Neural Injury Repair Flashcards
Injury to the soma caused by?
Excitotoxicity – due to decreased ATP and increased intracellular ions. Then, then the cell dies, it releases all of its stuff and inflammation causes further cells to die.
Is there inflammation with apoptosis?
No.
Nerve injury processes and their prognoses
Best Prognosis: Focal demyelination Axon disrupted Endoneurium disruped Perineurium disrupted Epineurium disrupted \:Worst Prognosis
Demyelination on electromyography
Decreased conduction velocity
Axonal loss on electromyography
Decreased action potential amplitude
Wallerian degeneration
Injury to peripheral nerve? Axon distal to injury breaks down, schwann cells recruit macrophages. Macrophages clear debris, path cleared for axonal regrowth.
What happens with wallerian degeneration in the CNS?
In the CNS, clearance of debris is not efficient and inhibitory factors disrupt axon extension. Oligodendrocytes and astroglia aren’t as helpful as schwann cells because they form scars and also inhibit growth
RAG
Regeneration associated genes that help regrow axons 1-5 mm per day in the PNS. Only about .1 mm/day in CNS.
What cell feature mediates regeneration?
Axonal growth cones with actin as filopodia and lamellipodia and microtubules at the growing end.
What does failed regeneration look like?
Retraction bulbs (kinda like weird acid trip features)
Pruning
Trimming back the overgrowth of neurons from birth into infancy.
Circuit regrowth or rerouting?
Mostly rerouting.
Activity increases what growth factor?
BDNF
What types of activities are best for neuro rehab?
Skilled, specific, repetitive behaviors more beneficial than exercise alone. Random practice is better.
Embryonic stem cells
Derived from blastocyst inner cell mass (4-5d post fertilization). Results in non-viable embryo, but leads to pluripotent stem cells that can form all germ layers.
