Research Highlight

The sweet smell of adult neurogenesis

05/02/19

A new paper from a collaboration of researchers in Germany with Benedikt Berninger and Nicolas Marichal has demonstrated the utility of adult neurogenesis for complex tasks in a pioneering study.

Adult neurogenesis is known to be involved in cognitive performance and it is a source of frustration that we generally just don’t, and can’t, grow new neurons in the brain. There are, however, a couple of regions of the brain in most mammals that continually generate new neurons throughout adulthood: the subgranular zone and the subventricular zone (SVZ). In the SVZ, neural stems cells (NSCs) migrate to the olfactory bulbs where they differentiate into interneurons and contribute to a sense of smell. This rich neurogenic niche holds exciting potential for novel, transformative therapies and great efforts are being made to understand the mechanisms and effects of this phenomenon.

In this exciting new paper, published in The EMBO Journal, Bragado Alonso et al. examined a mouse model with increased neurogenesis in the SVZ through conditional expression of cell cycle regulators. They found that supernumerary neurons matured in the same manner as those naturally generated and were integrated into the olfactory bulb similarly. They tested these mice on olfactory distinction tasks ranging in difficulty from easy to complex and found that the increased neurogenesis in the mutant mice made no difference to performance in the easy odour distinction tasks but was a significant advantage to the mutants when the task was more challenging – the mutant mice performed better.

The findings in this paper have not only highlighted the utility of adult neurogenesis in SVZ for olfaction distinction but provide an appealing proof of concept model. In principle, the controlled multiplication of somatic stem cells can be applied to other tissues for further research and the development of therapies.