2017 Group Project 1

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2017 Student Projects 
Student Projects: 1 Cerebral Cortex | 2 Kidney | 3 Heart | 4 Eye | 5 Lung | 6 Cerebellum
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Cerebral Cortex

Mark Hill (talk) 15:59, 14 September 2017 (AEST) Feedback

  • lots of sub-headings, but no actual text.
  • no defined structure to the sequence of sub-headings.
  • no research images related to what is an extensively researched topic.
  • historic background of key research findings, put our understanding today in perspective.
  • Lon list of abnormalities, with no description.

Introduction

( Susannah )

What is it?

For concept: https://www.youtube.com/watch?v=dNngOlsLuGI

You might find this helpful (although you need to request copyright permission):

"Difference Between Cerebrum and Cerebral Cortex." DifferenceBetween.Com. August 7, 2012. < http://www.differencebetween.com/difference-between-cerebrum-and-vs-cerebral-cortex/ >

Histology of Cerebral Cortex

https://www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0024757/ Z5177691 (talk) 22:37, 23 August 2017 (AEST)

Stage 22 image 217.jpg


Early Development of the Brain (and Nervous System)

( Eden )

For concept:

https://www.youtube.com/watch?v=XdN9i_ZWGho

https://embryology.med.unsw.edu.au/embryology/index.php/Neural_-_Cerebrum_Development

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2989000/ https://embryology.med.unsw.edu.au/embryology/index.php/Neural_System_Development

Development of Cerebral Cortex

( Anna )

Terminology

Overview of zones in the human cortex:

  • Ventricular zone
  • Subventricular zone
    • Inner Subventricular Zone
    • Outer Subventricular zone
  • Preplate: neural progenitor cells split into 2 regions
    • Marginal zone:
    • Subplate:
  • Cortical Plate: where the 6 layers of the cortex form, exists in between the subplate and the marginal zone

Mouse Neurogenesis: forms fewer zones compared to human neurogenesis

  • ventricular zone
  • subventricular zone
  • intermediate zone
  • cortical plate

Timeline

Nature article: https://www.nature.com/nrn/journal/v9/n2/full/nrn2252.html

  • E10.5-- VZ (ventricular zone) single layer of cells- have feet that attach to cerebral wall and start dividing. Slightly polarized.
  • E11.5--cells begin to differentiate (PP/preplate) into “pioneer” neurons and move upward, laying molecular trail for subsequent differentiating neurons
  • E13.5--VZ cells form secondary progenitor population in SVZ, PP (preplate pioneer) cells split into 2 zones (MZ and SP)
    • MZ and SP cells tell newly differentiated and migrating cells where they are
  • E14.5-17.5-- deep layers populated first and then superficial layers later
    • The neuron senses the layer it is in and stops- condense in CP (cortical plate)

6 Layers

Layers I, II, III, IV, V, VI (see "Cortical Layer Review" Z5177691 (talk) 22:57, 23 August 2017 (AEST)


Cell Types

http://www.ruf.rice.edu/~lngbrain/Sidhya/

  • Radial Glial cells--in developing cerebellum, hippocampus, cortex
    • Migrating neurons glump onto radial glial to migrate- move up these RG cells
    • RG Cells for migrating neurons that extend from VZ to get to the outer part of the cortex.
    • Fibers that neurons use to migrate from VZ to their final destination
    • Allows dividing cells (projector neurons)- to migrate not randomly but radially.
    • Radial Glial Cells can divide as well→ overall process requires a lot of membrane

Cell Signaling

Anatomy of the Cerebral Cortex

( Jess)

You might find this helpful (although you need to request copyright permission): "Difference Between Cerebrum and Cerebral Cortex." DifferenceBetween.Com. August 7, 2012. < http://www.differencebetween.com/difference-between-cerebrum-and-vs-cerebral-cortex/ >

-layer grey matter outer surface of cerebrum

-2-4mm thickness

-most anterior (rostral) brain region

-outer zone of neuronal tissue (grey matter) containing neuronal cell bodies

-densely packed in humans with over 10 billion nerve cells (about 10% of all the neurons in the brain)

-where much of the neural activities of the cerebrum takes place

-divided left and right hemispheres by longitudinal fissure

-two hemispheres joined by corpus callosum at midline

-divided into functional areas that serve various sensory, motor and cognitive functions

-subdivisions of layers organizing input and output connectivity of resident neurons

-is folded in larger mammals to increase surface area, important allows addition and evolution of a greater diversity functional areas

-gyrus (gyri)= folds/ ridges

-sulcus (sulci)= groove

Layers

https://en.wikipedia.org/wiki/File:Gray754.png

Layer 1 -outer layer (pial surface)

-molecular layer, few scattered neurons

-mainly extensions of pyramidal neuron apical dentrite tufts

-some spiny stellate cells

-inputs to apical tufts crucial for feedback interactions in cortex in associative learning and attention

Layer 2 -external granular layer

-small pyramidal neurons

-many stellate neurons

Layer 3 -external pyramidal layer

-small and medium sized pyramidal neurons

-non-pyramidal neurons with vertically orientated intracortical axons

-layers 1, 2, 3 main target of interhemisphere corticocortical afferent fibres

-layer 3 main source of cortiocortical efferent fibres

Layer 4 -internal granular layer

-different types stellate and pyramidal neyrons

-main target thalamocortical afferents from thalamus type C neurons and intra-hemipsheric corticocortical afferents

Layer 5 -internal pyramidal layer

-large pyramidal neurons

-give rise to axons leaving cortex and run down to subcortical structures e.g. basal ganglia

-In primary motor cortex of the frontal lobe, this layer contains Betz cells and their axons travel through the internal capsule, the brain stem and the spinal cord forming the corticospinal tract

-which is the main pathway for voluntary motor control

Layer 6 -polymorphic/ multiform layer

-few large pyramidal neurons

-many small spindle like pyramidal and multiform neurons

-sends efferent fibers to thalamus forms exact reciprocal interconnection between thalamus and cortex

-connections are both inhibitory and excitatory

Other info three large surfaces: superolateral surface, medial surface, inferior surface

-surfaces characterised by sulci and gyri

three borders: superomedial border, inferomedial border, inferolateral border

lobes defined by large sulci (fissures)

named according to their relation to bones of skull

1) frontal lobe

2) parietal lobe

3) temporal lobe

4) occipital lobe


Blood Supply

Functions of the Cerebral Cortex

( Jess)

For concept:

https://www.youtube.com/watch?v=n6zQbTT0yoY

https://www.youtube.com/watch?v=X-m0JDCw6TE

Functional Areas

-Motor area (primary motor cortex)

-premotor area (motor association cortex)

-sensory area (pimary somatosensory cortex)

-auditory (acoustic) area

-olfactory area

-visual areas

-occipital eye field

-prefrontal areas (prefrontal cortex)

Abnormalities associated with Cerebral Cortex Development

( Zainab )

DRAFT:

https://www.youtube.com/watch?v=luXDQrmMoUU

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2992410/
[1]

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3547618/
[2]

http://www.cell.com/neuron/fulltext/S0896-6273(00)80749-7?_returnURL=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0896627300807497%3Fshowall%3Dtrue [3]

https://academic.oup.com/jnen/article/61/1/1/2916251

https://pdfs.semanticscholar.org/67ea/2ce13f57f4ddbfb7033b6bb1328a5dff7742.pdf

https://www.youtube.com/watch?v=l_nTggR7LTE [4]

A- Disorders due to abnormal proliferation, growth or differentiation of neuroblasts

1-Focal cortical dysplasia (FCD)

In Focal Cortical Dysplasia, neurons are arranged abnormally in the focal areas of the cerebral cortex.
In all patients who present with seizures, FCD is the cause for about 5-15% of them.
FCD is of two types: Type I and Type II.

2-Hemimegalencephaly
3-Microcephaly
4-Tuberous Sclerosis

B- Disorders due to abnormal neuronal migration

 5-Heterotopia

Migration of neurons occurs during the 8th week of development, along radial glial fibers (RGF).
RGFs can be damaged due to ischemia, which can be caused by infection resulting from trauma or metabolic errors.
RGF damage leads to the migration process arresting at the wrong time, resulting in abnormal or ectopic locations of neurons of the cortex.
This condition is known as Heterotopia.

There are two types of heterotopia:

  1. Subcortical band heterotopia
  2. Periventricular heterotopia


6-Lissencephaly

Lissencephaly is a congenital cortex malformation, in which gyri (and sulci) of the cerebral cortex are absent or largely absent, resulting in a smooth surface of the brain.

Lissencephaly is often characterised by the following features:

  • Total agyria (gyri and sulci absent resulting in 'smooth brain')
  • Pachygyria (gyri can be seen but are very few compared to normal brain)
  • Agyric brain with areas of pachygyria
  • Vertically oriented Sylvian fissures of the brain, giving the brain an 'hourglass' configuration

Lissencephaly has been associated with some other abnormalities as well, including corpus callosum hypoplasia, small brain stem and gray matter heterotopia.

Lissencephaly is further divided into types:

  • Classical (Type I) Lissencephaly- undermigration;
  • Cobblestone (Type II) lissencephaly- overmigration

Type II Lissencephaly also includes:

  1. Muscle-Eye-Brain Disease
  2. Walker-Warburg Syndrome
  3. Fragile X-Syndrome


  • Microlissencephaly


7-Kallmann Syndrome

C- Disorders due to abnormal cortical maturation and organization/folding

8-Polymicrogyria
9-Schizencephaly

•destructive lesions.

12-Fetal Alcohol Spectrum Disorder (FASD)

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3670687/

13-Corpus Callosum Agenesis

<html5media height="400" width="500">https://www.youtube.com/watch?v=7zOa3LLrHKc</html5media> [5]

Group Discussion Area (temporary heading)

We are supposed to discuss the project here:

https://moodle.telt.unsw.edu.au/mod/hsuforum/view.php?id=1416354

INFO/ Research Links (temporary heading)

PubMed Searches: Cerebral Cortex Development | Cerebrum Development

BMC Dev Biol Search: Cerebral Cortex Development

Recent papers

<pubmed limit=5>Cerebral+Cortex+Development</pubmed>

References

[Harvard Style]

  1. Squier, W. and Jansen, A. (2010). Abnormal development of the human cerebral cortex. Journal of Anatomy, [online] 217(4), pp.312-323. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2992410/ [Accessed 23 Sep. 2017].
  2. Pang, T., Atefy, R. and Sheen, V. (2008). Malformations of Cortical Development. The Neurologist, [online] 14(3), pp.181-191. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3547618/ [Accessed 23 Sep. 2017].
  3. Christopher A, C. (2017). Genetic Malformations of the Human Cerebral Cortex. Neuron, [online] 23(1), pp.19 - 29. Available at: http://www.cell.com/neuron/fulltext/S0896-6273(00)80749-7?_returnURL=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0896627300807497%3Fshowall%3Dtrue [Accessed 23 Sep. 2017].
  4. Mahfouz, M. (2015). Imaging of cortical formation disorders - DRE 4 - Prof. Dr Mamdouh Mahfouz. [video] Available at: https://www.youtube.com/watch?v=l_nTggR7LTE [Accessed 23 Sep. 2017].
  5. Ezzo - Izzo, D. (2007). How the Body Works : The Corpus Callosum. [video] Available at: https://www.youtube.com/watch?v=7zOa3LLrHKc [Accessed 23 Sep. 2017].