Alarm pheromone induces immediate-early gene expression and slow behavioral response in honey bees

Primer and releaser pheromones are molecules used for communication that induce species-specific responses. In contrast to primer pheromones, it is not known whether the quicker-acting releaser pheromones can affect brain gene expression. We show here that isopentyl acetate (IPA), a releaser pheromone that communicates alarm in honey bees, not only provokes a quick defensive response but also influences behavior for a longer period of time and affects brain gene expression. Exposure to IPA affected behavioral responsiveness to subsequent exposures to IPA and induced the expression of the immediate early gene and transcription factor c-Jun in the antennal lobes. Our findings blur the long-standing distinction between primer and releaser pheromone and highlight the pervasiveness of environmental regulation of brain gene expression.