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
  pH 4.6
  pH 4.3
Ultrastructure
Myosin HC types
Type grouping

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 may also stain endomysial capillaries

ATPase pH 4.3 stain

Muscle Fiber Types: Ultrastructure

Muscle Fiber Types: 1 (Right); 2 (Left)
  Z-lines (Dark arrow): Thicker
  Mitochondria (Light arrow): More
  Lipid bodies: More
  Glycogen granules: Fewer
  NOTES: Image below also shows
    2 atrophic muscle fibers in the center



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