Light-based method choreographs activity of brain circuits
Description

A new method lets scientists monitor and manipulate groups of neurons that communicate with a specific chemical messenger, or neurotransmitter. Researchers used the method, called iTango, to identify mouse brain circuits involved in reward and movement, and to selectively stimulate cells that make mice move.

They could use the same approach to identify brain circuits involved in autism behaviors.

The method builds on optogenetics, a technique that uses blue light to activate proteins called opsins. Scientists can engineer mice to express opsins in certain types of neurons or ones within a particular brain region.

iTango, described in the May issue of Nature Methods, provides an additional layer of specificity. It triggers neurons to fire — or in some cases, light up — only in the presence of both blue light and a particular neurotransmitter.

The switch is made up of three protein complexes. One of them is anchored to the cell membrane and fused to a receptor for the neurotransmitter. When that complex binds to the neurotransmitter outside the cell, it changes shape, allowing a second complex to attach. Blue light changes the shape of the third complex, allowing it to join the other two.

When all three complexes come together, the apparatus activates a protein that turns on genes inserted into the neurons. In the new study, the researchers switched on either of two genes: one that codes for a fluorescent protein, making the cell glow, or a gene for an opsin, so that the neuron fires in response to blue light.

Directed dance:

Researchers tested iTango in mice engineered to carry the gene for the fluorescent protein. They injected the iTango complexes into the striatum, a brain region that governs motivation and motor planning. Neurons in this region communicate using the neurotransmitter dopamine.

An optical fiber inserted into the mice’s brains delivered flashes of blue light and recorded the glow of active neurons. Only the neurons that contained iTango protein complexes and that respond to dopamine lit up.

The researchers placed the mice on a large, rotating Styrofoam ball that has four different textures. When the mice stopped on a certain texture, they received a sip of sugar water.

As the mice ran and sipped their sweet treat, the researchers saw one set of neurons glow when the mice moved and a separate set glow after the treat, presumably sending a reward response.

The researchers then used iTango along with blue light to selectively activate the neurons involved in locomotion. They were able to make the mice move when they were at rest.

Three additional versions of the iTango protein complexes work on brain systems that operate using the chemical messengers neuropeptide Y, cannabinoid or serotonin.

The post Light-based method choreographs activity of brain circuits appeared first on Spectrum | Autism Research News.

Comments
Order by: 
Per page:
 
  • There are no comments yet
Related Feed Entries
Babies who are later diagnosed with autism show aberrant connections between brain regions in their first year of life, according to a new study1. In particular, researchers found that nerve bundles in brain regions that process sound, vision and language seem to transfer information inefficiently. …
6 hours ago · From Spectrum News
Asperger’s Are Us is the first comedy troupe composed of all autistic people By Ron Sandison  On August 3rd at a comedy event in Detroit, I had the pleasure of meeting Ethan, Jack, New Michael, and Noah the cast of Asperger’s Are Us, the first comedy troupe composed of autistic people.&nb…
6 hours ago · From The Art of Autism
The post What baby siblings can teach us about autism appeared first on Spectrum | Autism Research News. Source: Spectrum News
2 days ago · From Spectrum News
The post Transcranial treatment; maternal inflammation; autism ants and more appeared first on Spectrum | Autism Research News. Source: Spectrum News
3 days ago · From Spectrum News
A new method reveals which drugs can cross the cellular barrier that separates the brain from the bloodstream1. The blood-brain barrier protects the brain from foreign invaders. But it also blocks out many chemical compounds, creating a major hurdle for drug development. Treatments for autism and ot…
3 days ago · From Spectrum News
Rate
0 votes
Info
17.06.2017 (17.06.2017)
11 Views
0 Subscribers
Recommend
Tags