Aspects of early postnatal development of cortical neurons that proceed independently of normally present extrinsic influences.
Aspects of early postnatal development of cortical neurons that proceed independently of normally present extrinsic influences.
复制标题
皮质神经元出生后早期发育的各个方面独立于正常存在的外在影响。
DOI：
10.1002/neu.480241103
复制
发表时间：
1993
期刊：
影响因子：
--
通讯作者：
O'Dowd,DK
中科院分区：
文献类型：
--
作者：
Annis,CM;Robertson,RT;O'Dowd,DK
为了研究局部与外部影响对皮质神经元出生后发育的贡献，我们比较了在器官型培养中生长的新皮质分离切片中的深层（颗粒下）神经元与体内发育的类似神经元的成熟。所有培养物均取自新生小鼠（P0）的感觉运动皮层，在体外培养（DIV）的前9天内，每天对这些培养物中的神经元进行检查。在相同的时间段内，在相同的出生后年龄（P1-P9）的动物制备的急性切片中评估了体内神经元发育的成熟状态。使用荧光黄填充的全细胞记录电极，从培养的和急性切片中的神经元获得电生理记录，从而能够对标记的细胞进行后续形态测定分析。我们报告的显着变化，细胞形态和电膜特性的这些深层皮层神经元在培养的第一周。在这段时间内形态成熟的特征是细胞体大小和总突起长度增加了2至3倍，树突复杂性增加。在相同的细胞群中，输入电阻降低了3倍，动作电位波形也发生了变化，包括AP持续时间降低了2倍。个体神经元的形态和电生理分化程度在发育年龄之间高度相关，表明细胞的成熟状态反映在细胞形态和内在膜特性上。在P1-P9之间从动物制备的急性切片中检查的层V、VI/SP中的神经元中观察到神经元成熟的非常相似的模式。因为我们的文化系统在排除正常外在影响的同时，（包括丘脑，脑干和胼胝体连接），我们的研究结果认为，神经元分化的早期阶段，包括树突生长的速率和程度以及AP波形的发育，是由指导性和/或许可性的局部影响引起的，并且似乎独立于许多通常存在的外在因素而进行。John Wiley & Sons，Inc.
To examine the contribution of local versus extrinsic influences on postnatal development of cortical neurons, we compared the maturation of deep (infragranular) layer neurons in isolated slices of neocortex grown in organotypic culture to a similar population of neurons developingin vivo. All slice cultures were prepared from sensorimotor cortices of newborn mice (P0) and neurons in these cultures were examined at daily intervals during the first 9 daysin vitro(DIV). The maturational state of neurons developingin vivoover this same time period was assessed in acute slices prepared from animals of equivalent postnatal age, P1–P9. Electrophysiological recordings were obtained from neurons in both cultured and acute slices, using Lucifer yellow filled whole‐cell recording electrodes, enabling subsequent morphometric analysis of the labeled cells. We report significant changes in both cellular morphology and electrical membrane properties of these deep layer cortical neurons during the frist week in culture. Morphological maturation over this time period was characterized by a two‐ to three‐fold increase in cell body size and total process length, and an increase in dendritic complexity. In this same population of cells a three‐fold decrease in input resistance and changes in the action potential waveform, including a two‐fold decrease in the AP duration, also occur. The degree of morphological and electrophysiological differentiation of individual neurons was highly correlated across developmental ages, suggesting that the maturational state of a cell is reflected in both cellular morphology and intrinsic membrane properties. A remarkably similar pattern of neuronal maturation was observed in neurons in layers V, VI/SP examined in acute slices prepared from animals between P1–P9. Because our culture system preserves many aspects of the local cortical environment while eliminating normal extrinsic influences (including thalamic, brainstem, and callosal connections), our findings argue that this early phase of neuronal differentiation, including the rate and extent of dendritic growth and development of AP waveform, results from instructive and/or permissive local influences, and appears to proceed independently of the many normally present extrinsic factors. © 1993 John Wiley & Sons, Inc.