New knowledge on how different brain cell types contribute to our movements

January 28, 2020

Researchers at Karolinska Institutet have mapped how different nerve cells in the brain area striatum process information to plan and execute our movements at just the right time and with the right vigour. The results, presented in the journal Cell Reports, show that different cell types in the striatum receive signals from completely different parts of the cerebral cortex and thus respond to different types of information.

Many behaviours occur in response to sensory input from our environment. For example, when playing a new piece on the piano, we adjust our finger movements according to the sound we hear and the sensory feedback from the keys. Researchers at Karolinska Institutet in Sweden aimed to increase our understanding of how this works by studying the neuronal network that allows us to align our planned movements to sensory information such as touch. The nerve cells (neurons) that underlie this function are in the striatum, which is part of a larger structure in the brain called the basal ganglia.

While playing piano, sensory feedback from our fingertips is processed in the somatosensory cortex, the brain area specialised for touch. Movements are planned in a separate part of the brain called motor cortex. Information from the somatosensory cortex, the motor cortex and other brain areas such as thalamus are sent to the striatum, which is the first instance where movement plans and sensory information are combined. Based on the broad information delivered by these inputs, the striatum is able to generate a precisely timed output signal that is sent back to the muscles and allows us to press the next keys correctly on the piano.

"Although it has long been known that the striatum is composed of different types of nerve cells, it is unclear how striatal cells achieve this complex function," says Yvonne Johansson, PhD student at the Department of Neuroscience, Karolinska Institutet. "To address this question, we asked which striatal cell populations process which incoming information."

The researchers have used optogenetics, among other technologies, to analyse which of five important cell types in the striatum are responsible for the communication from the motor cortex, the somatosensory cortex and the thalamus.

Studies on mice revealed that striatal medium spiny neurons strongly respond to sensory inputs representing a sensation of touch. Another class of striatal neurons, the low-threshold spiking interneurons, hardly respond to inputs carrying sensory information but are strongly activated by inputs from motor cortex. In sharp contrast, cholinergic interneurons respond most strongly to thalamic inputs which are thought to notify us that something important is happening in our environment.

The researchers also found that the responses of the different neuron classes are mediated by different receptor compositions. As some receptors open faster than others, the receptors strongly shape the timing of the response.

The findings shed new light on how the striatum is systematically processing the vast amount of information that it receives.

"Our work shows that the flow of information into the striatal network is highly organised and that the properties of the numerous inputs targeting different striatal neuron populations are pathway-specific," says Gilad Silberberg, professor at the Department of Neuroscience, Karolinska Institutet.
The study was supported by the Knut and Alice Wallenberg Foundation, the European Research Council (ERC Starting Grant), The Swedish Research Council and The Swedish Brain Foundation.

Publication: "The Functional Organization of Cortical and Thalamic Inputs onto Five Types of Striatal Neurons is Determined by Source and Target Cell Identities." Yvonne Johansson & Gilad Silberberg. Cell Reports, online 28 January 2020, doi: 10.1016/j.celrep.2019.12.095.

Karolinska Institutet

Related Neurons Articles from Brightsurf:

Paying attention to the neurons behind our alertness
The neurons of layer 6 - the deepest layer of the cortex - were examined by researchers from the Okinawa Institute of Science and Technology Graduate University to uncover how they react to sensory stimulation in different behavioral states.

Trying to listen to the signal from neurons
Toyohashi University of Technology has developed a coaxial cable-inspired needle-electrode.

A mechanical way to stimulate neurons
Magnetic nanodiscs can be activated by an external magnetic field, providing a research tool for studying neural responses.

Extraordinary regeneration of neurons in zebrafish
Biologists from the University of Bayreuth have discovered a uniquely rapid form of regeneration in injured neurons and their function in the central nervous system of zebrafish.

Dopamine neurons mull over your options
Researchers at the University of Tsukuba have found that dopamine neurons in the brain can represent the decision-making process when making economic choices.

Neurons thrive even when malnourished
When animal, insect or human embryos grow in a malnourished environment, their developing nervous systems get first pick of any available nutrients so that new neurons can be made.

The first 3D map of the heart's neurons
An interdisciplinary research team establishes a new technological pipeline to build a 3D map of the neurons in the heart, revealing foundational insight into their role in heart attacks and other cardiac conditions.

Mapping the neurons of the rat heart in 3D
A team of researchers has developed a virtual 3D heart, digitally showcasing the heart's unique network of neurons for the first time.

How to put neurons into cages
Football-shaped microscale cages have been created using special laser technologies.

A molecule that directs neurons
A research team coordinated by the University of Trento studied a mass of brain cells, the habenula, linked to disorders like autism, schizophrenia and depression.

Read More: Neurons News and Neurons Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to