Neuroplasticity | Nervous system physiology | NCLEX-RN | Khan Academy

Summary

Neuroplasticity is the brain's ability to reorganize itself by forming new neural connections in response to experiences, learning, and injury. It involves two primary processes: synaptic neuroplasticity, where the strength of synaptic connections increases (potentiation) or decreases (depression), and structural neuroplasticity, where neurons grow new branches or undergo pruning. This process is vital for memory, learning, and recovery after nervous system injuries. Neuroplasticity is most active during development, but it continues throughout life, adapting to changes and shaping how we think, learn, and heal.

Takeaways

• 😀 Neuroplasticity refers to the ability of the nervous system to change in response to experience, including memory formation and learning.
• 😀 Neuroplasticity involves changes in synapses and neurons that affect how information is processed and transmitted.
• 😀 Potentiation strengthens information flow through the nervous system, while depression weakens it. These terms don't relate to emotional depression but to cellular activity.
• 😀 Neuroplasticity is highest during development but continues throughout life, with transient increases following nervous system injury.
• 😀 Frequent use of neurons strengthens their connections (potentiation), while less frequent use leads to weakened connections (depression).
• 😀 Synaptic neuroplasticity refers to changes at the level of individual synapses, affecting the strength of neurotransmission.
• 😀 Structural neuroplasticity involves changes in the number of synapses or the growth and pruning of dendrites and axon terminals.
• 😀 Synaptic potentiation can involve the release of more neurotransmitter from the axon terminal or an increase in the number of neurotransmitter receptors on the target cell.
• 😀 Synaptic depression results in a decrease in neurotransmitter release or a reduction in receptor sensitivity, leading to a weaker response from the target cell.
• 😀 Structural changes such as the growth of new synapses (sprouting) occur when neurons are frequently active, while inactivity leads to pruning, where unused connections or neurons are eliminated.

Q & A

What is neuroplasticity?

Neuroplasticity refers to how the nervous system changes in response to experiences, such as learning new things or forming memories. It involves changes in synapses and neurons, affecting how information is processed and transmitted.

What is the difference between potentiation and depression in neuroplasticity?

Potentiation refers to an increase in the strength of information flow through a part of the nervous system, while depression refers to a decrease in this strength. Potentiation makes the neural response stronger, while depression weakens it.

Why is the term 'depression' used in neuroplasticity, and how is it different from emotional depression?

In neuroplasticity, 'depression' refers to the weakening of neural responses, not the emotional or psychiatric disorder. It describes a reduction in the sensitivity or activity of neurons in response to stimuli.

Does neuroplasticity continue throughout life?

Yes, neuroplasticity is present throughout life, though it is most active during the development of the nervous system. It transiently increases after injury, aiding in recovery and adaptation.

What is the role of synaptic neuroplasticity?

Synaptic neuroplasticity involves changes at the level of synapses, where neurons communicate. These changes can make synaptic responses stronger (potentiation) or weaker (depression), depending on how frequently the synapse is used.

How does synaptic potentiation occur?

Synaptic potentiation happens when frequent activity at a synapse leads to a stronger response from the target cell. This can occur by releasing more neurotransmitters from the axon terminal or by increasing the number or sensitivity of neurotransmitter receptors on the target cell.

What happens during synaptic depression?

Synaptic depression occurs when there is infrequent activity at a synapse, leading to weaker responses. This can involve a decrease in neurotransmitter release or a reduction in the number or sensitivity of receptors on the target cell.

What is structural neuroplasticity?

Structural neuroplasticity refers to changes in the overall structure of neurons, including the growth of dendrites or the formation of new synapses between neurons. It plays a crucial role in learning, memory, and recovery from injury.

How do potentiation and depression affect neuron structures?

In potentiation, frequent activity leads to the growth of more dendritic branches and the formation of new axon terminals, enhancing communication between neurons. In depression, inactive neurons may lose dendritic branches, simplify their connections, or even undergo pruning, where entire neurons are eliminated.

What is the difference between short-term and long-term neuroplasticity?

Short-term neuroplasticity refers to temporary changes that can last seconds or minutes, often associated with synaptic adjustments. Long-term neuroplasticity involves more permanent changes, such as structural remodeling, that can last months or years, playing a key role in memory and learning.