This is a critical comment that should be upvoted widely. The reason that this is such a difficult challenge is that the rate of adult hippocampal neurogenesis, even in rodents where everyone believes it happens, is on the order of between 1 neuron per minute and 1 neuron per hour. In a brain of 100 billion neurons, that's hard to detect.
The original SlateStarCodex post addresses this. He argues that a microscopic amount of neurogenesis that is too small to be responsible for the effects everyone cares about (depression, brain plasticity, etc.) should be rounded to zero.
It is entirely possible that the base-rate of neurogenesis in adult humans is very low, but in response to new stimuli (a new exercise regimen, for example) responds by generating neurons..Perhaps I am missing the information in one of the supplemental pages, but I do not see info on history of exercise or anti-depressant use in the Nature paper.
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This is a critical comment that should be upvoted widely. The reason that this is such a difficult challenge is that the rate of adult hippocampal neurogenesis, even in rodents where everyone believes it happens, is on the order of between 1 neuron per minute and 1 neuron per hour. In a brain of 100 billion neurons, that's hard to detect.
The original SlateStarCodex post addresses this. He argues that a microscopic amount of neurogenesis that is too small to be responsible for the effects everyone cares about (depression, brain plasticity, etc.) should be rounded to zero.
It is entirely possible that the base-rate of neurogenesis in adult humans is very low, but in response to new stimuli (a new exercise regimen, for example) responds by generating neurons..Perhaps I am missing the information in one of the supplemental pages, but I do not see info on history of exercise or anti-depressant use in the Nature paper.