Lectures and seminars Fysiologföreningen presents Dr. Marco Tripodi: "Modules for action: Mapping three-dimensional space in motor coordinates"

Title

"Modules for action: Mapping three-dimensional space in motor coordinates"

Presenter

Dr. Marck Tripodi

MRC Laboratory of Molecular Biology, Cambridge, Great Britain

Abstract

From the act of catching a prey to that of grasping an object, animals need to map objects location within a body-centred spatial reference frame. In the motor domain this map must be defined by an array of three-dimensional displacement vectors whose recruitment allows motion in the direction of the target.

Dr. Tripodi has identified collicular neurons decoding three-dimensional displacement vectors for goal-directed head movements in the mouse. Moving from in vitro preparations to in vivo electrophysiological recordings and imaging in freely moving mice, he has dissected the intrinsic properties, tuning, genetics and circuit organisation of neurons involved in the control of spatially tuned reorienting movements. He shows that genetically defined neurons in the superior colliculus decode one, two or three Eulerian components of the head-displacement vectors. These neurons are sufficient to guide spatially-tuned goal-oriented actions, bridging spatial encoding and action initiation and potentially providing a shared platform serving both motor and cognitive demands. His study also shows that spatially coherent motor units are anatomically clustered in genetically defined modules, giving origin, at least at this level of decoding, to a discrete representation of the motor space.

Such a modularity provides an anatomical substrate for the convergence of spatially coherent sensory and motor signals of cortical and subcortical origins, thereby promoting the recruitment of appropriate movement vectors. Overall, these findings support the view of the superior colliculus as a selectively addressable and modularly organized spatial-motor register.

Host

Andreas Kardamakis