Histologically, denervated muscle tissue shows several characteristic changes:
1. Muscle Fiber Atrophy: Muscle fibers shrink in diameter due to the loss of protein content. This reduction in size is often one of the earliest indicators of denervation. 2. Increased Connective Tissue: As muscle fibers atrophy, the space between them is often filled with connective tissue. This fibrotic response can further impair muscle function. 3. Necrosis and Phagocytosis: In some cases, muscle fibers may undergo necrosis, where the cells die and are subsequently removed by phagocytic cells such as macrophages. 4. Changes in Fiber Type Composition: Normally, muscle fibers are categorized into different types (Type I, Type IIa, Type IIb) based on their metabolic and contractile properties. Denervation can cause a shift in the distribution of these fiber types.
