Neuroplasticity Flashcards
LTP generally refers to
Increase in synaptic strength
LTP generally refers to
Decrease in synaptic strength
LTP/LTD involves synaptic connections between…
Schaffer Collaterals & CA1 Pyramidal Cells
Schaffer & CA1 are located where?
Hippocampus
When Shaffer stimulated with high frequency APs…
Prolonged increase of EPSP in CA1
What receptor is involved in LTP?
NMDA Glutamate
What happens at the NMDA receptor with LTP?
High freq APs –> keeps Mg2+ out of NMDA receptors –> allows more Ca2+ entry
More Ca2+ allows…
Stimulates kinases –> increase in # of receptors and/or channels stay open longer.
Kinases –> activates CREB –> protein synthesis –> increased synaptic connections.
What causes LTD
Schaffer stimulated with low frequency APs for long periods
Purpose of LTD
Decrease EPSP
OR
Bring the elevated EPSP (from LTP) back down to baseline
Molecular Mechanism of LTD
Ca2+ stimulates Phosphatases
Result of experiment with 3rd digit amputated
Somatotopic maps for digits 2 & 4 increased in size.
Sensory N that previously responded to 3, now respond to 2 & 4.
Result of experiment with only using digits 2-4 to perform a task
Motor areas for digits 2-4 increased in size
Somatotopic maps changing size is an example of
Functional Reorganization
Which nerves can regenerate?
PNS
What facilitates PNS repair? (3)
- Increased gene expression of growth factors.
- Macrophages remove debris.
- Schwann increased production of neurotrophic factors.
Which repairs easier: sensory or motor PNS?
Sensory
What prevents CNS repair? (4)
- Damaged myelin not removed - creates roadblock.
- Oligodendrocytes produce Nogo - inhibits axon growth.
- Astrocytes produce additional inhibitors.
- No upregulation of growth genes.
New research has found that production of new N in these areas is possible
Olfactory Bulb
Hippocampus
New research has found that these are the only type of CNS neurons that can be produced
Interneurons
New neurons in the CNS appear to arise from where?
Sub-Ventricular Zone
