lecture 1 cells of nervous system Flashcards
Fmri vs mri functions
fmri (functional magnetic resonance imaging) allows you to see the rate of blood flow to certain parts of the brain. mri (magnetic resonance imaging) allows you to see detailed images of internal structures in the body
types of nervous system (in terms of studying)
systems (visual, motor, autonomic)
cells (neurons and their parts)
molecules (gene product)
central dogma of molecular biology
genes created in dna are transcribed into mrna then translated into proteins
why is protein important
it’s needed as building blocks for muscles, repairing tissue, for oxygenating blood (hemoglobin), making digestive enzymes, regulating protein, and more
what is in situ hybridization
assays used to reveal which mrna is being translated (so which genes are being expressed)
how is dna packaged
wraps around histone octamers (chromatin) then condenses into chromosomes
how many chromosomes do we have
23 pairs (46)
difference between major and minor groove
major has more information and can differentiate between nucleotides actg
how do transcription factors identify base pairs to start transcribing
major and minor grooves
most known transcription factor
tata box
process to make mature mrna
cap tail splice
what enzyme needs to be recruited by transcription factors
rna polymerase, to start synthesizing mrna
what are the cap and tail of mature mrna made of
adenine
what must be spliced out before mrna can leave the nucleus
introns
where must the mature mrna go to be translated into protein
ribosomes
how many amino acids are there
20
how long is a codon
three nucleotides
start and stop codons
aug (methionine) and uag/uga/aaa
how do trna charge
covalent coupling of amino acid to respective trna in enzyme synthetase (with help of atp)
steps of translation
1) trna charging
2) charged trna enters binding site in ribosome
3) peptide bond formed between amino acids
4) ribosome translocates to next codon
what is the golgi stain
made by camillo golgi, first technique to reveal full neurons
who is santiago ramon y cajal
neuroscientist who used golgi stain to identify different cell types in cerebellum
neural doctrine vs reticular theory
neural doctrine: neurons are discrete cellular units
reticular theory: neurons are part of a net-like structure of an interconnected network, no individual cellular entities
what is a cell
basic structural unit of life
parts of a cell
nucleus (has dna)
mitochondria (makes energy)
golgi apparatus (sorts proteins) and makes vesicles (transports proteins)
ribosomes (make proteins)
lysosomes (destroys proteins)
smooth endoplasmic reticulum (makes lipids)
peroxisomes (destroys lipids)
what parts of a cell does the nerve cell have
nucleus
mitochondria
rough endoplasmic reticulum
ribosomes
*only cells with synaptic vesicles
features of a neuron
excitability
compartmentalization (soma, dendrites, axon)
synaptic connections
post-mitotic
what is dynamic polarization
information is received by the dendrites (through synapses), integrated by the axon, and conducted by the axon before being sent out again
dendrite look and function
relatively short, has spines, many of them
axon look and function
only one comes from soma, can be quite long, no spines, cant make protein
sometimes myelinated
has caliber (how wide) and wider caliber=faster conduction
axoplasmic transport
types of axoplasmic transport
anterograde (toward axon)
retrograde (away from axon)
proteins used in axoplasmic transport
dynein (retrograde) and kinesin (anterograde)
what is a synapse
junction between two neurons that allows transmission of electrical nerve impulse
parts of synapse
presynaptic: axon of neuron
postsynaptic: dendrite of another neuron
process of synapse
presynaptic axon terminal has synaptic vesicles with neurotransmitters
vesicles dumped into extracellular space
navigate and attach to receptors on postsynaptic dendrite (or soma)
what are glial cells
supporting cells that are smaller than neurons but outnumber them
types of glial cells
astrocytes (form blood brain barrier
myelinating (oligodendrocytes in cns, schwann cells in pns)
microglia (clean up debris from sites of damage)
why is there retrograde transport
possibly to recharge mitochondria
what are parts of soma
mitochondria
cytoskeleton
ribosomes
golgi apparatus
where are proteins synthesized in a neuron
soma (has extra rer)
features of an axon
highly branched, long, thick, sometimes myelinated
comes out from soma
cant make proteins
makes up most of neuron volume
higher caliber=better conduction
what do motor proteins do
kinesin holds onto the anterograde cargo and “walks” it across microtubule
dynein does the same the other way
types of transport, most effective in terms of speed
electrical signals are faster- diffusion would take years!
nerve terminal function
axon terminal makes synaptic contact with dendrites of other neurons to share information
why do dendrites have spines
give wider net to catch synapse
difference between glial cell and neuron
smaller, more of them, can replicate, unexcitable, only few types
nissl stain made of what, and what is the function
nissl bodies made of rer
used to stain nucleus and look at structure
what is gene expression
types of genes transcribed and where
what is cytosol
protein rich intracellular fluid that fills the cell
what do mitochondrion do
energy stored in glucose bonds broken down to form atp in oxygen dependent reactions
what is a neurite
neuronal process that comes out of cell body (dendrite and axon)
what do microtubules do
provide structural support and mechanism for transport since axons are so long
what is the axon initial segment
site of action potential initiation
what is myelin made of and what does it do
made from glial cells (depending on cns or pns which type
sheathes axons with layers of glial cells to stop electrical current leakage
increases speed axons can send signals
makes white matter
what are motor neurons
neurons that innervate (supply) muscles
what are sensory neurons
neurons that carry sensory info from the periphery
types of axon length
projection neurons (long, connect one part of brain to another)
interneurons (short, connect locally)
fmri
functional magnetic resonance imaging
Cytosol
the protein rich liquid that fills the cell, also referred to as intracellular fluid (oppose to
extracellular fluid, that surrounds the cell).
Rough endoplasmic reticulum (RER)
a system of membrane stacks with many ribosomes
attached. The rough endoplasmic reticulum is responsible for the synthesis of proteins and is enriched in neurons with long axons compared to other cell types.
Golgi apparatus
organelle consisting of many folded membranes and vesicles that is
involved in the secretion and transport of proteins
Mitochondria
organelles involved in energy production. Within a mitochondrion, the energy
stored in glucose bonds is broken down to form ATP in oxygen dependent reactions
Central Dogma
explains how genetic information flows within an organism. DNA is copied into
RNA in a process call transcription, and RNA is used to create proteins in a process called translation
Neurite
a neuronal process or projection that arises from the cell body, either an axon or a
dendrite
Dendrite
type of neurite, usually branched and shorter than the axon, that receives much of
the synaptic input to that neuron
microtubules
provide structural support and provide a mechanism for transport
Myelin
insulation around some axons composed of layers of glial membrane. Myelin
increases the speed that axons can send information (electrical pulses)
Number of “neurites”
most neurons have 1 axon and many dendrites extending from off the
cell soma. There are some important exceptions.
The pseudo-unipolar cells that send sensory information (like touch or stretch) seem to have just one long axon with the soma in the middle. (1a axon)
Bipolar cells can be found in the in the eye
Astrocyte
type of glial cell located in the central nervous system (CNS) which aids in
maintaining the appropriate chemical environment of the brain including formation of the blood brain barrier, transferring nutrients from the blood to the neurons, and removing chemicals from the extracellular fluid surround synapses
Oligodendrocyte
type of glial cell responsible for myelinating axons within the CNS. A single
oligodendrocyte wraps part of its membrane many times around segments of multiple axons
Schwann cell
type of glial cell responsible for myelinating axons within the peripheral
nervous system (PNS) . A single Schwann cell wraps itself many times around a single segment of one axon.
Microglia
type of glial cell that has many immune response properties including removal of
cellular debris, modulating local inflammation and influencing neuronal survival
Define the neuron doctrine and describe the initial evidence for it
answer yourself
Understand and apply the law of dynamic polarization to a simple neuronal circuit diagram to predict the direction of the flow of information
answer yourself
Draw a neuron from memory; label and be able to differentiate all of the neuronal specific parts
answer yourself
List the main properties and distinguishing characteristics of axons and dendrites
answer yourself
Define “glial cell” and describe the main classes of glia
