Lectures 1-2 : Basics Flashcards
3 components of behavior?
1) Sensory input
2) intergration
3)Motor output
Types of Nuerons
uni - multi - bi polar
axon types
golgi 1 - long
golgi 2 - short
connections with periphery
primary sensory - first neurons to receive information from sensory pathways
primary motor - neurons that have axons that synapse with motor cells
interneurons - neurons that synapse with other neurons
dendrite types
spiny - aspinous
how many neurons in the brain
100 bil
sulci
grooves
gyri
bumps
dorsal
back of spine
ventral
front of spine
cerebrum
soft - perception, memory, sensory fibers
cerebellum
hard - motor fibers, movement control
what do glia do?
- the glue - insulate, support, nourish neurons
- make up 50% of brain
- 85 billion
what are the types of glia
astrocytes, oliodengrolia & shwan cells, microglia
what do astrocytes do? (6)
- regulate the content of extracellular space
- regulate ion concentrations around neurons
- protect neurons by taking up toxins
- mechanisms that take up K
- guide neurons in development
what does microglia do?
remove debris from dead cells
what do olio and schwan cells do?
involved in mylenation
what is the purpose of mylintating the axon?
- speed electrical conduction down axons
- electrically insulate axons with myelin (fat)
- nodes of raniver
what disease is associated with loss of myelination?
MS - Multiple sclerosis
shwan cells
- PNS
- insulates a single axon
oliodengrolia
- CNS
- insulates many axons
what are the most common type of CNS cancer?
Glial cancers
- gioblastoma
- oliodendroglioma
nissl stain
- see cell bodies, neurons vs. glia
golgi stain
- see specific parts of the neurons
what are the of neurites
axon - dendrites
dendrite facts? (4)
1) receive input from thousands of synapses
2) one neuron can have multiple dendrites
3) dendrites have special receptor proteins that bind neurotransmitters
4) taper in diameter
where does synapse on the dendrite occur? (4)
1) 1 dendritic spine receives a single synapse
2) sites for transmission and input of information
3) shape and density can shape strength of interactions between neurons
4) have been shown to change during learning
dendritic spine abnormalities + info?
General Intellectual impairment
- long, spindly, sparse density
Fragile X
- long, spindly, high density (hereditary autism)
- Hyper anxiety, hyper arousal - due to over excitation
what does the soma contain?
- cytosol, organelles, nucleus
cytoplasm
all organelles except nucleus
where does protein synthesis occur?
rough er
dna - protein pathway
what is important about gene expression?
- every cell in the human body has the same DNA
- cell specialization is determined by what genes of a cells DNA are translated and transcribed
how do ribosomes synthesize proteins?
they use mRNA as a blueprint to make proteins from raw material
ribosomes attached to rough er make …
proteins that are inserted to the cell membrane
free ribosomes make …
proteins that reside within cytosol
what are polyribosomes
- appear to be attached to a thread of mRNA
- make multiple copies of the same protein
what does smooth er do? (3)
1 - packages proteins and give them their 3 dimensional figure
2 - regulate internal concentrations of substances
3 - prominent in muscles - sarcoplasmic reticulum
functions of golgi apparatus? (2)
1 - site of post translational chemical processing of proteins
2 - sorts proteins according to the area they are supposed to be located in
function of mitochondria (2)
- cellular respiration
- generates ATP
what is the neuronal membrane?
- it separates cytoplasm from extracellular fluid
- studded with ribosomes
what does protein composition depend on?
location of the protein
cytoskeleton function
- skeleton of cell
- scaffold proteins affect neuron shape and function
what are the internal scaffolding of the cytoskeleton? (3)
- microtubules
- microfilaments
- neuro fillaments
microtubules analogy
thick walled - hollow pipe
what are micro tubules made of?
smaller strands of tubulin proetin - small and globular
how is tubulin joined to form a polymer?
via polymerization
what is the function of MAPS
microtubule associated proteins - anchor microtubules to one another and other parts of the neuron
what is a disease associated with MAPS?
Alzheimers
Alzheimers indicators (6)
- memory loss
- confusion
- difficulty with speech and navigation
- cell death
- gryi shrink
- sulci expand
What is a MAP associated with Alzheimers
Tau
what are microfilaments made of?
braids of two thin strands that are polymers of the protein actin
facts about microfilament structure?
- anchor to the membrane via a meshwork of fibrous proteins
- same thickness of cell membrane
what are neurofilaments? (3)
1 - intermediate filament specific neurons
2 - resemble the bones and ligaments of the skeleton
3 - consist of multiple subunits
axon facts
1) constant diameter
2) contain axon terminal / terminal button
what occurs on the axon terminal?
- end of the axon
- terminates at the synapse
recurrent collaterals?
axon branches that communicate with the same cell that give rise to axon or neighboring dendrites
proteins and axons
there is no rough er = no-few ribosomes
axon terminal vs. axon (4)
1 - microtubules don’t extend to the terminal
2 - terminal contins synaptic vesicles
3 - inside surface of the axon terminal membrane that faces the synapse contains many proteins
4 - there are alot of mitochondria in the axon terminal
how do proteins reach the axon?
synthesized in soma - then reach axon via axoplasmic transport
analogy for axoplasmic transport?
microtubules = train track
dynein and kynesin = legs of the train
vesicle = cargo
anterograde transport?
- to axon terminal: uses kynesin
retrograde transport
- to soma: uses dynein
what diseases use anterograde and retrograde
rabies, coldsores
