Evoked 23NA MR imaging of sodium currents in the brain

A system for measuring neuronal activity in a subject's brain, said system comprising:

• means for causing said subject's brain to produce neuronal activity;
• nuclear magnetic resonance imaging (MRI) means, for producing sodium magnetic resonance images, wherein said magnetic resonance images are primarily a measure of the momentary extracellular sodium concentration in said portion of the subject's brain;
• host computer for controlling said MRI means to generate a temporal sequence of said images;
• means for displaying said plurality of MRI images;
• and
• means for measuring neuronal activity from the location of changes in the sodium concentration between successive images which correlates with the location of neuronal activity produced by said means for said subject to produce neuronal activity.

A system for measuring neuronal activity in a subject's brain, said system comprising:

• means for stimulating said subject's brain to produce neuronal activity;
• nuclear magnetic resonance imaging (MRI) means for producing sodium magnetic resonance images, wherein said magnetic resonance images are primarily a measure of the momentary extracellular sodium concentration in said portion of the subject's brain;
• host computer means for controlling said MRI means to generate a plurality of said images, each of said images comprising the T2 echo from said sodium;
• means for displaying said plurality of MRI images;
• and
• means for measuring neuronal activity from the location of changes in the sodium concentration between successive images which correlates with the location of neuronal activity produced by said means for stimulating said subject to produce neuronal activity.