The Interplay between Reproductive Social Stimuli and Adult Olfactory Bulb Neurogenesis

Figure 1

The mate pheromonal imprinting is a vomeronasal-dependent sex behavior. When a recently mated female is exposed to an unfamiliar male (brown mice) or unfamiliar male urine, a neuroendocrine reflex leads to pregnancy block and in turn triggers a return to estrus. This male chemosensory-induced block of pregnancy is known as the Bruce effect (see the text for details). The Bruce effect does not occur if the female is exposed to the mate’s chemosignals, since in this case a restricted pool of AOB granule interneurons (Gr) efficiently inhibits mitral cell signal transmission to the forebrain nuclei involved in estrus induction. Such kind of “protection” to the mate’s pheromones implies the formation of an olfactory recognition memory for the stud male chemosensory cues at the granule-to-mitral synaptic interface in the AOB (right). Gr: granule cells; M: mitral cells (figure modified from [16]).