24. Nöral kabartılar
ileri servikal
(boyun)
kısmında başlar,
rostral (burun)
ve
kavdal(kuyruk)
yönlerine doğru
ilerler.
16 Days 20 Days 22 Days
3 vesicle
stage, Week 4
5 vesicle stage,
Week
5 vesicle
stage, Week 6
24 Days
29. 29
MYELİNİZASYON
• MS TRAKTUSLARINDA 4.AYDA
BAŞLAR,9.AYDA TAMAMLANIR
• ANA MOTOR YOLLAR 2 YAŞINDA
TAMAMLANIR
• SEREBELLUM VE SEREBRUMDA İSE
BLÜĞ ÇAĞINDA TAMAMLANIR.
30. • NÖRAL BORUNUN ÇOK KATLI EPİTELE
FARKLILAŞMASI
-NÖROEPİTEL HÜCRELERİ KÖK HÜCRELERİDİR
-NÖROEPİTEL HÜCRELERİ BÖLÜNEREK NÖROBLAST VE
GLİYOBLASTLARA FARKLILAŞIR
• -NÖROBLASTLAR VE GLİYOBLASTLAR PİYAMATERİN
ÜSTÜNDEKİ BAZAL LAMİNAYA DOĞRU RADİYER OLARAK
GÖÇ EDERER VE ÇOK KAYLI EPİTEL ÖZELLİĞİ ORTAYA
ÇIKAR KALINLIĞI BÖLGESEL HÜCRE BİRİKİMLERİ İLE
FARKLIDIR
- EPENDİMAL HÜCRELER EPİTELOİD HÜCRELERDİR KOROİD
PLEKSÜSÜSNÜ YAPARAK SSS YI SALGILAR
43. AVE
HİPOBLAST
EPİBLAST
Hex
BLASTOKİST
Hex
Kalp
alanı
V
P A
Ensefalon
alanı
Hex
Hex
Mrg1
Hesx1
A
ANTEROPOSTERİYÖR ASİMETRİ
VİTELLÜS
KESESİ
AMNİYON
KESESİ
P
AVE
AVE
Mrg1
Hesx1
D
PAX
3-7
BMP
4-7
44. AVE
MS
VE 1 ANTİJENİ
Otx2
Lim 1
Goosecoid
Hex
Serebrus
ilişkili 1
ENSEF
47. FİBROBLAST BÜYÜME FAKTÖRÜ (FGF)
HEDGEHOG PROTEİNLERİ SONİC HEDGEHOG(SHH)
Wnt ailesi salgılanmış glikoproteinler
Dönüştürücü büyüme faktörü beta(TGFb) süper ailesi
Aktivin,kemik biçimlendirici protein(BMP),VG1
AİLESİ ,Nodal
48. Nerve Pathways are Precisely Defined
Figure Shows nerve pathways in left & right chick limbs
Near perfect mirror-image symmetry
Thus, neurons follow precisely defined paths
50. BAŞIN GELİŞİMİNE
ARACILIK EDEN GENLER
NÖROEKTO
DERM
KORDA
MEZODERM
EPİTELYAL
EKTODERM
EKTODERM
İLKEL ÇİZGİ
NÖRAL
PLAK
İLERİ
BEYİN
51. MSS
İNDÜKTÖRLERİ
A) NOTOKORDA
VE
PARAKORDAL
MEZENKİM
B)PROKORDAL
(PREKORDAL)
PLAK-MEZENKİM
PROKORDAL
PLAK
NOTOKORDA
52. Inhibition of either F-Actin or microtubules inhibits neurulation
F-Actin acts like purse strings to pull apex of cell
Microtubules elongate cell to give it polarity for movement
Induction of Neural Tissue by Chordamesoderm
During gastrulation special region of mesoderm underlies overlying
ectoderm
Chordamesoderm is future notochord
Signals emitted by chordamesoderm have not been identified
53. The Primary Germ Layers
The following diagram shows the general arrangement of tissues in a
cross-section of the human embryo after gastrulation. During
gastrulation the chordamesoderm projected through the primitive node
by convergent extension as the notochordal process. After gastrulation,
three germ layers are evident: Ectoderm, mesoderm, endoderm. After
forming, the notochordal process then embedded within the endoderm as
shown in the following figure. As neurulation progresses, the
chordamesoderm will again separate out as the presumptive notochord.
54. Notochord Formation
At this point the presumptive notochordal tissue will separate from the
endoderm and re-organize as the notochord below the neural ectoderm as
the neural ectoderm begins folding to form the neural tube.
Folding of the neural ectoderm results in the neural tube
The neural tube is the precursor of the brain & spinal cord
55. Bottle Cells
Bottle cells appear at time of neurulation
Change in shape of epithelial to bottle cell is one of driving forces for
event
Cytoskeletal changes lead to bottle cell shape
Microfilaments (F-actin) at apex
Microtubules down long axis of cell
57. BMPs
SHH s
s
s
F s
N
N
BMPs
F
N
BMPs
BMP NÖRAL OLUK VENTRALİZASYONU
SHH BAZAL VE TABAN PLAKLARI
58. NÖRAL BORU ALAR—BAZAL
PLAKLAR PAX 3,7
PAX 3,7
PAX 3,7
S
PAX 6
N N
PAX 3,7
S
S
S
N
F
F
PAX 6
BMP
PAX 3,7
PAX 6
SHH
ALAR
BAZAL
MSX 1.2
59. P M MS
T----TELENSEFALON
D---DİENSEFALON
M---MEZENSEFALON
ROMBENSEFALON
Rombomerler
NOTOKORDA
60. Late Neurula
Neural Tube: One layer of cells surrounding a lumen & covered by
external limiting membrane
Neural Crest have separated out--begun to migrate
Neural Tube thickens & folds to form brain
New layers of nerve cells will appear in brain & spinal cord
(neurogenesis)
61. Formation of Neural Crest: An Epithelial-Mesenchymal
Transformation
Because they play such an important part in embryonic development and
because they contribute so many different cell types to the developing
embryo, the neural crest is considered by some to be the fourth germ
layer. The neural crest cells are interesting because they will form many
critical cell & tissue types and certain cancers and other problems are
associated with them. While little is known about the migration of neural
crest in humans, the situation has been well studied in frogs, birds and
more recently in mammals.
Prior to their departure
from the neural tube neural
crest cells exist as part of
an epithelium. First they
must digest the
extracellular basal lamina
(shown in grey), a process
that involve matrix
metallo-proteinases
(MMPs). After leaving
they have taken on a
62. “Fig. 1. Development of βgal expression in dorsal regions of WlacZ/+
embryos. (A) Low-power view through the trunk section of an E9.5
embryo. (B) High-power view reveals faint βgal+ cells (arrow) within
the dorsal midline at E9.5. (C) Low-power view through the trunk at the
level of the forelimb of an E10.5 embryo. (D) High-power view of the
dorsal midline reveals strong βgal+ cells (filled arrow) on the dorsal
midline of the NT. (E) High-power view of the ectoderm reveals strong
βgal+ cells (filled arrows). There are also βgal+ cells in ventrolateral
regions of the NT and surrounding it (open arrows in C and E). ect,
ectoderm. Scale bars: 250 μm in A,C; 50 μm in B,D,E.)”
80. ÇOK SIRALI
EPİTEL .
(nöroepitel
1
Mustafa
Taşyürekli
ENSEFAL MS
ON
VENTRİKÜLMERKEZİ
KANAL
NÖRAL
KANAL
ÇOK KATLI
EPİTEL(sinir
dokusu)
DİKEY
MİTOZ
NÖROBLASTİK
MİTOZ DALGASI GLİYAL
MİTOZ
DALGASI EPENDİMAL M
2
3
4
Ç.S E
MİTOZ
DALGASI
PİYAMATER
81. NÖRAL KANAL
AKMADDE
BOZ MADDE
KANALİS SENTRALİS
ÇOK SIRALI
NÖROEPİTELYUM
ÇOK KATLI
NÖROEPİTELYUM
BAZAL
LAMİNA
Ependimal epiteloid
BAZAL
LAMİNA
107. KRİSTA NÖRALİSİN GÖÇÜ:EMT
EMBRİYONİK GELİŞİMDE OLDUKÇA ÖNEMLİ OLAN VE BİRÇOK FARKLI HÜCRE
TİPİNİ VERMESİ AÇISINDAN KRİSTA NÖRALİS DÖRDÜNCÜ GERM TABAKASI
OLARAK NİTELENDİRİLEBİLİR. KRİTİK HÜCRE VE DOKULARI VERMESİ
AÇISINDAN VE BAZI KANSER TÜRLERİ VE DİĞER PROBLEMLERE YOL AÇAR.
MEMELİDE ĞÖÇ EPİTELİYOMEZENKİMAL DÖNÜŞÜMLE SERBEST MEZENKİMAL
HÜCRELERE DÖNÜŞEREK HAREKET VE GÖÇ YETENEĞİ KAZANIR.
ÖNCE HÜCRE DIŞI BAZAL LAMİNAYI SİNDİREREK ALTTAKİ MEZENKİMLE
TEMASA GEÇER.SİNDİRMEDE MATRİKS METALOPROTEİNAZLARIDA İŞE KARIŞIR.
(MMPs).BÖYLECE MEZENKİMAL HÜCRELERE DÖNÜŞÜR.
Gövde bölgesinde krista
nöralis göçü
Nöral plak
Nöral plak
Epitelyal ektoderm
krista nöralis
krista nöralis
Bazal
lamina
111. Neuropilin 1 signaling guides neural crest cells to coordinate pathway choice with cell specification. Schwarz Q, Maden CH, Vieira JM, Ruhrberg C. Proc Natl Acad Sci U S A.
2009 Mar 26. [Epub ahead of print] PMID: 19325129 | PMCID: PMC2661313 | PNAS Link
Neuropilin 1 signaling guides
neural crest cells to coordinate
pathway choice with cell
specification. Schwarz Q, Maden
CH, Vieira JM, Ruhrberg C. Proc
Natl Acad Sci U S A. 2009 Mar 26.
[Epub ahead of print
112.
113. ALAR
PLAK
BAZAL
PLAK
EPENDİMA
DORZAL
KÖK
SPİNAL
GANGLİY
ON
VENTRAL
KÖK
TAVAN PLAĞI
TABAN PLAĞI
129. 1-Ektomezenkim
a)Başın dermisi
b)Yumuşak meninksler
c)branşiyal yay iskelet ve kasları
2-Spinal,sempatik ve parasempatik
gangliyonlar ile suprarenel medudüller
hücreler
3-Periferal sinir lifi myelinini
yapan Schwann hücreleri
4-Deri melanositleri
130.
131.
132. BAZAL
PLAK
VENTRAL KÖK MOTOR NÖRON 1-NÜKLEUS ŞİŞME ÖKRATİN BİRİKİMİ
2-NİSSL MADDESİ -ENZİMLER
3-NÖROFİBRİLLERİN BELİRMESİ
4-FONKSİYONEL AKTİVİTE GELİŞİMİ