PT - JOURNAL ARTICLE AU - He, Jie AU - Ma, Limei AU - Kim, Sangseong AU - Schwartz, Joel AU - Santilli, Michael AU - Wood, Christopher AU - Durnin, Michael H. AU - Yu, C. Ron TI - Distinct Signals Conveyed by Pheromone Concentrations to the Mouse Vomeronasal Organ AID - 10.1523/JNEUROSCI.0825-10.2010 DP - 2010 Jun 02 TA - The Journal of Neuroscience PG - 7473--7483 VI - 30 IP - 22 4099 - http://www.jneurosci.org/content/30/22/7473.short 4100 - http://www.jneurosci.org/content/30/22/7473.full SO - J. Neurosci.2010 Jun 02; 30 AB - In mammalian species, detection of pheromone cues by the vomeronasal organ (VNO) at different concentrations can elicit distinct behavioral responses and endocrine changes. It is not well understood how concentration-dependent activation of the VNO impacts innate behaviors. In this study, we find that, when mice investigate the urogenital areas of a conspecific animal, the urinary pheromones can reach the VNO at a concentration of ∼1% of that in urine. At this level, urinary pheromones elicit responses from a subset of cells that are tuned to sex-specific cues and provide unambiguous identification of the sex and strain of animals. In contrast, low concentrations of urine do not activate these cells. Strikingly, we find a population of neurons that is only activated by low concentrations of urine. The properties of these neurons are not found in neurons responding to putative single-compound pheromones. Additional analyses show that these neurons are masked by high-concentration pheromones. Thus, an antagonistic interaction in natural pheromones results in the activation of distinct populations of cells at different concentrations. The differential activation is likely to trigger different downstream circuitry and underlies the concentration-dependent pheromone perception.