Neural System Development: Difference between revisions

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==Introduction==
==Introduction==
[[File:Stage10_neural_sm.jpg|thumb|300px|Neural groove closing to neural tube, early week 4 <br>([[Carnegie_stage_10|Stage 10]])]]
[[File:Stage10_neural_sm.jpg|thumb|300px|Neural groove closing to neural tube, early week 4 <br>([[Carnegie_stage_10|Stage 10]])]]
[[File:Human brain growth 01.jpg|thumb|300px|alt=Brain size embryonic (week 4, 5, 6, and 8) and late fetal (third trimester)|Brain size embryonic (week 4, 5, 6, and 8) and late fetal (third trimester)]]
[[File:Human brain growth 01.jpg|thumb|300px|alt=Brain size embryonic (week 4, 5, 6, and 8) and late fetal (third trimester)|Relative brain size embryonic (week 4, 5, 6, and 8) and late fetal (third trimester)]]
Neural development is one of the earliest systems to begin and the last to be completed after birth. This development generates the most complex structure within the embryo and the long time period of development means in utero insult during pregnancy may have consequences to development of the nervous system.
Neural development is one of the earliest systems to begin and the last to be completed after birth. This development generates the most complex structure within the embryo and the long time period of development means in utero insult during pregnancy may have consequences to development of the nervous system.



Revision as of 16:06, 7 February 2016

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Stage10 sem6.jpg

Introduction

Neural groove closing to neural tube, early week 4
(Stage 10)
Brain size embryonic (week 4, 5, 6, and 8) and late fetal (third trimester)
Relative brain size embryonic (week 4, 5, 6, and 8) and late fetal (third trimester)

Neural development is one of the earliest systems to begin and the last to be completed after birth. This development generates the most complex structure within the embryo and the long time period of development means in utero insult during pregnancy may have consequences to development of the nervous system.


The early central nervous system begins as a simple neural plate that folds to form a groove then tube, open initially at each end. Failure of these opening to close contributes a major class of neural abnormalities (neural tube defects).


Within the neural tube stem cells generate the 2 major classes of cells that make the majority of the nervous system : neurons and glia. Both these classes of cells differentiate into many different types generated with highly specialized functions and shapes. This section covers the establishment of neural populations, the inductive influences of surrounding tissues and the sequential generation of neurons establishing the layered structure seen in the brain and spinal cord.


  • Neural development beginnings quite early, therefore also look at notes covering Week 3 - neural tube and Week 4 - early nervous system.
  • Development of the neural crest and sensory systems (hearing/vision/smell) are only introduced in these notes and are covered in detail in other notes sections.


Neural Links: ectoderm | neural | neural crest | ventricular | sensory | Stage 22 | gliogenesis | neural fetal | Medicine Lecture - Neural | Lecture - Ectoderm | Lecture - Neural Crest | Lab - Early Neural | neural abnormalities | folic acid | iodine deficiency | Fetal Alcohol Syndrome | neural postnatal | neural examination | Histology | Historic Neural | Category:Neural
Neural Parts: neural | prosencephalon | telencephalon cerebrum | amygdala | hippocampus | basal ganglia | diencephalon | epithalamus | thalamus | hypothalamus‎ | pituitary | pineal | mesencephalon | tectum | rhombencephalon | metencephalon | pons | cerebellum | myelencephalon | medulla oblongata | spinal cord | neural vascular | ventricular | lateral ventricles | third ventricle | cerebral aqueduct | fourth ventricle | central canal | meninges | Category:Ventricular System | Category:Neural
Historic Neural Embryology  
1883 Nervous System | 1893 Brain Structure | 1892 Nervous System Development | 1900 fourth ventricle | 1905 Brain Blood-Vessels | 1909 corpus ponto-bulbare | 1912 nuclei pontis - nucleus arcuatus | 1912 Diencephalon | 1921 Neural Development | 1921 Anencephaly | 1921 Brain Weight | 1921 Brain Vascular System | 1921 Cerebellum | 1922 Brain Plan | 1923 Neural Folds | 1904 Brain and Mind | 1904 Brain Structure | 1909 Forebrain Vesicle | 1922 Hippocampal Fissure | 1923 Forebrain | 1927 Anencephaly | 1934 Anencephaly | 1937 Anencephaly | 1945 Spinal Cord | 1945 cerebral cortex | Santiago Ramón y Cajal | Ziegler Neural Models | Historic Embryology Papers | Historic Disclaimer

Some Recent Findings

  • Secondary neurulation of human embryos: morphological changes and the expression of neuronal antigens[1] "The morphological changes and expression patterns of neuronal antigens of human embryos, obtained from the therapeutic termination of pregnancy or from surgical procedures, were analyzed in order to characterize the secondary neurulation. ...The formation of the caudal neural tube to the tip of the caudal portion of the embryo was finished at stage 17. The postcloacal gut had completely disappeared at stage 18, and multiple cavities of the caudal neural tube were clearly visible. The caudal portion of the neural tube showed findings suggestive of involution at stage 19. The expression patterns of neuronal antigens were as follows: N-CAM and NeuN showed immunoreactivity at the germinal layer of the spinal cord at stages 17 and 18. Neurofilament-associated protein (3A10) showed persistent immunoreactivity at the caudal cell mass and notochord during the observation period, along with the spinal cord, and the positive reactions were mainly located at the dorsal white matter at stage 17. Synaptophysin showed a weak positive reaction at the caudal cell mass and notochord at stages 13 and 14, evident by staining observed at the spinal cord at stages 15 and 16. There was no definite positive reaction for GFAP."
  • Neural induction and early patterning in vertebrates[2]"Work on the molecular circuitry underlying neural induction, also in the same model system, demonstrated that elimination of ongoing transforming growth factor-β (TGFβ) signaling in the ectoderm is the hallmark of anterior neural-fate acquisition. This observation is the basis of the 'default' model of neural induction. Endogenous neural inducers are secreted proteins that act to inhibit TGFβ ligands in the dorsal ectoderm. In the ventral ectoderm, where the signaling ligands escape the inhibitors, a non-neural fate is induced. Inhibition of the TGFβ pathway has now been demonstrated to be sufficient to directly induce neural fate in mammalian embryos as well as pluripotent mouse and human embryonic stem cells."
  • Cell cycle and lineage progression of neural progenitors in the ventricular-subventricular zones of adult mice[3] "Proliferating neural stem cells and intermediate progenitors persist in the ventricular-subventricular zone (V-SVZ) of the adult mammalian brain. This extensive germinal layer in the walls of the lateral ventricles is the site of birth of different types of interneurons destined for the olfactory bulb. The cell cycle dynamics of stem cells (B1 cells), intermediate progenitors (C cells), and neuroblasts (A cells) in the V-SVZ and the number of times these cells divide remain unknown. Using whole mounts of the walls of the lateral ventricles of adult mice and three cell cycle analysis methods using thymidine analogs, we determined the proliferation dynamics of B1, C, and A cells in vivo."
  • Dynamic imaging of mammalian neural tube closure[4] "Here we use laser point scanning confocal microscopy of a membrane expressed fluorescent protein to visualize the dynamic cell behaviors comprising neural tube closure in the cultured mouse embryo. In particular, we have focused on the final step wherein the neural folds approach one another and seal to form the closed neural tube. Our unexpected findings reveal a mechanism of closure in the midbrain different from the zipper-like process thought to occur more generally. Individual non-neural ectoderm cells on opposing sides of the neural folds undergo a dramatic change in shape to protrude from the epithelial layer and then form intermediate closure points to "button-up" the folds. Cells from the juxtaposed neural folds extend long and short flexible extensions and form bridges across the physical gap of the closing folds."
  • Apoptosis is not required for mammalian neural tube closure[5] "Apoptotic cell death occurs in many tissues during embryonic development and appears to be essential for processes including digit formation and cardiac outflow tract remodeling. Studies in the chick suggest a requirement for apoptosis during neurulation, because inhibition of caspase activity was found to prevent neural tube closure. In mice, excessive apoptosis occurs in association with failure of neural tube closure in several genetic mutants, but whether regulated apoptosis is also necessary for neural tube closure in mammals is unknown. Here we investigate the possible role of apoptotic cell death during mouse neural tube closure. We confirm the presence of apoptosis in the neural tube before and during closure, and identify a correlation with 3 main events: bending and fusion of the neural folds, postfusion remodeling of the dorsal neural tube and surface ectoderm, and emigration of neural crest cells."
More recent papers
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Search term: Neural System Embryology

<pubmed limit=5>Neural System Embryology</pubmed>

Objectives

Human embryo cortex (Week 8, Carnegie stage 22)
  1. Understand early neural development.
  2. Understand the formation of spinal cord.
  3. Understand the formation of the brain; grey and white matter from the neural tube.
  4. Understand the role of migration of neurons during neural development.
  5. To know the main derivatives of the brain vesicles and their walls.
  6. To know how the nervous system is modelled, cell death etc.
  7. To understand the contribution of the neural crest.
  8. Understand the developmental basis of certain congenital anomalies of the nervous system, including hydrocephalus, spina bifida, anencephaly and encephalocele.

Reading

UNSW Embryology

Logo.png Citation: Hill, M.A. (2020). UNSW Embryology (20th ed.) Retrieved March 28, 2024, from https://embryology.med.unsw.edu.au
Neural Links: ectoderm | neural | neural crest | ventricular | sensory | Stage 22 | gliogenesis | neural fetal | Medicine Lecture - Neural | Lecture - Ectoderm | Lecture - Neural Crest | Lab - Early Neural | neural abnormalities | folic acid | iodine deficiency | Fetal Alcohol Syndrome | neural postnatal | neural examination | Histology | Historic Neural | Category:Neural
Neural Parts: neural | prosencephalon | telencephalon cerebrum | amygdala | hippocampus | basal ganglia | diencephalon | epithalamus | thalamus | hypothalamus‎ | pituitary | pineal | mesencephalon | tectum | rhombencephalon | metencephalon | pons | cerebellum | myelencephalon | medulla oblongata | spinal cord | neural vascular | ventricular | lateral ventricles | third ventricle | cerebral aqueduct | fourth ventricle | central canal | meninges | Category:Ventricular System | Category:Neural

The Developing Human: Clinically oriented embryology

The Developing Human, 8th edn.jpg Citation: The developing human : clinically oriented embryology 8th ed. Moore, Keith L; Persaud, T V N; Torchia, Mark G Philadelphia, PA : Saunders/Elsevier, c2008. The following chapter links only work with a UNSW connection and can also be accessed through this UNSW Library connection.

Larsen's human embryology

Larsen's human embryology 4th edn.jpg Citation: Larsen's human embryology 4th ed. Schoenwolf, Gary C; Larsen, William J, (William James). Philadelphia, PA : Elsevier/Churchill Livingstone, c2009. The following chapter links only work with a UNSW connection and can also be accessed through this UNSW Library connection.


Neural Movies

Neural Development
Neuralplate 001 icon.jpg
 ‎‎Neural Plate
Page | Play
Neuraltube 001 icon.jpg
 ‎‎Neural Tube
Page | Play
Secondary neurulation 01 icon.jpg
 ‎‎Secondary Neurulation
Page | Play
Stage13-CNS-icon.jpg
 ‎‎Stage 13 Neural
Page | Play
Stage13 MRI 3D02 icon.jpg
 ‎‎Embryo CNS
Page | Play
Mouse neural tube 01 movie icon.jpg
 ‎‎Neural Tube Close
Page | Play
Stage16 MRI 3D02 icon.jpg
 ‎‎Embryo CNS
Page | Play
Stage16 MRI S01 icon.jpg
 ‎‎Embryo Stage 16
Page | Play
Human embryo tomography Carnegie stage 17.jpg
 ‎‎Stage 17 Embryo
Page | Play
Stage22-CNS-icon.jpg
 ‎‎Stage 22 Neural
Page | Play
Stage23 MRI 3D02 icon.jpg
 ‎‎Embryo CNS
Page | Play
Stage23 MRI S01 icon.jpg
 ‎‎Sagittal Head
Page | Play
Abnormalities Ultrasound
Brain fissure development 03.jpg
 ‎‎Sylvian Fissure
Page | Play
Adult human brain tomography.jpg
 ‎‎Adult Brain
Page | Play
US Dandy-Walker 01.jpg
 ‎‎Dandy-Walker
Page | Play
US Spina bifida GA19week.jpg
 ‎‎Spina Bifida
Page | Play
Fetal-Brain-icon.jpg
 ‎‎Neural
Page | Play


Links: Movies | Postnatal - Neural Examination Movies

Human Early Neural Development

Adult human brain

The stages below refer to specific Carneigie stages of development (modified from O'Rahilly and Müller 1994[6]).

  • stage 8 - (about 18 postovulatory days) neural groove and folds are first seen
  • stage 9 - the three main divisions of the brain, which are not cerebral vesicles, can be distinguished while the neural groove is still completely open.
  • stage 10 - (two days later) neural folds begin to fuse near the junction between brain and spinal cord, when neural crest cells are arising mainly from the neural ectoderm
  • stage 11 - (about 24 days) the rostral (or cephalic) neuropore closes within a few hours; closure is bidirectional, it takes place from the dorsal and terminal lips and may occur in several areas simultaneously. The two lips, however, behave differently.
  • stage 12 - (about 26 days) The caudal neuropore takes a day to close.
    • the level of final closure is approximately at future somitic pair 31.
    • corresponds to the level of sacral vertebra 2.
  • stage 13 - (4 weeks) the neural tube is normally completely closed.

Secondary neurulation begins at stage 12 - is the differentiation of the caudal part of the neural tube from the caudal eminence (or end-bud) without the intermediate phase of a neural plate.

Week 4 to Week 8

Embryonic Central Nervous System
Stage 13 Stage 14 Stage 16 Stage 21
Human Stage13 sagittal upper half01.jpg

scale bar = 1 mm

Human Stage14 neural01.jpg Human Stage16 neural03.jpg Human Stage21 neural01.jpg
Week 4 Week 5 Week 6 Week 8


Development Overview

Neuralation begins at the trilaminar embryo with formation of the notochord and somites, both of which underly the ectoderm and do not contribute to the nervous system, but are involved with patterning its initial formation. The central portion of the ectoderm then forms the neural plate that folds to form the neural tube, that will eventually form the entire central nervous system.

Early developmental sequence: Epiblast - Ectoderm - Neural Plate - Neural groove and Neural Crest - Neural Tube and Neural Crest


Neural Tube Development
Neural Tube Primary Vesicles Secondary Vesicles Adult Structures
week 3 week 4 week 5 adult
neural plate
neural groove
neural tube

Brain
prosencephalon (forebrain) telencephalon Rhinencephalon, Amygdala, hippocampus, cerebrum (cortex), hypothalamus‎, pituitary | Basal Ganglia, lateral ventricles
diencephalon epithalamus, thalamus, Subthalamus, pineal, posterior commissure, pretectum, third ventricle
mesencephalon (midbrain) mesencephalon tectum, Cerebral peduncle, cerebral aqueduct, pons
rhombencephalon (hindbrain) metencephalon cerebellum
myelencephalon medulla oblongata, isthmus
spinal cord, pyramidal decussation, central canal

Notochord

Does not contribute to the final nervous system, but is critical to patterning the development.

  • forms initially as the Axial Process, a hollow tube which extends from the primitive pit , cranially to the oral membrane
  • the axial process then allow transient communication between the amnion and the yolk sac through the neuroenteric canal.
  • the axial process then merges with the Endodermal layer to form the Notochordal Plate.
  • the notochordal plate then rises back into the Mesodermal layer as a solid column of cells which is the Notochord.

Ectoderm

Two main parts with different morphology

  • columnar - midline neural plate forming neural tube and neural crest
  • cuboidal - lateral surface ectoderm forming epidermis and sensory placodes
    • epidermis of skin, hair, glands, anterior pituitary, teeth enamel
    • sensory placodes

Neural Plate

The neural plate forms above the notochord and paraxial mesoderm and extends from the buccopharyngeal membrane to primitive node. The cells are described as neuroectodermal and form initially two regions along the head to tail axis: a cranial broad plate region (brain plate) and caudally a narrower plate region (spinal cord).

Neural Determination

Neuronal populations are thought to be specified before the plate folds by signals from underlying notochord and mesoderm, as well as signals spread laterally through teh plate.

  • secrete noggin, chordin,follistatin
  • all factors bind BMP-4 an inhibitor of neuralation bone morphogenic protein acts through membrane receptor

Lateral Inhibition

  • generates at spinal cord level 3 strips of cells
  • expression of delta inhibits nearby cells, which express notch receptor, from becoming neurons
  • Delta-Notch- generates "neural strips"

Neural Bending

There are two bending processes occurring in the formation of the neural groove and neural tube.

  1. occuring in the midline due to cells in this region having a basal nuclear localisation. This initial bending leads to formation of the neural groove.
  2. occuring at the dorsolateral hinge points by different mechanism involving "buckling". This later bending leads to formation of the neural tube.


Mouse neural tube bending model.jpg

Mouse neural tube bending model (see review[7])

Neural Groove

  • forms in the midline of the neural plate (day 18-19)
  • either side of which are the neural folds
  • continues to deepen until about week 4
  • neural folds begins to fuse
  • at 4th somite level

Neural Tube

  • fusion of neural groove extends rostrally and caudally
  • begins at level of 4th somite, "zips up" neural groove
  • leaves 2 openings at either end- Neuropores
  • forms the brain and spinal cord
  • Secondary Neuralation - caudal end of neural tube formed by secondary neuralation, develops from primitive streak region, solid cord canalized by extension of neural canal. mesodermal caudal eminence

Neuropores

  • cranial (anterior) neuropore closes before caudal (posterior)
  • failure to close - Neural Tube Defects (NTD), severity dependent upon level, spina bifida anancephaly (More? [neuron2.htm Neural Abnormalities])
  • found that supplementation of maternal diet with folate reduces incidence of NTDs
    • A randomised controlled trial conducted by the Medical Research Council of the United Kingdom demonstrated a 72% reduction in risk of recurrence by periconceptional (ie before and after conception) folic acid supplementation (4mg daily).
    • Women who have one infant with a neural tube defect have a significantly increased risk of recurrence (40-50 per thousand compared with 2 per thousand for all births)

Neural Crest

(More? Neural Crest Development)

  • a population of cells at the edge of the neural plate that lie dorsally when the neural tube fuses
  • dorsal to the neural tube, as a pair of streaks
  • cells migrate throughout the embryo
  • studied by quail-chick chimeras - transplanted quail cells have obvious nucleoli compared with chicken Neural Crest Derivitives
  • pluripotential, forms many different types of cells: dorsal root ganglia (neurons, sheath cells, glia), autonomic ganglia, adrenal medulla, pia-arachnoid sheath, skin melanocytes, connective tissue of cardiac outflow, thyroid parafollicular cells, craniofacial skeleton and teeth odontoblasts.

Early Brain Structure

Primary Vesicles

CNS primary vesicles.jpg

  • rostral neural tube forms 3 primary brain vesicles (week 4)
  • 3 primary vesicles: prosencephalon (forebrain), mesencephalon (midbrain), rhombencephalon (hindbrain)

Secondary Vesicles

CNS secondary vesicles.jpg

From the 3 primary vesicles developing to form 5 secondary vesicles

  • prosencephalon- telencephalon (endbrain, forms cerebral hemispheres), diencephalon (betweenbrain, forms optic outgrowth)
  • mesencephalon
  • rhombencephalon- metencephalon (behindbrain), myelencephalon (medullabrain)
Carnegie Stage 14 Secondary Vesicles (Week 5)
Human Stage14 neural01.jpg Human Stage14 neural02.jpg
Cranial Nerves 
Nerve Number Name Type Origin Function
CN I Olfactory sensory telencephalon smell placode
CN II Optic sensory retinal ganglial cells vision
CN III Oculomotor motor anterior midbrain extraocular muscles eye movements and pupil dilation (motor)
CN IV Trochlear motor dorsal midbrain extraocular muscles (superior oblique muscle)
CN V Trigeminal motor/sensory pons touch, mastication
CN VI Abducent motor extraocular muscles control eye movements (lateral rectus muscle)
CN VII Facial motor/sensory pons facial expression, taste (tongue anterior and central regions) regulate salivary production.
CN VIII Acoustic sensory vestibular and cochlear nuclei hearing, placode
CN IX Glossopharyngeal motor/sensory medulla swallowing and speech, taste (tongue posterior region)
CN X Vagus motor/sensory medulla larynx and pharynx muscles (speech and swallowing), regulates heartbeat, sweating, and peristalsis
CN XI Accessory motor motor neurons sternocleidomastoid and trapezius muscles
CN XII Hypoglossal motor motor neurons tongue muscles (speech, eating and other oral functions)
Lateral view of the central nervous system of embryo at Carnegie stage 14 (Scale bar is 1 mm).

Ventricles

CNS ventricles
  • cavity within tube will form the contiguious space of the ventricules of the brain and central canal of spinal cord
  • this space is filled initially with amniotic fluid, later with CerebroSpinal Fluid (CSF)
  • CSF is secreted by a modified vascular structure, the chorioid plexus, lying within the ventricles

(More? Neural - Ventricular System Development)

Brain Flexures

Rapid growth folds the neural tube forming 3 brain flexures

  • cervical flexure - between brain stem and spinal cord
  • midbrain flexure - pushes mesencephalon upwards
  • pontine flexure - generates 4th ventricle

Neural Layers

Human Embryo (Week 8, Stage 22) developing head section
Stage 22 developing cortex
Neuron and supporting glial cells
  • neural stem cells lie in the layer closest to the ventricular space, the ventricular layer
    • this layer generates both neuroblasts and glioblasts

Neuroblasts - neurons arise first as neuroblasts and migrate along radial gial, their migration stops at cortical plate. Glioblasts - glia arise later as glioblasts

Both neurons and glia undergo a complex process of growth, differentiation and interaction over a long developmental time period.

Spinal Cord Axes

    • Experimental manipulation of interactions.
    • Initial experiments looked at how isolated tissues may influence the development of the spinal cord.
    • Repositionining of specific tissues both in vivo and in vitro
    • specific markers of or alteration of differentiation.

Notocord Induction

    • Ventral- Sonic Hedgehog
    • notochord secretes sonic hedgehog
    • Gene expression studies (ISH) showed shh gene expression occured in a subset of inducing tissues
    • has a patterning role elsewhere (limb, sclerotome, lung)
    • 2 signaling activities acting (locally and at a distance) Ventral- Sonic Hedgehog
    • Binds to cell surface receptor patched
    • without shh, patched (Ptc) binds smoothened (Smo)
    • with shh shh-Ptc releases Smo activating G protein pathway

Early Development and Neural Derivatives

  • bilaminar embryo- hyoblast
  • trilaminar embryo then ectoderm layer, neural plate, neural groove, neural tube and neural crest
  • cranial expansion of neural tube- central nervous system
  • caudal remainder of neural tube- spinal cord
  • neural crest
  • dorsal root ganglia
  • parasympathetic / sympathetic ganglia.
  • ectodermal placodes- components of the special senses: otic placode (otocyst), nasal placode, lens placode

Links: Placodes

Neural tube and Genes: neural specification- Notch/Delta, patched receptor. Border- fibroblast growth factor (fgf), BMP (BMP4, msx1) Rostral border- Dlx5

Neural tube patterning

    • segmented along its length- Hox/Lim gene expression
    • ventral identity- sonic hedgehog, BMP7/chordin interaction
    • dorsal identity- dorsalin

Fetal Development

Human Fetus CRL240mm brain.jpg

Human Fetus (CRL 240mm) Brain (left dorsolateral view)

For more details see Neural System - Fetal

Neural-development.jpg

Fetal - Second Trimester

Brain ventricles and ganglia development 03.jpg Brain fissure development 02.jpg
Brain and Ventricular Development[8] Brain Fissure Development[8]

Third Trimester

Human Fetus (CRL 240mm) Brain

Three-dimensional magnetic resonance imaging and image-processing algorithms have been used to quantitate between 29-41 weeks volumes of: total brain, cerebral gray matter, unmyelinated white matter, myelinated, and cerebrospinal fluid (grey matter- mainly neuronal cell bodies; white matter- mainly neural processes and glia). A study of 78 premature and mature newborns showed that total brain tissue volume increased linearly over this period at a rate of 22 ml/week. Total grey matter also showed a linear increase in relative intracranial volume of approximately 1.4% or 15 ml/week. The rapid increase in total grey matter is mainly due to a fourfold increase in cortical grey matter. Quantification of extracerebral and intraventricular CSF was found to change only minimally.[9]


Thyroid System and Neural Development

Human thyroid system and neural development

Timeline of human thyroid system and brain development from conception to birth.[10] (Estimation of neurogenesis adapted from Bayer et al.[11])

Links: Endocrine - Thyroid Development

Gliogenesis and Myelination

Glial cells have many different types and roles in central and peripheral neural development, though they are typically described as "supportive", and have the same early embryonic origins as neurons. (More? [neuron7.htm Gliogenesis and Myelination])

Early in neural development a special type of developmental glia, radial glia, provide pathway for developing neuron (neuroblasts) migration out from the proliferating ventricular layer and are involved in the subsequent lamination and columnar organization of the central nervous system.

Types of glia: radial glia, astroglia, oligodendroglia, microglia and Schwann cells.

Gene Diseases - Sonic Hedgehog

SHH Human mutation- holoprosencephaly 3

  • characteristic facies of the severe form of HPE which included a single fused eye (cyclopia) and a nose-like structure (proboscis) above the eye
  • Downstream targets of Sonic hedgehog signalling: transcription factors like Gli3 (responsible for Greigs polycephalosyndactyly in humans), d Hoxd13 (responsible for polysyndactyly)

References

  1. <pubmed>23760472</pubmed>
  2. <pubmed>24014419</pubmed>
  3. <pubmed>23431204</pubmed>
  4. <pubmed>20558153</pubmed>
  5. <pubmed>19420217</pubmed>
  6. <pubmed>8005032</pubmed>
  7. <pubmed>26079577</pubmed>| PMC4528075 | Dev Biol.
  8. 8.0 8.1 <pubmed>19339620</pubmed>| PMC2721010 | J Neurosci.
  9. <pubmed>9485064</pubmed>
  10. <pubmed>12060827</pubmed>
  11. <pubmed>8361683</pubmed>

Journals

Online Textbooks

Developmental Biology (6th ed) Gilbert, Scott F. Sunderland (MA): Sinauer Associates, Inc.; c2000. Formation of the Neural Tube | Differentiation of the Neural Tube | Tissue Architecture of the Central Nervous System | Neuronal Types | Snapshot Summary: Central Nervous System and Epidermis

Neuroscience Purves, Dale; Augustine, George J.; Fitzpatrick, David; Katz, Lawrence C.; LaMantia, Anthony-Samuel; McNamara, James O.; Williams, S. Mark. Sunderland (MA): Sinauer Associates, Inc. ; c2001 Early Brain Development | Construction of Neural Circuits | Modification of Brain Circuits as a Result of Experience

Molecular Biology of the Cell (4th Edn) Alberts, Bruce; Johnson, Alexander; Lewis, Julian; Raff, Martin; Roberts, Keith; Walter, Peter. New York: Garland Publishing; 2002. Neural Development | The three phases of neural development

Health Services/Technology Assessment Text (HSTAT) Bethesda (MD): National Library of Medicine (US), 2003 Oct. Developmental Disorders Associated with Failure to Thrive

Search NLM Online Textbooks- "neural development" : Developmental Biology | The Cell- A molecular Approach | Molecular Biology of the Cell | Endocrinology

Reviews

<pubmed>16314867</pubmed> <pubmed>19206138</pubmed>

Articles

<pubmed>18230116</pubmed>

Search PubMed

Search Pubmed: Neural System Development | Neural Development | Neural Tube Development | Spinal Cord Development


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Cite this page: Hill, M.A. (2024, March 28) Embryology Neural System Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Neural_System_Development

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© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G