In vivo imaging Notes

MRI - magnetic resonance imaging

SPECT - single photon emission tomography

PET - positron emission tomography

X ray

CT - computerised tomography

PET can be used to answer the question: does the drug reach brain tissue?

- drug pharmacokinetics and BBB penetration determined

MRI:

Signals are generated by nuclei with a positive charge

most commonly uses the signal from hydrogen atoms

single proton that possesses spin, rotates around its axis like a spinning top

this spin generates a tiny magnetic charge

Apply a radiofrequency (RF) pulse

this causes the magnetisation of the protons to change direction

As the RF pulse is switched off the spins relax back to their natural alignment

As the protons relax they induce a voltage - which can be recorded by a receiver coil

*mutation in the Plp1 gene (which is expressed in oligodendrocytes) - fail to synthesise normal CNS myelin - shaking pups

Transgene = any gene expressed in an animal that does not normally carry this gene

In vivo imaging