Test 4 material Flashcards
What is neuroplasticity?
changes in the brain as a result of experience
What kinds of information are acquired from the environment?
1- expected (general info all members of a species get from the environment)
2- (unexpected) idiosyncratic info that individuals use to adapt to environment
What are the two tenets of Hebb’s postulate?
1-strengthening of synapses that correlate with output pattern
2- loss of synapses driven by unrelated output patterns
What is a critical period for axon growth in the human brain?
between 2-6 years
What parallels critical periods in humans?
increased and decreased gray matter volumes
Cortical circuits are capable of ______ in adults.
reorganization
What are the three types of neural repair?
1- regrowth of axons
2-restoration of damaged central nerve cells
3-wholesale genesis of new neurons
What is required for regrowth of axons?
sensory and motor nerves are intact and the spinal cord is intact
Where does regrowth of axons primarily occur?
in the periphery
Why does restoration of damaged CNS cells often fail?
because of glial cells responding via inflammatory response and they produce signals that inhibit regrowth
New dendrites, axons, and synapses must grow from what?
an existing cell body
Where do stem cells exist in adults?
in the olfactory areas
What is required for wholesale genesis of new neurons?
- must have multipotent stem cells
- the need must be in an area that has an appropriate environment for genesis
- regeneration must preserve the capacity to recapitulate the migration, outgrowth, and synapse formation
What happened in Head’s peripheral nerve regeneration experiment?
it took approximately 6-13 weeks to recover and specific sensations took longer to recover and did not completely (light touch, temperature, discrimination)
At present no evidence that adult neurogenesis occurs outside of the ____.
hippocampus
What encourages the growth of new spines and dendrites?
challenge/enrichment
What type of matter do you have more of when you’re 20?
white matter
What leads to spontaneous recovery in stroke patients?
reorganization
What cell type is essential to regrowth of axons?
Schwann cells
