[Changes in response of neurons in visual area of cerebral cortex of rabbits to flashes of light under the influence of low-intensity physical factors of non-ionizing nature].

The effect of various physical factors (SM F: 460 O; microwave EMF: 6 GHz, continuous mode, 200 microW/sm2; sound: clicks of 50 Hz, 6 db above a threshold of EEG response) on responses of neurons in visual area of cerebral cortex of rabbits to light flashes (1 Hz, 1 ms, 0.62 J) has been studied in experiments on 27 rabbits. The character of changes depended on the indicators for a background and for the response to the isolated action of light. Inhibition, rather than activation, was observed at a significantly higher initial frequency. Effect of the factors of magnetic nature was similar to the action of sound (inadequate irritant for the visual area). Inhibitory reactions were observed more frequently (significant result for the group of neurons), with their amplification at a combined action of irritants (SMF and microwave EMF; SMF and sound). The basic character of changes was limited to the drop in the pulsation frequency at the first phase of activation and to the increase in the latent periods of the first and second active phases. Other indicators for reaction to light flashes actually didn't change.

[Effect of plasma membrane ion permeability modulators on respiration and heat output of wheat roots].

A study was made of changes in the rates of respiration, heat production, and membrane characteristics in cells of excised roots of wheat seedlings under the modulation of plasma membrane ion permeability by two membrane active compounds: valinomycin (20 microM (V50)) and chlorpromazine (50 microM (CP50) and 100 microM (CP100)). Both compounds increased the loss of potassium ions, which correlated with the lowering of membrane potential, rate of respiration, and heat production after a 2 h exposure. The differences in alteration of these parameters were due to specific action of either compound on the membrane and to the extent of ion homeostasis disturbance. V20 had a weak effect on the studied parameters. V50 caused an increase of the rate of respiration and heat production, which enhanced following a prolonged action (5 h) and were associated with ion homeostatis restoration. The extent of alteration of membrane characteristics (an increase of potassium loss by roots, and lowering of cell membrane potential) as well as energy expense under the action of CP50 during the first period were more pronounced than in the presence of V50. During a prolonged action of CP50, the increase of respiration intensity and heat production correlated with partial recovery of ion homeostatis in cells. Essential lowering of membrane potential and substantial loss of potassium by cells, starting from the early stages of their response reaction, were followed by inhibition of respiration rate and heat production. Alterations of the structure and functional characteristics of excised root cells indicate the intensification of the membrane-tropic effect of a prolonged action of CP100, and the lack of cell energy resources.