Week Fifteen Post One

While reading chapter twenty-four, I felt most informed by the section on the aging brain.  It interests me how senescence reduces production of glutamate, acetylcholine serotonin, and dopamine, which allows a nerve impulse to jump quickly across the synapse from one neuron to another.  I am a biology major and never heard of this before so it really struck my interest. Neural fluid then decreases, myelination thins the corpus callosum and is then reduced, and cerebral blood circulates more slowly. I find this process very intriguing.  The result of this is an overall slowdown, evident in reaction time, talking, and thinking.  These are a lot of different senses that are affected in this process. According to most neuroscientists, brain aging is measurable not only in speed but also in size: The brain gets smaller. I was honestly shocked when I learned this fact; I truthfully thought your brain stayed the same size no matter what through life, because as a kid I used to believe my brain would continue to grow as I learned new things. Some areas shrink more than others, among them the hypothalamus and prefrontal cortex. Prefrontal shrinkage may explain inadequate inhibition, evident when some older people talk too much, with “off target verbosity,” to inattentive listeners. And lastly I didn’t ever know the explanation of the elderspeak and what caused it. I think I found the section on the brain to be most interesting because I love to learn how the body develops. Each and every organ, and how it affects our actions.