Metode/forelæsning 1 Flashcards
what is transduction?
A method for moving DNA from one foreign cell to another. (wiki)
What is the method called, which makes cells light-sensitive, so you can control and monitor them with light?
Optogenetics (Gazzinga p. 73).
What is cognitive neuroscience (i think) a fusion of?
Neurologi, neuroscience and cognitive psychology (Gazzinga, p. 118)
What is the imaging method called, used to evaluate the circular system of the brain?
Angiography (Gazzinga, p. 82)
Blodprop på Engelsk?
Embolus
what do you call a restricted blood supply for instance due to an embolus??
Ischemia (Iskæmi)
what is cerebral artherioschlerosis?
A condition in which thickening and hardening of the vessels leads to chronical restricted blood supply. (Gazzinga, p. 79)
Name three degenerative diseases
Huntingtons, parkinson’s and alzheimer’s
Which kind of diseases are huntingtons, Parkinsons and alzheimer’s?
Degenerative diseases
What do you call the study of effects of diseases in the structure and function of the brain?
Behavioral neurology (Gazzinga, p. 84)
What does ‘in vivo’ mean
Investigations in the living organism
Which neurochemical lesion mimics parkinsons disease?
systemic injection of MPTP - destroys dopaminergic cells in the substantia nigra. (Gazzinga, p.83).
which two kinds of lesions are used in animal lesion studies?
Surgical and neurochemical (Gazzinga, p. 83)
What is the benefits of double dissociation studies compared to single dissociations?
That the double dissociation study controls for general impairments of brain injury, making it possible to investigate whether a patient has a selective impairment on a certain cognitive function and thus, that two cognitive functions are independent of each other (Gazzinga, p.83).
Which properties of the atoms that makes up organic tissue does MRI exploit?
The magnetoc properties (Gazzinga 92)
Why is the image provided by a MRI much clearer than the CT?
Because it distinguishes better the white matter from the grey matter (because the grey matters density of protons is much higher than in the white) (Gazzinga 93).
How does MRI work?
A magnetic field makes the protons of the atoms in the tissue point to a certain direction. Radiowaves makes the protons move again (because of the energy) in a predictable direction. When radiowaves are turned off the protons go back to pointing in the direction as before, and that movement produces some energy that is pivked up by detectors outside the brain (Gazzinga 93)
What method is used to study
the anatomical structure of the axon tracts that form the
brain’s white matt er
Diffusion tensor imaging (DTI)
What property of the diffusion of water in the brain does DTI expliot?
The fact that the diffusion in the brain is Anisotropic (restricted, by the axons), rather than isotropic, as in the rest of the body. So the water moves along the axons.
Which graph is used to visualise the date from a single-cell recording?
A raster-plot (Gazzinga 96).
Why is it more reliable to use MEG to localize the source of a signal, than it is with EEG?
Because magnetic fields don’t get distorted on their way through the brain, skull and scalp. ((Gazzinga 102)
What are the two drawbacks of MEG?
1) Can only detect current flow parralel to the scull-surface, 2) you have to keep out all other magnetic fields, to catch the small magnetic field from the brain. This requires that the SQUIDS are encased in large, liquid-helium-containing cylinders that
kee p them cold
What method is similar to EEG, except the electrodes are placed directly on the brain?
Electrocortogram (ECoG). (Gazzinga 102)
What does MEG measure?
ERF (event related fields) (Gazzinga 103)
Hvilken pensumtekst roser
Alan Gevins i 1997
How do Alan Gevins (1997) think that we can overcome the technical problem with EEG, that is doens offer high spatial resolution?
1) by recording EEGs from more electrodes,
2) by registering EEG data with anatomical information from each subject’s
MRI
3) by correcting the distortion caused by volume conduction of EEG signals through the skull and scalp, 4) by computing hypotheses about the sources of signals recorded at the scalp
What does PET ang fMRI measure rather than direct neural activity?
They measure metabolic activity (correlted with neural activity)
How are the results in a PET-scan reported
As changes in regional cerebral blood flow rCBF
What does PET measure?
Increases in blood flow
What method measures increases in blood flow?
PET. Positron emission topography.
How does PET measure changes in blood flow?
By injecting a radioactive substance into the blood. This substance decays, by sending positrons from the isotops. When these positrons hit an electron, they meka gamma-waves that can be easured.
What substanca does fMRI measure the magnetic properties of?
deoxyhemoglobin. Because it is paramagnetic, as opposed to hemoglobin. By measuring the ratio between deoxyhemoglobin and hemoglobin, you can see where there is activity. The more hemoglobin compared to deoxyhemoglobin, the more activity.
What are the benefits of fMRI over PET?
it is cheaper and easier to maintain and does not use any radioactive tracers (it measures megnetism from the blood). The individual can thus be tested several times. Plus better spatial resolution.
