Not only can you teach an old dog new tricks, you can actually make him create new neurons. Actually, dogs aren’t involved, just humans, but it’s good news for those of us well past the age of majority. Jim’s Neuronal Misfirings blog mentions research findings:
…new neurons grow in the adult visual cortex as a result of activity. This research supports previous findings of neurogenesis (or brain “plasticity”) in the hippocampus, and appears to confirm that adults can generate new neurons IF the brain is kept active.
The research findings are described in Adult Brain Cells Do Keep Growing.
Previous studies have shown that engaging in activity that is mentally challenging seems to prevent or at least slow the debilitating effects of brain damaging conditions like Alzheimers.
In rats, electroconvulsive seizure (ECS) treatment increases neurogenesis (neuron creation) in the adult frontal cortex according to a report here. I’m guessing most humans will prefer to use the more benign mental stimulation approach.