
Most complete human brain model to date is a ‘brain changer’ - jaoued
https://news.osu.edu/news/2015/08/18/human-brain-model/
======
cryoshon
Cool. Let's see the methods paper they used to produce this model, then let's
see the independent validation papers which would show us that the model is
accurate in compared to previously established information. Then let's see an
independently authored paper on a unique speculative use of this model that
has positive results.

This model is in its infancy. It still needs a lot of experimental work (5
years? 10 years?) and in general the more complex models take a longer amount
of time to be validated and widely trusted. A great example is the humanized
mouse model, which is super complex (though not as complex as a brain) and
took somewhere between 3 and 10 years depending on who you ask to go from the
point of the OP model to mainstream accepted usage for some purposes. Maybe 5
years down the line we'll see something come out of the new brain model.

Brain science isn't my expertise, but there's a couple of other tidbits that
caught my attention about this model. First, its vascular structure is missing
entirely. I'm guessing the level of oxygenation of the fetal brain is
important, but there may be ways of controlling for this gap. Second, gene
expression isn't 100% equivalent to an actual human fetal brain at this level
of development. There are probably ways to control for this also, but it's
still a flaw. We don't expect models to be 100% true to reality (after all,
it's a model), so I expect that these holes aren't going to prevent this model
from being successful and useful.

~~~
stenl
Brain science _is_ my expertise, and you're right that the lack of vasculature
will limit the viability of this. It will never grow beyond a few mm, and will
have a dead core most likely. Plus, at "5 weeks" there will be no astrocytes
or oligodendrocytes. You need astrocytes to make proper synapses and oligos to
get proper signalling speeds. Others have shown more advanced brain organoids,
incl astrocytes, but this tech is still very far from a conscious piece of
tissue in a dish.

~~~
scrumper
> but this tech is still very far from a conscious piece of tissue in a dish.

I suspect that will help its adoption. Not so many ethical or para-ethical
issues for the press to get upset about. It's just meat.

------
themgt
Increasing probability that you are in fact a brain in a vat, part of an
undergrad science experiment in the outerworld.

I mean, more seriously I am pro-choice, but do we draw a line somewhere? "The
main thing missing in this model is a vascular system. What is there – a
spinal cord, all major regions of the brain, multiple cell types, signaling
circuitry and even a retina – has the potential to dramatically accelerate the
pace of neuroscience research"

Of a 5 week old fetus? Is it ok to make 10,000 of these for random
experiments? What about 10 weeks, or 15 or 19 or 40 weeks maturity?

I'm not saying I believe this in and of itself is unethical, but it seems
extremely dangerous to do this research and publish and promote it without
even beginning a discussion of, where would we draw a line? Does anyone really
believe the line will be here, and not an inch farther?

~~~
cryoshon
Meh, better we use these models than entire living mice or rats, which would
be the alternative. I highly doubt there is any kind of sensation or
consciousness inside of the brain models, seeing as how they have no sensory
inputs or organic energy inputs (especially oxygen) whatsoever. On top of
that, even 5 week old fetuses (which these model brains are definitively not)
aren't remotely viable or sensate anyway, and don't even have an associated
behavior model AFAIK.

The ethical boundaries for experimenting on living mice are, in my opinion, a
bit perverse at the extremes. There's a general consensus that mice are
sensate and can experience in some form basic emotions and learning behaviors.
Despite this, it's acceptable to do experiments which deplete or wildly
manipulate various neurotransmitters or neural circuits inside of the mouse's
brain far beyond normal physiology.

Imagine having 100% of the "feel good" chemicals removed from your brain and
replaced with 10,000% the normal concentration of "feel bad" chemicals.
Obviously this is a huge simplification, but it's pretty clear that it would
be hellish-- and that experiment has actually been done using mice. Sure, it's
not as bad as if it were done with a real person, but it'd be much better if
we could spare the mice and use a model brain in a vat instead.

~~~
niels_olson
I gave an answer on Reddit a week or two ago to a what might be considered the
current limiting case in clinical practice. In another comment in the same
thread I tried to point out that there are a lot of edge cases, even where it
seems to be a bright line.

It seems reasonable to me that we should monitor this train of research
closely, and I'm pretty confident people will.

[https://www.reddit.com/r/askscience/comments/3g31m0/are_fetu...](https://www.reddit.com/r/askscience/comments/3g31m0/are_fetuses_considered_a_living_thing/ctuetts)

------
logicallee
The lab-grown brain...contains 99 percent of the genes present in the human
fetal brain.

"We are thrilled to have finally created a living human brain in a vat. This
is an exciting experiment and one that has absolutely no possible ethical
ramifications of any kind whatsoever, now or wherever it may lead in the
future," the not-evil scientist Anand added enthusiastically and without
visibly fighting the urge to twirl his totally not-evil mustache.

"It's simply completely obvious that this is a great direction to go in and
one that will never give anyone any pause. More biscuits?"

------
smithkl42
Wait a sec, I thought five week old fetuses weren't human.

------
pera
Why is this being called a "model"?

~~~
streptomycin
Because the word "model" is very overloaded. In this context, it means
something like
[http://www.bio.umass.edu/biology/kunkel/modelsys.html](http://www.bio.umass.edu/biology/kunkel/modelsys.html)

So yeah, it sucks that when you read a headline, you don't know if it's
talking about an animal model, an in vitro model, a computational model, or
something in between. But that's how it is. They're all models.

