• Original Articles By Dr. Lavin Featuring Expert Advice & Information about Pediatric Health Issues that you Care the Most About

    Where Exactly is a Memory? Amazing News from Recent Studies

    By Dr. Arthur Lavin

    What day is your firstborn child’s birthday?

    It seems very obvious (I hope) that every parent would know the answer to that question.  Certainly for the vast majority of parents, it is trivial to come up with an answer to a question like that.

    But try asking that question to someone who has never met your child or your family, none of them would know the answer.

    What accounts for our ability to hang on, sometimes for the rest of our healthy lives, to certain items of information?

    We all do this, and we all call this ability memory, and we all are pretty sure that it happens in our brains, but how exactly?

    Are facts stored like information on a thumb drive, set into place and left alone until needed sometime later?

    Are facts coded in some sort of sequence of nerve connections, that once made, make the memory occur and stored?

    We still do not really have answers for these questions, but a truly fascinating clue was published recently, and reported on in the NY Times:

    https://www.nytimes.com/2018/05/15/science/memory-transfer-snails.html

    The Sea Slug

    The story begins with a large snail like creature from under the sea, the sea slug.  It’s not a pretty sight for most people, but it has an incredibly simple nervous system, including a very, very large nerve that moves a siphon through which they expel wastes.  This big nerve is connected to a very visible action, so one can study how the nerve changes and the action responds with any change you care to study.

    Eric Kandel and the Nobel Prize

    A Professor Kandel, an incredibly erudite physician, devoted much of his early days as a researcher studying how these sea slugs learned.  His findings established evidence that it is the development of connections between nerves where the memory exists.   As those connections, or synapses, grew, as the DNA that directed theses synapses to grow activated, memories involving motions of the sea slug’s siphon would be created and kept current.

    For that work he won the Nobel Prize.  A truly fascinating book by him about this work is still available:

    https://www.amazon.com/Search-Memory-Emergence-Science-Mind/dp/0393329372/ref=sr_1_2?s=books&ie=UTF8&qid=1528230469&sr=1-2&refinements=p_27%3AEric+Kandel

    Enter RNA as the Unit of Memory

    Now comes Dr. David Glanzmann at UCLA and his work on the power of tiny bits of RNA to hold memory.

    In standard understandings of genetics, the code for how the body works is in the sequence of atoms in a very long chain of atoms called DNA.  That sequence dictates what proteins the body makes, which in turn dictates what the body does and how it is structured.

    DNA sequences that dictate structure or function are called genes.  Some genes make an animal grow wings, others legs.

    But DNA can have no say on what is made in the body, that is which proteins are made, without RNA.

    The signal goes like this:

    • Activate the gene (DNA)
    • That active gene makes a copy in the form of the closely related molecule, RNA
    • The specific sequence of RNA’s made dictates which proteins are made
    • The specific sequence of proteins made define what the body will look like and what it will do.

    So RNA forever has been seen as a messenger.  Very passive.  DNA calls all the shots, RNA simply translates the info in DNA into actual proteins.

    A messenger, that’s how we thought about RNA, but recently there has been an explosion of interest in tiny little bits of RNA that act to turn genes off and on, that is, decide what the DNA will or will not demand the body do.

    So here is what they did.  They took all the RNA from sea snails trained to retract their siphon for a long time after an electric shock.

    They took that RNA and injected it into untrained snails, they acted like trained ones, with no training.

    Then they took nerve cells in a lab, from untrained snails, and bathed them in RNA from trained snails, the untrained nerve changed its firing to a pattern only seen in trained snails.

    Lastly, the snails were given a chemical that keeps these tiny bits of RNA from turning genes on and off, and the exposure to RNA from trained snails did nothing to the untrained snails.

    So, where is memory?

    Again, we have no complete answers, but amazingly, part of the answer is, in the tiny bits of RNA, the microRNA!

    BOTTOM LINES

    1. We tend to think of memory as a storage system, you learn something, and the nerves in the brain change so that the info is stored forever.
    2. The role of microRNA bits to transfer memory suggests that now tiny bits of chemicals, that can be coded, like RNA, may be a way that memory is created.
    3. The fact that almost any healthy parent can tell you the birthday of their child(ren), and thousands of other memories, are quite a wonder.  We may find how it happens to be surprisingly material.

    To your health,
    Dr. Arthur Lavin

     

    No comments yet.

    Leave a Reply