Aging and Plasticity Flashcards
What are the 4 R’s of neural plasticity?
1.) Re-wiring
2.) Re-weighting
3.) Re-connection
4.) Re-generation
What are Hebbian modifications?
Synapses get stronger when the pre-synaptic cell repeatedly stimulates the post-synaptic cell
What are 3 things potentially being modified in re-weighting?
1.) Amount of neurotransmitter released by pre-synaptic cell
2.) Number of receptors on post-synaptic cell
3.) Amount of re-absorption by the pre-synaptic cell
What is re-wiring?
Sprouting new axons or dendrites to make new connections with other neurons
What is re-connection paired with?
Re-wiring
What is re-connection?
Restoration of lost synaptic connections or creating new synapses
What does cell migration require to facilitate movement?
Astrocytes
Where do neurons need to go for re-connection to occur?
Neurons need to migrate to locations where synapses can be formed
What is a process involved in re-connection?
Cell migration
What is re-generation?
New neurons being created
Where does regeneration rarely occur?
In the CNS
What is the optimal age for triggering language?
3-5 years
What is the critical period for language?
Birth to puberty
What happens after puberty that makes it difficult to learn language?
Brain/Neuronal pruning
How does the auditory system attempt to compensate for lost input?
Recruitment effects
What are 3 hypotheses for why plasticity occurs in the critical periods?
1.) Axon regrowth in CNS diminishes after a certain point in development
2.) Synaptic transmission hits maturity point and then plasticity is reduced
3.) Cortex activation by certain stimuli ceases inducing neuronal action potentials
What is aging?
The process of getting older through the passage of time
What is senescence?
Physical deterioration associated with advancing age; cells lost power of division and growth
What is the true process we think of as geriatric aging?
Senescence
What is dementia?
Memory decline or loss of thinking skills severe enough to affect functionality; not a normal part of the aging process
What is senility?
Normal age related declines in function
What are 2 major causes of dementia?
1.) Alzheimer’s disease
2.) Vascular dementia
How many cases of dementia does Alzheimer’s disease account for?
60-80%
What is vascular dementia?
Loss of vascular supply from a stroke
