1. Structure and Function of the Nervous System Flashcards
what are the three functions of the nervous system, explain each one.
sensory function = senses internal and external changes
integrative function = analyses and stores information
motor function = initiates muscular activity or glandular secretions
name the two cell types of the nervous system, which is more common?
neurons
glia
- there is more glial cells
name the pronounced rough ER of neurons
Nissl Substance
what is the difference between anterograde and retrograde transport
anterograde = materials transported from cell body to axon terminals
retrograde = material transported from the axon terminals to the cell body
what are ion concentrations like at rest
10x higher sodium concentration outside the neuron
higher conc of potassium inside the neuron
where are action potentials generated
in the axon hillock
the action potential jumps from one node to another, what is the term for this?
saltatory conduction
define a ‘quantum’
the amount of neurotransmitter in one vesicle
define behaviour (Dugatkin)
the coordinated responses of whole living organisms to internal and/or external stimuli
why are invertebrates a good model to study neurobiology?
master regulatory genes are so similar across species that they are interchangeable. it is more ethical to study these species.
which is the better model organism, mouse or drosophila? explain
drosophila = cheap, more ethical, few chromosomes, easy to grow, short life cycle, complex behaviours just like multicellular organisms
mouse = less ethics (tighter regulations), more expensive. however has a closer resemblance to humans.
how many neurons in C. elegans
302
why are C. elegans a good model organism
transparent, good visualisation, display all the characteristics of a multicellular organism.
what is the sea snail typically used to study?
habituation & sensitisation
what is forward genetics
where researchers randomly alter the genotype and observe the effect on phenotype - they can then go back and identify the mutated gene that caused this altered phenotype.
what is backward genetics
where researchers alter specific genes and observe the effects of that one gene on phenotype
name a tool for forward genetics
random mutagenesis
name a tool for backward genetics
site directed mutagenesis
name 3 differences between vertebrates and invertebrates
- Neurons - vertebrates have more, invertebrates have fewer but larger and more complex
- CNS - vertebrate skull encased in bony skull and spinal column, invertebrates CNS are built around the digestive tract
- Myelin sheath - mammalian neurons are myelinated, invertebrates have no myelin, just giant icons that communicate quickly.
what surrounds the nervous system in drosophila
the oesophagus
what does UAS stand for
upstream activating sequence
what is the GAL4/UAS system taken from
yeast
what is GAL4
a transcription activator found in yeast that binds to UAS enhancer sequences to induce transcription.
what happens when you cross GAL4 carrying flies with UAS carrying flies
the GAL4 drives the expression of the UAS target gene in the offspring
what is used to identify the pattern of expression of a particular GAL4 driver line
UAS reporter transgenes
how many glial cells are there compared to neurons
glial cells= 10^12
neurons = 10^11
what are glial cells involved in
support and development and nueorinflammation
ER: explain the role of glial cells in stroke!
following a stroke, activated micoglial cells release cytokines which stimulate the inflammasome to secrete IL-1beta
when these cytokines enter systemic circulation via the damaged BBB, it can cause systemic inflammation
describe the three types of neurons
multipolar = one axon and many dendrites
unipolar = cell body in the middle of the axon
bipolar = one axon and one dendrite
quick fire!
- which is the most common type of neuron
- what are unipolar neurons used for
- what is another name for cell body
- name the substance that makes up the ER of the cell body
- multipolar
- sensory functions - pain, temperature
- soma
- Nissl substance
what materials are typically transported in neuronal transport
vesicles, enzymes and proteins
how is synaptic transmission instigated
depolarisation reaches the axon terminals, triggers calcium channels to open which mobilises vesicles to fuse with the presynaptic membrane
name 3 neuroimaging techniques
MRI
DTI
FMRI
how does MRI work
strength of MRI
magnetic field causes the protons of water molecules in the brain to emit radio signals which are picked up by radio receivers
good spatial resolution
briefly how does DTI work
diffuser tensor imaging:
a variant of MRI used to detect the diffusion of water
how does fMRI work
Blood-oxygenated-level-dependent signal (BOLD) is different for oxygenated and non-oxygenated blood
active neurons which discard O2 become more magnetic = bigger FMRI signal
why do we use model organisms
master regulatory genes are similar across species
- more ethical to study model organisms over humans
- can manipulate genes easier
why are master regulatory genes similar across model organisms and humans
they have been conserved via evolutionary processes
what are some similarities between invertebrates and vertebrates
same basic plan: a central and peripheral nervous system
and majority of them all have a brain
if there is no GAL4, what happens to the genes downstream of UAS
they are not transcribed
give an example of where the GAL4/ UAS system could be used to manage gene transcription
a fly containing a desired gene controlled under UAS is mated with a fly expressing GAL4 in the tissue type of interest
= expression of the target gene in offspring
