Impact of forest fire smoke on the state of the central nervous system of rats

Introduction. The adverse negative effect of forest fire smoke on human health represents a unique interdisciplinary challenge to the scientific community. The influence of forest fire smoke on locomotor activity, cognitive indices, and brain bioelectrical activity parameters in exposed rats is presented.

Materials and methods. Experimental studies were carried out on outbred white male rats. The animals of the experimental group were exposed to smoke inhalation forest fire for one day. Immediately after the end of the exposure, the animals were examined, including testing in an open field and Morris water maze, as well as an electroencephalographic examination.

Results. At twenty-four-hour exposure to wildfire smoke in the model, conditions showed increasing motor and research activity of male rats against the backdrop of growing anxiety. Disorders of indicators of spatial memory and navigation learning were not revealed. On the encephalogram of the exposed animals, in comparison with the control group, the δ-rhythm range predominated, more pronounced in the leads of the right hemisphere. A decrease in the power spectrum and the average amplitude β1-rhythm, as well as a tendency to decrease the average amplitude of θ-rhythm, were revealed. The indices of the primary EEG rhythms did not have statistically significant differences when compared with the control group.

Conclusion. The results showed that forest fire smoke leads to changes in the bioelectric activity of brain structures and dysregulation of individual behaviour in animals, all of which may indicate the formation of increased levels of stressing beyond physiological adaptation.

Contribution:
Sosedova L.M. — concept, literature search, writing, design of the article;
Vokina V.A. — concept, literature search, conducting an experiment, writing, designing an article;
Novikov M.A. — search and translation of literary sources, conducting an experiment, writing a text;
Andreeva E.S. — conducting an experiment, processing the results;
Rukavishnikov V.S. — leadership, analytical work, discussion of relevance and results.

Conflict of interest. The authors declare no conflict of interest.

Acknowledgment. Financing was carried out at the expense of funds allocated for the implementation of the state task. 

The conclusion of the Local Ethical Committee  (LEC) of the East-Siberian Institute of Medical and Ecological Research: the work was carried out in compliance with the rules of humane treatment of animals following the requirements of the International Recommendations for Biomedical Research Using Animals (WHO, Geneva, 1985) and the Rules of Laboratory Practice (Order of the Ministry of Health and Social Development of Russia dated August 23, 2010, No. 708n). Local Ethics Committee (Protocol of the LEC of the East-Siberian Institute of Medical and Ecological Research No. Е32 / 19 dated 09/10/2019) permitted to conduct experiments.

Received: May 12, 2021 / Accepted: September 28, 2021 / Published: November 30, 2021