Motor learning

…discoveries about movement control and motor learning, she connects differences in brain damage with variation in therapeutic benefit. The session traces the clinical questions that led from physical therapy to neuroscience and considers how research on the human motor system can inform more individualized rehabilitation.

Investigate how neural circuits support motor learning and skilled movement. The work combines electrophysiology, genetic targeting, circuit manipulation and analysis of behaviour and neural activity.

…diving into a groundbreaking paper: "Motor learning selectively strengthens cortical and striatal synapses of motor engram neurons

…Sensorimotor learning provided a rich quantitative framework for approaching this question. Here we build on a recent theoretical model, COIN (Heald, Lengyel, and Wolpert 2021), that has been successful in unifying motor learning paradigms, to understand how training schedules affect learning of multiple memories. A classic result in motor learning (Shea and Morgan 1979) showed that training tasks A and B in a blocked order (AAABBB) results in faster learning of A and B but poorer retention than in

We propose a novel dual-model framework that integrates reinforcement learning (RL) and adaptive control to model cerebellar function in motor learning and adaptation. Our approach distinguishes between the roles of the basal ganglia and cerebellum, addressing limitations of current models in complex motor control tasks. We introduce a decomposition of the value function where the RL component optimizes the mean expected value while the cerebellar module minimizes deviations from optimal latent trajectories. This decomposition approximates a normative information-theoretic objective where the

Understanding the neural dynamics underlying motor learning is pivotal for revealing how the brain adapts to acquire new skills. Plasticity in the primary motor cortex is essential for motor skill learning, with Layer 5 pyramidal tract (L5 PT) neurons playing a key role in the process. Previous studies have shown dendritic spines undergo plasticity changes during motor learning, yet the resulting changes at the dendritic level remain unknown. To investigate changes occurring in apical tuft dendrites during motor learning, we performed repeated two-photon calcium imaging of the same L5 PT apic

To study how motor circuits control bodies in robust, adaptive, and flexible ways, we often break down the complex control system into individual components to be studied in isolation. However, it is increasingly recognized that we need to consider biomechanically realistic models when interpreting the neural computations underlying movement and motor learning. Training an artificial neural network (ANN) to control a biomechanical model and have it reproduce the behavior of real animals allows the probing of neural control of movement in a fully transparent and configurable system. To make thi

Task acquisition in the brain relies on both reward-based and error-based learning (RBL, EBL), yet how the brain brings these two learning signals together remains elusive. Here, we build on the traditional view that dopamine (DA) projections within the basal ganglia (BG) drive RBL via reinforcement learning, while the cerebellum (CB) supports EBL via supervised learning. In doing so, we introduce a novel learning framework that combines DA-driven RBL with CB-driven EBL. Specifically, we reformulate the traditional RBL and EBL synaptic weight updates in terms of a shared ‘action-gradient’ spac

Learning is fundamental for interacting with a changing environment. Critical to this process is the ability to rapidly adapt previously acquired skills to external perturbations while avoiding catastrophic forgetting of previous tasks. For the learning system, this corresponds to a trade-off between being able to maintain stable memories of learned tasks, and the ability to swiftly adapt such memories to changes. We hypothesize that such a problem can be addressed by using a two-timescale [1,2] strategy, where memorization and adaptation are performed by two separate modules. This structure a

Aims: Converging evidence indicates beneficial effects of aerobic exercise on motor learning performance. Underlying mechanisms might be an impact of aerobic exercise on neuroplasticity and cortical excitability. Evidence suggests that motor learning and cortical excitability alterations correlate with the intensity of aerobic exercise and the activity level of participants. Thus, this study aims to investigate the effects of different aerobic exercise intensities on motor learning and cortical excitability in healthy individuals. Methods: The study was conducted in a cross-over and double-bli

…for dysregulated LC-NA function in motor learning delays of the 16p11.2 deletion (+/-) mouse-model of ASD. We found that reduced NA levels in primary motor cortex (M1) caused delays in motor learning and increased neuronal activity in M1 pyramidal neurons. Both behavioral and neuronal phenotypes were rescued by chemogenetic activation of LC-NA. We next

…having significant implications for motor control and cognition.We recently identified one of the most abundant populations of GABAergic interneurons in the striatum that express Pthlh and varying levels of Pvalb, which correlates with intrins

The cerebral cortex is structured into functional areas and six horizontal layers. Within the cortex, different subtypes of neurons have distinct projections patterns and functions. To better understand how information is processed, and how the pyramidal cell output signal is formed, we need specific markers to investigate the function of more homogenous subpopulations of interneurons. In this study we used Chrna2 to specifically label a subset of Martinotti cells. With rabies viral tracers, combined with immunohistochemistry, we investigated the presynaptic connectivity of these cells, in dif

Aim: Motor learning significantly impacts daily life, triggering notable changes in the primary motor cortex (M1) and basal ganglia (BG). Dopamine (DA) mediates these changes, with Darpp-32 playing a key role in DA transmission. Although extensively studied in the BG's striatum, Darpp-32's function in the motor cortex remains largely unexplored. This study aims to characterize Darpp-32 in motor cortices, examining cellular expression and its impact on motor behavior, synaptic and structural plasticity.Methods: Anatomical study: Using C57BL/6 mice, we examined Darpp-32 distribution across corti

Mitochondrial trafficking is essential for neuronal development as well as for maintenance of functional mitochondrial pools at synaptic terminals. Nevertheless, the relevance of this process for mature neurons and the mechanisms governing the inherent motility of mitochondria across neuronal compartments remains unknown. By imaging mitochondrial transport in developing Purkinje neurons (PN) in situ, we observed progressive the formation of stable pools in the distal regions of dendrites, while larger dendritic calibers and axonal shaft kept a considerable extent of organelle motility up and b

The cerebellum has a well-established role in fine motor control and motor learning. In the cerebellar cortex, the first stage of information processing takes places at synapses between mossy fiber (MF) and cerebellar granule cell (GC) synapses, where synaptic transmission occurs at ultra-high frequencies (up to kHz). MF presynaptic machinery is capable of releasing glutamate at such extreme frequencies but the molecular determinants and ultrastructural organization underlying this presynaptic efficiency have yet to be elucidated. In several synapse types, the actin cytoskeleton, which is dyna

…will increase the efficiency of learning. Our aim was to investigate the effects of haptic electrical stimulation on motor learning and corresponding brain activity. The learning was carried out in a VR simulator with a full-body haptic suit (Teslasuit, https://teslasuit.io) to reinforce

Motor learning, skill-learning or habit formation share conceptual similarities, but it is debated how much biology these processes have in common. There is genetic evidence linking motor learning and habit formation in flies, song-learning in birds and language acquisition in humans to an evolutionary conserved operant self-learning process. Here we show different biological manipulations of Drosophila that all enhance motor learning. Mutations in genes involved in classical conditioning, such as rutabaga or radish, enhance motor learning. Overexpression of an operant learning gene, atypical

Astrocytes are glial cells that participate in crucial processes in brain homeostasis and play a key role in modulating neuronal activity. Numerous astrocytic receptors transduce signals via cAMP although how changes in astrocytic cAMP levels modulate brain activity or animal behaviour is not fully understood. Our goal is to control cAMP in cortical astrocytes using DdPAC, a recently developed phytochrome photoreceptor that increases cAMP upon red light, and evaluate its responses at three levels: a) cellular, by analysing neuronal activity using multi-electrode arrays b) systemic, by measurin

The cerebellum plays a key role in motor learning, adapting movements in response to perturbations or errors. For simple tasks like eyeblink classical conditioning, climbing fibers originating in the inferior olive and projecting to the cerebellum provide neural instructive signals sufficient to drive learning. For complex whole-body behaviors like locomotion, however, it is not known what role climbing fibers play. We recently demonstrated (Darmohray et al., 2019) that mice running on a split-belt treadmill (that controls the speed under each side of the body independently) exhibit a form of

…goal-directed behaviors, including motor learning. Motor adaptation, a specific type of adaptive learning where one needs to rapidly learn a new sensorimotor mapping has been an excellent way to behaviorally test how motor learning may be enacted. For example, in humans, perturbing visual feedback results in deviated trajectories that participants can restore to baseline performance over time. Yet, the neural circuits that underlie these visuomotor adaptations remain poorly understood. Here, we developed an implicit v

The cerebellum critically contributes to motor, cognitive and emotional functions. Cerebellum-dependent motor learning is believed to be processed within the cerebellar cortex, and specifically via changes in synaptic plasticity of Purkinje cells (PCs), which are the main cortical output. However, whether and how motor learning can influence the actual connectivity of PCs is unknown. To address this question, we use a rabies virus (RABV)-based approach to map structural modifications of PC presynaptic inputs in young (3-month-old) and middle-aged mice (1-year-old). To promote motor skill learn

…vertebrate behavior, ranging from motor learning to emotions, but comprehensive maps of their canonical synaptic architecture are missing. In mammals, three spatially separated main neuronal pathways through the BG were described - the direct, indirect, and hyperdirect pathways - that work together to orchestrate behavior. In songbirds, the cell types associated with these pathways appear intermingled in the basal ganglia nucleus Area X, essential for song learning. Here, we describe the first vertebrate basal ganglia connectome, compris

…control of GPe takes place to support motor and cognitive functions remain an open question. Using an optogenetic approach, we first e