The First Mating Experience Induces New Neurons in the Olfactory Bulb in Male Mice

• Published in: Neuroscience Vol. 396; pp. 166 - 174
• Main Authors: Velazco-Mendoza, M., Camacho, F.J., Paredes, R.G., Portillo, W.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.01.2019
• Subjects: glomerular cell layer; neurogenesis; olfactory bulb; sexual behavior; MOB; OBs; olfactory bulb; glomerular cell layer; BDNF; GL; GR; Ara-C; AOB; NeuN; sexual behavior; SVZ; neurogenesis; CNGA2; RMS; MI; BrdU
• ISSN: 0306-4522; 1873-7544
• DOI: 10.1016/j.neuroscience.2018.11.019

•In male mice the first sexual experience did not increase the number of new cells in the OB.•In male mice sexual experience increases the percentage of new glomerular neurons in the MOB.•Exposure to a receptive female did not increase the arrival of new cells to the OB. In rodents, neurogenesis in the olfactory bulbs (OBs) is enhanced by exposure to olfactory enriched environments including sexually relevant odors. In the present study we evaluated whether sexual stimulation in male mice increases the number of newly generated cells that reach the OB and whether these cells differentiate into neurons. To this end, we used sexually naive male C57BL mice randomly assigned to one of three groups: (1) control, in which animals were left alone in their home cages; (2) exposure, in which animals were exposed to a receptive female precluding any physical contact; and (3) mating, in which males copulated with females. Males were given three injections of the DNA synthesis marker 5-bromo-2′-deoxyuridine (BrdU) 2 h before, at the end and 2 h after the test. Fifteen days after BrdU administration, brains were removed and processed to identify new cells and evaluate if they had differentiated into neurons in the granular (GR), mitral (MI) and glomerular (GL) cell layers of the main and accessory OB (MOB and AOB, respectively). We found an increase in the percentage of new cells that differentiate into neurons in the GL cell layer of the MOB of males from the mating group compared with those from the exposure and control groups. No differences were found in the number of new cells or percentage of new neurons in the rest of the analyzed regions. In male mice, the first sexual experience increases the percentage of new cells that differentiate into neurons in the GL cell layer of the MOB.