Aging Brain Series: The Mechanisms Behind It All — Part 1

Written by Anil Bajnath, MD
Posted January 19, 2021

Dear Longevity Insider,

Understanding how our brains are wired and what keeps them running is a significant component of keeping an aging brain healthy.

Two weeks ago, we covered contributing factors to the aging brain...

Last week, we elaborated on how lifestyle choices affect the health of our brain as we age...

In our final installment, we will look at the more technical side.

Out with the old, in with the new

There is a popular saying in neuroscience that goes, “Neurons that fire together, wire together.” Neurons are fundamental cells in the brain and spinal column, and we have between 86 billion to 100 billion of them! They act like electrical devices that are responsible for sensory input, sending motor commands, forming memories, and transforming many other signals in our brains.

Glia, or glial cells, are known as the neuron’s sidekick. They don’t produce electrical impulses, yet they maintain homeostasis so that neurons can do their job efficiently. Just as important as building synaptic connections between neurons, it is equally as important to break down neuronal connections that are no longer needed – and that’s what glial cells do! This is actually part of the learning process in our brains – in order to learn something new, we need to get rid of the old.

The health and function of our neurons and glial cells determine how aging will affect our brain. Some researchers even think that cognitive decline is not necessarily a consequence of old age. On page 13 of my book, The Longevity Equation, I mention that “in what researchers call ‘Blue Zones,’ people routinely live one hundred or more. Despite their advanced age, they remain virtually free from . . . age-related illnesses that take so many lives. At the same time, they retain their mobility, their sharpness of mind, and their zest for life.”

Use it or lose it

During a literature review, researchers found that learning creates neurogenesis, which is the ability to grow new neurons. They asserted that “Concurrent and synchronous activity provides a mechanism whereby the new neurons become integrated with the other neurons. This integration allows the present experience to become integrated with memories from the recent past in order to learn and predict when events will occur in the near future. In this way, neurogenesis and learning interact to maintain a fit brain.”

Here’s where the glial cells come in. Some of them can help to speed up signals between certain neurons. And as our bodies make new neurons, others, called microglial cells, break down old neuronal cells in a process called synaptic pruning. This allows our bodies to build new and stronger connections so that we can learn more.

It’s also important to pay attention to our thoughts and patterns. Synaptic connections that we use less get marked with a protein for removal and those same microglial cells search for that marker and prune the synapse. In other words, what you focus on, you get more of. In a literature review, researchers elaborated on this concept and stressed the significance on the part microglial cells in strengthening neurogenesis.

And on Thursday, I'll discuss the final component that brings this all together.

To your longevity,

Anil Bajnath MD
CEO/Founder, Institute for Human Optimization
Chief Medical Officer, Longevity Insider HQ

P.S. Brain health means everything to me. That's why I created a five-part formula, designed to boost memory, focus, and over-all brain health. If brain health is high on your priority list, take a look at my prized brain research.