Nav: Home

Midbrain 'start neurons' control whether we walk or run

January 17, 2018

Locomotion, or moving from one place to another, is one of the most fundamental movements we perform. We do it when we want or we need to, and it is a complex sequence from initiating the first step, to stopping when we reach our goal. At the same time, locomotion is executed at different speeds to regulate how fast we travel from one place to another depending on the purpose that drives us.

Now, a new study the scientific journal Nature by researchers Vittorio Caggiano, Roberto Leiras, Haizea Goñi-Erro and colleagues together with Professor Ole Kiehn who lead the study shows that two regions in the midbrain play specific roles in controlling the start, speed and context dependent selection of locomotion in mice. They are called the Cuneiform Nucleus or CnF and the pedunculopontine nucleus or PPN.

"We find that neurons in both PPN and CnF can start locomotion and that activity in these areas contribute to the maintenance and speed regulation of slower locomotion. However, only CnF is able to elicit the high-speed escape locomotor activity. In contrast, activity in PPN neurons favours slow explorative locomotion," says Professor Ole Kiehn Department of Neuroscience, UCPH.

While the precise coordination of locomotor movements is controlled by neuronal circuits in the spinal cord, the episodic control of locomotion is attributed to descending signals from the brainstem that activate neuronal circuits in the spinal cord.

The midbrain circuits are complex and contain neurons of many different types although the main players are shown to be the so-called glutamatergic neurons.

The researchers have utilised a number of advanced techniques, including optogenetics, to study which types of neurons are involved and the location of the neural networks. By using light and designer drugs, they have been able to activate or inactivate selected groups of nerve cells and then study how this affects the locomotor output in mice.

The researchers identify populations of 'start neurons' and show, for the first time, how the two regions in the midbrain can act both in common or separately to control speed and to select context dependent locomotor behaviours.

"By identifying the midbrain 'start' neurons we complement a previous study where we found 'stop cells' in the brainstem that halt locomotion. Together, the start and stop cells define the episodic nature of locomotion," says Ole Kiehn.

The study breaks new grounds in locomotor control and is important for understanding the normal brain function in mice. And the authors believe that the results might benefit humans with disabled locomotion as well.

"In Parkinson's disease which affect the basal ganglia - one of the main source of inputs to the PPN - gait disturbances and freezing of gait are very pronounced. By implanting fine electrodes in the brain - a technique called deep brain stimulation which is already used to treat some symptoms in Parkinson's disease - circuits in either CnF or PPN might now be targeted with new precision and used to increase the locomotor capabilities. Similar approaches may also be attempted after damage to the spinal cord, where initiation of locomotion is strongly affected," says Ole Kiehn.
-end-
The research funded by ERC advanced grant (LocomotorIntegration), Novo Nordisk Foundation (Laureate Award), NINDS, and The Swedish Research Council.

University of Copenhagen The Faculty of Health and Medical Sciences

Related Neurons Articles:

New tool to identify and control neurons
One of the big challenges in the Neuroscience field is to understand how connections and communications trigger our behavior.
Neurons that regenerate, neurons that die
In a new study published in Neuron, investigators report on a transcription factor that they have found that can help certain neurons regenerate, while simultaneously killing others.
How neurons use crowdsourcing to make decisions
When many individual neurons collect data, how do they reach a unanimous decision?
Neurons can learn temporal patterns
Individual neurons can learn not only single responses to a particular signal, but also a series of reactions at precisely timed intervals.
A turbo engine for tracing neurons
Putting a turbo engine into an old car gives it an entirely new life -- suddenly it can go further, faster.
Brain neurons help keep track of time
Turning the theory of how the human brain perceives time on its head, a novel analysis in mice reveals that dopamine neuron activity plays a key role in judgment of time, slowing down the internal clock.
During infancy, neurons are still finding their places
Researchers have identified a large population of previously unrecognized young neurons that migrate in the human brain during the first few months of life, contributing to the expansion of the frontal lobe, a region important for social behavior and executive function.
How many types of neurons are there in the brain?
For decades, scientists have struggled to develop a comprehensive census of cell types in the brain.
Molecular body guards for neurons
In the brain, patterns of neural activity are perfectly balanced.
Engineering researchers use laser to 'weld' neurons
University of Alberta researchers have developed a method of connecting neurons, using ultrashort laser pulses -- a breakthrough technique that opens the door to new medical research and treatment opportunities.

Related Neurons Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Bias And Perception
How does bias distort our thinking, our listening, our beliefs... and even our search results? How can we fight it? This hour, TED speakers explore ideas about the unconscious biases that shape us. Guests include writer and broadcaster Yassmin Abdel-Magied, climatologist J. Marshall Shepherd, journalist Andreas Ekström, and experimental psychologist Tony Salvador.
Now Playing: Science for the People

#513 Dinosaur Tails
This week: dinosaurs! We're discussing dinosaur tails, bipedalism, paleontology public outreach, dinosaur MOOCs, and other neat dinosaur related things with Dr. Scott Persons from the University of Alberta, who is also the author of the book "Dinosaurs of the Alberta Badlands".