Development of the human gracilis nucleus: a morphometric evaluation.
The development of the human gracilis nucleus was studied on serial sections of the brain of 9 fetuses and neonates at 18-40 weeks of gestation, a two-month-old infant and a 63-year-old adult using a microscope with a drawing tube and an image-analyzing computer system. A morphometric evaluation revealed that the human gracilis nucleus, whose neurons were distinguished from glia from 18 weeks of gestation onward, showed a gradual development in terms of the columnar volume, neuronal size and number, and revealed two kinds of phenomenon: a normal process which occur in the development of the fetus, viz. natural cell death (also called apoptosis), and a phenomenon due to yet unknown causes regarding a discrepancy between the number of neurons and the neuropil index.
Ma
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Department of Anatomy, Showa University School of Medicine, 5-8, Hatanodai 1, Shinagawa-Ku, Tokyo 142-8555, Japan.
Goto
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N
Goto
J
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Ezure
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H
Lu
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S
D017209:Apoptosis; D002452:Cell Count; D005314:Embryonic and Fetal Development; D005865:Gestational Age; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D007231:Infant, Newborn; D008526:Medulla Oblongata / Q000166:cytology / Q000196:embryology* / Q000254:growth & development*; D008875:Middle Aged; D009024:Morphogenesis; D009474:Neurons / Q000166:cytology; D019581:Neuropil / Q000166:cytology