Your brain’s got rhythm – Medical Xpress

By NEVAGiles23

February 14, 2017 Salk scientists create synthetic brain systems called 'circuitoids' to better understand dysfunctional movements in Parkinson's, ALS and other diseases. Confocal microscope immunofluorescent image of a spinal cord neural circuit made entirely from stem cells and termed a 'circuitoid.' Credit: Salk Institute

Not everyone is Fred Astaire or Michael Jackson, but even those of us who seem to have two left feet have got rhythmin our brains. From breathing to walking to chewing, our days are filled with repetitive actions that depend on the rhythmic firing of neurons. Yet the neural circuitry underpinning such seemingly ordinary behaviors is not fully understood, even though better insights could lead to new therapies for disorders such as Parkinson's disease, ALS and autism.

Recently, neuroscientists at the Salk Institute used stem cells to generate diverse networks of self-contained spinal cord systems in a dish, dubbed circuitoids, to study this rhythmic pattern in neurons. The work, which appears online in the February 14, 2017, issue of eLife, reveals that some of the circuitoidswith no external promptingexhibited spontaneous, coordinated rhythmic activity of the kind known to drive repetitive movements.

"It's still very difficult to contemplate how large groups of neurons with literally billions if not trillions of connections take information and process it," says the work's senior author, Salk Professor Samuel Pfaff, who is also a Howard Hughes Medical Institute investigator and holds the Benjamin H. Lewis Chair. "But we think that developing this kind of simple circuitry in a dish will allow us to extract some of the principles of how real brain circuits operate. With that basic information maybe we can begin to understand how things go awry in disease."

Nerve cells in your brain and spinal cord connect to one another much like electronic circuits. And just as electronic circuits consist of many components, the nervous system contains a dizzying array of neurons, often resulting in networks with many hundreds of thousands of cells. To model these complex neural circuits, the Pfaff lab prompted embryonic stem cells from mice to grow into clusters of spinal cord neurons, which they named circuitoids. Each circuitoid typically contained 50,000 cells in clumps just large enough to see with the naked eye, and with different ratios of neuronal subtypes.

With molecular tools, the researchers tagged four key subtypes of both excitatory (promoting an electrical signal) and inhibitory (stopping an electrical signal) neurons vital to movement, called V1, V2a, V3 and motor neurons. Observing the cells in the circuitoids in real time using high-tech microscopy, the team discovered that circuitoids composed only of V2a or V3 excitatory neurons or excitatory motor neurons (which control muscles) spontaneously fired rhythmically, but that circuitoids comprising only inhibitory neurons did not. Interestingly, adding inhibitory neurons to V3 excitatory circuitoids sped up the firing rate, while adding them to motor circuitoids caused the neurons to form sub-networks, smaller independent circuits of neural activity within a circuitoid.

"These results suggest that varying the ratios of excitatory to inhibitory neurons within networks may be a way that real brains create complex but flexible circuits to govern rhythmic activity," says Pfaff. "Circuitoids can reveal the foundation for complex neural controls that lead to much more elaborate types of behaviors as we move through our world in a seamless kind of way."

Because these circuitoids contain neurons that are actively functioning as an interconnected network to produce patterned firing, Pfaff believes that they will more closely model a normal aspect of the brain than other kinds of cell culture systems. Aside from more accurately studying disease processes that affect circuitry, the new technique also suggests a mechanism by which dysfunctional brain activity could be treated by altering the ratios of cell types in circuits.

Explore further: Scientists discover new mechanism of how brain networks form

More information: Matthew J Sternfeld et al, Speed and segmentation control mechanisms characterized in rhythmically-active circuits created from spinal neurons produced from genetically-tagged embryonic stem cells, eLife (2017). DOI: 10.7554/eLife.21540

Journal reference: eLife

Provided by: Salk Institute

Scientists have discovered that networks of inhibitory brain cells or neurons develop through a mechanism opposite to the one followed by excitatory networks. Excitatory neurons sculpt and refine maps of the external world ...

A new study presented in the journal Nature could change the view of the role of motor neurons. Motor neurons, which extend from the spinal cord to muscles and other organs, have always been considered passive recipients ...

When you're taking a walk around the block, your body is mostly on autopilotyou don't have to consciously think about alternating which leg you step with or which muscles it takes to lift a foot and put it back down. That's ...

We humans walk with our feet. This is true, but not entirely. Walking, as part of locomotion, is a coordinated whole-body movement that involves both the arms and legs. Researchers at the Biozentrum of the University of Basel ...

Dr. Kevin Collins carefully places a petri dish with what looks like a blotch of yellowish slime under a microscope. Magnified, the slime comes alive as hundreds of translucent worms, known as Caenorhabditis elegans, slither ...

Imagine yourself sitting in a noisy caf trying to read. To focus on the book at hand, you need to ignore the surrounding chatter and clattering of cups, with your brain filtering out the irrelevant stimuli coming through ...

Not everyone is Fred Astaire or Michael Jackson, but even those of us who seem to have two left feet have got rhythmin our brains. From breathing to walking to chewing, our days are filled with repetitive actions that ...

Whether we're navigating a route to work or browsing produce at the grocery store, our brains are constantly making decisions about movement: Should I cross the street now or at the intersection? Should I reach for the red ...

Pain is a signal of actual or potential damage to the body, so it is natural to think of it as a localized sensation: knee pain in the knee, back pain in the back and so on.

Researchers from the University of Toronto, Canada, have discovered a reason why we often struggle to remember the smaller details of past experiences.

The feel-good brain chemical dopamine appears to play a role in the development of a healthy bond between a mother and baby, a new study suggests.

Proteins are the building blocks of all cells. They are made from messenger RNA (mRNA) molecules, which are copied from DNA in the nuclei of cells. All cells, including brain cells regulate the amount and kind of proteins ...

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

See original here:
Your brain's got rhythm - Medical Xpress

Related Post


categoriaSpinal Cord Stem Cells commentoComments Off on Your brain’s got rhythm – Medical Xpress | dataFebruary 15th, 2017

About...

This author published 858 posts in this site.
Just for fun

Share

FacebookTwitterEmailWindows LiveTechnoratiDeliciousDiggStumbleponMyspaceLikedin

Comments are closed.





Personalized Gene Medicine | Mesenchymal Stem Cells | Stem Cell Treatment for Multiple Sclerosis | Stem Cell Treatments | Board Certified Stem Cell Doctors | Stem Cell Medicine | Personalized Stem Cells Therapy | Stem Cell Therapy TV | Individual Stem Cell Therapy | Stem Cell Therapy Updates | MD Supervised Stem Cell Therapy | IPS Stem Cell Org | IPS Stem Cell Net | Genetic Medicine | Gene Medicine | Longevity Medicine | Immortality Medicine | Nano Medicine | Gene Therapy MD | Individual Gene Therapy | Affordable Stem Cell Therapy | Affordable Stem Cells | Stem Cells Research | Stem Cell Breaking Research

Copyright :: 2024