October 2013 - Lichtenberg professor Marc Spehr publishes important study in Nature magazine
Tears don’t lie – how pheromones of prepubescent mice influence social behavior
Lichtenberg professor Marc Spehr, head of the chemosensory communication laboratory at RWTH Aachen University, has published an important study in Nature magazine. In cooperation with colleagues at Harvard and Tokyo University, the authors investigated the function of pheromones released by prepubescent mice and their relevance for social behavior of these animals.
Pheromones signal information about gender, reproductive state as well as social and sexual state to other individuals of a group. In the present study, the authors could demonstrate that a novel pheromone called ESP22 can signal information about the age of mice. This pheromone is released into tear fluid within the lacrimal glands of prepubescent mice. Reaching puberty, ESP22 production stops. Besides this age-dependent production, the authors of the study also report on the neural detection of ESP22 in the vomeronasal system as well as the major influence of this pheromone on mating behavior in mice.
Spehr and his team members revealed that a small number of neurons (1-2%) in the vomeronasal organ (VNO) detect ESP22 and propagate this neuronal signal to the medial amygdala in the brain. Although only a fraction of VNO neurons respond to ESP22, pheromone detection triggers massive changes in social behavior. Experiments showed that male individuals lacking a functional VNO displayed increased mating behavior towards prepubescent mice. On the other hand, juvenile mice with disrupted ESP22 production were exposed to more frequent mating attempts of adult mice than compared to juveniles with intact lacrimal glands. Moreover, artificial ESP22 painting of adult female mice resulted in a dramatic reduction of male mating behavior, demonstrating the powerful social effect of the pheromone. Interestingly, only mating behavior is affected by ESP22 whereas other social behaviors remain unaffected.
These results elegantly demonstrate the impact of a sensory organ optimized for the detection of pheromones and the direct effect on complex social behavior. In cooperation with their colleagues at Harvard and Tokyo University, Marc Spehr’s group is currently working on decoding those neural circuits in the brain that mediate ESP22-dependent reactions. Therefore, we can expect more fascinating details of this striking chemosignaling mechanism to be unraveled in the future.
The article can be found using this link: http://dx.doi.org/10.1038/nature12579
For more information please contact Professor Marc Spehr:
Prof. Dr. Marc Spehr
Worringer Weg 3
Phone: 0049 –(0)241-8020802
Authors: Dr. Martin Singheiser, Prof. Dr. Marc Spehr