A lab mate of mine pointed out a rather interesting article published recently in the NY Times. The article discusses the research of Dr. Todd Sacktor at SUNY Downstate Medical Center in Brooklyn. Sacktor’s group has spent several years working on PKMζ (PKMzeta) an atypical, constitutively active isoform of protein kinase C (PKC) in the brain, a molecule which functions in the storage of long-term memories.
PKMζ was originally identified by Sacktor’s group in 1993. They found that PKMζ protein expression correlated with maintenance of long term potentiation (communication between neurons). They then went on to examine PKMζ in hippocampus-dependent spatial memory formation by injecting mice in the hippocampus with ZIP, an inhibitor of PKMζ. They assayed spatial memory using a technique called active place avoidance where mice learn to avoid a spot on a rotating platform where they had previously received a shock. After a two-hour lag in testing, mice injected with ZIP did not avoid the shock zone while control mice did. This suggests that inhibition of PKMζ blocked the formation of long- term memories in mice. It is important to note that these mice were able to learn shock avoidance when taken off ZIP, suggesting that ZIP had no long-term effects on memory retention1.
While this is quite exciting scientifically, the article also discussed the ethical implications of altering memories. It would be ideal to use an inhibitor of PKMζ to block traumatic memories or to help people overcome addictions, but what about enhancers of PKMζ? If they do improve memory formation (which is only speculative at this point), will people feel they have to use these drugs to compete? Surely regulations and tests for these drugs will be necessary. On the flip side, enhancing PKMζ expression could help to improve dementia, Alzheimer’s disease, and age-related memory decline.
As scientists delve deeper into understanding brain function and memory formation ethical issues will surely develop. What are your thoughts? Should enhancers of memory be freely available? If not, how should they be controlled? Do the therapeutic possibilities outweigh the likelihood of abuse?
I welcome your thoughts.
1 A more extensive review on PKMζ is available here (subscription required).