Abstract
Conscious perception of limb movements depends on proprioceptive neural responses in the somatosensory cortex. In contrast to tactile sensations, proprioceptive cortical coding is barely studied in the mammalian brain and practically non-existent in rodent research. To understand the cortical representation of this important sensory modality we developed a passive forelimb displacement paradigm in behaving mice and also trained them to perceptually discriminate where their limb is moved in space. We delineated, for the first time, the rodent proprioceptive cortex with wide-field calcium imaging and optogenetic silencing experiments during awake behavior. Our results reveal that proprioception is represented in both sensory and motor cortical areas. In addition, behavioral measurements and responses of layer 2/3 neurons imaged with two-photon microscopy reveal that passive limb movements are both perceived and encoded in the mouse cortex as a spatial direction vector that interfaces the limb with the body’s peripersonal space.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
- Addition of neuroanatomical tracing of the conscious proprioceptive pathway in the mouse brain. - Addition of cortex-wide imaging of neural activity during proprioceptive stimulation. - Updated optogenetic silencing results during perceptual proprioceptive discrimination. - Addition of a behavioral measure of what the mice perceive during the discrimination task.
