Effect of olfactory stimulation on neurogenesis in the rostral migratory stream
The subventricular zone retains the capacity to generate new neurons from stem cells. The newly generated cells migrate along the rostral migratory stream (RMS) to the olfactory bulb (OB) where they differentiate into interneurons. The OB is the fi rst relay on the olfactory sensory pathway. We have previously shown that the number of proliferating cells in the RMS of young rats depends on their age. The aim of this study was to investigate if olfactory stimulation (OS) can infl uence the number of proliferating cells in the RMS of young rats. Since it is known that nitric oxide have antiproliferative action we have also studied occurrence of nitrergic NADPH-d positive cells in the vicinity of proliferating cells. We used 15 natural or synthetic odorants to stimulate olfaction. The rats were olfactory stimulated from the day of their birth (postnatal day 0 – P0) for 2 weeks (P14 group) or for 3 weeks (P21 and P28 groups). Control rats were alike divided into three groups according to the age. To label proliferating cells in the RMS, the rats were injected with proliferation marker – bromdeoxyuridine (BrdU). Brain sections were processed for BrdU immunohistochemistry and NADPH-d histochemistry. We found that OS signifi cantly increased the number of proliferating cells in the RMS of young rats and concurrently number of nitrergic cells decreased. These results indicate positive effect of OS on postnatal neurogenesis in the RMS. Support: VEGA grants 2/0147/09; 2/0058/08.