Remember when...

To ensure that a memory lasts, gene activity regulation is needed. Usually a protein latches onto a DNA and inhibits or enhances the expression of certain genes. A new study has also shown that neurons and also regulate gene activity by modifying the genes chemically. DNA methylation is where enzymes chemically modifies a gene that silences it. A study was recently done to test this. Rats were injects with a drug that inhibited DNA methylation right after receiving three electric shocks. Normal rats remember getting shocked and freeze up when placed in the same enclosure the next day. The injected rats showed about 25% of the freezing up behavior. This shows a much weaker memory for the injected rats. More experiments are being done to see how long DNA methylation effects memory and the duration of these effects. Recent studies suggest that DNA methylation may be a far more dynamic process than many researchers assumed.

http://sciencenow.sciencemag.org/cgi/content/full/2007/314/3