Developmental and regional patterns of GAP-43 immunoreactivity in a metamorphosing brain.
Developmental and regional patterns of GAP-43 immunoreactivity in a metamorphosing brain.
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变态大脑中 GAP-43 免疫反应性的发育和区域模式。
DOI：
10.1159/000127045
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
Brown,RebeccaA
中科院分区：
文献类型：
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作者：
Simmons,AndreaMegela;Tanyu,LeslieH;Horowitz,SethS;Chapman,JudithA;Brown,RebeccaA
生长相关蛋白43在发育过程中通常在神经系统中高水平表达。在成年动物中，其表达较低，但在显示结构或功能可塑性的大脑区域中仍可观察到。我们研究了牛蛙大脑中GAP-43免疫反应的模式，牛蛙的神经系统在变形发育过程中经历了相当大的重组，并在成年期保持了很强的可塑性。免疫标记在蝌蚪幼体中主要是分散的，但随着幼虫发育的进行，免疫标记逐渐变得更加离散。在许多脑区，免疫标记的强度在变质高潮时达到顶峰，即从水生生物最终过渡到半陆生生物的时候。前庭内侧核、橄榄核上核和半规环体中GAP-43表达强度的变化与听觉刺激处理的阶段性功能变化相关。小脑浦肯野细胞层和小脑核的免疫标记在大多数发育时间点均可检测到。从幼虫早期到顶极结束，丘脑（腹内侧核、前核、后核和中央核）都存在大量免疫标记。蝌蚪端脑在侧脑室周围、中隔和腹侧纹状体均可见免疫标记。在变质后的动物中，免疫反应主要局限于心室区和紧邻的细胞层。在整个幼虫和变质后的生命中，嗅觉、听觉和视神经都有GAP-43的表达。从发育到成年，脑核和脑神经中GAP-43的持续表达反映了牛蛙中枢神经系统的高再生潜力。
Growth-associated protein-43 is typically expressed at high levels in the nervous system during development. In adult animals, its expression is lower, but still observable in brain areas showing structural or functional plasticity. We examined patterns of GAP-43 immunoreactivity in the brain of the bullfrog, an animal whose nervous system undergoes considerable reorganization across metamorphic development and retains a strong capacity for plasticity in adulthood. Immunolabeling was mostly diffuse in hatchling tadpoles, but became progressively more discrete as larval development proceeded. In many brain areas, intensity of immunolabel peaked at metamorphic climax, the time of final transition from aquatic to semi-terrestrial life. Changes in intensity of GAP-43 expression in the medial vestibular nucleus, superior olivary nucleus, and torus semicircularis appeared correlated with stage-dependent functional changes in processing auditory stimuli. Immunolabeling in the Purkinje cell layer of the cerebellum and in the cerebellar nucleus was detectable at most developmental time points. Heavy immunolabel was present from early larval stages through the end of climax in the thalamus (ventromedial, anterior, posterior, central nuclei). Immunolabel in the tadpole telencephalon was observed around the lateral ventricles, and in the medial septum and ventral striatum. In postmetamorphic animals, immunoreactivity was confined mainly to the ventricular zones and immediately adjacent cell layers. GAP-43 expression was present in olfactory, auditory and optic cranial nerves throughout larval and postmetamorphic life. The continued expression of GAP-43 in brain nuclei and in cranial nerves throughout development and into adulthood reflects the high regenerative potential of the bullfrog’s central nervous system.