Bollé T, Lauweryns J M, Lommel A V
Katholieke Universiteit Leuven, Faculty of Medicine, Laboratory of Histopathology, Minderbroedersstraat 12, B-3000 Leuven, Belgium.
J Neurocytol. 2000 Apr;29(4):241-8. doi: 10.1023/a:1026567603514.
The intrapulmonary airways contain oxygen-sensitive chemoreceptors which may be analogous to the arterial chemoreceptors: the neuroepithelial bodies (NEB). While the NEB are prominent in the neonatal lung, physiological studies indicate that the carotid bodies are still relatively inactive at birth. This points to an unequal degree of development of both during the early neonatal period. As a reflexogenic chemoreceptor function depends on a well-developed innervation, we undertook a comparative investigation of the development of the NEB and the carotid body glomus cell innervation. Two morphological aspects of the innervation of NEB and carotid body glomus cells were quantified in rabbits of different age groups. The total sectional area of intracorpuscular and intraglomerular nerve endings per NEB or glomus cell group, respectively, was measured and the area percentage of mitochondria and synaptic vesicles was determined. In the NEB, no significant difference in total sectional area of the nerve endings between the age groups was observed, while in the carotid body there was a significant increase in the adult age group. In addition, the area percentage of mitochondria and synaptic vesicles of the nerve endings did not change significantly with age in the NEB, while in the carotid body these increased and decreased, respectively, with age. These observations point to a shift from morphologically efferent nerve endings, rich in synaptic vesicles, to morphologically afferent nerve endings, rich in mitochondria. Our interpretation of these findings is that, at birth, the NEB innervation is more mature than the carotid body glomus cell innervation and that the latter matures at a later time than the former. These findings support the theory that the NEB may act as complementary chemoreceptors to the carotid body during the early postnatal period.
肺内气道含有对氧敏感的化学感受器，可能类似于动脉化学感受器，即神经上皮小体（NEB）。虽然NEB在新生肺中很突出，但生理学研究表明，颈动脉体在出生时仍相对不活跃。这表明在新生儿早期两者的发育程度不均衡。由于反射性化学感受器功能依赖于发育良好的神经支配，我们对NEB和颈动脉体球细胞神经支配的发育进行了比较研究。在不同年龄组的兔子中，对NEB和颈动脉体球细胞神经支配的两个形态学方面进行了量化。分别测量了每个NEB或球细胞组内的球内和球内神经末梢的总截面积，并确定了线粒体和突触小泡的面积百分比。在NEB中，各年龄组之间神经末梢的总截面积没有显著差异，而在颈动脉体中，成年年龄组有显著增加。此外，NEB中神经末梢的线粒体和突触小泡的面积百分比随年龄没有显著变化，而在颈动脉体中，这些分别随年龄增加和减少。这些观察结果表明从富含突触小泡的形态学传出神经末梢向富含线粒体的形态学传入神经末梢转变。我们对这些发现的解释是，出生时，NEB的神经支配比颈动脉体球细胞的神经支配更成熟，且后者比前者成熟得晚。这些发现支持了NEB在出生后早期可能作为颈动脉体的互补化学感受器的理论。
