<p>One of the fundamental components of how we age has to do with the maintenance of physical exercise. In addition, mental activity and heredity play big roles in our ageing process, but when we exercise, we create more brain-derived neurotrophic factor (BDNF) which fertilizes brain cells and propels the growth of new neurons. Studies have found that rodents who exercise produce two times as much BDNF as their ore sedentary counterparts. The brains of elderly people who exercise are in far better shape, on average, than those who don’t.</p><p>Similar to the body, in a metaphorical sense, the brain is like a muscle. The more that you exercise it with information and novelty, the better it gets. Suddenly, at seventy, you realize the declines of your twilight years have aggregated and that you are not cognitively what you used to be. The more unfamiliar the information, the more trouble you are going to have as an elderly person. A perfect example is the difficulty many baby boomers have with computers, if they did not adopt use of the new hardware (and software) and maintain abreast of the changes as they aged.</p><p>When we learn something new, neurons in the hippocampus send messages across the gaps that connect the terminal buttons, strengthening networks associated with learning. Essential to the strength of the connections are calcium molecules, which go into a neuron and make the connection more reliable. Calcium travels through NMDA receptors, which are inextricably linked to cognitive decline in age. NMDA receptors are glutamate receptor and ion channel proteins found in nerve cells. These receptors are very important for controlling synaptic plasticity and memory function.</p><p>While we may see the diseases and pathologies related to age wreak havoc on the body, they area also wreaking havoc on the brain. As we age, our processing rate slows down from its peak (typically 9 -11 Hz) to a slowed version. We become less able to retain new information and the areas of the brain most recently developed for evolution are the most vulnerable. This is notably the temporal lobes and the pre-frontal cortex (in combination responsible for auditory processing, memory and executive functioning).</p>