Neuroscience: Experience-Dependent Plasticity

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Questions and Answers

What impact does increasing the number of postsynaptic receptors have on the postsynaptic response?

Increase postsynaptic response (correct)

No change

Decrease postsynaptic response

Alter the type of neurotransmitter released

Which of the following receptors open when glutamate binds and the postsynaptic neuron is already depolarized?

GABA receptors

AMPA receptors

NMDA receptors (correct)

Dopamine receptors

To ensure an increase in postsynaptic response at a glutamatergic synapse, what change should be made to the postsynaptic receptors?

Increase the number of GABA receptors

Decrease the number of NMDA receptors

Increase the number of AMPA receptors (correct)

Increase the ratio of NMDA:AMPA receptors

What is required for sustained long-term potentiation (LTP)?

Sufficient protein synthesis for LTP Signup and view all the answers

Which of the following statements about protein synthesis and long-term potentiation is true?

Protein synthesis blockade impedes LTP Signup and view all the answers

Which neurotransmitter is primarily discussed in the context of the synaptic transmission in this content?

Glutamate Signup and view all the answers

Which type of plasticity is characterized by a sustained increase in synaptic strength?

Long-term potentiation Signup and view all the answers

What is the primary effect of inserting additional AMPA receptors into the postsynaptic membrane?

Increase cation influx when glutamate is present Signup and view all the answers

What is a key characteristic of synaptic plasticity?

It is the ability of a synapse to strengthen or weaken over time. Signup and view all the answers

What does experience-dependent plasticity imply?

Unused brain regions may shrink over time. Signup and view all the answers

Which of the following best exemplifies experience-dependent loss of brain function?

The loss of representation in the homunculus after amputation of digit 3. Signup and view all the answers

How do AMPA receptors and NMDA receptors differ fundamentally?

NMDA receptors are always present at the synapse, while AMPA receptors can be added or removed. Signup and view all the answers

Which characteristic would likely increase with enhanced synaptic transmission?

Dendritic spine volume. Signup and view all the answers

What could be concluded about the “skilled reaching task” based on motor cortex reorganization?

It involves complex coordination of multiple limbs. Signup and view all the answers

What does sufficiency in synaptic plasticity studies refer to?

A specific condition needed for synaptic strength changes. Signup and view all the answers

What change is expected in the postsynaptic response when synaptic transmission increases?

Enhanced long-term potentiation of response. Signup and view all the answers

Study Notes

Learning Objectives

Motor cortex reorganizes with specific motor task training.
Experience-dependent loss of brain function provides an example.
Synaptic plasticity is defined.
AMPA and NMDA receptors are compared and contrasted, relating to synaptic plasticity.
Synaptic plasticity studies distinguish sufficiency from necessity.
A postsynaptic recording showing synaptic plasticity or long-term potentiation is described.
The number of postsynaptic receptors, dendritic spine volume, and synapses change with increased or decreased synaptic transmission.

Experience-Dependent Plasticity

Specific brain regions expand with increased use, but shrink with disuse.
Skilled reaching tasks can be related to motor cortex reorganization. For example, the examples presented are:
- Wriggling toes while rotating wrists.
- Using elbows and shoulders in a chicken dance.
- Hanging from a tree by the tail while throwing bananas.
- Keeping toes completely still.
Motor cortex reorganization can be seen as a response to skilled movements.
An example of experience-dependent plasticity given is amputating a digit causing the somatosensory cortex to lose representation of the digit.

Synaptic Plasticity

Synaptic plasticity is the ability of a synapse to strengthen or weaken over time due to activity levels.
There are synaptic transmissions between neurons, and action potentials within individual neurons.
An example of synaptic plasticity is long-term potentiation (LTP).
- LTP is a special type where a postsynaptic response will increase with subsequent stimulation.
Example data showing EPSP (% of baseline) versus time (minutes).
Protein synthesis is required for sustained long-term potentiation (LTP), as shown by data.
Protein synthesis of AMPA receptors will allow sustained enhancement of synaptic plasticity.
Synaptic plasticity and pruning unused circuits are linked. Larger synapses and more synapses show additional AMPA receptors.

Synaptic Anatomy and Function

Synapses are described as locations where neurotransmitters are passed.
Vesicles, receptors, and other associated elements form a synapse.
Different ways the synapse can function to enhance transmission are discussed in the context of different players involved in synapses.
Increase in AMPA receptors increases postsynaptic response.
NMDA receptor function is related to depolarization.

AMPA and NMDA Receptors

AMPA receptors open when glutamate binds, allowing cations to flow in.
NMDA receptors open when glutamate binds and the postsynaptic neuron is already depolarized. A Mg$^2$⁺ ion plug needs to be dislodged.
Increasing the number of AMPA receptors will increase the postsynaptic response.

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Description

Explore the fascinating world of experience-dependent brain plasticity in this quiz. Learn about the motor cortex's ability to reorganize, the role of synaptic plasticity, and how different tasks influence brain function. Test your understanding of key concepts like AMPA and NMDA receptors and their relationship to learning and memory.