Functional Neurogenesis

I was recently reading a number of old papers on memory and synaptic tagging and found myself wondering whether they were bloggable. My instincts said yes but the more I thought about it the more I realized they’re several years old and that is ancient by the standards of Twitter and the blogosphere*. I enjoyed reading them but would my readers enjoy them? Is it useful to report on “old” science? If it is then why is it so rare? Read the rest of this entry »

Two recent papers have attracted a lot of media attention because they draw direct links between adult neurogenesis and behavioral disorders: Noonan et al. showed that rats lacking adult neurogenesis (stopped with irradiation) are more susceptible to cocaine addiction. Jin et al. showed that mice lacking adult neurogenesis (using a transgenic model) suffer greater infarct size and have more severe motor deficits after stroke.

While the papers themselves have important implications, what caught my attention was the angle taken by press releases: both articles studied the effects of reducing neurogenesis but the media focused on potential benefits of increasing neurogenesis. See speculation that antidepressants, by increasing neurogenesis, might be stroke-protective here. And, from Science Daily:

While the research specifically focused on what happens when neurogenesis is blocked, the scientists said the results suggest that increasing adult neurogenesis might be a potential way to combat drug addiction and relapse.

It may very well be the case that increasing neurogenesis is good in the same way decreasing neurogenesis is bad but it shouldn’t be assumed – maybe we have all the neurogenesis we need and, while completely arresting neurogenesis could be harmful, increasing neurogenesis beyond normal levels is just redundant. Read the rest of this entry »

I recently became re-acquainted with the neurogenesis literature while writing the last post, re-finding data in papers whose gist, but not details, I had remembered. I reached out a little bit, asking others if I had forgot any studies and indeed I had, including this study by Okano, Pfaff and Gibbs from 1993.

I’ve been interested in new neuron function since 1999 and so I’m actually quite surprised I missed this study until so recently. In 1999 the neurogenesis literature was so scant that it was easy to know ALL of the studies, even the early Altman, Kaplan and Nottebohm studies from the 1960s through 1980s. Even studies that were not interesting were interesting, because there was nothing else to read! So, had I known about it back then, I would have been pretty interested in this study by Okano et al. if only for its focus on cell cycle markers. But I really would have been interested in it because it has a small functional experiment that was way ahead of it’s time:

Read the rest of this entry »