Continuous neurogenesis in the olfactory brain of adult shore crabs, Carcinus maenas
Continuous neurogenesis in the olfactory brain of adult shore crabs, Carcinus maenas
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成年滨蟹（Carcinus maenas）嗅脑的持续神经发生
DOI：
10.1016/s0006-8993(97)00376-4
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发表时间：
1997
期刊：
影响因子：
2.9
通讯作者：
Manfred Schmidt
中科院分区：
文献类型：
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作者：
Manfred Schmidt
为了仔细研究人们普遍认为的成年十足类甲壳动物中枢神经系统中神经元数量保持恒定，尽管它们在幼虫后体积急剧增加，我对不同大小的幼虫后海岸蟹（Carcinus maenas）大脑中的嗅觉投射神经元（OPN）进行了计数。并在成年人的大脑中用5-溴-2 '-脱氧尿苷（BrdU）对增殖细胞进行体内标记。OPNs的数量不断增加，在整个海岸蟹的postlarval生活和大约一倍，从非常年轻的最古老的动物。来自用BrdU标记的成年蟹的脑切片揭示了外侧索马簇中的细胞的持续增殖，所述外侧索马簇由OPN细胞体组成，并且在半椭圆体局部中间神经元的胞体簇中，所述半椭圆体局部中间神经元是OPN的靶。注射后5.5 - 120 h的存活时间显示，在所有标本的两个索马簇中，标记的具有神经元形态的细胞核数量较少但相对恒定（31.3±9.5 S.D.）。每侧群29个核，20.1±4.5个S.D.。每个半椭圆体簇的核数，n=10）。标记的细胞核位于每个簇中不同的增殖区。在注射后1个月的延长存活时间后，在两个索马簇中有显著更多的标记核（71.3±7.8 S.D.）。每侧核团4个，每半椭圆体团38.2±7.1个。在这两个索马集群标记的细胞核形成一个紧凑的组，从增殖区向集群的外缘错位。在外侧簇的增殖区，组织学染色显示典型神经元形状的细胞体，其比周围的OPN胞体略小且染色更强烈。这些细胞体中的一些在有丝分裂的各个阶段被捕获。总的来说，这些数据表明，连续的神经发生在中央嗅觉通路的海岸的大脑在其整个成年生活。这种意想不到的结构可塑性可能使长寿的十足类甲壳动物能够适应不断变化的嗅觉环境。
To scrutinize the common belief that the number of neurons in the CNS of adult decapod crustaceans stays constant, in spite of their dramatic postlarval increase in size, I counted olfactory projection neurons (OPNs) in the brains of differently-sized postlarval shore crabs, Carcinus maenas, and performed in vivo labeling of proliferating cells with 5-bromo-2′-deoxyuridine (BrdU) on brains of adults. The number of OPNs increases continuously throughout the postlarval life of shore crabs and approximately doubles from the very young to the oldest animals. Brain sections from adult crabs labeled with BrdU revealed ongoing proliferation of cells in the lateral soma cluster, which consists of OPN cell bodies, and in the cluster of somata of hemiellipsoid body local interneurons, which are the targets of the OPNs. Post-injection survival times from 5.5 to 120 h revealed a small but relatively constant number of labeled nuclei with neuronal morphology in both soma clusters of all specimens (31.3±9.5 S.D. nuclei per lateral cluster, n=29; 20.1±4.5 S.D. nuclei per hemiellipsoid body cluster, n=10). The labeled nuclei were located in a distinct proliferative zone in each cluster. There were significantly more labeled nuclei in both soma clusters after a prolonged post-injection survival time of 1 month (71.3±7.8 S.D. nuclei per lateral cluster, n=4; 38.2±7.1 nuclei per hemiellipsoid body cluster, n=6). In both soma clusters the labeled nuclei formed a compact group that was dislocated from the proliferation zone towards the outer edge of the cluster. In the proliferation zone of the lateral cluster histological stainings revealed cell bodies of typical neuronal shape that are slightly smaller and more intensely stained than the surrounding OPN somata. Some of these cell bodies were captured in various stages of mitosis. Collectively, these data indicate that continuous neurogenesis occurs in the central olfactory pathway of the brain of shore crabs throughout their entire adult life. This unexpected structural plasticity may enable long-lived decapod crustaceans to adapt to ever-changing olfactory environments.