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Scanning Mice Brains

  • Posted on January 23, 2012 at 8:00 AM

Okay, so I get that it is unethical to kick off medical experiments on people before we have some assurance of their safety.  I get that.  I’m onboard with that.

But, creating autistic mice?  Really?  First, that which we call “autism” is a collection of observed behaviors.  Most observable human behaviors can have multiple causes.  Just because you can recreate a facsimile of those observed behaviors in mice doesn’t mean there’s any causal relationship between what you did to the mice and what happens in a normal, naturally-developing autistic human.  That seems pretty obvious to me.

So what is the scientific value of scanning the brains of these artificially created autistic mice?

I totally get testing out the scanning technology to make sure it works.  I also see the value of the scanning technology; I suspect it’s going to help researchers gain a better understanding of the working differences between so-called “normal” brains and autistic brains.  (Though, I disagree with these researchers starting with the assumption of pathology or wrongness.)

But what conclusions can we really draw from scanning the brains of mice which scientists have manipulated to demonstrate autistic-like behaviors?  Do these scientists really think they’re going to gain insight into naturally-occurring human autism by scanning the brains of these mice?

Am I missing something?  Really, if you understand this leap of logic, which to me seems like driving off a cliff versus jumping to a different level of reasoning, please share!

On another note, this seems a bit more promising:

This type of finding—an inherited difference that cannot be explained by variations in genes themselves—has become increasingly common, in part because scientists now know that genes are not the only authors of inheritance. There are ghostwriters, too.

It also adds another layer of significance to our daily lives. A number of environmental factors, from nutrients to temperature to chemicals, are capable of altering gene expression, and those factors that manage to penetrate germline chromatin and escape reprogramming could, in theory, be passed on to our children and possibly our grandchildren.

Given the elusive nature of inherited epigenetic modifications, it seems that, despite decades of investigation, scientists remain on the brink of understanding. The possibilities, however, seem endless, even with the constraint that, to be inherited, epigenetic modifications must affect gene expression in the germline, a feat that even genetic mutations rarely accomplish. But with the skyrocketing prevalence of conditions such as obesity, diabetes, and autism, which have no clear genetic etiology in the majority of cases, as Brunet pointed out, “It seems that all complex processes are affected by epigenetics.

While scientists continue to search for definitive evidence of transgenerational epigenetic inheritance in humans, the implications so far suggest that are our lifestyles and what we eat, drink, and breathe may directly affect the genetic health of our progeny.”

What can I say?  I like it when scientists discover that what they knew wasn’t all there was to be known.  This is the science that attracted me so much in my childhood:  Science as exploration and discovery, not science as a god or using science to “prove” politically- or ideologically-motivated beliefs.

The idea that nurture might affect nature as a ghostwriter appeals to me.  Our lives are not predetermined by the genetic makeup of our ancestors, but products of on-going choices that echo through generations.  And we just might have a scientific way to study a portion of that phenomenon.