The relationship between memory and DNA is a complex and fascinating area of active scientific research.
Here's a breakdown of what we know and what's still being explored:
How Memory Works (the basics)
First let us clear up some misconceptions. I misunderstood this for the longest time, but I use to believe the memories were encoded into living DNA and that this was the method used in the animal kingdom for particular actions or traits being passed down. For example, there is a wasp that has an interesting way of providing for its young. The Emerald Cockroach Wasp
First the wasp finds a cockroach, and then with it's stinger, performs a quick brain surgery and removes from the roach its Will. Will to do anything or go anywhere. Then the wasp puts its larva in the abdomen of the roach. The larva eat the organs of the roach -- but they know which ones to eat and which to leave alone so they don't kill their protector before they are finished with them.
Now, in the unpacking of that little trivia tale, there are some seriously puzzling actions, which would seem to be required for the wasp to procreate effectively, and yet should require some college level roach biology classes. At least a lecture. But even after that, how do we get the information to the larva?
Not Stored Like Files: Memories aren't stored in a single location in the brain like files on a computer. Instead, they are distributed patterns of activity across networks of neurons.
Synaptic Changes: The core of memory formation involves strengthening or weakening the connections between neurons (synapses). This is called synaptic plasticity.
Long-term Memories: For a memory to stick, it needs to transition into long-term storage through a process involving protein synthesis and potentially even changes to gene expression – this is where DNA comes in.
DNA's Role
Epigenetics: This field studies how environmental factors can switch genes on or off without changing the underlying DNA sequence. Experience can leave epigenetic marks on DNA, which may influence the formation and recall of memories.
DNA Breaks: Studies in mice suggest that a temporary break in DNA strands – caused by increased neuronal activity – could be a part of how the brain signals which experiences should be encoded into long-term memory.
Genetic Predispositions: Our genes can influence baseline memory capacity and our susceptibility to memory disorders like Alzheimer's.
Controversies and Unknowns
Inherited Memories: The idea that specific memories (like a fear of snakes) could be directly passed down through DNA is highly debated. While certain predispositions or tendencies might be influenced by epigenetics, most scientists believe this type of direct memory inheritance is unlikely.
Precision of the Process: We don't fully understand how the brain "chooses" which experiences get the DNA-level treatment for long-term memory, and how those memories are later accurately retrieved within complex networks.
Research into memory and DNA is ongoing, particularly in the areas of epigenetics and neuronal signaling mechanisms. While we're far from understanding all the mysteries, exciting discoveries are being made about the intricate biological basis of our ability to remember.
