We should be thankful that scientists are among the leading advocates of learning something new every day. Case in point: We've always believed that our brain cells die and stop regenerating once we get old.
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.
When dendrites change and their number decreases, brain function is reduced as we age. Neurons are connected to each other by dendrites, something like entrance ramps that connect surface roads to the interstate. When these entrance ramps are destroyed or are dilapidated, you will not be able to continue your journey.
When nerve impulses are also destroyed or are in poor condition, they similarly have a hard time continuing on their path and reach a 'dead end'. The good news is that we don't have to suffer from brain cell deterioration as we get older.
Disuse is often the cause of brain function and dendrites deterioration. Another old saying referring to this is, use it or lose it. This is true especially when it comes to our body. If neural pathways become inactive, their strength and function will gradually decrease until they can no longer function properly.
An example would be elderly people's difficulty in sitting on the floor. The reason for this is that they stopped sitting on the floor at some point in their lives. Movements are made when the brain combines the electrical signals of many neurons and makes a muscle movement. If the movements needed to make one sit on the floor is not used, those pathways between neurons become too weak to carry the signal and the brain's memory of how to sit on the floor is forgotten.
We need to stay active mentally and physically to make new brain cells (called neurogenesis). It's interesting to note that stress can also prevent new brain cells from forming. So we need physical exercise to enhance it.
We can stay active mentally by doing mentally challenging things, like crossword puzzles and brain teasers. By staying mentally and physically active, we can make the brain continue generating new brain cells and reduce our changes of suffering from senility.
