Measurement of Imposed Voltage Gradient Adequate to Modulate Neuronal Firing

Abstract

results when the protein intake is 24 per cent is any higher than the level of calcium which gives the best results when the protein intake is 14 per cent. The present studies seem to indicate that the most beneficial level of calcium intake when the protein intake is liberal lies in the range of 0.4-0.6 per cent, or two to three times the level of minimal adequacy. In earlier studies,8 where calcium alone was added to Diet A, the level of optimum intake appeared to be at least three, and perhaps as much as four, times the level of minimal adequacy. Finally, it would seem justifiable to conclude that a diet liberal both in calcium and in protein is clearly superior to a diet liberal only in protein. * This work has been aided by grants to Columbia University, at first from the John and Mary Markle Foundation, more recently from the Nutrition Foundation, Inc., the Williams-Waterman Fund in the Research Corporation, and Swift and Company. t Deceased October 7, 1955. ' A comparison will soon be published of the life-histories of such late-generation Diet A animals with those of their ancestors whose families had been on the diet only about half as many generations and with those of their early forebears whose families had only recently been transferred to the diet.

Transcranial Stimulation over Frontopolar Cortex Elucidates the Choice Attributes and Neural Mechanisms Used to Resolve Exploration–Exploitation Trade-Offs

“…Our findings identify a locus of transcranial stimulation that may be used to help steer decision making in cases of pathologies involving deficits in task switching or stereotyped behavior (Ehring and Watkins, 2008;Stuss, 2011;Kleinman et al, 2013). The rFPC is thought to be embedded within a larger neural network regulating the exploration-exploitation tradeoff (Boorman et al, 2011) and is most likely not the only site where transcranial stimulation can have such effects.…”

Transcranial direct current stimulation (tDCS) in a realistic head model

“…Even at the level of individual neurons and microcircuits, the effects of tDCS have been unclear. Animal studies (Purpura and McMurtry, 1965;Terzuolo and Bullock, 1956) have suggested that the current densities created during tDCS are below the threshold necessary to trigger individual pyramidal cells, suggesting that tDCS exerts its effects by more subtle influences on large numbers of interneurons. Furthermore, temporal and largerscale neural network effects are undoubtedly important in the in vivo situation, but involve complexities and unknowns that are outside the scope of this modeling effort.…”

Modulation kortikaler Erregbarkeit beim Menschen durch transkranielle Gleichstromstimulation

“…Zerebrale Stimulation mit schwachem Gleichstrom wurde tierexperimentell besonders in den 60er-Jahren untersucht [3,5,21,29]. Als grundlegender Wirkungsmechanismus wird eine Verschiebung des neuronalen Ruhemembranpotenzials angenommen, belegt mittels epiduraler oder intrazerebraler Reizelektroden [5,21]: So wurde mit Summenpotenzialableitungen an der Katze unterschwellig depolarisierende Auswirkungen anodaler Polarisierung an den Somata von Pyramidenbahnneuronen und an nicht pyramidalen kortikalen Neuronen nachgewiesen, wogegen kathodale Polarisierung zu einer Hyperpolarisierung dieser Neurone führte.…”

“…Wie aufgrund der Membranphysiologie zu erwarten, kommt es auf der Grundlage dieser Potenzialverschiebungen zu vermehrten spontanen neuronalen Entladungen bei anodaler und verminderten Entladungen bei kathodaler Polarisierung sowie analogen Verände-rungen der Amplituden evozierter Potenziale [3,5,29] …”