Modulation of red cell metabolism by states of decreased activation: comparison between states.

Marked decline of red cell metabolism has been described during the acute state of decreased activation associated with the stylized mental technique of transcendental meditation (TM) in long-term meditators (5-10 years regular elicitation, TM instructors). It is not known whether unstylized rest is accompanied by a similar effect and it is not known what effector(s) may contribute to red cell metabolic changes in these states. In the present study ordinary, unstylized rest was found to be accompanied by small increase of red cell glycolytic rate. Apparently, either repeated elicitation of TM behavior or some special feature of this practice become associated with new mechanisms of metabolic control than those previously in operation. Although the data of this study do not permit isolation of the precise psychological determinants of this effect, the range of possible physiological effectors can be delimited. Blood pH, PCO2, PO2, and phosphate can be eliminated as significant for red cell metabolic control during both TM and rest, and based upon related studies, several known hormones such as insulin, T3, T4, arginine vasopressin, oxytocin, prolactin and growth hormone can also be eliminated as responsible effector(s)

EEG delta, positron emission tomography, and memory deficit in Alzheimer's disease.

Quantitative scalp EEG from 32 channels and the cerebral glucose metabolic rate from the 32 underlying cortical positions as assessed by positron emission tomography (PET) with 18F-2-deoxyglucose (FDG) were obtained on 36 patients with mild to moderate senile dementia of the Alzheimer type and 17 age- and sex-matched normal control subjects. Subjects performed a verbal memory task during uptake of FDG. There were significant correlations between both delta amplitude and metabolic rate and memory performance during FDG uptake. Patients with Alzheimer's disease had significantly greater left temporal delta amplitude and lower glucose metabolic rates. Both EEG delta in microvolts and metabolic rate had similar diagnostic sensitivity, but PET had fewer false positives among normals. The left amygdala had the highest sensitivity and percent correct diagnosis of any brain area. Temporal lobe EEG delta activity showed higher correlations with hippocampal metabolic rate than metabolic rate directly under the electrode