Proprioception

Proprioception is essential for planning and executing precise motor actions. It relies on sensory signals from mechanosensory neurons distributed within muscles, tendons, and joints. Muscle spindles convey information through sensory afferents to the central nervous system. While traditionally viewed as stretch receptors encoding muscle length and velocity, recent insights suggest they may function as adaptable signal-processing devices. Spinal gamma motor neurons are believed to drive this adaptability by modulating the responses of sensory afferent to task demands. However, the mechanisms b

Proprioception is the sensation of the position and movement of the body in space. Forelimb proprioceptive afferents not only drive reflexes circuits in the spinal cord, but also ascend to the brain via projections to the external cuneate nucleus (Ecu) in the brainstem. Secondary neurons in the Ecu relay the incoming information via two major pathways: 1) the cuneo-cerebellar track which innervates the cerebellum and allows movement adaptation to unexpected perturbations and 2) the dorsal column-medial lemniscus pathway targeting the somatosensory cortex and allowing for the perception of prop

Proprioception enables an organism to sense the position and motion of its limbs and body in space. Comparative evolutionary studies have proposed that the organization of the proprioceptive cortex does not emerge as a consequence of innervation density but rather as a result of the actual use of a limb. We tested this hypothesis by quantifying if and how the proprioceptive cortical representation reorganizes after skilled motor training in adult mice as well as enriched environmental exposure during development.We performed wide-filed calcium imaging of cortical activation in response to mult

Brain-organ communications play a crucial role in maintaining the body's physiological and psychological homeostasis, and are controlled by complex neural and hormonal systems, including the internal mechanosensory organs. However, the progress has been slow due to technical hurdles: the sensory neurons are deeply buried inside the body and are not readily accessible for direct observation, the projection patterns from different organs or body parts are complex rather than converging into dedicate brain regions, the coding principle cannot be directly adapted from that learned from conventiona

Proprioception is fundamental for the control of movement, its loss producing profound motor deficits. Yet basic questions of how pose and movement are represented, as well as how these representations are arranged across the somatosensory cortex, are unclear. To this end, we adopt a task-driven modelling approach, using a spiking variational autoencoder to approximate a population of cortical neurons. We optimize the model to encode natural movement stimuli derived from recordings of human kinematics and impose biological constraints which we hypothesise to be important for reproducing charac

…be initiated by motor activity and proprioception, and then distributed to higher brain areas (“bottom-up”). To distingui

…which govern the processing of proprioception, are poorly understood. Here, we employ a task-driven modeling approach to quantitatively test hypotheses about the functional role of proprioceptive neurons in cuneate nucleus, which is the projection target of ascending spindle neurons in the brain stem. We generated datasets of realistic proprioceptive, muscle spindle inputs for a large, diverse repertoire of movements (following Sandbrink et al., bioRxiv, 2020), and used them to

…for the mechanical senses of touch and proprioception, but our understanding of internal organ sensing, interoception, is far behind. I will describe our findings on the role of PIEZO ion channels in the lesser-known interoceptive senses in multiple organ systems.

Electric Gymnotiform fish live in muddy, shallow waters near the shore – hiding in the dense filamentous roots of floating plants such as Eichornia crassipes (“camalote”). They explore their surroundings by using a series of electric pulses that serve as self emitted carrier of electrosensory signals. This propagates at the speed of light through this spongiform habitat and is barely sensed by the lateral line of predators and prey. The emitted field polarizes the surroundings according to the difference in impedance with water which in turn modifies the profile of transcutaneous currents cons

…This sense of proprioception is mediated by diverse populations of internal mechanosensory neurons distributed throughout the body. My lab is trying to understand how proprioceptive stimuli are detected by sensory neurons, integrated and transformed in central circuits, and used to guide motor output. We approach these questions using genetic tools, in vivo two-photon imaging, and patch-clamp electrophysiology in Drosophila. We recently found that the axons of fly leg proprioceptors are o