Physiological molecular and biochemical characterization of rodent extraocular muscles : implications for Duchenne Muscular Dystrophy The six extraocular muscles (EOMs) are arranged around the eyeball as agonist antagonist pairs performing the eye movements. The EOMs comprise a distinct muscle group that is fundamentally different from other skeletal muscle which is reflected on many levels such as functionality anatomy as well as in their molecular make up. Physiologically EOMs are considered superfast high endurance muscles that are continuously active. In addition EOMs contain unusual slow tonic fibers that share features with amphibian and avian slow tonic fibers. EOMs also express slow cardiac isoforms of proteins and genes along with the typical isoforms of fast muscle fibers. Another striking hallmark of EOM is their differential involvement in a number of diseases. For instance EOMs are preferentially spared in Duchenne Muscular Dystrophy (DMD). DMD is the most common fatal genetic disease in males clinically characterized by progressive muscle wasting. Mutations in the dystrophin gene result in a destabilization of the muscle membrane causing muscle fiber damage. While all other skeletal muscles deteriorate the EOMs remain morphologically and functionally healthy... Calcium Calcium ATPasen Calciumhomöostase Duchenne Syndrom Quergestreifte Muskulatur Phospholamban Augenmuskeln SERCA mdx Maus TRP Kanäle STIM1 extraocular muscles calcium homeostasis TRP channels