Exposure to pheromones increases plasma corticosterone concentrations in a terrestrial salamander

Ready for a fight? The physiological effects of detecting an opponent's pheromone cues prior to a contest

“…crayfish, Orconectes rusticus; [2][3]), amphibians (e.g. red-legged salamander, Plethodon shermani; [4]), fish (e.g. Mozambique tilapia, Oreochromis mossambicus; [5]), and small and large mammals (e.g.…”

“…Male crayfish produce pheromones during agonistic interactions; pheromone production increases as contest intensity increases, and eventual winners often produce higher quantities of pheromones during agonistic interactions compared to eventual losers [2][3]. At the conclusion of agonistic interactions, dominant male crayfish continue to produce pheromones and claim upstream territories while subordinate males cease pheromone production and are Physiology & Behavior 149 (2015) [1][2][3][4][5][6][7] relegated to downstream territories [3]. By doing so, subordinate individuals are constantly exposed to pheromones produced by dominant individuals, which potentially reinforces subordinate status.…”

“…Pheromones also can elicit significant physiological responses [4,7,13], which may mediate adaptive behavioral changes [14][15][16][17][18]. Pheromone-induced neuroendocrine changes have been well documented in mice and principally for male-female interactions [7].…”

“…Female mice exposed to the pheromones of dominant males rapidly enter into and synchronize their estrous cycles (Whitten effect) but exposure to an unfamiliar male's pheromone signature can interrupt this cycle and cause females to abort their current pregnancy (Bruce effect; reviewed in [1,7]). Exposure to female pheromones elicits significant increases in male androgens (testosterone) and luteinizing hormone, a peptide hormone that regulates spermatogenesis, in male Syrian hamsters [6] and glucocorticoid levels (corticosterone -a stress-related steroid hormone) in male red-legged salamanders [4]. Furthermore, exposure to androstanedione, an androgen and a component of male sweat, elicited a significant elevation in stress hormone (cortisol) levels in human females [13].…”

“…testosterone and cortisol) can change in response to pheromone cues (e.g. [4,6]). We predicted that pairs of rivulus that are visually, but not chemically, isolated from one another would exhibit significant increases in hormone levels compared to individuals that receive no chemical cues from a potential adversary.…”