NZ-421

Question 1

Consider the configuration where an excitatory neuron of interest is receiving input from a
nearby excitatory and inhibitory neuron. Which technique can you use to directly measure the
membrane potential?

Answer 1

single and multi-unit recordings*

Question 2

Vad betyder T1 recovery?

Answer 2

T1 Recovery refers to the process in MRI where the longitudinal magnetization (along the magnetic field axis) recovers after being disturbed by a radiofrequency pulse. This recovery happens as protons realign with the external magnetic field. T1 relaxation time is the time it takes for the magnetization to recover about 63% of its equilibrium value, and it varies for different tissues, making it useful in distinguishing them.

Question 3

Vad betyder T2 decay?

Answer 3

T2 Decay refers to the process where the transverse magnetization (perpendicular to the magnetic field) decreases after the same pulse. This decay occurs due to dephasing of proton spins, which lose coherence over time. T2 decay is faster than T1 recovery, and T2 relaxation time is the time it takes for the transverse magnetization to fall to 37% of its initial value. It’s also used to differentiate between tissue types.

Question 4

Diffusion weighted imaging measures the diffusion properties of water molecule, and could be used to model the tissue microstructure

True or False?

Answer 4

True

Question 5

What is the main diffusion directorion for DTI?

Answer 5

The main diffusion direction is along the eigen-vector corresponding to the maximum eigen-vector of the measured diffusion tensor,

Question 6

What is Tractography

Answer 6

Tractography is a modelling technique to infer the presence of continuous axons that traverse multiple voxels.

Question 7

fMRI provides an absolute blood-oxygen-level-dependent signal

True or False

Answer 7

False