healthmedicinet

2013 will be remembered as the year when President Obama’s BRAIN Initiative began to give scientists “the tools they need to get a dynamic picture of the brain in action,” as pledged in an April Rose Garden ceremony.

It’s a pivotal period for understanding the auditory, visual and tactile hallucinations that plague people with schizophrenia. But exciting new techniques such optogenetics promise to help unlock what the president has called “the mystery of the three pounds of matter that sits between our ears.”

We’ll be keeping a watchful eye out for these tools as they arise in the new year.

One reported last month, and flagged yesterday on National Public Radio, might help explain why people with schizophrenia can be overwhelmed by bright lights or loud sounds.

Harvard neurobiologist Rachel Wilson said she believes a glitch in brain circuits that adjusts the “volume” of sensory signals might induce sensory overload.

There’s no easy way to tell in people yet, so Wilson is using genetically manipulated fruit flies to see how similar volume-control mechanisms process odors in their small brains.

Wilson, whose Harvard lab uses electrophysiological techniques (patch clamp recording and extracellular recording), told the annual meeting of the Society for Neuroscience that the activation of sensory circuits is like the foot on the gas pedal that makes the car go; meanwhile, she said, other circuits work like brakes to slow things down so that the mind isn’t overwhelmed.

In fruit flies when odors are too faint to smell too well, “the gas dominates,” Wilson explained. “But when odors are intense, then it’s the brakes that dominate.”

Hot Field of Opto-Genetics

NPR’s report segues from what fruit flies smell to how the human brain learns sees the world in three dimensions.

Depth perception, it turns out, is not in-born but develops as the brain gets trained to sort out information from two eyes–a process known as visual plasticity, also called visual learning, that happens during the first few years of life.

One promising technique comes from the burgeoning field of opto-genetics.

MRI scans can offer a glimpse of which brain cells are active during a task.  And you can manipulate individual cells during brain surgery. Otherwise, optogenetics offers a much less invasive way in.

But beaming fiber optic light into a brain area shows how light-sensitive proteins can be activated or certain neurons silenced. The trick will be to probe deep beneath the surface layers of brain tissue to transmit light more precisely.

UCLA’s Joshua Trachtenberg has been using optogenetics to look at how very specific single neurons and synaptic connections work. Links between brain cells are labile when we are young, but  grow less so as we move out of adolescence, into adulthood, and old age, so Trachtenberg’s lab is striving to find out why.

Using a variety of new tools to probe neural circuitry in the  brains of adolescent and adult mice over hours, days, or weeks, he is fine tuning his probes with the hope of  one day helping people with schizophrenia, Parkinson’s disease, and depression.

So there’s lots to anticipate in 2014.

As for 2013, it may go down as the year when some of the most basic mysteries of the mind were beginning to unravel.

 

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And they are apparently too stupid to realize how easy it is to ensure they are called out for their bad behavior.

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    Last reviewed: 28 Dec 2013