The present invention provides novel irisin peptides (e.g, irisin
glycosylation mutants and biologically active fragments thereof). Also provided are methods for preventing or reducing degeneration of
dopaminergic neurons and / or preventing or ameliorating at least one motor deficit in a subject in need thereof, such as in a subject with α-synucleinopathy, using the novel irisin peptides to modulate irisin-induced
integrin signaling. The novel irisin peptides can also be used in methods for increasing expression of brain-derived neurotrophic factor (BDNF), and / or treating or preventing neurological diseases or disorders that would benefit from decreased neuronal
cell death and / or increased neuronal survival in a subject. In addition, the novel irisin peptides may be used in methods for preventing or treating muscular
atrophy or
muscular dystrophy.