Background and objectives: During the last years the effects of pulsative electromagnetic fields have been studied in the human and animals nervous system. The using of these fields in today living has caused worriment in safety of human. Stress causes very problems in behavior and function of biological systems. In this survey the effects of electromagnetic fields on stress behaviors of rats have been studied.

 Methods: In this study we aimed to investigate the effects of electromagnetic fields with 700 milli Gauss currency produced by triangle electrical currents with low (10 Hz) and high (110 kHz) frequencies on stress behaviors in 60 adult, male Wistar rats. The rats were divided to two groups of control and test. The animals were exposed to the field for 80 minutes and in order to evaluate the possible effect of electromagnetic fields the Tail pinch (T.P.) test was conducted. The results were analyzed using statistical tests.

  Results: Analyzing of the results of response time and stress behavior by T-test. In the group exposed electromagnetic fields of triangular low waves (10 Hz) for 80 min the results were meaningful (p < 0.05). The response and stressed behavior with this field is decreased very much. The results of two groups after 80 min under this field that have a difference in frequency showed that effects of frequency in behavior was meaningless.

  Conclusion: The results of this study showed that electromagnetic fields produce anti-stress effect in rats. The radio waves (A.W) have higher effects.

  Background & Objectives: The development of technology has naturally given rise to an increase in environmental low-frequency electromagnetic fields and consequently has attracted scholars' attention. Most of the studies have focused on transmission lines and power system distribution with 50 Hz. This research is an attempt to show the effect of 50 Hz magnetic fields on bioelectric parameters and indicates the possible influence of this change in F1 cells of Helix aspersa .

  Methods: The present research used Helix aspersa neuron F1 to identify the location of magnetic fields as well as the rate of effects of environmental magnetic fields on nervous system. Control group was used to study the effect of elapsed time, electrode entering and the cell membrane rupture. Intuition group and environmental group were considered in order to study the potential impact of interfering environmental factors and identify the effectiveness rate of magnetic fields, respectively. For the purpose of producing uniform magnetic field Helmholtz coil was used. Electrophysiological recording was realized under the requirements of current clamp. And, in order to show the impacts from magnetic fields on ion channels Hodgkin-Huxley cell model was applied. All data were analyzed taking the advantage of SPSS 16 software and two-way ANOVA statistical test. P < 0.05 was considered as significance level. And MATLAB software environment and PSO were used in order for applying the algorithm and estimating the parameters.

  Result: No statistically significant difference was found between control and sham groups in different time intervals. Once the 45.87 microtesla was applied significant differences were observed 12 minutes after the application. The highest amount of change happened 14 minutes after the application of more fields. With the application of the field, the amplitude of the sodium action potential shows decreasing trend . No significant changes were observed in different time intervals, whereas significant differences were seen in frequency of action potential during different time intervals. The amplitude of AHP shows no significant changes .

  Conclusion: The results indicated that low-frequency magnetic fields with 50 Hz frequency will directly lead to change in bioelectric activities of neurons through a change in amount and rate of opening and closing of ionic channels and the conductivity of sodium and potassium channels reduces together with increase in conductance of potassium dependent calcium channel (AHP).