The reason ‘old sayings’ become ‘old sayings’ is because they’ve been proven to be universally true and because they’re true, they’ve been handed down and passed around for generations. One such old saying is “You learn something new every day”.
It’s fortunate for us that scientists are among the foremost people who actively pursue learning something new every day. Case in point: for years, most people have understood and accepted the fact that our brain cells die as we age and cannot be regenerated.
But scientists, in their quest for learning, have produced recent studies that show new brain cell growth in adults, particularly in the hippocampus area of the brain, where learning and memories are stored. Another study shows that even senior citizens can have the same number of brain cells as they did as teenagers.
The brain does shrink in size over time. After reaching full size at around age 20, it begins to shrink by about 1% every year. The decrease in size is not due to neuron (nerve cell) death, but rather to changes of the dendrites that branch out from the neurons and the synapses (the spaces between adjacent neurons) between them.
The changes in the dendrites and the decrease in their numbers is the primary reason for a reduction in brain function as we age. Dendrites serve to connect the neurons to each other, in much the same way as entrance ramps connect surface roads to the interstate. If interstate entrance ramps are destroyed or in extremely poor condition, can you see how much harder it would be to continue on the path to your destination?
The same thing happens when dendrites are destroyed or in poor condition. Nerve impulses have a similar difficulty continuing on their path and often meet a literal ‘dead end’. The good news is our brain cells don’t have to deteriorate just because we get older.
Brain function in general and the dendrites in particular, deteriorate because of disuse. Which may bring to mind another ‘old saying’; use it or lose it. This is especially true when it comes to our body. If neural pathways are not kept active, they will gradually decrease in strength and function until they are no longer able to perform properly.
For example, do you know the biggest reason so many elderly people can’t sit in the floor? Because at some point in their lives, they stopped sitting in the floor. In order to make a particular movement, the brain combines the electrical signals of many neurons and makes a muscle movement. If the movements required to lower oneself to the floor are never used, those pathways between neurons become too weak to carry the signal and the brain’s memory of how to perform that movement is not able to be recovered.
In order to promote neurogenesis (the making of new brain cells), it’s important to stay active, both mentally and physically. An interesting note is that stress inhibits the formation of new brain cells. Can you guess what enhances it? If you guessed physical exercise, you’re right.
Staying mentally active, through learning new things, doing crossword puzzles or brain teasers, and staying physically active, can keep your brain regenerating new cells and diminish your chances of suffering decreased brain function for the rest of your life.
Warm regards,
Christian Goodman