七——十月人胎听皮层发育的研究

A STUDY ON THE DEVELOPMENT OF AUDITORY CORTEX IN HURMAN CIRTEX FROM THE SEVENCN THROUGH THE TENTH MONTHS

本文用光镜观察了七至十月人胎听皮层的发育。结果：１．Ｎｉｓｓｌ染色材料四个月份的材料均呈现典型新皮层的六层结构，七至十月份皮层总厚度依次为０．９７ｍｍ，１．０４ｍｍ，１．７９ｍｍ，和１．８５ｍｍ；内颗粒层神经细胞的体积密度依次为１３．６４％、１７．４９％、２６．０３％和３４．０５％；面数密度为５８．８７个／ｍｍ＾２、４０．４５个／ｍｍ＾２、２３．４８个／ｍｍ＾２和１１．６２个／ｍｍ＾２；轴比为１．

The development of auditory cortex in human fetus from the seventh through the tenthmonths has been oloacrved with light microscope . The results showed: 1. With -Nissl staining materials , typical neo-cortcx with structure of six layers was displayed in all specimens from each month ; the total thickness of cortex in the seventh ,eighth ,ninth and tenth months was 0.97mm , 1.04mm, 1,79mm,and 1.85mm respectively) the volume density of nerve cells in internal granular layer was 13.64%, 17.49% ,26.03% and 34.05% respectively;the plane density was 58,87/mm2,40. 45/mm2, 23.48. mm2 and 11. 62/mm2 res pectivcky; the axis ratio was 1:1. 32, 1:1.65, 1:1.75 and 1:1.86 respectively; the dispersal degree was 0.89, 0.83, 0.74 and 0.67 respectively . 2. With Golgi staining materials ,all kinds of neurons in ncocortex could be seen in auditory cortex , most of them were granular cells, the next were pyramidal cells and fusiform cells , and Martinotti cells were the least ;the ratio of cell number being 17:9:1:1 respectively ; the dcndritcs field of granular cells formed a circle around the cell body ; the bottom dcndrites field of pyramidal cells was fan - shaped; the top dcndritcs extended far from the cell body , the length in the seventh , eighth, ninth and tenth months being 11.71 ± 5.34μm/μm3, 13.01 ± 4.06μm/μm3, 15.01 ±6.17μm/μm3 and 16.09 ±5.63μm/μm3 respectively; the length of axon was 22.12 ± 0.66μm/μm3, 26.96±8. 49μm/μm3, 30.69 ± 11.44μm/μm3 and 34.52 ± 7.62μm/μm3 respectively; there was no branch on the dcndrite of pyramidal cells in the seventh month, the first grade branch could be seen in the eighth month but without side spine and the second and third grade branches with a lot of sessile side spines could be seen in the ninth and tenth months