Adult neurogenesis in human-being is a debated topic, and will probably take several years to get resolved.
I am under impression that it is relatively easier to settle the debate on non-human primates because there are fewer ethical barriers in conducting direct experiments on non-human subjects.
But, through my readings and interaction with people who know, it seems that the debate is far from being settled even in the case of non-human primates (am I correct?). The only consensus seems to be that neurogenesis happens in rodents.
My question is regarding adult neurogenesis in non-human primates only.
My Question has two levels. Pasko Rakic, who is one of the critics of adult neurogenesis, admits in the conclusion of this 2002 paper that adult neurogensis does exist in the dentate gyrus and olfactory bulb of primates, but he questions the existence of 'massive neuronal migratory stream' in the primate neocortex.
So, the argument against adult neuorgenesis in primates appears to be- 'It does not exist, and if it exists, it is not important.'
My question is- Is there still a convincing argument against the existence or biological importance of adult neurogenesis in non-human primates? What are these arguments that make us suspect the importance of neurogenesis in non-human primates? Why is the adult neurogenesis debate easier to settle on rodents than primates? Any explaination or reference to a source will be highly appreciated?