Your Memories Are Made Of This

摘要

Remember your first kiss? Experiments in mice suggest that patterns of chemical "caps" on our DNA may be responsible for preserving such memories.rnTo remember a particular event, a specific sequence of neurons must fire at just the right time. For this to happen, neurons must be connected in a certain way by chemical junctions called synapses. But how they last over decades, given that proteins in the brain, including those that form synapses, are destroyed and replaced constantly, is a mystery.rnNow Courtney Miller and David Sweatt of the University of Alabama in Birmingham say that long-term memories may be preserved by a process called DNA methylation - the addition of chemical caps called methyl groups onto our DNA.rnMany genes are already coated with methyl groups. When a cell divides, this "cellular memory" is passed on and tells the new cell what type it is - a kidney cell, for example.