Assal F, Innocenti G M
Institute of Anatomy, Lausanne, Switzerland.
Cereb Cortex. 1993 Jul-Aug;3(4):290-303. doi: 10.1093/cercor/3.4.290.
Transient axons reaching the medialmost part of area 17 were demonstrated with anterogradely transported biocytin injected in the dorsal part of the lateral gyrus in kittens during the first and second postnatal weeks. The axons decreased in number during the third postnatal week and were only exceptionally found thereafter. Computer-aided reconstructions from serial sections demonstrated axons with different degrees of complexity. The most complex ones were found at postnatal days 7-9 and were characterized by multiple branches terminating with growth cones in the white matter. Characteristically, endings of axons that entered the cortex remained confined to the infragranular layers V and VI. A few axons entered the supragranular layers. Transient axons terminated with different endings, which may indicate different stages of maturation. A few, possibly permanent, axons were still found in the medial part of area 17 at the end of the first, and during the second postnatal months; they arborized widely in the infragranular layers, and modestly or not at all supragranularly.
在出生后的第一周和第二周，通过向幼猫外侧回背侧注射顺行运输的生物素，证实了到达17区最内侧部分的短暂轴突。在出生后的第三周，这些轴突数量减少，此后仅偶尔能发现。对连续切片进行计算机辅助重建显示轴突具有不同程度的复杂性。最复杂的轴突出现在出生后第7 - 9天，其特征是有多个分支，在白质中以生长锥结束。典型的是，进入皮层的轴突终末局限于颗粒下层V层和VI层。少数轴突进入颗粒上层。短暂轴突以不同的终末结束，这可能表明不同的成熟阶段。在出生后的第一个月末和第二个月期间，在17区内侧仍可发现少数可能是永久性的轴突；它们在颗粒下层广泛分支，在颗粒上层分支适度或根本没有分支。
