Factors of Solar Activity Enhance Locomotor and Exploratory Behavior in Rats

Resumo

According to the literature, solar activity affects the functioning of the human brain. However, its effect has not been studied on experimental animals. The purpose of this study was to investigate whether factors of solar activity influence the behavior of rats. From October 26 to December 24, 2011, the behavior of individual rats or small groups of them (N = 19) was recorded in an open field test and operant food-uptake behavior test. Parameters of solar activity were obtained from public databases on the Internet. Results of the correlation analysis have demonstrated that the number of sectors travelled by the rats in the open field test, number of holes they investigated, and number of food pellets they earned while learning a food-uptake task were positively associated with solar activity on the day of the study and in the days before and after that. Such associations were revealed for the number of sunspots, the intensity of solar radiation in the radio range, and number of solar flares in the X-ray and Hα ranges. Factor analysis made it possible to distinguish two factors positively associated with the behavior of rats. One of them closely correlated with the solar radio flux and can therefore be presumably attributed to its electromagnetic component. The other is closely related to the 3-h planetary index of oscillations of the Earth’s magnetic field K, and this indicates its corpuscular nature. These results correspond to the literature data on the association between the parameters of solar and geomagnetic activity and the characteristics of electrical activity of the brain of humans and animals. The behavior of rats is associated most closely with the number of sunspots on the day of the study, the parameter of which significantly correlates with both factors of solar activity. Therefore, this index can be used to consider the influence of solar activity on the behavior of rats in experimental practice.