PHEROMONE-LIKE OLFACTORY CUES MODULATE MALE RODENT COURTSHIP AND AGGRESSION: A SYSTEMATIC REVIEW OF BEHAVIORAL AND NEUROENDOCRINE MECHANISMS

Abstract

Olfactory cues that resemble pheromones are important to male rodents in directing courtship and aggression, but the interplay among behavioral, neural, and hormonal processes remains incompletely understood. The systematic review had pooled 25 studies reporting on the effects of urinary, glandular, and synthetic pheromones on male social behavior published between 2000 and 2025. Exposure techniques included natural cues, diet chemicals, genetic manipulation, and behavioral measures, and results were mounting, including intromission, ultrasonic vocalizations, and resident-intruder aggression. The neural systems of the vomeronasal organ, medial amygdala, MPOA, and VMH were often involved, as well as the endocrine correlates (testosterone, corticosterone, and luteinizing hormone). The results were consistent and indicated that male courtship and aggression are dose and context-dependent and are regulated by pheromone type, social experience, and hormonal state. There were decreased pheromone-mediated behaviors under the environmental impact of high-dose chemicals (e.g., DEHP, phthalates), underscoring interactions between olfactory and endocrine regulation. This review provides an overall picture of how chemical signals regulate male reproductive and aggressive behaviors, which will guide future studies of neuroendocrine and behavioral plasticity.