CONTROL OF NEURON POPULATION SIZE IN POLYPLOID ANURANS

神经元精确发育调控的主流解释 数字是神经元和突触后靶点的大小匹配 涉及竞争和神经细胞死亡的过程。华南爪哇爪哇 不同的倍性具有相同的体大小，但在神经元大小和 数。这些差异提供了一种测试细胞死亡是否匹配的方法 神经元数量与外周大小之比。另一种可能性，那就是总数 神经元体积而不是神经元数量与外周大小相匹配， 也将接受测试。腰椎运动神经元和感觉神经元种群大小 (细胞数量和神经元核大小)将被测量并与 肢体大小(表面积、体积和肌纤维数量)。这个 将对发育正常的二倍体、三倍体和 四倍体在细胞死亡之前、期间和之后的阶段，并显示 神经元数量或总数之间是否存在相关性 神经元体积和一些外周大小的测量。此外，后肢 早期发育阶段的芽将在捐赠者之间移植 以及不同倍性的寄主。测量发育的神经元数量 将展示四肢是否具有调节 细胞死亡以产生适当数量的神经元群体。这 信息与理解相似之处和不同之处 在神经元中，群体大小是由正常或异常发育造成的。

The prevailing explanation for precise developmental regulation of neuron numbers is that neurons and postsynaptic targets are size matched by a process involving competition and neuronal cell death. Xeonpus laevis of different ploidy have the same body size, but differ in neuron size and number. These differences provide a way to test whether cell death matches neuron numbers to peripheral size. An alternate possibility, that total neuronal volume rather than neuron number is matched to peripheral size, will also be tested. Lumbar motor and sensory neuron population sizes (cell numbers and neuronal nuclear size) will be measured and compared with limb size (surface area, volume, and muscle fiber number). The measurements will be made for normally developing diploids, triploids and tetraploids at stages before, during, and after cell death, and show whether there is any correlation between either neuron number or total neuron volume and some measure of peripheral size. Additionally, hindlimb buds at an early developmental stage will be transplanted between donors and hosts of different ploidy. Measuring neuron populations that develop in the hosts will show whether limbs have intrinsic qualities that regulate cell death to produce neuron populations of appropriate numbers. This information is relevant to understanding how similarities and differences in neuron population size result from normal or abnormal development.