psychological psychology
NA19811981
12.recovery.pptNervous System Damage and Recovery
Discussion question…
- Suppose you are part of an organization such as a social club or church. What would be the effects on the organization if there was a constant turnover of membership…new members joining each week and old members leaving?
- Generally, we don’t grow new neurons (Neurogenesis)
- Axons, dendrites may be re-grown
- New synapses may form (Synaptogenesis)
- Recovery better in PNS than CNS
Olfactory receptors:
- Last about a month
- Constant replacement
Hippocampus neurons:
- Songbirds, some mammals
- Humans!
- Related to learning?
Neurogenesis in the CNS:
*
Stroke
Blood clot (ischemic stroke)
Burst artery (hemorrhage stroke)
Tissue surrounding stroke may die:
- Overstimulation (glutamate)
- Understimulation - apoptosis
Recovery from Damage
Behavioral adjustments
- Use unimpaired abilities
- Use abilities which only seemed lost
Mechanisms of Recovery from Nervous System Damage
A
B
Recovery
- Regenerative sprouting -- Axon regrowth (Neuron A)
A
B
A
B
Recovery
A
B
A-1
A-2
Recovery
- Collateral sprouting (Neurons A1, A2, etc.)
A
A-1
A-2
B
B
A-1
A
A-2
Recovery
Super-sensitivity in Neuron B
- More receptor sites
- More efficient receptor sites
Recovery
- Reorganization of sensory representation in cortex
