To focuses on the challenges faced by individuals with spinocerebellar ataxia (SCA), highlighting the major clinical sign of ataxia that affects their stability and ability to perform daily activities, thereby impacting their quality of life. It outlines the concept of neural plasticity, which is the brain's ability to adapt through changes in excitability, and notes that these changes are more enduring in the central nervous system (CNS) than in the peripheral nervous system (PNS). This adaptability, crucial for memory and motor learning, is compromised in SCA patients due to impaired brain areas and pathways. The summary further delves into motor learning, distinguishing between explicit and implicit learning, and points out that SCA patients exhibit deficiencies in procedural learning and cerebellar function. It also introduces the concept of priming as a preparatory mechanism that can enhance the effectiveness of physical therapy by modifying subsequent responses to stimuli. The document suggests that cycling, as an aerobic exercise, could prime the brain for improved blood flow and oxygenation, thereby supporting synaptic plasticity and the release of beneficial neurotrophic factors. Finally, the project aims to deepen the understanding of motor performance and learning mechanisms in SCA patients and apply these insights to clinical rehabilitation strategies.

Ataxia is the major clinical sign of spinocerebellar ataxia (SCA) patients. Increased postural sway and instability during volitional movements appear and hinder SCA patients from performing normal daily life activities and influence quality of life of victims.

Neural plasticity comes from excitability changes. Changes in excitability produced by repetitive activities at synapses maintain a longer time in the central nervous system (CNS) than the changes in the peripheral nervous system (PNS). The long duration of synaptic excitability changes may be linked to memory and motor learning. Neural plasticity could be investigated by several non-invasive instruments, such as Transcranial Magnetic Stimulation (TMS). The excitability is suppressed in SCA patients due to corrupted brain areas and pathways.

Motor learning is the process of obtaining the capability for movement. Motor learning is not merely focusing on changes in performance during practice but also being evaluated during retention and/or transfer. Motor learning can be divided into explicit and implicit learning. One type of implicit learning is the acquisition of motor skills, often referred to as procedural learning. Serial reaction time task (SRTT) is used to describe implicit sequence motor learning. A series of implicit motor sequence learning tasks is to clarify the role and function of the cerebellum. And this function is deficient in SCA patients.

Priming is an unconscious process associated with learning to alter the later response by the proceeding stimulus. Priming is applied to physical therapy; it could result in behavioral change and strengthen the training effect afterward.

Cycling could be an aerobic exercise priming that may help to raise brain blood flow and oxygenation, facilitate synaptic plasticity, augment the release of neurotrophic factors, to transmit neuroendocrine and myokines.

This project will advance the knowledge of the mechanism of motor performance and motor learning in SCA individuals. The result of this project can be applied to the clinical rehabilitation of people with SCA.

Health subjects:

Exclusion Criteria:

• Musculoskeletal injuries on legs.
• Osteoporosis.

SCA subjects:

Inclusion Criteria:

- Clinical diagnosis of SCA.

Exclusion Criteria:

• Musculoskeletal injuries on legs
• Osteoporosis.
• Any peripheral or central nervous system injury or disease patients.