Along with eyesight, hearing, and other abilities we take for granted during our youth, our sense of memory also (generally) decreases with age. Recent research has found a relationship between the amount of DNA acetylation in brain cells and the effects it has on forming memory in mice. This discovery has the potential to decipher the memory-making process in humans and perhaps lead to a drug concoction that will solve the “issue” of forgetfulness.
To study the correlation between age and memory, initial research compared the memory capacity of young mice versus older mice. These mice were placed in boxes with various sensory cues that they should be able to remember; these mice were then given a foot shock in this box. 24 hours later, young mice “froze in fear” when they were placed in the same box. Older mice (middle-aged 16-month old) acted as they normally would because they could not recall the foot shock they received in that box just 24 hours ago.
Andre Fischer's team of the European Neuroscience Institute in Gottingen, Germany delved further into this evidence by trying to figure out what specifically was causing this decline in memory with age by looking at tiny chemical changes that may affect how memory genes are switched on and off. Information from previous studies have shown that over 1,000 genes are involved in the memory-making process. To activate these “helper genes”, tightly wrapped DNA has to be loosened by acetyl groups to signal that these helper genes are ready to start the process of storing memory.
Fischer's team found that older mice have fewer acetyl groups present compared to younger mice when the memory of pain and danger of the box and foot shock were supposed to start processing and storing in the brain. When researchers injected a drug that helps increase histone acetylation in older mice, these mice reacted and stored the memory of the shock just as well as the younger mice. If humans form memories like mice, increasing acetylation may help older people combat memory loss.
While these findings are exciting, it is obvious that much more research needs to be done before applying any sort of memory-boosting drug or treatment to humans. One problem is that acetylation occurs in various body processes, so this memory drug would have to specifically target brain cells. We also have to debate the question of whether it is beneficial to add another drug to the collection of other drugs people are now taking in the quest for immortality. Another question we can also ask is whether the ability to forget is actually underappreciated. While college life might be deemed as the “best years of your life” and while it would be great to remember all those facts for the final exam, it is possibly a blessing that some of these college day shenanigans are forgotten as we grow older.
Sanders, Laura. “Genetic Switch Makes Old Mice Forgetful.” ScienceNews. May 2010. Web. 28 May 2010. <http://www.sciencenews.org/view/generic/id/58940/title/Genetic_switch_makes_old_mice_forgetful>.
Agis-Balboa, R.C., Bahari-Javan, S., Burkhardt, S., Chen, W., Cota, P., Dettenhofer, M., Farinelli, L, Fischer, A., Gogol-Doering, A., Kang, H., Opitz, L., Peleg, S., Salinas-Riester, G., Sananbenesi, F., Wittnam, J.L., Zovoilis, A., (2010). Altered Histone Acetylation Is Associated with Age- Dependent Memory Impairment in Mice. Science, 328, 753-756.
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