Cerebellar White Matter Structural Correlates of Locomotor Adaptation: Do They Reflect Neural Adaptation?

Understanding the neural underpinnings of locomotor adaptation in humans is critical to induce favorable gait characteristics in individuals at risk for imbalance and subsequent falls. It is well established that the cerebellum and motor cortical regions functionally interact to encode the motor routines necessary to learn a novel motor task. The cerebellum is widely known for its role in the detection and prediction of motor errors, key functions during the motor adaptation process [1]. While an abundance of literature demonstrates the importance of cerebellar structural and functional properties to motor adaptation in humans, such research has primarily investigated cerebellar contributions to upper extremity movement dynamics. For instance, a study conducted by Della-Maggiore and colleagues discovered that the rate of upper extremity visuo-motor adaptation is positively associated with the microstructural quality of the superior cerebellar peduncle [2] and increases in cortico-cerebellar functional activity were found to accompany early stages of upper extremity motor adaptation [3, 4]. Further, a number of studies found substantial increases in cerebellar activity after learning had been acquired and during recall of the previously learned motor skill, during upper extremity adaptation [5, 6]. Conversely, the cerebellar structures responsible for motor adaptation during human locomotion have mostly been unexplored until this contemporary investigation by Jossinger and colleagues [7].