Brain Development

Brain Development

Brain Development

Brain and NeuroDevelopment

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- Neuro Development Health
The Brain and NeuroDevelopment - Know how the brain works. Brain Functions

Brain and Neurodevelopment


How the brain works? Brain Functions. Know your brain and what it does.
Amygdala: Lying deep in the center of the limbic emotional brain, this powerful structure, the size and shape of an almond, is constantly alert to the needs of basic survival including sex, emotional reactions such as anger and fear. Consequently it inspires aversive cues, such as sweaty palms, and has recently been associated with a range of mental conditions including depression to even autism. It is larger in male brains, often enlarged in the brains of sociopaths and it shrinks in the elderly.
Brain Stem: The part of the brain that connects to the spinal cord. The brain stem controls functions basic to the survival of all animals, such as heart rate, breathing, digesting foods, and sleeping. It is the lowest, most primitive area of the human brain.
Cerebellum: Two peach-size mounds of folded tissue located at the top of the brain stem, the cerebellum is the guru of skilled, coordinated movement (e.g., returning a tennis serve or throwing a slider down and in) and is involved in some learning pathways.
Cerebrum: This is the largest brain structure in humans and accounts for about two-thirds of the brain’s mass. It is divided into two sides — the left and right hemispheres—that are separated by a deep groove down the center from the back of the brain to the forehead. These two halves are connected by long neuron branches called the corpus callosum which is relatively larger in women’s brains than in men’s. The cerebrum is positioned over and around most other brain structures, and its four lobes are specialized by function but are richly connected. The outer 3 millimeters of “gray matter” is the cerebral cortex which consists of closely packed neurons that control most of our body functions, including the mysterious state of consciousness, the senses, the body’s motor skills, reasoning and language.
The Frontal Lobe is the most recently-evolved part of the brain and the last to develop in young adulthood. It’s dorso-lateral prefrontal circuit is the brain’s top executive. It organizes responses to complex problems, plans steps to an objective, searches memory for relevant experience, adapts strategies to accommodate new data, guides behavior with verbal skills and houses working memory. Its orbitofrontal circuit manages emotional impulses in socially appropriate ways for productive behaviors including empathy, altruism, interpretation of facial expressions. Stroke in this area typically releases foul language and fatuous behavior patterns.
The Temporal Lobe controls memory storage area, emotion, hearing, and, on the left side, language.
The Parietal Lobe receives and processes sensory information from the body including calculating location and speed of objects.
The Occipital Lobe processes visual data and routes it to other parts of the brain for identification and storage.
Hippocampus: located deep within the brain, it processes new memories for long-term storage. If you didn't have it, you couldn't live in the present, you'd be stuck in the past of old memories. It is among the first functions to falter in Alzheimer's.
Hypothalamus: Located at the base of the brain where signals from the brain and the body’s hormonal system interact, the hypothalamus maintains the body’s status quo. It monitors numerous bodily functions such as blood pressure and body temperature, as well as controlling body weight and appetite.
Thalamus: Located at the top of the brain stem, the thalamus acts as a two-way relay station, sorting, processing, and directing signals from the spinal cord and mid-brain structures up to the cerebrum, and, conversely, from the cerebrum down the spinal cord to the nervous system.
Brainwaves are electrical impulses generated by the brain at frequencies from 0 to 40 cycles per second, or Hertz (Hz) and can be measured with an EEG device. Gamma greater than 30(Hz), beta (13-30hz), alpha (8-12 hz), theta (4-8 hz), and delta (less than 4 Hz).
NeuroAnatomy and Neurodevelopment. Know the human nervous system.
Nutrition and Neuro Development and Neural Health Factors. Brain Nutrients.
Experiences Build Brain Architecture. Center on the Developing Child at Harvard University. The basic architecture of the brain is constructed through a process that begins early in life and continues into adulthood.

The Brain

Brain Test Questions and Answers. Notes and Hint. Know your brain. Citology course and neurosciences.
What percentage of your energy is used by your brain?
/ 40%
What protein is associated with Alzheimers?
/ Tau
As an axon extends farther and farther, what happens to its diameter?
/ It doesn't change.
When the brain swells, which cells are swelling?
/ the glia. the neurons dont swell that much.
Which cell type is larger in general? Neuron or Glial
/ Neuron
Of the 10^13 cells in the brain, what percentage are neurons and what percentage are glial cells?
/ 1. 10-20% Neurons
2. 90-80% Glial
What percentage of space do neurons and glial space take up respectively?
/ 50%
What percentage of the brain is extracellular space? In cc's?
/ 15% or 250cc
As dendrites branch more and more, what happens to their diameter?
/ It gets smaller.
Almost all of a neuron's cell membrane is where?
/ Dendrites
What manner is information collected by a neuron transmitted?
/ In a graded fashion
Dendrite information propagation is (Active/Passive)?
/ Passive
What is concentrated at Nodes of Ranvier?
/ Sodium Channels
What type of stain is specific for myelin?
/ Hiedenheim Stain
Tthe fastest neuron transmits signals up to what frequency?
/ 300Hz
Half the energy used by the CNS is used for what?
/ Maintaining ion concentrations after action potentials (Na/K pump)
What specific type of cell never uses axons?
/ Retinal amacrine cells
What type of cell has a fusion of the dendrite and the axon?
/ Pseudounipolar neuron
How much of the cell body does the nucleus take up?
/ 1/3
How many genes make up the CNS set of genes?
/ 5000
The outermost nuclear membrane is continuous with what?
/ the ER
Where does post-transcriptional modification take place in the cell?
/ the Golgi
What part of a neuron will you find the highest levels of mitochondria?
/ the nodes of ranvier
The cytoskeleton of a neuron typically contains what three types of fibers?
/ 1. Neurofilaments
2. Microfilaments
3. Microtubules
What is the substrate for axonal transport?
/ Microtubules
What does the drug Vincristine do? What is it used for?
/ It interferes with microtubule formation. This drug is used to fight cancerous tumors.
What is a side-effect of Vincristine?
/ Tingling in the extremities
How fast is bulk flow of material down an axon?
/ 1 mm/day
How fast is microtubule flow down an axon?
/ 40 mm/day
What is delivered to the cell body by way of retrograde transport? What do they let the cell body know?
/ 1. Neurotrophic factors
2. All is well
The cell nucleus will only replenish what type of NT?
/ Neuropeptides
Most excitatory synapses are found where?
/ Dendritic spines
What do spines contain?
/ Actin and myosin; contractile
What about your neurons is abnormal in Rett or Down syndrome?
/ Abnormal dendritic spines
Are chemical synapses unidirectional or bidirectional?
/ Unidirectional
Which faster, chemical synapse or an electrical synapse?
/ Electrical synapse
Are electrical synapses unidirectional or bidirectional?
/ Bidirectional
How large is the gap between two cells (connexons)?
/ 4nm
What types of materials pass through connexons?
/ Second messangers, ions and macromolecules
All spaces not occupied by neurons or blood vessels are occupied by what?
/ Glial cells
Are glial cells polar? Are they signaling cells?
/ No and No
A lot of healing in the CNS and PNS is due to what?
/ Scarring of glial cells
The symbiotic relationship between what two cells is very important to the CNS?
/ Glial cells and Neurons
Glial cells get their energy through what process?
/ Glycolysis -anaerobic respriration
How many glial cells are their per neuron in a human?
/ 10 per neuron
What are the two broad categories of glial cells?
/ Microglial and Macroglial
What are microglial cell's derived from?
/ Mesoderm; macrophages
What are macroglial cells derived from?
/ neuroectoderm
What are the two type of astrocytes?
/ 1. Type I: associated with grey matter
2. Type II: Fibrous astrocytes -associated with white matter
What are the two type myelin-forming cells?
/ 1. Oligodendrocytes - CNS
2. Schwann Cells -PNS
What is the only glial cell associated with the PNS?
/ Schwann Cell
Where are electrical synapses found?
/ retina and pacemaking functions (myocardium)
What is a connexon?
/ a connexon is a gap junction made up of 4 connexins
Do glia have connexons/electrical synapses b/t eachother
/ yes, why else would i ask?
What invades an ischemic area in a stroke?
/ glia (they dont need O2)
What are the 2 types of glia?
/ macroglia -everything else
microglia -macrophages
Embryological origin of microglia?
/ mesoderm (they are macrophages)
2 types of astrocytes, structure, location and function
/ type 1 -short and stubby -in grey matter
type 2 - Long processes -in white matter -form end feet on blood vessels
What is principally responsible for enforcing the blood brain barrier?
/ the astrocytic end feet?
Where are radial glial cells cell bodies located?
/ near the ventricles
Why is heroin more potent than morphine?
/ heroin is more lipophilic and can therefore cross the BBB more easily
What are 3 of the substances that form the BBB?
/ occludin
claudin
cadherins
What do astrocytes release that cause the formation of new blood vessels in response to ischemia?
/ vacular endothelial growth factor (VEGF)
What substance do type 2 astrocytes release that induces the blood vessels to form tight junctions?
/ angiopoietin-I
What must be given along w/ L-Dopa to allow it to cross the BBB?
/ MAO inhibitors
What substances are actively transported across the endothelial cell in the brain?
/ glucose
amino acids
vitamins
Why can glial tumors be given chemotherapeutic agents w/o worrying about the BBB?
/ they dont have a BBB
Why can the loss of one oligodendrocyte in the CNS cause so much damage?
/ an oligodendrocyte may myelinate 50 different axons.
What molecule makes the initial contact b/t the oligodendrocyte processes and the axon in the CNS?
/ MCAM
What molecule anchors adjacent layers of myelin in the CNS?
/ PLP -phospolipid proteins
What molecule anchors adjacent layers of myelin in the PNS?
/ P0 -protein zero
What molecule serves as a spacer b/t adjacent layers of myelin in the CNS and PNS?
/ myelin basic protein -MBP
What is the signal conduction velocity in a myelinated axon?
/ 200 m/s
What determines if an axon will be myelinated in the PNS?
/ the size of the axon
greater than 1/3 micrometer and it will be myelinated
How does a progenitor cell produce either an oligodendrocyte or an astrocyte?
/ the progenitor cell will divide exactly 8 times in the presence of PDGF (platelet derived growth factor)
it has a set number of PDGF receptors and after 8 divisions, it can no longer respond
in the presence of CNTF (cellular neurotrophic factor), the daughter cells
will become astrocytes. by default, they become oligodendrocytes
What forms a scar in the CNS when an axon is damaged?
/ astrocytes
What molecules do oligodendrocytes produce that are paralyzing neurites?
/ NOGO
and
neurite outgrowth factor
When do schwann cells release Ach?
/ when a muscle is denervated, schwann cells will release Ach to stimulate it so it does not atrophy
Where does the different regenerative abilities of the CNS and PNS come from?
/ differences in the glia?
Where are ERB-2 and ERB-4 receptors expressed?
/ on radial glial cells
What happens to radial glial cells after they stop interacting with neurons
/ they collapse, retract their processes, and become astrocytes or interneurons
How do astrocytes control the potassium concentration in the extracellular space in the brain?
/ they take up K (from lots of AP) with their end feet on nodes of ranvier and dump K into the blood vessels via their end-feet on vessels
How do astrocytes and neurons eat off the same plate?
/ astrocytes take up glucose from epithelial cells and turn it into lactate taking 2 ATP's from the 36. they then deliver lactate to the neuron's far reaching axons, etc.
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