Summary
Summary Adaptive brain chapter 22
- Course
- Institution
- Book
This document contains a summary of the lectures and book Purves Neuroscience, about chapter 22 “Early brain development”.
[Show more]
Connected book
Book Title:
Author(s):
- Edition:
- ISBN:
- Edition:
More summaries for
-
Summary Neurosciences (AB_1200)
-
Summary of Purves Chapter 22: Early Brain Development
-
Samenvatting Fundamentals of Neuroscience, UvA
Seller
Follow
Jylan13
Reviews received
Content preview
Early brain development chapter 22The cells that will generate the nervous system become distinct Neurulation of the embryo takes place to enclose the layers from
early in the generation of the embryo, concurrent with the the middle in the cranial-caudal way (from the middle to the
establishment of the midline and the basic body axes: anterior- head and tail). Sometimes this goes wrong and which causes
posterior (mouth-anus), dorsal-ventral (back-belly), and medial- meningomyelocele where the back is still exposed due to wrong
lateral (midline-periphery). In addition, the unique curvature of closing. Other neural tube defects such as anencephaly cause no
the human CNS generates a distinctive rostral-caudal axis (nose- brain to develop and exencephaly cause the brain to develop
tail) in the developing brain. outside of the body.
Gastrulation Formation of the major brain subdivisions
The zygote develops into an eight-cell state, which is then cleaved After the neural tube forms the tube bends and folds to form
to form a Blastula, which is a hollow ball. The hollow ball the major brain regions. The prosencephalon gives rise to the 6
invaginates and forms 3 different germ layers. The ectoderm is forebrain segments, the mesencephalon gives rise to the midbrain
the outside layer that later develops into the skin (epidermis) and and the rhombencephalon gives rise to the 8 hindbrain segments.
the nervous system. The layer that is underneath the ectoderm is Caudal to the cervical flexure, the neural tube forms the
the mesoderm, which later develops into skeletal, muscular and precursor of the spinal cord. The bending and folding diminish or
cardiovascular systems. The inner layer is the endoderm, which enlarge certain structures that eventually become the different
develops into all the tube-like structures in the body, such as the ventricles of the mature brain.
urinary tubes and the digestive system.
Neurulation
The notocord is a vertebral column that is involved in the
formation of the neural tube and consists of mesodermal cells. As
a result of these cell movements, the notochord defines the
embryonic midline, and thus the axis of symmetry for the entire How are these brain structures produced?
body. The notochord eventually disappears once the early Part of the answer comes from an observation, made in the early
development is complete. The notochord is involved in early neural 20th century, that the neural tube is organised into repeating
differentation and sends inductive signals to innitiate the units called neuromeres and that the animal embryos are
invagination and to the overlying ectoderm that causes cells to segmented. They observed this in the fruit fly, Drosophila, in this
differentiate into neuroectodermal percursor cells, this process is fly the early expression of Hox genes guides the differentiation
called neurulation. The midline ectoderm that contains these cells of the embryo into distinct segments that give rise to the head,
thickens into a columnar epithelium called the neural plate, which thorax, and abdomen.
invaginates to form the neural tube. There are also other cells
formed, called crest cells that eventually migrate and develop into
the peripheral nervous system (sensory ganglia, autonomic
ganglia, adrenal chromaffin cells, and melanocytes). The notochord
remains later develop into the vertebrate column.
These Hox genes code for transcription factors that help change
the gene expression of other genes that mediate morphogenesis
(Hox, Pax, Msx, etc). Morphogens are these inductive signals that
are produced by surrounding cells that induce the expression of
the transcription factors. Example: the notochord produces
chordin.
Teratogens
This is am agent that causes malformation in embryos, happens
when the inductive signals are a little bit different in
concentration, which causes developmental deficits in the brain.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Jylan13. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $4.88. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
64438 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now