Biradical spin labeling for nerve membranes

We have explored the behavior of pair interaction in a suitable biradical when it is bound by van der Waals' forces in a nerve membrane. We have concomitantly examined a set of model solvents to represent this situation. It appears that the biradical suffers a restriction of internal motion with a minimal restraint on its external motion in the nerve medium. The biradical is so situated as not to respond to the passage of the action potential.

Periventricular cerebral impedance after intraventricular injection of calcium

Injection of small volumes of calcium solution into the lateral ventricle of the cat wa followed by large electrical-impedance changes in gray matter bounding the ventricle, including the caudate nucleus and hippocampus. These changes lasted more than 24 hours and were accompanied by epileptiform electroencephalographic activity. Biweekly injections led to status epilepticus. Injections of similar amounts of magnesium ions were without comparable effects. Possible interactions between calcium ions and intercellular macromolecular material are discussed as a basis for certain impedance shifts in cerebral tissue.