For a long time, scientists have believed that rodents detect pheromones through their specialized structure known as the vomeronasal organ. Pheromones refer to chemicals the sexual and social behavior of rodents. The chemical composition of pheromones is only known in very few rodents such as a sex attractant found in hamster vaginal secretion, the ventral gland pheromone found in the male Mongolian gerbil, and the preputial gland found in a house mouse. Pheromones in rodents exist in two groups: (1) releasers or signal pheromones, which are substances responsible for triggering immediate behavioral responses, and (2) primers, which are substances responsible for producing effects that manifest only after passage of time as they work through some neuroendocrine pathway (Novotny, 2003). However, recent scientific evidence shows that the main olfactory system of rodents also plays a significant role in picking up the signals that influence mating and aggression.
According to experimental results on mice done by Nirao Shah and his colleagues at the University of California, San Francisco, male mice modified to lack a gene that detects odor showed no interest at all in female mice. In addition the mutants showed less aggression in the face of confrontation by other male mice. Earlier researches had established the key role of pheromones in rodents such as the tendency of house mice to feed on their own offspring if they lack the olfactory bulb. This implies that rodents are rendered unable to identify their own offspring if deprived of the olfactory clues (Novotny, 2003). Nonetheless, the study of pheromonal effects in rodents is hampered by the relatively more complex behavioral nature of rodents as compared to insects.
Reference:
Novotny, V.M. (2003). Pheromones, binding proteins and Receptor Responses in Rodents. Retrieved from: http://www.indiana.edu/~kettlab/A501/Novotny2003.pdf
