Dynamics of Local Changes and Oscillations in Energy Metabolism in the Rabbit Cerebral Cortex during the Formation of a Conditioned Defensive Reflex

Brain energy metabolism associated with different functional states and different types of human and animal activity is accompanied by dynamic changes in the degree of linkage between glycolysis and oxidative phosphorylation in different cell compartments [20–23, 25]. These processes are reflected in the redox state of brain tissue [27] and can be recorded potentiometrically as changes in the redox state potential (E) of brain tissue [24]. Studies of E in the cortex of rabbits using implanted platinum electrodes showed that during the acquisition of a conditioned defensive reflex using a combination of a light and a mild electric shock to one of the rabbit's ears, cortical E showed oscillations with periods of several seconds after 5–15 combinations. This number of combinations started to be accompanied by generalized changes in E in the cortex, which, at 20–100 combinations, could be either an increase or a decrease in E. As the number of combinations increased, increases in E were gradually replaced by decreases. By 200–400 combinations, oscillations in E disappeared and the episodes of decreased E accompanying combinations acquired a stable local character. These results suggest that there is a change in the balance of the major sources of brain tissue energy supply during the formation and stabilization of a conditioned defensive reflex: at the initial stages of acquisition of the conditioned reflex a number of cortical points have an energy supply dominated by tissue respiration, while the main energy source for brain function during performance of the acquired conditioned defensive reflex is glycolysis.     

Water-Soluble Anionic C60-Fullerene Derivatives as Antidotes for HG(II) Ions in Tests on Escherichia Coli Cells

Pharmaceutical Chemistry Journal - Three water-soluble C60-fullerene derivatives functionalized by anionic adducts of various chemical compositions and structures were prepared in highly specific...     

Instrument for biomechanical studies of soft tissues

The instrument for study of mechanical properties of tissue, in particular for definition of strengthening and elastoplastic properties of stomach mucous, umbilical artery, skin cicatrix is offered. The instrument can find application for multi-purpose biomedical studies in morphology, surgery, etc.     

Effect of disulfiram on energy metabolism (redox potential shift) coupled to paradoxical sleep episodes in rat cerebral cortex

Disulfiram (DS) is widely used to treat patients with chronic alcoholism. DS treatment multiplies PS episodes. In this work, DS effect on the number of PS episodes and on the energy metabolism changes in the cerebral cortex (coupled to PS episodes) was investigated for the first time in rats. Polygraphic recording of the redox potential E (with platinum electrodes implanted in several cortical sites), electrocorticogram, neck electromyogram, and general motor activity were made in sleep-wake cycles. Rats received DS (100 mg/kg) with meals for two nights, after which the number of PS episodes increased almost twice during two subsequent sessions (prior to receiving DS). This was evidence of an increase in PS pressure coupled to a decrease of norepinephrine level in the brain. DS also evoked sharp decrease in the amount of the positive E shifts related to PS, which were replaced by the negative E shifts or by the two-phase E shifts (negative-positive waves). The absolute mean amplitude decreased both for the positive E shifts and the negative E shifts. These findings demonstrate prevailing glycolytic compartment as a source of fuel supporting PS and the inhibition in all brain energetic compartments. The data presented well agree with the conception that glycolysis becomes the main source for the brain activity under pathology conditions.