<html>
<head>
<meta content="text/html; charset=UTF-8" http-equiv="Content-Type">
</head>
<body bgcolor="#FFFFFF" text="#000000">
On 2016-01-24 16:30, John Clark wrote:<br>
<blockquote
cite="mid:CAJPayv0jx2Dx9F_DQ2yUa9wt2z_10-YxkEgBb_7ziiULVBVhDw@mail.gmail.com"
type="cite">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<div dir="ltr">
<div class="gmail_extra">
<div class="gmail_quote"><br>
<div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif;display:inline"></div>
<font size="4">
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif;display:inline">As
I understand it </div>
the extracellular matrix
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif;display:inline">
is</div>
the space between brain cells
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif;display:inline">
and that is where the </div>
<font face="arial, helvetica, sans-serif">perineuronal
net
<div class="gmail_default" style="display:inline">is
located along with a lot of fluid, and the volume of
the </div>
</font>extracellular matrix
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif;display:inline">
changes a great deal between sleep and wakefulness so
the net must be tough enough to resist damage even
when things get crowded. But I'm no expert on this so
I may have misunderstood. <br>
</div>
</font></div>
</div>
</div>
</div>
</blockquote>
<br>
Yup, the matrix is a complicated place. It is not as simple as fluid
plus the net proteins. They are part of it, but there are various
other components too (basal lamina where the brain connects to
connective tissue and blood vessels, various glycoproteins linking
cells mechanically, myelin extensions from Schwann cells etc). And
it is really important for brain development and responds to neural
activity: <a class="moz-txt-link-freetext" href="http://cshperspectives.cshlp.org/content/3/1/a005108.full">http://cshperspectives.cshlp.org/content/3/1/a005108.full</a><br>
<br>
<blockquote
cite="mid:CAJPayv0jx2Dx9F_DQ2yUa9wt2z_10-YxkEgBb_7ziiULVBVhDw@mail.gmail.com"
type="cite">
<div dir="ltr">
<div class="gmail_extra">
<div class="gmail_quote"><br>
<div><font size="4">
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif;display:inline">
I wish we knew how much redundancy there is in the
brain, biological operations are not nearly as
reliable as the electronic operations we use in
computers so I would guess there must be a lot of </div>
<font face="arial, helvetica, sans-serif">redundancy</font>
<div class="gmail_default" style="display:inline"><font
face="arial, helvetica, sans-serif"> to
ensure accuracy.</font></div>
</font></div>
</div>
</div>
</div>
</blockquote>
<br>
<font size="4"><font face="arial, helvetica, sans-serif">It might
not be a simple number. But generally it is clear that there is
a fair bit of redundancy given the noisiness of the environment.
</font></font><br>
<br>
<pre class="moz-signature" cols="72">--
Anders Sandberg
Future of Humanity Institute
Oxford Martin School
Oxford University</pre>
</body>
</html>