Structure of typical neuron... image from Wikipedia.
Taking a Brain Fitness class. Notes from first three hours... learned that MRIs show "Islands of Inactivity" in the brains of those fried by marijuana.
Twelve or so students show up and, when asked why we are taking the class, one woman says she'd had a brain aneurism (sp?) and wanted "to find out what's left." Another had had electric shock therapy... others, like myself, were having problems remembering names. Insomnia can mess with the brain... poor diet, booze, drugs, trauma... all of us, for whatever reason, sensing some slippage. A loose connection of two...
Learned that there are as many brain cells (billions!) as there are visible (?) stars in the galaxy. That some dendrites are very long. Several inches... That giraffes, so said the instructor, have brain cells that are 6 to 8 feet long and that every cell in the brain is replaced every 7 or 8 years. So you have, so speak, a different brain now than you did eight years ago when George Bush first became President.
Talked to 81 year old man who lives in a Senior Trailer park. "There are funerals every day... they're going like flies... they're going like dying is going out of style."
Just as continents eons ago were once joined in a solid mass, for example, Australia and South America; China, Alaska and North America, so too were our brains once more of a piece, so said the instructor. "You generate new brain cells all the time... right up to the minute you die, you're generating new brain cells." And brain cells travel to where they are needed. The brain of a musician is different from the brain of an athlete. But if an athlete seeks to become a musician, the brain cells begin to accommodate. There's something called brain plasticity... instructor says, Until your last breath your mind can change.