Nerve CH 9 Flashcards
Nervous system
- Central Nervous System (CNS):
1. Brain
2. Spinal Cord - Peripheral Nervous System (PNS)
- All other nerve tissues
- Three types of tissue groups for staining
1. Neuronal cell bodies and processes
2. Glial cells and processes
3. Myelin sheath
Neurons
- 14 billion. Consists of cell body
(perikaryon) with nucleus and one or more cell processes (axons-output and
dendrites-input) - Nissl substance
- Also called tigroid substance and chromidal substance is basophilic
- Stained well with thionin and cresyl echt violet.
- Loss of substance is referred to as chromatolysis
Myelin
- Complex, white, fatty, nonliving material containing protein, cholesterol, phospholipids, and cerebrosides
- Formed by Schwann cells in the PNS
Neuroglia
- “nerve glue” provide support throughout CNS.
- Ependymal cells
- Form the blood brain barrier. True epithelial cells that line ventricals and spinal canal
- Microglia
- Fixed phagocytic cells in brain and spinal cord
- Astrocytes
- Stellate cells, protoplasmic found in gray matter. Fibrous found in white matter
- Forms scar network for neurons, exchange fluids, gases, metabolites for tissue
- Oligodendroglia
- Small cells that produce and maintain the myelin sheath
- Most numerous glial cell found in both gray and white matter
Nerve Staining techniques
◦ Cresyl echt violet
◦ Bodian
◦ Holmes silver nitrate
◦ Bielschowsky
◦ Sevier – Munger
◦ Thioflavin S
◦ PTAH
◦ Holzer
◦ Cajal
◦ Weil
◦ Luxol fast blue
◦ Cresyl echt violet
◦ Bodian
◦ Holmes silver nitrate
◦ Bielschowsky
◦ Sevier – Munger
◦ Thioflavin S
◦ PTAH
◦ Holzer
◦ Cajal
◦ Weil
◦ Luxol fast blue
Nissl Substance: CRESYL ECHT VIOLET
◦ Demonstrates neurons or loss of nissl substance.
- Demonstrates neurons or loss of nissl substance. Called chromatolysis.
- 10% NBF is preferred fixative
- Cut at 6-8um
- Spinal cord is good control
- Results
- Nissl substance – blue to purple
- Nuclei – blue to purple
- Background – colorless
Cresyl Echt Violet Method II
- Used in an acidic pH
- Used in an acidic pH
- Lower pH restricts staining to RNA-DNA containing structures and nuclei
- This enhances the contrast of nuclei and nissl substance compared to colorless background
BODIAN METHOD
- Demonstrates nerve fibers, can show Wallerian degenerations
- Demonstrates nerve fibers, can show Wallerian degenerations
- Uses Protargol: silver impregnation solution, and hydroquinone for reducing
- 10% NBF is preferred fixative
- Peripheral nerve or cerebral cortex is good control. NO spinal cord (cross section)
- Results
- Nerve fibers: black
- Background: light blue or gray
- Nuclei: black
BIELSCHOWSKY-PAS STAIN
- nerve fiber, neurofibrillary tangles, senile
plaques
- Demonstrates the above cells involved in Alzheimers
disease
- Demonstrates the above cells involved in Alzheimers
disease - 10% NBF preferred fixative
- Cut at 8-10um
- Tissue must be from CNS, should contain senile
plaques and neurofibrillary tangles ** CORTEX - Uses formaldehyde and not hydroquinone
◦ Results
- Neurofibrillary tangles – dark black
- Neuritic plaques – dark black
- Axons – black
- Amyloid – magenta
- Lipofuscin - magenta
HOLMES SILVER NITRATE METHOD
- Demonstrates nerve fibers and neurofibrils
- Demonstrates nerve fibers and neurofibrils
- 10% NBF perferred fixative
- Cut at 10-15um
- Cerebral cortex is good control
- NO metal forceps
- Uses pyridine instead of Protargol* not basic enough?
- Argyrophil silver method
- Similar to Rio-Hortega which uses ammonical silver
carbonate
◦ Results
- Axons and nerve fibers: black
- Neurofibril: black
Sevier – Munger (modification of Bielschowsky method)
- Cut at 6-8um
- CNS tissue must be used
- NO gold chloride used, which leaves background yellowish
◦ Results
- Nerve endings and neurofibrils: black
- Neurofibrillary tangles and neuritic plaques:
black
THIOFLAVIN S METHOD
Neurofibrillary tangles and senile plaques
- Demonstrates presence of neurofibrillary degeneration and amyloid deposit in Alzheimer’s.
- Demonstrates presence of neurofibrillary degeneration and amyloid deposit in Alzheimer’s.
- Fluorescent dyes for amyloid
- 10-20% NBF preferred fixative
- Cut at 6um, let air-dry overnight
- CNS tissue containing senile plaques as control
◦ Results
- Alzheimer plaques, neurofibrillary tangles, senile
amyloid: bright green
- Diffuse plaques: paler yellow green
MALORY PTAH
- Demonstrates glial fibers
- Demonstrates glial fibers
- 10% NBF is preferred fixative
- Cut at 6-8um
- Cerebral cortex for control (not spinal cord)
◦ Results
- Glial fibers: blue
- Nuclei: blue
- Neurons: salmon
- Myelin: blue
HOLZER METHOD
- Demonstrates glial fibers and areas of gliosis
- Demonstrates glial fibers and areas of gliosis
- Crystal violet is stain used
- 10% NBF is preferred fixative
- Cut at 6-8um
- Cerebral cortex for control (not spinal cord)
◦ Results
- Glial fibers: blue
- Background: pale to colorless
CAJAL STAIN
- Demonstrates astrocytes, replaced by IHC
- Demonstrates astrocytes, replaced by IHC
- Antibody GFAP now used in IHC
- FORMALIN AMMONIUM BROMIDE no less than 2 days, no longer than 25 days
- Frozen sections cut at 20-30um
- Cerebral cortex control (not spinal cord)
◦ Results
- Astrocytes with perivascular feet: black
