http://www.youtube.com/watch?v=sH9KCHiuu8E
Scientists have successfully grown complex human brain tissue from
stem cells using a new 3D culture system, according to a study
published in the journal Nature.
Researchers from the Institute of Molecular Biotechnology (IMBA)
at the Austrian Academy of Sciences (OeAW) say the newly created
tissue could be the start of developing model systems for the
human brain.
The scientists began the research by using established human
embryonic stem cell lines and induced pluripotent stem (iPS) cells
from mouse embryonic fibroblasts. They identified growth conditions
that helped the stem cells differentiate into a variety of brain
tissues.
The researchers used "media" for neuronal induction and differ-
entiation, which allowed them to avoid "patterning growth factor
conditions." They say that these conditions are usually applied to
generate particular cell identities from stem cells.
Dr. Jürgen Knoblich from the IMBA and lead study author explains
the process:
"We modified an established approach to generate so-called neuroectoderm, a
cell layer from which the nervous system derives. Fragments of this tissue were
then maintained in a 3D-culture and embedded in droplets of a specific gel that
provided a scaffold for complex tissue growth."
"In order to enhance nutrient absorption, we later transferred the gel drop-
lets to a spinning bioreactor. Within 3 to 4 weeks, defined brain regions were
formed."
'Mini-brains' grown after 2 months
"Cerebral organoids" formed after 15-20 days. These organoids had continuous
tissue (neuroepithelia) around a fluid-filled cavity similar to a cerebral ven-
tricle - a cavity in the brain that is continuous with the central canal of the
spinal cord.
Defined regions of the brain - including a cerebral cortex, retina, meninges
and a choroid plexus - developed after 20-30 days.
After 2 months, full size "mini-brains" had been created that have continued
to survive in a spinning bioreactor, and they are currently surviving at 10
months.
The study authors say:
"We have established a novel approach to studying human neurodevelopmental
processes through in vitro culture of cerebral organoids from human pluripotent
stem cells.
This method recapitulates not only fundamental mechanisms of mammalian neur-
odevelopment, but also displays characteristics of human brain development. We
are hopeful that this method will allow for the study of a variety of neuro-
developmental processes specific to human brain development."
Potential for 'model brains'
The researchers say that this method could potentially be used to create
"model systems" for human brain disorders.
They have already used the "mini-brains" in order to analyze the onset of mi-
crocephaly - a genetic neurological condition where the brain is significantly
reduced in size.
The team created induced pluripotent stem cells from a patient with micro-
cephaly. In doing so, they were able to create "mini-brains" that were all af-
fected with the disorder.
The brains grew to a smaller size, just as the researchers expected. However,
they were interested to find that although the neuropithilial tissue grew to a
smaller size in the microcephaly mini-brains compared with those that did not
have the disorder, there was increased neuronal outgrowth.
From this, the study authors believe that during the brain development of mi-
crocephaly patients, the differentiation in neuronal development begins "prema-
turely at the expense of stem and progenitor cells which would otherwise contri-
bute to a more pronounced growth in brain size."
Additionally, they discovered that another cause of the disorder could be due
to a change in direction when the stem cells divide.
Dr. Madeline Lancaster, first author of the study, says that in addition to
the potential for new insights into the development of human brain disorders,
mini-brains will also be of great interest to the pharmaceutical and chemical
industry.
"They allow for the testing of therapies against brain defects and other
neuronal disorders," Dr. Lancaster adds. "Furthermore, they will enable the
analysis of the effects that specific chemicals have on brain development."
http://www.medicalnewstoday.com/articles/265363.php
http://www.sciencedaily.com/releases/2013/08/130829093539.htm
https://www.youtube.com/watch?v=y2dPzfvpvsQ
http://en.wikipedia.org/wiki/They_Saved_Hitler's_Brain