Vol. 57, 2018 (update: 2018.07.02; 07.18) Effect of Group Density on the Physiology and Aggressive Behavior of Male Brandt's Voles (Lasiopodomys brandtii)Xin Dai, Ling-Yu Zhou, Jie-Xia Cao, Yan-Qi Zhang, Feng-Ping Yang, Ai-Qin Wang, Wan-Hong Wei, and Sheng-Mei Yang* doi:10.6620/ZS.2018.57-35
College of Bioscience and Biotechnology, Yangzhou University, 48 East Wenhui Road, Yangzhou 225009, P.R. China (Received 21 January 2018; Accepted 21 June
2018; Communicated by Jian-Nan Liu) Xin
Dai, Ling-Yu Zhou, Jie-Xia Cao, Yan-Qi Zhang, Feng-Ping Yang, Ai-Qin
Wang, Wan-Hong Wei, and Sheng-Mei Yang (2018) Population
density is well known to influence animal physiology and behavior. How
population density affects the aggressive behavior of the Brandt’s vole
(Lasiopodomys brandtii) is,
however, little known. The aim of this study was to investigate the
effect of group density on physiologic responses and aggressive
behavior of male Brandt’s voles and their potential underlying
neuro-mechanism. The results show that increasing group density led to
elevated serum corticosterone levels and increased spleen weight; it
also induced more male-male aggressive behavior. By contrast, it had a
negative effect on body growth and the weight of testis and epididymis.
Aging also increased male-male aggressive behavior. Higher density
reduced mRNA levels of tryptophan hydroxylase 2 (TPH2), 5-hydroxytryptamine receptor
1A (5HT1A), and
5-hydroxytryptamine receptor 1B (5HT1B)
in the amygdala and the dorsal raphe nucleus (DRN). Our results
demonstrate that higher population density can intensify stress
reactions and male-male aggressive behavior in Brandt’s voles at the
price of inhibiting body growth and reproduction. Serotonergic systems
in the amygdala and the DRN may take part in the control of aggressive
behavior among male voles. Our results provide novel insights into the
neuro-mechanism underlying the influence of population density on
aggressive behavior in Brandt’s vole, and imply that aggressive
behavior may play an important role in the population fluctuation of
the animal. Key words: Brandt’s vole, Group
density, Aggressive behavior, Physiological response,
5-hydroxytryptamine. *Correspondence: E-mail: smyang@yzu.edu.cn |