DEZVOLTAREA DEZVOLTAREA SISTEMULUI NERVOSSISTEMULUI NERVOS

Stadiile Carnegie pentru dezvoltarea embrionară umană

După st. C. 23: fetus

FecundaŃia

FecundaŃia

Mayer W, Smith A, Fundele R, Haaf T. (2000) Spatial separation of parental genomes in preimplantation mouse embryos. J Cell Biol. 2000 Feb 21;148(4):629-34.

Formarea morulei

FecundaŃia, formarea blastocistului şi nidarea

Formarea blastocistului şi nidarea

Formarea blastocistului şi nidarea

Formarea blastocistului şi nidarea

13-15 zile

Formarea blastocistului şi nidarea

St. C. 7 (15-17 zile)

Discul embrionar şi şanŃul primitiv

NeurulaŃia

REPERELE MORFOLOGICE ALE STADIILOR EMBRIONARE REPERELE MORFOLOGICE ALE STADIILOR EMBRIONARE (toate duratele sunt exprimate (toate duratele sunt exprimate îîn zile n zile gestagestaŃŃionale ionale trecute de la trecute de la fecundafecundaŃŃie)ie)

• nidarea: 7-12 zile

• apariŃia şanŃului primitiv: 13-15 zile

• gastrulaŃia şi apariŃia notocordului: 15-17 zile

• apariŃia curburii cefalice, a primordiului cardiac şi şanŃului neural: 19-21 zile (1-3 somite)

• încheierea neurulaŃiei: 22-23 zile (12 somite)

• închiderea neuroporului rostral: 23-23 zile (13-20 somite)

• închiderea neuroporului caudal: 26-30 zile (21-29 somite)

• apar mugurii picioarelor: 28-32 zile (30 somite)

• începe osificarea: 44-48 zile

• se disting capul rotund, corpul şi membrele

Published by AAAS J. C. Venter et al., Science 291, 1304 -1351 (2001)

Factori de transcripŃie

Molecule de semnalizare

Sindrom Waardenburg

Aniridia

Chick, 60-70hour , whole mount, chicken (H 2195)

Golgi-stained sections of human cerebral cortex taken from equivalent areas of the anterior portion of the middle frontal gyrus at different ages. Note that there is a tremendous increase in the complexity of dendritic aborizations with increasing age. There are 30 billion neurons and 62,000 miles of axons and dendrites in the human cerebral cortex. Each one of these neurons will make up to 10,000 connections with other neurons. This maturational process is going on at the same time children are usually exposed to the highest levels of lead paint dust by virtue of their normal hand-to-mouth behavior.

Ref: Conel, JL. The postnatal development of the human cerebral cortex.Cambridge, Mass: Harvard University Press, 1959.

Figure 2. Major routes of tangential migration.Numbered arrows are superimposed on Fig. 1 to broadly depict the major routes of cell migration in the developing telencephalon. The question mark on arrow (2) indicates that this route is less well characterized than the others. Key to migratory routes: (1) MGE to the dorsal telencephalon (2) CGE to dorsal telencephalon (3) Cortical-striatalboundary to the ventrolateral telencephalon (lateral cortical stream) (4) LGE to the olfactory bulb (rostral migratory stream).

Nature Neuroscience 4, 1177 - 1182 (2001) Published online: ; | doi:10.1038/nn749 Telencephalic cells take a tangent: non-radial migration in the mammalian forebrainJoshua G. Corbin, Susana Nery & Gord Fishell

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