Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New insights into the information processing of motor neurons

22.02.2017

Scientists at Max Planck Florida Institute for Neuroscience are working to understand how neurons in the cerebellum, a region in the back of the brain that controls movement, interact with each other

In a study published in Cell Reports in February 2017, Matt Rowan, Ph.D., a Post-doctoral researcher in the lab of Dr. Jason Christie, sought to understand the molecular mechanisms behind a type of short-term neuronal plasticity that may have importance for motor control.


A form of short-term neuronal plasticity known as analog-to-digital facilitation can result from brief somatic depolarizations lasting as little as 100 milliseconds. Such activity transiently makes Kv3.4 subunit containing channels unavailable thereby increasing the duration of the presynaptic spike and enhancing neurotransmitter release.

Credit: Max Planck Florida Institute for Neuroscience

The team showed that this type of plasticity can impact neurotransmission in as little as 100 milliseconds and depends upon inactivation of Kv3 channels. Interestingly, the team also found that this type of plasticity occurs more readily in juvenile brains than in mature ones.

Neuronal communication is frequently described simply as an all-or-nothing event. If a neuron is depolarized enough, it will fire and release neurotransmitters to communicate with another neuron; if it doesn't reach the threshold to fire, it doesn't send a signal at all.

However, depolarizations that don't reach the threshold to make the neuron fire can still impact neurotransmission. The depolarization spreads throughout the neuron, and when the neuron does eventually reach the threshold to fire, it releases a stronger signal with more neurotransmitters. This is known as analog-to-digital facilitation, a type of short-term plasticity.

"This has been seen before, and we're adding a molecular mechanism showing exactly the molecule you need to get this sort of facilitation," explained Rowan.

Researchers were already aware that this type of short-term plasticity exists, but had struggled to view it directly because the axons that utilize this type of plasticity are difficult for scientists to access. This means that some of the molecular mechanisms behind the phenomenon remain mysterious. For the current study, the team used novel techniques for voltage imaging and patch clamp recordings that allowed them to visualize and record from these tiny sections of individual neurons.

The researchers observed analog-to-digital facilitation as it occurred in experimental models. They showed that subthreshold depolarization spreads from the body of the neuron down its axon, the long extension through which action potentials travel before causing the neurons to release neurotransmitters into a synapse.

Here, subthreshold depolarizations impacted neurotransmission in the juvenile models by briefly making Kv3.4 channel unavailable thereby increasing the duration of the presynaptic spike. The fact that the group observed less of this same plasticity in mature models suggests that learning and experience may temper this type of plasticity as an animal matures.

The team chose to study inhibitory interneurons in the cerebellum because they play an especially important role in the function of circuits throughout the cerebellum as well as the rest of the brain. Understanding this type of neuronal plasticity may have important implications for understanding motor disorders such as cerebellar ataxia, a disorder that can cause a variety of motor problems in humans ranging from increased falling to difficulty with speech and swallowing.

###

This work was supported by the National Institutes of Health (NS083127 and NS083894) and funding from The Max Planck Florida Institute for Neuroscience and the Max Planck Society.

About MPFI

The Max Planck Florida Institute for Neuroscience (Jupiter, Florida, USA) specializes in the development and application of novel technologies for probing the structure, function, and development of neural circuits. It is the first research institute of the Max Planck Society in the United States.

Jennifer Gutierrez | EurekAlert!

More articles from Life Sciences:

nachricht One step closer to reality
20.04.2018 | Max-Planck-Institut für Entwicklungsbiologie

nachricht The dark side of cichlid fish: from cannibal to caregiver
20.04.2018 | Veterinärmedizinische Universität Wien

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Magnetic nano-imaging on a table top

20.04.2018 | Physics and Astronomy

Start of work for the world's largest electric truck

20.04.2018 | Interdisciplinary Research

Atoms may hum a tune from grand cosmic symphony

20.04.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>