Towards Cell and Subtype Resolved Functional Organization: Mouse as a Model for the Cortical Control of Movement

Abstract

Despite a long history of interrogation, the functional organization of motor cortex remains obscure. A major barrier has been the inability to measure and perturb activity with sufficient resolution to reveal clear functional elements within motor cortex and its associated circuits. Increasingly, the mouse has been employed as a model to facilitate application of contemporary approaches with the potential to surmount this barrier. In this brief essay, we consider these approaches and their use in the context of studies aimed at resolving the logic of motor cortical operation.

Keywords: behavioral paradigm; cell types; corticospinal; motor control; motor cortex; motor learning.

Fig. 1.

Illustrations of recently developed forelimb movement paradigms for mice. (A) A head-fixed mouse reaches to grasp and retrieve a food pellet on a conveyor. (B) A head-fixed mouse moves a joystick to a reward position, potentially in the presence of a force field acting on the joystick. (C) A head-fixed mouse reaches to retrieve a water droplet from a spout. (D) A freely behaving mouse reaches to grasp and retrieve a food pellet through a narrow slot.