1. Structure and Function of the Nervous System

Question 1

what are the three functions of the nervous system, explain each one.

Answer 1

sensory function = senses internal and external changes
integrative function = analyses and stores information
motor function = initiates muscular activity or glandular secretions

Question 2

name the two cell types of the nervous system, which is more common?

Answer 2

neurons
glia
- there is more glial cells

Question 3

name the pronounced rough ER of neurons

Answer 3

Nissl Substance

Question 4

what is the difference between anterograde and retrograde transport

Answer 4

anterograde = materials transported from cell body to axon terminals

retrograde = material transported from the axon terminals to the cell body

Question 5

what are ion concentrations like at rest

Answer 5

10x higher sodium concentration outside the neuron

higher conc of potassium inside the neuron

Question 6

where are action potentials generated

Answer 6

in the axon hillock

Question 7

the action potential jumps from one node to another, what is the term for this?

Answer 7

saltatory conduction

Question 8

define a ‘quantum’

Answer 8

the amount of neurotransmitter in one vesicle

Question 9

define behaviour (Dugatkin)

Answer 9

the coordinated responses of whole living organisms to internal and/or external stimuli

Question 10

why are invertebrates a good model to study neurobiology?

Answer 10

master regulatory genes are so similar across species that they are interchangeable. it is more ethical to study these species.

Question 11

which is the better model organism, mouse or drosophila? explain

Answer 11

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.

Question 12

how many neurons in C. elegans

Answer 12

302

Question 13

why are C. elegans a good model organism

Answer 13

transparent, good visualisation, display all the characteristics of a multicellular organism.

Question 14

what is the sea snail typically used to study?

Answer 14

habituation & sensitisation

Question 15

what is forward genetics

Answer 15

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.

Question 16

what is backward genetics

Answer 16

where researchers alter specific genes and observe the effects of that one gene on phenotype

Question 17

name a tool for forward genetics

Answer 17

random mutagenesis

Question 18

name a tool for backward genetics

Answer 18

site directed mutagenesis

Question 19

name 3 differences between vertebrates and invertebrates

Answer 19

1. Neurons - vertebrates have more, invertebrates have fewer but larger and more complex
2. CNS - vertebrate skull encased in bony skull and spinal column, invertebrates CNS are built around the digestive tract
3. Myelin sheath - mammalian neurons are myelinated, invertebrates have no myelin, just giant icons that communicate quickly.

Question 20

what surrounds the nervous system in drosophila

Answer 20

the oesophagus

Question 21

what does UAS stand for

Answer 21

upstream activating sequence

Question 22

what is the GAL4/UAS system taken from

Answer 22

yeast

Question 23

what is GAL4

Answer 23

a transcription activator found in yeast that binds to UAS enhancer sequences to induce transcription.

Question 24

what happens when you cross GAL4 carrying flies with UAS carrying flies

Answer 24

the GAL4 drives the expression of the UAS target gene in the offspring

Question 25

what is used to identify the pattern of expression of a particular GAL4 driver line

Answer 25

UAS reporter transgenes

Question 26

how many glial cells are there compared to neurons

Answer 26

glial cells= 10^12 neurons = 10^11

Question 27

what are glial cells involved in

Answer 27

support and development and nueorinflammation

Question 28

ER: explain the role of glial cells in stroke!

Answer 28

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

Question 29

describe the three types of neurons

Answer 29

multipolar = one axon and many dendrites unipolar = cell body in the middle of the axon bipolar = one axon and one dendrite

Question 30

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

Answer 30

1. multipolar 2. sensory functions - pain, temperature 3. soma 4. Nissl substance

Question 31

what materials are typically transported in neuronal transport

Answer 31

vesicles, enzymes and proteins

Question 32

how is synaptic transmission instigated

Answer 32

depolarisation reaches the axon terminals, triggers calcium channels to open which mobilises vesicles to fuse with the presynaptic membrane

Question 33

name 3 neuroimaging techniques

Answer 33

MRI DTI FMRI

Question 34

how does MRI work strength of MRI

Answer 34

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

Question 35

briefly how does DTI work

Answer 35

diffuser tensor imaging: a variant of MRI used to detect the diffusion of water

Question 36

how does fMRI work

Answer 36

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

Question 37

why do we use model organisms

Answer 37

master regulatory genes are similar across species - more ethical to study model organisms over humans - can manipulate genes easier

Question 38

why are master regulatory genes similar across model organisms and humans

Answer 38

they have been conserved via evolutionary processes

Question 39

what are some similarities between invertebrates and vertebrates

Answer 39

same basic plan: a central and peripheral nervous system and majority of them all have a brain

Question 40

if there is no GAL4, what happens to the genes downstream of UAS

Answer 40

they are not transcribed

Question 41

give an example of where the GAL4/ UAS system could be used to manage gene transcription

Answer 41

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