears to be reached at about the same time that the anatomical and functional maturation of the pigeon visual system is completed. The present results suggest that this temporal correlation reflects the important role that retinal afferents play in the development of these putative peptidergic and cholinergic systems.
采用免疫细胞化学方法，研究了三种神经活性物质（神经肽Y、P物质和胆碱乙酰转移酶）在成年、发育中和去视网膜的鸽子脑中枢视觉区域的分布。在正常成年脑中，神经肽Y阳性细胞和突起存在于顶盖前核、基底视根核、边缘视束核和视叶。P物质阳性细胞和突起见于视顶盖和视叶。在几个视觉丘脑核中也观察到染色纤维和终末样突起，但未见细胞。胆碱乙酰转移酶阳性细胞和突起位于视顶盖、视叶、峡视核、峡核和某些视觉丘脑核。在连合前主核、视交叉上核和中脑豆状核大细胞部有胆碱能纤维和突起，但未见细胞。在发育过程中，发现这三种物质的免疫反应性分布有所不同。这些变化通常涉及标记细胞、神经毡和/或终末样轮廓密度的逐渐增加或减少。对去视网膜鸽子的实验清楚地表明，只有在孵化后立即摘除视网膜，即在视网膜神经纤维连接建立之前，免疫反应性分布的正常模式才会发生变化。这三种物质的成年免疫反应模式似乎在鸽子视觉系统的解剖和功能成熟完成的同时达到。目前的结果表明，这种时间上的相关性反映了视网膜传入在这些假定的肽能和胆碱能系统发育中所起的重要作用。
