  Glycerol titration distinguished from free water the local hydration shell
involved in ATPase transition from active to inactive, with cooperativity for
water n=16. Rat brain cortex: NE-stimulated and its basal AC in the absence of
free Mg2+, allows a refractive state of AC with negative cooperativity for
MgATP and ATP4-. The erythrocyte-Hb system operates as a metabolic sensor to
match glucose availability with the release of Hb-carried, O2 and Mg2+ at CSF.
[Mg(H2O)6](H2O)122+ by chelating either a protein or ATP4- losses most of its
hydration shell. The ion pump ATPase by forming ADP3- releases an incompletely
hydrated Mg2+, which could capture H2O from either [Na.(H2O)6]+ or [K.(H2O)6]+.
Thus, sieve-sizing their hydration shells for fitting into Na+-pump channels.
An AC refractory period may participate in STM. Mg2+ with cooperativity n=3.7
activates NE-AC. CREB-generated receptors coupled by Mg2+ may modulate
hydration shells-dependent oscillations for retrieval of LTM
