August 23, 2018

Motor cortex needed for sensory-guided control of movement

In a collaboration, Matthias Heindorf (FMI/Biozentrum), Silvia Arber (FMI/Biozentrum), and Georg Keller (FMI) investigated the role of motor cortex in the control of movement. Their study - published in ‘Neuron’ today - demonstrates that motor cortex is necessary for the execution of corrective movements in response to unexpected changes of sensory input but not when the same movements are executed spontaneously. Signatures of differential neuronal usage in the cortex accompany these two phenomena. This represents a big step towards understanding how motor cortex controls movement – an important unresolved question in neuroscience.

In mammals, movement is controlled by circuits spanning throughout the central nervous system from the cortex to the spinal cord. The role of motor cortex in the control of movement is still unclear. In humans, lesions to motor cortex can result in a loss of voluntary control of movement. Building on the expertise of studying motor circuits and the control of movement of the Arber laboratory and the expertise in vivo physiology and cortical processing of the Keller laboratory, the authors teamed up to shed new light on the function of motor cortex.

The aim of the study was to test how and under which conditions motor cortex is required for movement control. The authors developed an assay in which they trained mice to navigate a virtual tunnel, a task requiring the adjustment of the heading direction by spontaneous turning on a spherical treadmill. They also probed the response to unexpected changes in visual feedback that mice had to correct for – for example by suddenly shifting the direction the mouse is running in in the virtual environment. This allowed them to compare the same movements mice executed either spontaneously or as induced by unexpected changes to the visual feedback. The authors found that motor cortex is only necessary for movement control when movements are executed in response to unexpected sensory feedback.

Recording neuronal activity in motor cortex as mice corrected for unpredicted sensory perturbations, the authors found that the activity patterns observed during the resultant motor corrections were different from those when the mouse executed the same movement spontaneously. This is consistent with a role of motor cortex in the corrective motor response, where it is required to engage in triggering an appropriate movement in response to the unexpected event.

"We believe that these findings change the way we think about how motor cortex functions from a view that it 'simply' controls movement to a role in which motor cortex is needed for sensory-guided control of movement in instances where the sensory processing is also cortically dependent," says Matthias Heindorf, first author and former PhD student in the Arber and Keller laboratories.

Original publication:
Heindorf M, Arber S¹ and Keller GB^1,2. Mouse Motor Cortex Coordinates the Behavioral Response to Unpredicted Sensory Feedback, Neuron (2018),
https://doi.org/10.1016/j.neuron.2018.07.046
1 These authors contributed equally
2 Lead contact

Watch video of Georg Keller talking about his research in general and to see the experimental set-up used here in action.

About Georg Keller
Georg Keller has been a senior group leader at the FMI since 2017. He and his group aim to elucidate the key principles underlying sensory processing in the cortex.
» More about Georg Keller

About Silvia Arber
Silvia Arber holds a dual appointment at the Biozentrum of the University of Basel and the FMI. She has been a full professor for Neurobiology at the Biozentrum since 2008 and a senior group leader at the FMI since 2004. She and her group aim to dissect the development and function of the neuronal circuits controlling movement.
» More about Silvia Arber