Neuroscience Cell Differentiation and Plasticity

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Questions and Answers

What primarily regulates the differentiation of neural cells during prenatal development?

Delta signaling

Notch signaling (correct)

Oligodendrocyte differentiation

Astrocyte differentiation

Which signaling pathway promotes the generation of glial cells during post-natal development?

Notch signaling (correct)

Delta signaling

Numb regulation

Proneural gene activation

What happens when Delta binds to Notch?

Formation of oligodendrocytes

Translocation of the Notch domain into the nucleus (correct)

Inhibition of transcription factors

Activation of the achaete-scute gene

Which phase of cell differentiation peaks around the time of birth?

Astrocyte differentiation Signup and view all the answers

What role does the protein 'numb' play during cell differentiation?

Inhibits Delta signaling Signup and view all the answers

Which type of cells does Notch signaling favor in a developing neural context?

Neuronal precursor cells Signup and view all the answers

Which transcription factor is activated by the intracellular domain of Notch after Delta binding?

Suppressor of hairless Signup and view all the answers

What is the primary function of oligodendrocytes in the nervous system?

Form myelin sheaths Signup and view all the answers

What happens to neurons that do not receive adequate neurotrophic factors?

They undergo apoptosis. Signup and view all the answers

Which neurotransmitter is primarily used at neuromuscular junctions?

Acetylcholine Signup and view all the answers

What role does acetylcholinesterase play in neuromuscular transmission?

It breaks down acetylcholine into acetic acid and choline. Signup and view all the answers

How does an action potential trigger the release of acetylcholine at the neuromuscular junction?

By depolarizing the pre-synaptic terminal and opening voltage-gated calcium channels. Signup and view all the answers

What is the function of the junctional folds on the sacrolemma of muscle fibers?

To serve as receptors for acetylcholine. Signup and view all the answers

What role does the growth cone play in neuron maturation?

It directs the neurite elongation towards targets. Signup and view all the answers

Which of the following accurately describes long-term potentiation?

A long-lasting enhancement in synaptic signal transmission. Signup and view all the answers

What initiates the formation of dendrites during neuron maturation?

The proliferation of axon neurites. Signup and view all the answers

Which receptors are primarily involved in long-term potentiation?

AMPA receptors and NMDA receptors. Signup and view all the answers

What is the role of lamellipodia and filopodia in neuronal growth?

They search for targets in the environment for connection. Signup and view all the answers

Which statement about synaptic plasticity is true?

It allows synapses to strengthen or weaken based on activity. Signup and view all the answers

What outcome results when a synapse of one neuron repeatedly excites another neuron?

Long-term potentiation occurs. Signup and view all the answers

What distinguishes structural plasticity from synaptic plasticity?

Structural plasticity involves the amount of synapses, whereas synaptic plasticity pertains to the strength of synapses. Signup and view all the answers

What is a structural similarity between central and peripheral nervous system synapses?

Bi-directional signaling Signup and view all the answers

Which type of synapse lacks basal lamina?

Central nervous system synapses Signup and view all the answers

What neurotransmitter is primarily excitatory in the central nervous system?

Glutamate Signup and view all the answers

What is a key difference between neurotransmitter receptors in CNS and PNS?

CNS receptors have distinct excitatory neurotransmitters Signup and view all the answers

During which stage does the development of basic visual and auditory functions begin?

Sensorimotor stage Signup and view all the answers

Which neurotransmitter is inhibitory in both the central and peripheral nervous systems?

GABA Signup and view all the answers

What happens to synapses during development according to this information?

They are eliminated if not needed Signup and view all the answers

What structural feature is unique to peripheral nervous system synapses?

Presence of junctional folds Signup and view all the answers

What characterizes the preoperational stage of cognitive development?

The child begins to think symbolically. Signup and view all the answers

At what age range does the concrete operational stage of cognitive development occur?

7 to 11 years Signup and view all the answers

Which neural process refers to the degradation of the axon and loss of function in neighboring cells following an injury?

Wallerian degradation Signup and view all the answers

What role do oligodendrocytes and Schwann cells play following axonal damage?

They contribute to the formation of a glial scar. Signup and view all the answers

What significant change occurs in the prefrontal cortex during the formal operational stage?

It begins to prune excessive synapses. Signup and view all the answers

What is a major characteristic of the formal operation stage in cognitive development?

Improved logical reasoning and abstract thinking. Signup and view all the answers

What triggers local inflammation following axonal injury?

Dissociation of myelin sheaths Signup and view all the answers

Which statement about synapse pruning is true?

It focuses on retaining essential synapses. Signup and view all the answers

Study Notes

Cell Differentiation

Neural differentiation occurs primarily prenatally, astrocyte differentiation peaks around birth, and oligodendrocyte differentiation is the third phase.
Notch signaling plays a crucial role in cell differentiation. Notch is a cell surface receptor that, when bound by Delta, triggers a cascade that ultimately activates transcription factors.
Prenatally, Notch promotes self-renewal of developing stem cells.
Postnatally, Notch promotes glial cell generation.
The "suppressor of hairless" transcription factor, activated by Notch signaling, inhibits "achaete-scute" gene expression leading to a decrease in Delta expression, ultimately determining cell fate.
The protein Numb, localized to one daughter cell after cell division, prevents Notch signaling in that cell, ensuring one daughter cell becomes a neuron and the other a glial cell.

Synaptic Plasticity

Growth cones, at the tip of neurites, are complex structures crucial for finding appropriate targets for neuronal connections.
Growth cones extend lamellipodia and filopodia, searching for targets.
Once a target is found, neurites form, with one becoming the axon and the others becoming dendrites.
Synaptic plasticity refers to the ability of synapses to strengthen or weaken over time, key for learning and memory.
Potentiation strengthens synapses, while depression weakens them.
Neurotrophic factors, like nerve growth factor (NGF), play a role in neuronal survival and synaptic plasticity. They signal through receptors like TRKA, inducing changes in gene expression.
Long-term potentiation (LTP) is a form of synaptic strengthening that involves AMPA and NMDA receptors, both activated by glutamate.
AMPA receptor activation allows Na+ influx, while NMDA receptor activation leads to Ca2+ influx, triggering a cascade of processes that ultimately strengthen the synapse.

Central vs. Peripheral Nervous Systems

Central and peripheral synapses share structural similarities but differ in their neurotransmitter systems.
Glutamate is the primary excitatory neurotransmitter in the CNS, while acetylcholine is the primary excitatory neurotransmitter in the PNS.
GABA and glycine are inhibitory neurotransmitters in the CNS, while GABA is an inhibitory neurotransmitter in the PNS.

Development of Neurogenesis in Stages

Sensorimotor stage (birth to 2 years) involves the development of basic motor skills, linked to the formation of synapses in visual (occipital lobe) and auditory (temporal lobe) cortices.
Preoperational stage (2-7 years) is characterized by the development of symbolic thought and language, connected to the formation of synapses in the angular gyrus (parietal lobe) and Broca's area (frontal lobe).
Concrete Operational stage (7-11 years) sees the development of logical thinking and conservation concepts, attributed to the formation of synapses in the prefrontal cortex.
Formal Operational stage (12 years onwards) involves advanced reasoning and complex problem-solving, attributed to the maturation of the prefrontal cortex, which can take until the age of 25.

Regeneration and Damage in the Nervous System

Axons, being long and vulnerable, are often the site of damage in the nervous system.
Axotomy, or axon damage, triggers Wallerian degradation, a process that results in degeneration of the axon and its synapses.
Myelin sheaths are also affected by axotomy, leading to oligodendrocyte/Schwann cell degeneration and inflammation.
Macrophages, neutrophils, and glial cells form a glial scar at the site of injury.
Regeneration is possible in the peripheral nervous system (PNS), where Schwann cells help guide axonal regrowth.
However, regeneration is limited in the central nervous system (CNS) due to factors like the formation of glial scars and the absence of the same supporting cells found in the PNS.

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Description

Explore the intricate processes of neural differentiation and synaptic plasticity in this quiz. Understand the roles of Notch signaling, growth cones, and the critical phases of cell fate determination. Test your knowledge on the mechanisms underlying neuronal and glial cell generation.