STH MULTIDISCIPLINARY INTERNATIONAL

Conference of Biological Psychiatry

«Stress and Behavior»

Proceedings of the 9th International Multidisciplinary Conference «Stress and behavior» Saint-Petersburg, Russia, 16-19 May 2005 Editor: Allan V. Kalueff, PhD

CONFERENCE ABSTRACTS

4. EXPERIMENTAL MODELS:

M.A. DERYAGINA MEMORIAL SYMPOSIUM

THE INFLUENCE OF ELECTROSTATIC FIELD (ESF)

ON THE BIOCHEMISTRY AND BEHAVIOR OF ORGANISM

J. Porozovs, N. Tolmacha, J. Vandans

Postgraduate Medicine Education Institute of Latvian University, Riga, Latvia

The electrostatic field (ESF) is the most widespread class of stationary physical fields in electrotechnical industry. In chemical industry, textile and some other branches of industry, near electrical equipment and high voltage leads people have to meet the greatest quantities of ESF. The influence of electrostatic field on organism has been shown in experimental research, as well as hygienic observations. Nevertheless there is a little information about that, how and with what mechanisms ESF effects the central nervous system (CNS). The influence of ESF on organism in vivo is thought to begin from skin receptors and then through the humoral and the nervous system is transmitted to inner organs. It is ascertained that people who work for a long time under ESF has an increased sickness rate.

Methods. Male Wistar rats (180—250 g) were used in experiments. The animals were exposure to ESF for 2 or 4 hours daily over a period of one, three, fourteen or thirty days. The used ESF had an intensity 30—200 kV/m. Exposure to ESF was practised in a condensing chamber. The determination of the content of biogenic monoamines was performed according to the chromatographic method of Earley and Leonard. Another studies were dedicated to the investigation of the ESF influence on the activity of ATPases in brain mitochondria according to the method of Rathbun and Betlach. Rat’s behavior reactions were analysed after 30 days of ESF exposure (4 h daily) to animals. Rat’s food conditioned reflexes in the complex labyrinth and run away conditioned reflexes after pain stimuli were worked out.

Results and discussion. The results of investigation showed that 30 days (4 h daily) exposure to ESF of 30—60 kV/m intensity facilitates elaboration of simple and complex conditioned reflexes but slows down extinction of already elaborated conditioned reflexes. ESF of 90 kV/m intensity leads to the specific effects of rat’s behavior. ESF of 150—200 kV/m intensity leads to the diminish of capability to work out rat’s food and run away conditioned reflexes as well as change for the worse rat’s behavior in the maze. Exposure to ESF of 200 kV/m leads to the stereotypical behavior of rats and their rigidity. The experiments showed that 4 hours exposure to ESF of 150 kV/m intensity leads to the considerable decline of noradrenaline (NA) in the brain stem and especially in diencephalon (by 29%). The content of other biogenic monoamines remained unaltered. Similar kind alternations induced 2 hours exposure to ESF of 200 kV/m and 3 days (4 hours daily) exposure to ESF of 60 kV/m intensity. 4 hours expose to ESF of 200 kV/m intensity leads to the significant increase of DA level in basal ganglia (by 41%). 3 days (4 hours daily) exposure to ESF of 90 kV/m intensity also leads to the increase of dopamine (DA) content in basal ganglia. Exposure of animals to ESF of 150 kV/m and 200 kV/m with longer exposure time (3, 14 or 30 days) alters brain serotonin (S) content. Thus, a 3-day exposure to ESF of 150 kV/m and 200 kV/m induces a drop of S in diencephalon and 14-day exposure to ESF of 200 kV/m decreases the content of S in diencephalon (by 30%). Functioning of neurotransmitters and ATPases are closely related. ATPases take part in

ISSN 1606-8181

the uptake and release of neurotransmitters. The obtained results show that ESF depending on its intensity causes a significant increase in the mitochondrial ATPases activity. Exposure of rats to ESF of 150 kv/m for 4 hours leads to the elevated HCO3-ATPase activity, while exposure of rats to ESF of 200 kv/m (4 hours) results in the significant increase in Mg2+; Ca2+ and HCO3-ATPases activity of rat’s brain stem and diencephalon.

Conclusion. Our experiments showed that the influence of ESF on the rat brain biogenic monoamines content depends on the intensity of ESF and exposure time. ESF causes stress like alterations in the organism. The most sensitive to this factor is brain noradrenergic system. Increased intensities of ESF cause to react dopaminergic system, but longer exposure — serotoninergic system. The ESF also causes a notable stress-like activation of ATPase activity in rat brain mitochondria indicating its strong disintegrating influence on cell membrane functioning. ESF causes alterations in animal behavior. Exposure to relatively low intensity ESF stimulates elaboration of conditioned reflexes, whereas high intensity ESF inhibits formation of conditioned reflexes and generally disintegrates animal’s behavior.

ISSN 1606-8181