neuro: methods of studying the NS

Question 1

what are the 5 non invasive methods?

Answer 1

CT scans
MRI
PET
fMRI
EEG

Question 2

describe CT scans in key words

Answer 2

X rays
structure
contrast agent absorbed
rotate to produce series of X-rays 
reveal structural abnormalities (lesions + vascular damage indicate location of tumours)

Question 3

describe MRI scans using key words

Answer 3

structure
strong magnetic field
high resolution images produced
form radio frequency waves that H+ ions emit when they align with magnetic field
protons release magnetic resonance energy

Question 4

describe fMRI using key words

Answer 4

O2 increase in the blood to active areas of the brain
more oxygenated blood
functional activity
signal = BOLD signal (blood oxygen level dependent)

Question 5

describe PET using key words

Answer 5

functional
positron emission tomography
radioactive dye injected into carotid artery
similar to glucose but doesn’t get metabolised
taken up by active cells
builds up in neurons
shows areas of brain activity from levels of radioactivity
colour coded

Question 6

describe EEG

Answer 6

net of electrodes placed on scalp
records electrical activity
current of ions flowing across cell provides potential current
shows activity of APs, postsynaptic potentials etc = the sum of all the electrical events

Question 7

what are ERPs?

Answer 7

event related potentials

EEG waves that accompany certain physiological events

Question 8

what are the advantages of MRIs?

Answer 8

provides clearer images of brain than CT
higher spatial resolution (where)
no ionising exposure of X-rays
provides horizontal, sagittal and frontal planes

Question 9

what are the disadvantages of MRIs?

Answer 9

expensive
no metal allowed
noisier

Question 10

what are the 4 advantages that fMRI has over PET?
fMRI = O2 levels/bold signal
PET = injected dye like glucose

Answer 10

nothing has to be injected into person
provides structural and functional info in same image
better spatial resolution (where)
produces 3D images of activity over entire brain

Question 11

what is a disadvantage of fMRI?

Answer 11

poor temporal resolution (when) → timing of neural events

Question 12

what are the pros and cons of EEGs?

Answer 12

high temporal resolution (when) but poor spatial resolution (where) → can’t localise as recordings made on the scalp

less expensive than fMRI
direct reflection of neuronal activity

Question 13

what is the difference between spatial and temporal resolution?

Answer 13

spatial = where
temporal = when

Question 14

what are the different invasive methods of studying NS function in animals?

Answer 14

intracellular recordings (electrophysiological technique)
extracellular recordings (electrophysiological technique)
electrical stimulation
optogenetic stimulation
micro dialysis (neuropharmacological technique)
immunohistochemistry (neuropharmalogical technique)
chemical lesions (disruptive technique)

Question 15

records individual neurons as they fire, measures the changes in the membrane potential of a neuron over time, microelectrode positioned directly into neuron.
what method is this and is it invasive or non invasive?

Answer 15

intracellular recording

invasive

Question 16

records near neurons as they fire action potentials, microelectrode positioned near neutron.
what method is this and is it invasive or non invasive?

Answer 16

extracellular recording

invasive

Question 17

in extracellular recording, spikes indicate an action potential from a nearby neuron.
spikes of the _________ are assumed to come from the ____ neuron

Answer 17

same amplitude

same neuron

Question 18

what is the difference between EEG and electrophysiology?

Answer 18

EEG = mass numbers of cells being recorded (not localised)
electrophysiology = recording of individual cells

Question 19

how does the electrical stimulating technique work?

Answer 19

examines neuronal circuits and the cause of bursts of APs
electrical stimulation = artificially activating nervous tissue
stimulating electrode → stuck in brain → switched on → activates tissue
can work out how parts of the brain relay info to each other via circuits

Question 20

what is ontogenetic stimulation technique?

Answer 20

uses opsin (photoreceptors) that are extracted from bacteria/algae and inserted into genome of neurons using a virus 
neurons are then artificially responsive to light due to artificial proteins being inserted into their membrane

proteins then produce either excitation or inhibition of neurons when light is on

Question 21

explain how ontogenetic stimulation is used in rats

Answer 21

opsin is inserted into genome of rats neurons in brain
laser light probe comes on → activates tissue in brain area linked to locomotion → activates light sensitive neurons → forces rat to run

Question 22

used to measure neurotransmitters and chemicals secreted by the neuron during synaptic transmission
what technique is this?

Answer 22

microdialysis

Question 23

how does microdialysis work?

Answer 23

small semi-permeable membrane is inserted into specific brain site of animal
solution circulates through the tube
chemicals in the extracellular fluid diffuse across membrane and are collected
samples then analysed using chomatography methods

Question 24

key words to describe/recognise the immunohistochemistry technique

Answer 24

antibodies used to identify enzymes
enzymes produce specific neurotransmitters in specific cells
reveals chemical identity of cells
inject antigens
radio active labelling of antibodies that attach to enzymes
black or fluorescent
brain tissue → removed → sliced → reveals locations where labels have accumulated

Question 25

method of disrupting neuronal function =

Answer 25

chemical lesions

Question 26

how do chemical lesions work?

Answer 26

selectively lesioning = taking away bits of the brain | see what happens when disrupt function → remove chemicals, block circuits, remove tissue

Question 27

give an example of a chemical lesion used to model a neurodegenerative disease

Answer 27

6-hydroxydopamine = neurotoxin that selectively destroys dopaminergic + noradrenergic neurons in the area of injected brain site kills neurons locally this models Parkinsons disease in order to pick apart what goes wrong in this specific disorder

Question 28

give examples of species common behaviours

Answer 28

grooming, swimming, nest building, mating, fighting, eating, drinking

Question 29

how does an open field test study species common behaviours?

Answer 29

animal placed in large, empty chamber activity levels and number of boluses (excretion) recorded low activity scores + high bolus content = indicator of fearfulness (rats are usually fearful when first placed in field but declines with repeated exposure to same field)

Question 30

if a fearful rat is highly THIGMOTAXIC what does its behaviour show?

Answer 30

rarely venture away from the walls of the test chamber and rarely engage in grooming and rearing activities

Question 31

explain the colony-intruder paradigm

Answer 31

``` study looking at social defeat male rats are territorial measure and observe introducing a smaller male intruder into the habitat of a larger dominant male dominant male → aggressive behaviour intruder → defensive behaviour ```

Question 32

why do learning paradigms play a major role in bio psychological research?

Answer 32

learning is a phenomenon of primary interest, effective for producing and controlling animal behaviour so animals behave to goals of experiment, can infer about sensory, motor, motivational, cognitive states of animals

Question 33

describe classical conditioning

Answer 33

``` bell (CS) → no salivation over time and training: bell (CS) + meat powder (UCS) → salivation (UCR) conditioning established: bell (CS) → salivation (CR) ```

Question 34

describe a study that tests the classical conditioning paradigm

Answer 34

place preference study testing drug addiction day 1: assess rats natural preference for white or black compartment day 2-4: am → give saline and place in black room → give drug and place in white room day 5: assess conditioned compartment preference results showed rats spent longer in white compartment

Question 35

describe operant conditioning

Answer 35

specific behaviour → reinforcement (reward) → increased voluntary response specific behaviour → punishment → decreased voluntary reward

Question 36

describe a study that tests operant conditioning

Answer 36

self stimulation paradigm animal pressers leaver → delivers electrical stimulation to pleasure centre → reward → increases response to pressing leaver also tested with self supplying food (chunking)

Question 37

what are the 4 semi natural animal learning paradigms

Answer 37

conditioned taste aversion radical maze morris water maze conditioned defensive burying

Question 38

why are semi natural learning paradigms studied in animals?

Answer 38

because they mimic situations that an animal might encounter in their natural environment

Question 39

what type of field observations are observed in animals?

Answer 39

social dominance, aggression, courtship display, sex