Neuroplasticity

1. What is neuroplasticity?

The natural ability of neurons to change their function, chemical profile, or structure.

2. What are the main processes involved in neuroplasticity?

Reaction to injury, development, and learning.

3. What is apoptosis?

Programmed cell death — the “cellular survival of the fittest.”

4. What is synaptic pruning?

Elimination of neurons or synapses due to a lack of stimulation.

5. What is axonal retraction?

The process where axons retract during neural development.

6. What is competitive elimination?

Synapses that are used often are strengthened, while unused ones are pruned to eliminate clutter.

7. What is dedifferentiation?

Process where specialized cells revert to a more primitive state and can re-specialize later.

8. What are the three main mechanisms of neuroplasticity?

Habituation, learning and memory, and cellular recovery after injury.

9. What is the habituation mechanism?

A decreased response to a repeated, harmless stimulus; can have short-term and long-term effects.

10. What are the short-term effects of habituation?

Reduced synaptic activity and decreased release of excitatory neurotransmitters (a physiological change).

11. What are the long-term effects of habituation?

Decreased post-synaptic receptor sensitivity due to reduced synaptic activity (a structural change).

12. What is the learning and memory mechanism?

Experience-dependent plasticity involving persistent long-term potentiation or depression.

13. What is potentiation?

Repeated stimulation increases neuron excitability and promotes growth of new synaptic connections at dendritic spines.

14. What is depression (long-term depression)?

Mechanism that weakens or inhibits the firing of other neurons.

15. What is the healing mechanism of neuroplasticity?

The CNS adapts or reorganizes itself to compensate for injury.

16. What is the neurite outgrowth inhibitor (Nogo)?

A molecule made by oligodendrocytes that prevents axonal regrowth in the CNS.

17. What is collateral sprouting?

When healthy neurons near damaged cells grow new branches to re-establish connections.

18. What is regenerative sprouting?

When a severed axon grows toward and attaches to a nearby neuron.

19. What is edema?

Swelling that compresses a cell body or axon, often after injury.

20. What is mirror region takeover?

When an unused area of cortex (due to injury) is taken over by adjacent functioning brain regions.