Inherited Neurological Disorders

Questions and Answers

What effect does inhibition of the JAK/STAT3 signaling cascade have on huntingtin aggregates?

It decreases the number of aggregates.

It has no effect on aggregates.

It stabilizes existing aggregates.

It increases the number of aggregates. (correct)

What is indicated by decreased expression of glial fibrillary acidic protein (GFAP) in astrocytes of PD human tissue?

Enhanced dopamine metabolism.

Increased astroglial neuroprotection.

Astrogliotic enhancement.

Astrogliotic atrophy. (correct)

What role do astrocytes serve in the metabolism of L-DOPA in Parkinson's disease?

They convert dopamine to L-DOPA.

They inhibit the effects of L-DOPA.

They nullify dopamine's function.

They act as a repository for L-DOPA. (correct)

Which changes occur in oligodendrocytes during neurodegeneration?

Degenerative changes reflect reduced remyelinating capacity. Signup and view all the answers

What was Alois Alzheimer’s observation regarding astroglia in dementia?

Activated glial cells are observed near altered neurons. Signup and view all the answers

What is a consequence of atrophic astrocytes in the context of cognitive impairment?

They fail to support neuronal function adequately. Signup and view all the answers

In Alzheimer's disease, what effect does oligodendrocyte degeneration have on white matter?

It causes substantial shrinkage of white matter. Signup and view all the answers

What does the activation of glial cells near pathologically altered neurons imply?

They may be involved in inflammatory processes. Signup and view all the answers

What is a common consequence of oligodendrocyte degeneration in the CNS?

Decrease in CNS myelination Signup and view all the answers

What function do astrocytes primarily serve in the central nervous system?

Regulate the chemical environment around neurons Signup and view all the answers

At what age does myelination in the CNS typically peak?

45 years Signup and view all the answers

What is the primary role of oligodendrocytes in the CNS?

Producing myelin to insulate axons Signup and view all the answers

Which factors contribute to oligodendroglial cell death associated with myelin shortages?

Dysregulation of calcium homeostasis Signup and view all the answers

Which type of glial cell is responsible for creating the myelin sheath in the central nervous system?

Oligodendrocytes Signup and view all the answers

Which type of cells have a decreased self-renewal capacity with aging, impacting myelination?

Oligodendroglial precursors/NG2 cells Signup and view all the answers

Which of the following statements about glial cells is correct?

Glial cells do not generate or propagate nerve impulses. Signup and view all the answers

What function do microglia serve in the central nervous system?

Acting as immune cells that phagocytose dead cells Signup and view all the answers

Which of the following statements about ependymal cells is accurate?

They line the ventricles and produce cerebrospinal fluid. Signup and view all the answers

Which of the following receptors expressed by oligodendrocytes is permeable to Ca2+?

P2X receptors Signup and view all the answers

In the peripheral nervous system, which type of neuroglia is specifically responsible for supporting neurons?

Satellite cells Signup and view all the answers

What are gliomas?

Tumors derived from glial cells Signup and view all the answers

What characteristic feature is often observed in the aging CNS related to myelination?

Decreased myelin levels Signup and view all the answers

Which neuroglial cells are primarily involved in maintaining brain homeostasis?

Astroglial cells Signup and view all the answers

Which condition does NOT typically involve degeneration of oligodendrocytes?

Hypothyroidism Signup and view all the answers

Which function is NOT performed by astrocytes?

Generate electrical impulses Signup and view all the answers

What can neuroglial changes lead to in the context of neurodegenerative diseases?

Facilitation of neuronal loss Signup and view all the answers

In the context of neurological diseases, how are neuroglial cells understood?

As the homeostatic and defensive arm of the nervous system Signup and view all the answers

What is associated with age-dependent myelin deterioration in the primary visual cortices of rhesus monkeys?

Decreased length of paranodes Signup and view all the answers

Which type of glial cell is responsible for immune responses in the CNS?

Microglial cells Signup and view all the answers

What distinguishes neurons from glial cells?

Neurons connect all body regions to the brain and spinal cord. Signup and view all the answers

What potential therapeutic role do neuroglia represent in neurological conditions?

Targeting them for prevention or treatment of neurodegeneration Signup and view all the answers

What impact does malfunctioning of astroglial cells have on the nervous system?

Causes degeneration and affects neuroprotection Signup and view all the answers

Which type of neuroglial cell is primarily associated with the clearance of β-amyloid in Alzheimer’s Disease?

Microglia Signup and view all the answers

What is an observed change in microglial function related to senile plaques in APP/PS1 mice?

Loss of phagocytotic function Signup and view all the answers

Which factors are secreted by activated microglial cells that may contribute to neuronal damage?

Proinflammatory factors Signup and view all the answers

What role do changes in oligodendroglia and myelin play in Alzheimer's Disease?

They contribute to cognitive deficiency. Signup and view all the answers

In the context of Alzheimer’s Disease, what is the significance of reactive phenotypes in neuroglia?

They are associated with neuronal damage. Signup and view all the answers

What is the impact of age-related degeneration of microglia in Alzheimer's Disease?

It defines vulnerability to AD pathology. Signup and view all the answers

What role do NG2 cells play in the context of Alzheimer’s Disease?

Serving as oligodendroglial precursors. Signup and view all the answers

Which of the following statements best describes the changes observed in neuroglia during the progression of neurodegenerative diseases like Alzheimer's?

Morphofunctional changes in glia occur in distinct temporal domains. Signup and view all the answers

Study Notes

Learning Objectives

Understand types and functions of neuroglia.
Explore the role of neuroglia in neuropathology and neurodegeneration.

Overview of Neuroglia

Nervous tissue consists of neurons and neuroglia; neuroglia support and protect neurons.
Neurons are specialized and cannot undergo mitosis, while neuroglia can divide throughout life.
Glial cells do not generate nerve impulses but are crucial for neuron health and maintenance.

Types of Neuroglia

Central Nervous System (CNS) Glial Cells:
- Astrocytes: Most abundant; maintain chemical balance, support neurons, and regulate blood-brain barrier.
- Oligodendrocytes: Produce myelin, increasing the speed of nerve signal transmission.
- Microglial Cells: Act as immune cells, clearing dead cells and pathogens.
- Ependymal Cells: Line brain ventricles, producing cerebrospinal fluid (CSF) for brain protection.
Peripheral Nervous System (PNS) Glial Cells:
- Schwann Cells: Myelinate peripheral neurons.
- Satellite Cells: Support neurons in ganglia.

Neuroglia in Neuropathology

Neurodegenerative diseases often start with neuronal death, but glial changes can precede this.
Astrocytes play a key role in defending the brain and homeostasis; their dysfunction can be linked to neurodegeneration.
Neuroglial cells are integral to maintaining the internal environment of the nervous system.

Neuroglia in Neurodegeneration

In Parkinson's Disease (PD):
- Astrocytes protect and contribute to dopamine metabolism, influencing L-DOPA conversion to dopamine.
- Reduction of glial fibrillary acidic protein (GFAP) indicates atrophy in astrocytes, suggesting impaired neuroprotection.
In Alzheimer's Disease (AD):
- Oligodendrocytes undergo degeneration, contributing to white matter shrinkage.
- Astrocytes initiate inflammatory responses; dysfunctional astrocytes fail to provide necessary support, leading to synaptic loss and cognitive decline.

Oligodendrocytes and Myelination

Myelination increases during postnatal development, peaks around age 45, and declines with aging.
Oligodendrocytes experience changes that affect cognitive functions in various neurological conditions, including psychiatric disorders and traumatic injury.
Aging leads to poor myelin maintenance and loss of oligodendrocytes, linked to cognitive decline.

Changes in Microglia

Microglia show both reactive and degenerative changes in AD progression.
Activated microglia are associated with senile plaques but show a loss in phagocytic function, impacting plaque clearance and buildup.
Age-related microglial degeneration can increase vulnerability to AD pathology.

Conclusion

Pathological changes in neuroglia are significant in neurodegenerative diseases, affecting astrocytes, oligodendrocytes, and microglia.
Early-stage neuroglial changes often precede neuronal damage, highlighting their potential as therapeutic targets to modify disease progression.

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Description

Explore the complex role of glial cells (neuroglia) in inherited neurological disorders in this HMG 44110A course quiz. Understand their types, functions, and significance in neurobiology and clinical aspects. Test your knowledge and enhance your understanding of neurology.

Inherited Neurological Disorders - HMG 44110A