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Front. Endocrinol. | doi: 10.3389/fendo.2019.00654

Alteration of testosterone levels changes brain wave activity patterns and induces aggressive behavior in rats

Daniel P. Estumano1,  Luan O. Ferreira2, Paulo Augusto L. Bezerra1,  Maria Clara P. da Silva1, Giovanna C. Jardim1,  George Francisco S. Santos1, Kayo S. Gustavo2,  Bruna G. Matos2, Jorge Amando B. Ramos3, Vanessa J. de Mello1, Edmar T. da Costa2,  Dielly Catrina F. Lopes2* and Moisés Hamoy1*
  • 1Laboratory of Pharmacology and Toxicology of Natural Products, Institute Biological Science, Federal University of Pará, Brazil
  • 2Hospital Universitário João de Barros Barreto (HUJBB), Brazil
  • 3Institute of Biological Sciences, Federal University of Pará, Brazil

Testosterone is responsible for several changes in the brain, including behavioral and emotional responses, memory and cognition. Given this, we investigated changes in the brain wave profile caused by supplementation with exogenous testosterone in both castrated and non-castrated rats. We also investigated the serum testosterone levels, renal and hepatic function, and the lipid and behavioral profiles. We found changes in the spectral wave power in both groups (castrated and non-castrated animals) supplemented with exogenous testosterone, consistent with an aggressive/hostile profile. These changes were observed in the electrocorticographic evaluation associated with increased power in low-frequency (delta and theta) and high-frequency (beta and gamma) activity in the supplemented animals. The castrated animals presented a significant decrease of wave power in the alpha frequency. This correlated with a decrease of the performance of the animals in the elevated plus-maze evaluation, given that the alpha wave is linked to the execution and visualization of motor processes. In the behavioral evaluation, the castrated animals presented a reduced permanence time in the elevated-plus maze, although this was prevented by the supplementation of testosterone. Testosterone supplementation induced aggressive behavior in non-castrated animals, but not in castrated ones. Supplemented animals had significantly elevated serum testosterone levels, while their urea levels were significantly lower, but without clinical significance. Our data indicate that testosterone supplementation in non-castrated rats, but not in castrated ones, causes electrocorticographic changes that could be associated with more aggressive and hostile behavior, in addition to indicating a potential for personality disorder. However, further studies are required to elucidate the cellular and molecular changes caused by acute testosterone supplementation.

Keywords: Testosterone, brain wave, Behavior, anabolic, supplementation, Electrocorticographic

Received: 23 May 2019; Accepted: 09 Sep 2019.

Copyright: © 2019 Estumano, Ferreira, Bezerra, da Silva, Jardim, Santos, Gustavo, Matos, Ramos, de Mello, da Costa, Lopes and Hamoy. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence:
PhD. Dielly Catrina F. Lopes, Hospital Universitário João de Barros Barreto (HUJBB), Belém, 66073-000, Pará, Brazil,
PhD. Moisés Hamoy, Laboratory of Pharmacology and Toxicology of Natural Products, Institute Biological Science, Federal University of Pará, Belém, Pará, Brazil,