Neuromuscular

Limb Muscles: Control

Acid phosphatase
Alkaline phosphatase
ATPase
Capillaries
Congo red
Cytochrome oxidase
Esterase
Gomori trichrome
Hematoxylin & Eosin (H&E)
NADH
PAS
Succinate dehydrogenase
Sudan
VvG
  Vessels, Large
  Perimysium
Sizes


H&E stain
Fiber size: Mild variation
Myonuclei: Dark-stained; Normally present at periphery of muscle fibers
Endomysial connective tissue: Normal
Capillaries, Endomysial: Small, Between muscle fibers

H&E stain


Congo red stain


Gomori trichrome stain
2 fiber types: Type 1 muscle fibers have darker, more punctate cytoplasm
Connective tissue: Stains Green
Lipid membranes: Stain red

Gomori trichrome stain


VvG stain
Perimysium: Contains connective tissue with irregular fibrils & intermediate-sized vessels
Muscle fibers: Mildly varied size; Peripheral nuclei
Endomysial capillaries: Between muscle fibers; Often contain nucleated endothelial cells

VvG stain

Internal architecture


NADH stain
Normal Intermyofibrillar Network
  Stained structures: Sarcoplasmic reticulum; Mitochondria
  Type 1 muscle fibers: Darker stained
  Subsarcolemmal staining
    Increased in regions of some muscle fibers     Reflects neighboring endomysial capillaries

NADH stain

Fiber Types

ATPase pH 9.4

ATPase pH 9.4 stain
Type 1 fibers: Intermediate color
Type 2 fibers: Dark color

ATPase pH 4.6

ATPase pH 4.6 stain
Type 1 fibers: Dark color
Type 2A fibers: Pale
Type 2B fibers: Intermediate color

ATPase pH 4.6 stain

ATPase pH 4.3

ATPase pH 4.3 stain
Type 1 fibers: Dark color
Type 2A fibers: Pale
Type 2C fibers (Immature; Abnormal) (Below): Intermediate color

ATPase pH 4.3 stain

ATPase pH 4.3 stain

Alkaline phosphatase stain

Alkaline phosphatase stain
Endomysial vessels
  Some penetrating vessels, more in a few areas than others, stain for alkaline phosphatase
  Small endomysial capillaries do not normally show staining

Alkaline phosphatase stain

Acid phosphatase stain
  Red, subsarcolemmal staining of regions with lipofuscin: More with increasing age

Acid phosphatase stain

Esterase stain

Esterase stain
  Neuromuscular junctions: Dark red regions on muscle fiber surface, normally contain 1 or 2 segments

Esterase stain

Mitochondrial Stains

  Cytochrome Oxidase (COX)

COX stain
Normal
  Fiber types

    Type 1: Dark
    Type 2: Intermediate or Pale
  Staining pattern: Punctate
Mitochondrial disease
  Dark staining: Due to mitochondrial proliferation, or
  Pale staining: Due to reduced COX synthesis

COX stain

  Succinate Dehydrogenase (SDH)

SDH stain
Fiber types
  Type 1: Dark
  Type 2: Intermediate or Pale
Staining pattern: Reticular & Punctate
Mitochondrial disease: Dark staining due to mitochondrial proliferation

SDH stain

Mitochondrial Disorders
  COX + SDH
    COX negative muscle fibers stain blue

COX + SDH stain

Lipid stain: Sudan Black


Sudan Black stain
Fiber types: Type 1 fibers stain darker than type 2
Myelin: In intramuscular nerves stains dark

Sudan Black stain

Glycogen stain: PAS


PAS stain
Fiber types: Type 2 fibers stain darker than type 1
Capillary basal lamina: Stains dark

PAS stain

Normal Muscle: Transverse section

A band: Thick filaments surrounded by thin filaments
Scattered mitochondria between fibrils

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2/5/2021