I sent this to an acquaintance who is a psychologist, and is always admonishing me to "give up the weed".
I thought that you might find this abstract on neuro(re)genesis and cannabinoids provocative, if not interesting. I have never believed the old adage that one "can't grow new brain cells". I have never heard anything so ridiculous. I don't care to be provocative, so I will not yammer more... Grin.
Cannabinoids promote embryonic and adult hippocampus neurogenesis and produce anxiolytic- and antidepressant-like effects
http://www.jci.org/articles/view/25509#ABS