Neural - Hippocampus Development: Difference between revisions

From Embryology
mNo edit summary
mNo edit summary
Line 42: Line 42:




{{Template:Neural Table}}
{{Neural Table}}


==Early Brain Vesicles==
==Early Brain Vesicles==

Revision as of 12:11, 31 October 2015

Embryology - 28 Mar 2024    Facebook link Pinterest link Twitter link  Expand to Translate  
Google Translate - select your language from the list shown below (this will open a new external page)

العربية | català | 中文 | 中國傳統的 | français | Deutsche | עִברִית | हिंदी | bahasa Indonesia | italiano | 日本語 | 한국어 | မြန်မာ | Pilipino | Polskie | português | ਪੰਜਾਬੀ ਦੇ | Română | русский | Español | Swahili | Svensk | ไทย | Türkçe | اردو | ייִדיש | Tiếng Việt    These external translations are automated and may not be accurate. (More? About Translations)

Introduction

Stage10 sem6.jpg
Adult hippocampus structure

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 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

Some Recent Findings

  • Neurogenesis in the Septal and Temporal part of the Adult Rat Dentate Gyrus[1] "Newborn neurons' migration from the neurogenic subgranular zone to the inner granular cell layer and expression of glutamate NMDA and AMPA receptors were also studied. BrdU immunocytochemistry revealed comparatively higher numbers of BrdU+ cells in the septal part, but stereological analysis of newborn and total granule cells showed an identical ratio in the two parts, indicating an equivalent neurogenic ability, and a common topographical pattern along each part's longitudinal and transverse axis. Similarly, both parts exhibited extremely low levels of newborn glial and apoptotic cells. However, despite the initially equal division rate and pattern of the septal and temporal proliferating cells, their later proliferative profile diverged in the two parts. Dynamic differences in the differentiation, migration and maturation process of the two BrdU-incorporating subpopulations of newborn neurons were also detected, along with differences in their survival pattern." Rat Development
  • 2014 Nobel Prize in Physiology or Medicine John O´Keefe, May-Britt Moser and Edvard I. Moser - for their discoveries of cells that constitute a positioning system in the brain (More? Nobel Press Release)
  • Development of laminar organization of the fetal cerebrum[2] "Heads of 131 fetal specimens of 14-40 weeks gestational age (GA) were scanned by 3.0T MRI. Eleven fetal specimens of 14-27 weeks GA were scanned by 7.0T MRI. On T(1)-weighted 3.0T MRI, layers could be visualized at 14 weeks GA and appeared clearer after 18 weeks GA. On 7.0T MRI, four zones could be recognized at 14 weeks GA. During 15-22 weeks GA, when laminar organization appeared typical, seven layers including the periventricular zone and external capsule fibers could be differentiated, which corresponded to seven zones in histological stained sections. At 23-28 weeks GA, laminar organization appeared less typical, and borderlines among them appeared obscured. After 30 weeks GA, it disappeared and turned into mature-like structures. The developing lamination appeared the most distinguishable at the parieto-occipital part of brain and peripheral regions of the hippocampus. The migrating thalamocortical afferents were probably delineated as a high signal layer located at the lower, middle, and upper part of the subplate zone at 16-28 weeks GA on T(1)-weighted 3.0T MRI."
More recent papers
Mark Hill.jpg
PubMed logo.gif

This table allows an automated computer search of the external PubMed database using the listed "Search term" text link.

  • This search now requires a manual link as the original PubMed extension has been disabled.
  • The displayed list of references do not reflect any editorial selection of material based on content or relevance.
  • References also appear on this list based upon the date of the actual page viewing.


References listed on the rest of the content page and the associated discussion page (listed under the publication year sub-headings) do include some editorial selection based upon both relevance and availability.

More? References | Discussion Page | Journal Searches | 2019 References | 2020 References

Search term: Hippocampus Embryology

<pubmed limit=5>Hippocampus Embryology</pubmed>

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

Early Brain Vesicles

Primary Vesicles

CNS primary vesicles.jpg

Secondary Vesicles

CNS secondary vesicles.jpg

Human Hippocampus Development

Neural - Human hippocampus marker expression.jpg

Human and rodent hippocampus developmental markers.[3]

Fetal

The following data (GA gestational age weeks) is from an imaging study of the human fetal hippocampus.[4]

  • 13 to 14 weeks - unfolded hippocampus, on the medial surface of the temporal lobe, surrounds a widely open hippocampal sulcus (hippocampal fissure)
  • 15 to 16 weeks - dentate gyrus and cornu ammonis have started to infold. The hippocampal sulcus remains open. The parahippocampal gyrus is larger and more medially positioned. The CA1, CA2, and CA3 fields of the cornu ammonis are arranged linearly. The dentate gyrus has a narrow U shape.
  • 18 to 20 weeks - fetal hippocampus begins to resemble the adult hippocampus. The dentate gyrus and cornu ammonis have folded into the temporal lobe. The hippocampus and subiculum approximate each other across a narrow hippocampal sulcus. The CA1-3 fields form an arc and the CA4 field has increased in size within the widened arch of the dentate gyrus.

Childhood

The following data is from a postnatal magnetic resonance imaging study.[5]

  • 3 months - a longitudinal fasciculus of high signal intensity was seen in the white matter beneath the subiculum
  • birth to 2 years - volume increases rapidly
  • after 2 years - volume increases slowly thereafter
  • hippocampal formations on the right side were larger than those on the left in 38 cases (91%)
  • anterior temporal lobes on the right were larger than those on the left in 32 cases (76%)
  • right-left asymmetry of the hippocampal formations and anterior temporal lobes was observed from early infancy

Adult

The following data is from an magnetic resonance imaging study of adult Chinese aged 6 to 82 years.[6] Other studies have described a reduction in the hippocampal volume during ageing.

  • volume of right hippocampus was larger than that of the left side (p<0.001)
  • right side volume of hippocampus - 2.204 to 2.944 cm3
  • left side volume of hippocampus - 2.068 to 2.700 cm3
  • no statistically significant differences among different age and gender groups (p>0.05)

Neuronal Development

The following data is from a histological study of postmortem hippocampi neurons.[7]

  • Bilateral coronal sections from postmortem hippocampus, 24 to 76 weeks postmenstrual age (gestational age plus postnatal age), were studied.
  • Cell body (soma) size correlated positively and significantly with age in CA2 and CA3, bilaterally.
  • CA2 somata were significantly larger (left, 34%; right, 32%) than adjacent CA3 somata.
  • Variability in soma form or size increased appreciably with age, in both subfields, bilaterally
  • Variability in soma orientation was weakly correlated with brain growth.

Mouse Hippocampus

Mouse- hippocampus dentate granule cells.jpg

The developmental changes of GFP+ newborn mouse dentate granule cells.[8]


Brain histology 02.jpg

References

  1. <pubmed>25394554</pubmed>
  2. <pubmed>20981415</pubmed>
  3. <pubmed>20126454</pubmed>| PLoS One.
  4. <pubmed>9090416</pubmed>
  5. <pubmed>10319988</pubmed>
  6. <pubmed>17601367</pubmed>
  7. <pubmed>9892421</pubmed>
  8. <pubmed>20824075</pubmed>| PLoS One.

Journals

Hippocampus - "source for investigators seeking the latest research on the hippocampal formation and related structures and is widely read by neuroscientists, anatomists, behavioral scientists, physiologists, biochemists, and cellular, developmental, and molecular biologists." Wiley

http://www.ncbi.nlm.nih.gov/pubmed?term=%22Hippocampus%22[jour]

Reviews

<pubmed>19206138</pubmed> <pubmed>19427519</pubmed> <pubmed>19021538</pubmed> <pubmed>17148945</pubmed> <pubmed>10675917</pubmed> <pubmed>9100228</pubmed>

Articles

<pubmed>15597062</pubmed> <pubmed>2748838</pubmed> <pubmed>8413958</pubmed>

Search PubMed

November 2010 search "Hippocampus Embryology" - All (3051) Review (208) Free Full Text (739)

Search Pubmed: Hippocampus Embryology | Hippocampus Development | Limbic Development


External Links

External Links Notice - The dynamic nature of the internet may mean that some of these listed links may no longer function. If the link no longer works search the web with the link text or name. Links to any external commercial sites are provided for information purposes only and should never be considered an endorsement. UNSW Embryology is provided as an educational resource with no clinical information or commercial affiliation.


Glossary Links

Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link



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

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