Origin, migration and fate of newly generated neurons in the adult rodent piriform cortex
- First Online:
- Cite this article as:
- Shapiro, L.A., Ng, K.L., Kinyamu, R. et al. Brain Struct Funct (2007) 212: 133. doi:10.1007/s00429-007-0151-3
- 301 Downloads
Newly generated neurons are continuously added to the olfactory epithelium and olfactory bulbs of adult mammals. Studies also report newly generated neurons in the piriform cortex, the primary cortical projection site of the olfactory bulbs. The current study used BrdU-injection paradigms, and in vivo and in vitro DiI tracing methods to address three fundamental issues of these cells: their origin, migratory route and fate. The results show that 1 day after a BrdU-injection, BrdU/DCX double-labeled cells appear deep to the ventricular subependyma, within the white matter. Such cells appear further ventral and caudal in the ensuing days, first appearing in the rostral piriform cortex of mice at 2 days after the BrdU-injection, and at 4 days in the rat. In the caudal piriform cortex, BrdU/DCX labeled cells first appear at 4 days after the injection in mice and 7 days in rats. The time it takes for these cells to appear in the piriform cortex and the temporal distribution pattern suggest that they migrate from outside this region. DiI tracing methods confirmed a migratory route to the piriform cortex from the ventricular subependyma. The presence of BrdU/NeuN labeled cells as early as 7 days after a BrdU injection in mice and 10 days in the rat and lasting as long as 41 days indicates that some of these cells have extended survival durations in the adult piriform cortex.
KeywordsNeurogenesis Olfactory system Doublecortin Bromodeoxyuridine DiI tracing
Time-lapse confocal microscopy of the piriform cortex 7 days after DiI-implantation. The video encompasses a 14 hour time period. Note that several DiI-labeled cells can be seen to come in and out of the plane of focus of the microscope and DiI-labeled cells can be seen to move ventrally into the piriform cortex. (AVI 63012 kb)