Topic 2: Neuroscience Foundations Flashcards
Glia
- Glue
- Insulate, support, and nourish neurons
- support neuronal function
Jobs of Neurons
- Process information
- Sense environmental changes
- Communicate changes to other neurons
- Command body response
Parts of a neuron
- Soma
- Neurites
The Soma
- cell body
- Contains nucleus and many organelles, cytosol and cytoplasm
Neurties
- Dendrites: receive information
- Axons: send information
-More concerned with connections rather than the inner workings/physiology of the neuron
Neuron vs Nerve
Neuron: Cells that sends and receives electrical signals
Nerve: a group of fibers that carry information
Cytosol of neuron
water fluid inside the cell, separate from outside by neuronal membrane
Organelles of neuron
- Membrance enclosed structures within the soma
- Nucleus, endoplasmic reticulum, mitochondria
Cytoplasm of neuron
Everything contained within the cell membrane
- Cytoplasm = cytosol + organelles - nucleus
Neuronal membrane of neuron
- Barrier that encloses cytoplasm and regulates membrance potential
- Embedded with proteins that grant access and regulate concentrations
- Structure of membrane varies based on neuron regions
Cytoskeleton of neuron
- “bones” of neuron
- not static (continually remodeling and in motion)
- made of:
MICROFILAMENTS: weave to form strict
NEUROFILAMENTS: weave to form structure
MICROTUBULES: run longitudinally
Inforgraphic
a wat to communicate important information in a more engaging way
Three stages of Alzheimer’s disease
- Preclinical: subtle changes in brain, biomarkers in the cerebrospinal fluid and blood. the disease is often undetectable in this stage, except in research setting.
- Mild Cognitive impairment: changes in memory and other cognitive functions, like problem-solving and changes in judgement, but not enough to affect daily function
- Dementia: more significant changes memory, cognitive and physical abilities. trouble completing simple everyday tasks. Changes in mood, behaviour and personality.
What causes Alzheimer’s Disease?
AMYLOID HYPOTHESIS
- Built up coagulated plaque made of proteins disturbs neural signals impacting brain function
- Aducanumab seen to reduce plaque in brain but doesn’t produce positive patient outcomes
TAU HYPOTHESIS
- tangling of microtubules may precede plaque formation (neurofibrillary tangle) causing a decrease in transmission
SYNTERGIST DANCE BETWEEN AMYLOID AND TAU
- inflammation and vascular dysfunction may initiate or accelerate the process
Axon
- Transfer information over distances (can range form less than 1mm to 1m)
- Made up of the hillock (beginning), proper (middle) and terminal (end)
- Not always a direct path (axon collaterals)
- Size does matter (1 - 25 nanometers in diameter, thick axons are faster)
Terminal of Axon
- no microtubules in terminal
- has synaptic vesicles
-abundance of membrane proteins - large number of mitochondria
Synapse
- Provides the contact site for transmission of signal
- Presynaptic - sends signal
- Postsynaptic - receives signal
Dendrites
- dendritic tree (all) with dendritic branches (individual)
- the antennae of neurons and covered in thousands of receptors
- receptors to receive neurotransmitters
What are the 4 ways to classify neurons
- Classification based on number of neurites
- Classification based on dendritic and somatic morphology
- Classification by connections within the CNS
- Classification based on axonal length
How can neurons be classified based on number of neurites
- Unipolar or pseudo-unipolar (single neurite)
- Bipolar (two neurites
- Multipolar (more than 2 neurites)
How can neurons be classified based on dendritic and somatic morphology
- Stellate cells (star shapes)
- lot of local connections - Pyramidal cells (pyramid shape)
- covers more distance
How can neurons be classified based on connections within the CNS
- Primary sensory neurons
- Motor neurons
- Interneurons
How can neurons be classified based on axonal length
- Golgi type I (long and go to other areas)
- Golgi type II (short and remain local)