Podcast
Questions and Answers
Can we grow new neurons?
Can we grow new neurons?
Yes, in the hippocampus and the olfactory bulb.
Is Alzheimer’s a normal part of aging?
Is Alzheimer’s a normal part of aging?
False
At what age does the brain fully develop?
At what age does the brain fully develop?
25
What are the main types of brain cells?
What are the main types of brain cells?
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What are the two divisions of the brain?
What are the two divisions of the brain?
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Neurogenesis is defined as the process through which new neurons are formed in the brain through ______.
Neurogenesis is defined as the process through which new neurons are formed in the brain through ______.
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What is the speed at which neurons can transmit signals?
What is the speed at which neurons can transmit signals?
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What is the function of the myelin sheath?
What is the function of the myelin sheath?
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What are the tiny bubbles at the end of an axon's branches called?
What are the tiny bubbles at the end of an axon's branches called?
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Which area of the brain has been cited as an exception where new neurons can grow in adults?
Which area of the brain has been cited as an exception where new neurons can grow in adults?
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Which of the following factors is linked to promoting neurogenesis according to the provided content?
Which of the following factors is linked to promoting neurogenesis according to the provided content?
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What is known as the early onset of Alzheimer’s disease?
What is known as the early onset of Alzheimer’s disease?
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What is the primary cause of Alzheimer’s disease as identified in the content?
What is the primary cause of Alzheimer’s disease as identified in the content?
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What effect does exercise have on the brain according to the information provided?
What effect does exercise have on the brain according to the information provided?
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Which of the following is a primary symptom of Alzheimer's Disease?
Which of the following is a primary symptom of Alzheimer's Disease?
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Which of the following factors is classified as a risk factor for developing Alzheimer's Disease?
Which of the following factors is classified as a risk factor for developing Alzheimer's Disease?
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What is primarily affected by Alzheimer's Disease, leading to cognitive decline?
What is primarily affected by Alzheimer's Disease, leading to cognitive decline?
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What type of memory loss is specifically mentioned as disruptive to daily life in Alzheimer's Disease?
What type of memory loss is specifically mentioned as disruptive to daily life in Alzheimer's Disease?
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Which brain structure's damage is commonly linked to various forms of dementia, including Alzheimer's?
Which brain structure's damage is commonly linked to various forms of dementia, including Alzheimer's?
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Study Notes
Alzheimer's and Aging
- Alzheimer’s is a genetic disease and is not a normal part of aging.
- Neurons in the brain die faster than new ones can grow, particularly in Alzheimer's.
Neurogenesis
- New neurons can be grown only in specific areas: the hippocampus and olfactory bulb.
- Despite the ability for neurogenesis, the loss of neurons in conditions like Alzheimer's is significant.
Brain Development
- The human brain is not fully developed at birth; it reaches full maturity around age 25.
Structure of the Brain
- The brain has two main divisions: the Central Nervous System (CNS) and the Peripheral Nervous System (PNS).
- The average brain weighs about 1,350 grams (less than 3 pounds) and resembles a small, wrinkled melon in consistency and color.
- The brain is fueled by glucose and contains approximately 1 trillion cells.
Brain Cells
- There are two primary types of brain cells: Glial cells (or neuroglia) and neurons.
- Approximately 900 billion glial cells support around 100 billion neurons in the brain.
Glial Cells Functions
- Provide structural scaffolding for neuron growth and support.
- Wrap around neurons to form insulation, preventing electrical signal interference.
- Release chemicals that influence neuron growth and functioning.
Neurons and Their Structure
- Neurons are the basic building blocks of the nervous system.
- Each neuron has a cell body (soma) that manufactures chemicals and maintains neuron function.
- Dendrites receive signals from other neurons, while axons transmit signals away from the cell body.
- End bulbs (or terminal buttons) release neurotransmitters for communication with other cells.
- Synapse refers to the tiny gap between an end bulb and an adjacent cell where transmission occurs.
- Myelin sheath wraps around axons, insulating them to prevent signal interference.
Signal Transmission
- Neurons communicate via electrical signals that can travel at speeds of up to 200 miles per hour.
- These signals enable functions such as sensory perception, muscle movement, digestion regulation, hormone secretion, and complex mental processes.
Neurogenesis in Adults
- Neurogenesis refers to the formation of new neurons, which occurs in prenatal development and continues, albeit at a limited capacity, in adulthood.
- Unlike some animals, humans have a restricted ability to regenerate neurons but can rewire or repair existing neuronal connections after injuries.
- Alzheimer's diagnosis is based on identifying a combination of symptoms and brain changes.
Neurogenesis
- Alzheimer’s diagnosed through a combination of behavioral, neurological, physical, and psychological symptoms.
- Joseph Altman reported new neuron formation in 1962; Michael Kaplan discovered neurogenesis in rats in the 1970s.
- Neurogenesis occurs primarily in the hippocampus and olfactory bulb.
- Omega-3 fatty acids from fish and flaxseed may promote neurogenesis.
- Zinc deficiencies can inhibit neurogenesis in the hippocampus.
- Neural pruning occurs alongside learning, leading to the loss of some neural networks.
Exercise Effects on the Brain
- Reduces stress and anxiety.
- Fights and prevents depression.
- Lowers risk of dementia and Alzheimer’s.
- Increases IQ and brain cell production.
- Enhances mood.
Alzheimer’s Disease
- Progressive disease and most common type of dementia.
- Affects 5.8 million people in the U.S. as of 2019.
- Characterized by memory cell death in the cerebral cortex, leading to brain atrophy.
- Early and late onset distinctions based on age of diagnosis.
- Abnormal protein buildup (amyloid plaques and tau tangles) is a major cause of cognitive decline.
Symptoms and Signs
- Initial symptoms: memory problems, getting lost, cognitive deficits, repeated questions.
- Signs include significant memory loss, planning challenges, familiar task difficulties, temporal disorientation, language problems, and misplacing belongings.
Risk Factors
- Stress as a contributing factor.
- Age as a risk factor but not a direct cause.
- Genetic predisposition and faulty glial cells can increase risk.
Neurons and Nervous System
- Neurons are fundamental units of the nervous system, transmitting signals via specialized extensions.
- Axons carry signals away, while the Myelin sheath insulates them for efficient transmission.
- Synaptic Vesicles contain neurotransmitters essential for communication between neurons.
Neurogenesis and Brain Growth
- Neurogenesis refers to the formation of new neurons; occurs mainly prenatally but limited in adults.
- Mature human brains can replace and repair damaged neurons to a limited extent.
Neurotransmitters
- GABA (gamma-aminobutyric acid): Inhibits neural activity, promoting calmness and reducing anxiety.
- Glutamate: Major excitatory neurotransmitter, essential for memory enhancement and brain function.
- Acetylcholine: Supports cognitive function, movement, and memory; typically low in Alzheimer’s patients.
- Dopamine: Associated with feelings of pleasure and reward; involved in addiction.
- Serotonin: Mood-regulating neurotransmitter; fluctuations linked to mood disorders.
Endorphins
- Inhibitory neurotransmitter discovered in the 1970s, acting as the body’s natural pain reliever during stress.
Reflex Sequence
- Reflex response involves sensors in skin responding to stimuli, relaying pain information via afferent neurons to the spinal cord for processing.
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Description
This quiz covers fundamental concepts related to neurons, aging, and Alzheimer’s disease. Learn about neurogenesis, brain development, and the implications of neurodegenerative diseases. Test your knowledge about how the brain functions over time.