Born D E, Rubel E W
J Comp Neurol. 1985 Jan 22;231(4):435-45. doi: 10.1002/cne.902310403.
The consequences of cochlea removal on neuron number and soma cross-sectional area were examined in the second order auditory nucleus (n. magnocellularis) of chickens. Both the age of the subjects at the time of cochlea (basilar papilla) removal (1-66 weeks) and the survival period (1-45 days) were varied. Neuron number and soma cross-sectional area were determined from Nissl stained sections. Additional material was processed to examine the relationship of ganglion cell loss to changes in n. magnocellularis. Neuron number decreased by 25-30% and soma cross-sectional area decreased by 10-20% ipsilateral to the cochlea removal in chickens operated on during the first 6 weeks after hatching. In contrast, in chickens operated on at 66 weeks posthatch neuron number decreased less than 10% and there was no change in soma area. The changes were rapid, being nearly complete 2 days after cochlea removal. An initial change (1 and 2 days after surgery) observed in animals operated on up to 6 weeks posthatch was the presence of a large number of neurons in which no Nissl substance could be detected. These results demonstrate an age-dependent change in the susceptibility of NM neurons to deafferentation. This change is not temporally related to other measures of functional maturation of the auditory system.
在鸡的二级听觉核（大细胞神经核）中，研究了切除耳蜗对神经元数量和胞体横截面积的影响。切除耳蜗（基底乳头）时实验对象的年龄（1 - 66周）以及存活期（1 - 45天）均有所不同。通过尼氏染色切片确定神经元数量和胞体横截面积。对额外的材料进行处理，以研究神经节细胞损失与大细胞神经核变化之间的关系。在孵化后前6周接受手术的鸡中，切除耳蜗同侧的神经元数量减少了25 - 30%，胞体横截面积减少了10 - 20%。相比之下，在孵化后66周接受手术的鸡中，神经元数量减少不到10%，胞体面积没有变化。这些变化很快，在切除耳蜗后2天几乎就已完成。在孵化后6周内接受手术的动物中，最初观察到的变化（手术后1天和2天）是大量神经元中检测不到尼氏体物质。这些结果表明，NM神经元对去传入作用的易感性存在年龄依赖性变化。这种变化在时间上与听觉系统功能成熟的其他指标无关。
