OUR EVOLVING MEMORIES

As an ever increasing percentage of people live beyond the age of 80, they are also experiencing the decaying memory of senescence. At the same time there are numbers of significant scientific breakthroughs in understanding the functioning of memory in the brain and amazing ways in which memory might eventually be improved. We are witnessing astounding explanations ranging from the exploration of specific hormones to the impact of magnetics. This gives me hope, as I write, because I am affected by a growing forgetfulness of the names not only of many garden plants but also of old acquaintances. As Thomas Jefferson noted some 200 years ago “Of all the faculties of the human mind that of memory is the first which suffers decay from age.”1

Since the days of Plotinus and Augustine memory has been recognized as the storehouse of experience as well as the mind’s unique knowledge of itself. It is at the base of what makes us human beings. Our longer life spans are also a factor in the incredible capacity of our memory.

I view memory as a kind of library of the mind. I wonder if I have built up my very large collection of books because I never really trusted my memory. Now I hope I do not blend imagination and remembrance or, for that matter, mix myth with memory. In old age these are not always differentiated. Some people have written down endless records of events and stages in their life, but then in later days add to their recollection of what happened. Such additions to their memories may become embellished as the years advance but the ways we distort past incidents is not related to memory loss. In many ways the mental evolution can even enrich our lives.

I remember the first telephone number of my parents in Paris some 80 years ago. I am concerned for our younger generation which no longer needs to memorize mobile numbers and, for that matter, has no need to memorize poetry, songs, or birthdays. The impact of modern technology on the memory of the millennial generation has not yet been examined seriously by sociologists. Teenagers today are unlikely to have the concentration and memory levels of past generations. I wonder what my grandchildren will remember of how we lived in 2020 AD? Indeed, will human interactions be recorded in their brains more than exchanges with their robots?

Hannah Arendt, recollecting the past in her important work, The Life of the Mind,  thought of remembrance as a form of witchcraft. She wrote “I can remember the past as though it had not disappeared… It is as though I had withdrawn into some never-never land, the land of invisibles, of which I would know nothing had I not this faculty of remembering and imagining.”2 Going back to Athenian history, Arendt pointed out that “Mnemosyne, memory, is the mother of the Muses, and remembrance, the most frequent and also the most basic thinking experience, has to do with things that are absent, that have disappeared from my senses.”

Age-related memory loss, as well as dementia and Alzheimer’s, begins within the area of the brain called the hippocampus. This was so named in 1564 by Julius Caesar Arantius a surgeon who cut into the temporal lobe where it meets the brain stem and was confronted with a worm-like form which resembled a sea horse — so he called it a hippo monster (in Latin). Some three hundred years later the German neuropathologist Alois Alzheimer (1864-1915) observed that patients who died with dementia also had developed clumps of insoluble material near the hippocampus. His discovery became the first published case of “pre-senile dementia.” Much later these Amyloid plaques, as they became known, were identified as masses of misfolding proteins.

Some 60 years ago in the United States, both sides of the hippocampus of a seriously epileptic patient, Henry Molaison, were removed. This succeeded in controlling his epilepsy but also cut his ability to remember. His condition paved the way for an intense focus by scientists into exploration of human memory loss. Was the problem with the gradual decay of the neurons in that section of the brain, or was it with the increase of cells blocking connections? It turned out that there were multiple possibilities for any resolution.

Microbiologists were among the first to realize that there are various forms of memory loss. Age-related memory loss is very different from dementia. In normal aging forgetfulness does not interfere with the ability to carry on with normal daily activities. My friend Clive Cookson wrote in the Financial Times that “various types of electric and magnetic stimuli are being used increasingly to improve cognitive performance. When Transcranial Magnetic Stimulation (TMS) was applied (near the hippocampus) activity in the associated brain regions became better synchronized.”3

Research on mice has shown that a hormone produced by bone cells (osteocalcin) influenced their memory as well as the launch of new neurons. Nobel laureate Eric R Kandel working in labs at Columbia University discovered that a deficiency in the RbAp48 protein contributed in age-related memory loss. Moreover, the interactions of drips of osteocalcin with that of the RbAp48 protein were able to restore muscle functions in aging mice. This has raised hopes that memory loss could be reversed in humans by restoring the hormone levels back to that of their youthful stages. Such findings are leading to a better comprehension of how the molecular mechanisms underlying human memory could be manipulated.4 Other lines of inquiry are being followed by scientists trying to understand exactly how, at molecular levels, exercise improves memory. (Is sprinting more effective than weight training?) Chemically, exactly how does aging of the body affect the condition of the brain? Dr Kandel believes the exploration in these fields “are just the beginning.”

Nuclear Magnetic Resonance (NMR) spectroscopy is widely used to determine the structure of organic molecules in solution and to study the molecular physics in addition to the chemical interactions. NMR is also routinely used in advanced medical imaging techniques, such as in magnetic resonance imaging. Ian Campbell and Sir Christopher Dobson, who died September 8th, were among the first to use nuclear magnetic resonance to demonstrate the misfolding alterations in the structure of lysozyme (protein) molecules. Among the multiple groups competing in ways to stave off cognitive decline are Wren Therapeutics, Microbiotica and the Pacific Neuroscience Institute. More conventional processes of examining the toxic clumps of amyloid fibrils are also underway by massive pharmaceutical companies.

It is exciting that, step-by-step, scientists are finding out more about how memory works in the brain and how it is connected to the body. Right now, for example, they are examining whether walking or gym exercise has a greater effect on memory. Before long scientists will discover what specific hormones are most effective in promoting memory and how these may best be prescribed. Such a slowdown to memory loss would be a tremendous boost in diminishing the disability of the aged. Realistic optimistic hopes do exist!


1Thomas Jefferson, letter to B.H. Latrobe (1812)
2Hannah Arendt, The Life of the Mind, Vol.1 (1971) p.85
3Clive Cookson, “How magnets can power memory,” The FT Magazine, September 6, 2014, p.49
4Chrissy Sexton, “Naturally occurring hormone could prevent of reverse memory loss,” Earth.Com, October 23, 2018.