Related Experiment Video

Updated: Aug 14, 2026

Tissue Triage and Freezing for Models of Skeletal Muscle Disease
05:58

Tissue Triage and Freezing for Models of Skeletal Muscle Disease

Published on: July 15, 2014

Electron microscopical study of a family with myotonia congenita

E R Fisher, T S Danowski, U Ahmad

    Archives of Pathology
    |November 1, 1975
    PubMed

    Insights

    This study examined skeletal muscle biopsies from a family with recessive myotonia congenita. Findings suggest the condition

    Area of Science:

    • Neurology
    • Genetics
    • Muscle Biology

    Background:

    • Myotonia congenita is a rare genetic muscle disorder characterized by delayed muscle relaxation.
    • Distinguishing between different types of myotonia is crucial for understanding pathogenesis and inheritance patterns.

    Purpose of the Study:

    • To investigate the ultrastructural changes in skeletal muscle of patients with recessive myotonia congenita.
    • To differentiate myotonia congenita from myotonia dystrophica based on muscle pathology.

    Main Methods:

    • Light and electron microscopy were used to examine muscle biopsy specimens.
    • Histopathological analysis focused on sarcolemma, sarcoplasmic reticulum, transverse tubules, mitochondria, and sarcomeres.

    Main Results:

    • Light microscopy revealed normal muscle fibers.
    • Electron microscopy showed focal variations in mitochondria and sarcomere fragmentation, but these were also present in unaffected family members.
    • No significant ultrastructural abnormalities were detected in key muscle components like sarcolemma or sarcoplasmic reticulum.

    Conclusions:

    • Recessive myotonia congenita appears to be distinct from myotonia dystrophica at the ultrastructural level.
    • The pathogenesis of myotonia congenita may involve biochemical abnormalities rather than detectable structural defects.

    More Related Videos

    Modeling Myotonic Dystrophy 1 in C2C12 Myoblast Cells09:39

    Modeling Myotonic Dystrophy 1 in C2C12 Myoblast Cells

    Published on: July 29, 2016

    Direct Reprogramming of Human Fibroblasts into Myoblasts to Investigate Therapies for Neuromuscular Disorders10:28

    Direct Reprogramming of Human Fibroblasts into Myoblasts to Investigate Therapies for Neuromuscular Disorders

    Published on: April 3, 2021

    Related Concept Videos

    Overview of Myosin Structure and Function01:15

    Overview of Myosin Structure and Function

    Myosins are a family of molecular motor proteins, first identified in the skeletal muscles, where they are responsible for muscle contraction. Along with their role in muscle contraction, these proteins also play a role in the intracellular transport of molecules and vesicles. There are twenty-four classes of myosins based on their domain sequence and organization. Of the twenty-four, six classes (Myosin I, Myosin II, Myosin V, Myosin VI, Myosin VII, and Myosin X)  have been well characterized.
    Satellite Stem Cells and Muscular Dystrophy01:21

    Satellite Stem Cells and Muscular Dystrophy

    Satellite stem cells or myosatellite cells are quiescent stem cells that Alexander Mauro first identified in 1961. These cells are located between the sarcolemma, the plasma membrane of muscle fibers, and the basal lamina, the connective tissue sheath covering it. These mononucleated cells are activated in response to muscle injury, can transform into myoblasts, and may form or repair muscle fibers. Myosatellite cells can provide additional myonuclei for muscle regeneration or return to a...
    Myasthenia Gravis: Diagnostic Tests01:15

    Myasthenia Gravis: Diagnostic Tests

    Myasthenia gravis is an autoimmune condition affecting neuromuscular transmission, causing generalized weakness in skeletal muscles. Initial diagnoses rely on patients' signs, symptoms, and medical history. The challenge lies in distinguishing myasthenia from other muscular dystrophies. An important diagnostic feature is the significant improvement of symptoms after administering anticholinesterase inhibitors.
    The edrophonium test is a diagnostic tool for myasthenia gravis. It involves...
    Microscopic Anatomy of Skeletal Muscles01:13

    Microscopic Anatomy of Skeletal Muscles

    Skeletal muscle cells, also called muscle fibers, are distinctly elongated, multi-nucleated, slender biological units. They are packed with specialized structures designed to facilitate their primary function, which is contraction.
    The muscle sarcolemma is a plasma membrane enclosing each muscle cell that conducts electrical signals called action potentials. The sarcolemma extends into the cell to form T-tubules, ensuring the neural impulses are uniformly distributed across the entire muscle...
    Alterations in Muscle Tone ll01:12

    Alterations in Muscle Tone ll

    Alterations in muscle tone are common manifestations of neurological disorders and reflect dysfunction within different nervous system regions. Spasticity, paratonia, and dystonia represent distinct forms of hypertonia, each with unique mechanisms, clinical features, and diagnostic importance.CharacteristicsSpasticity happens from upper motor neuron lesions and is characterized by velocity-dependent resistance to passive movement. Clinical features include:Exaggerated deep tendon reflexesClonus...
    Alterations in Muscle Tone lll01:11

    Alterations in Muscle Tone lll

    Rigidity and myotonia are distinct abnormalities of muscle tone that affect resistance and relaxation during movement. Although both involve altered muscle contraction, they arise from different neurological and muscular mechanisms.CharacteristicsRigidity is characterized by uniform resistance to passive movement across the entire range, independent of speed, affecting flexors and extensors equally. It may appear as lead-pipe rigidity (smooth, constant resistance) or cogwheel rigidity...