Ch.7, Research Methods Flashcards

Question

opsins, definition and two types

Answer 1

opsins: Opsins are G-protein-coupled receptors (GPCRs) that are light sensitive 1. Channelrhodopsin-2, ChR2: activation of a neuron, sensitive to blue light; results in Na+ influx into cell for excitation and K+ efflux = net depolarization 2. Halorhodopsin, NpHR: inhibits neuron, chloride pump activated by green yellow light, results in Cl-influx for net hyperpolarization

Answer 2

amygdala introduce haloropsin, inhibitory light = loss of normal fear response in rats, wander in center space which is abnormal for them when usually they stick to the walls of the area theyre in

Answer 3

high spatial and temporal resolution

Answer 4

ONLY USED ON ANIMAL MODELS measures activity with microelectrodes MEASURES ACTION POTENTIALS AND GRADED POTENTIALS Extracellular: poor spatial resolution, good temporal precision, non invasive, done in mobile animal, low cost, less expertise required, Intracellular: in sitro or in vitro, must more difficult, not done on mobile animal, good spatial resolution, good temporal resolution, an get one neuron easier in invertebrates, harmful to cells

Answer 5

Continous direct measure only measures graded potentials bc they are occuring in dendrites closer to the surface, can't measure AP bc they are too short, occuring too far down very superficial, only first bit of cortex overview: simple, inexpensive, non-invasive, USED FOR: sleep rythms, anaesthesia depth, brain injury detection, severity of brain injury Current sink: drop in current, EPSP, positive inside cell but negative outside Currrent source: rise in current, IPSP, negative inside cell, positive outside

Answer 6

1. eeg changes as behavior changes 2. an eeg recorded from the cortex displays patterns 3. the liivng persons electrical activity is never silent

Answer 7

event related potentials complex EEG waveforms time locked to stimulus stimuli can be anything low spatial resolution, high temporal precision, inexpensive, noninvasive, easy, shows related to stimulus, simple, data requires cleaning has current sink and current source, p is positive n is negative wave, they functionally image brain activity

Answer 8

static: just picture, MRI, CT functional/dynamic: mapping using blood flow or something else, indirect

Answer 9

computed tomography radiation problem is huge, gives 3D picture, inexpensive, tomo means to slice, good spatial resolution, no temporal resolution, harder areas show up white soft tissue areas show up dark/fluid, shows lesions/brain injuries well

Answer 10

process: strong magnetic field through the brain, followed by a radio wave (which is a large wavelength, low energy, type of radiation but still very safe), the measuring the radiation emitted from hydrogen atoms -grey matter shows up darker bc it has more water and less dense tissue -white matter shows up light bc its very dense, but not a lot of water OVERALL FUNCTION: MAPS THE LOCATION OF HYDROGEN ATOMS/WATER AND HOW DENSE IT IS -noninasive have to lie completely still people with claustrophobia, children, or parkinsons would struggle

Answer 11

Some IUDs, pacemakers, and tattoos can be affected by the scanner body weight limit due to the strength of its magnetic field:L 60,000 times stronger than the earth , 1.5Tesla to 3Tesla very good spatial resolution much better with soft tissue no temporal?

Answer 12

hydrogen atoms behave as tiny bar mnagnbets that can be aligned by a magnetic field once magnetic field is on,m hydrogen lines up with radio wave pulse , the radio transmitter is turned off, and then the particles re-emit radio waves

Answer 13

functional magnetic resonance imnaging assumes that when a brain region is active, the amount of blood, oxygen and glucose flowing to the region increases unlike EEG, not a direct measure of electrical activity when human brain activity increase = produces overcompensation bc the increase in oxygen produced by the increased blood flow exceeds the tissue's need for oxygen: FMRI MEASURES THIS OVERCOMPENSATION

Answer 14

Oxygen-rich hemoglobin is LESS magnetic than oxygen poor hemoglobin deoxygenated blood distorts surrounding magnetic fields, reducing signal of protons in the near vicnity= less overall MRI signal BECAUSE Hemoglobin is diamagnetic when oxygenated but paramagnetic when deoxygenated. This difference in magnetic properties leads to small differences in the MR signal of blood depending on the degree of oxygenation. Diamagnetic materials are slightly repelled by a magnetic field; Paramagnetic materials are slightly attracted by a magnetic field and do nold t retain the magnetic properties when the external field is removed.

Answer 15

1. baseline recorded 2. oxygen use, dip in signal; this lower signal = means more deoxygenated blood 3. after stimulus introduction, we are now measuring overcompensation; delivery of oxygenated blood

Answer 16

1 millisecond

Answer 17

good spatial resolution, but changes in blood flow take as long as 2-6 seconds, making the tempora;l resolution bad expensive people

Answer 18

used to detect changes in blood flow by measuring changes in the uptake of radiolabeled compounds such as water or glucose ^^by swapping out oxygen with something radioactive, measures unstable radioactivity radioactive "tracers" are injected: half life is very short: has to be done bedside positrons emitted by nuceli and produce gamma rays water collects in more active tissue activity increases =inbcrease in radiation

Answer 19

anti-matter: electron with positive charge

Answer 20

could look at proteins, ph, cellular function, very good at detecting cancer cells since they tend to consume more glucose

Answer 21

good spatial, but both FMRI and CT ARE BETTER poor temporal costly expertise have to average participant scans to the get the "mean difference image"

Answer 22

CT= best MRI FMRI PET is the worst

Ch.7, Research Methods Flashcards

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