Neuronas

Underneath the new-fangled cortex, the brain stem, the limbic system, and the basil ganglia date back to the mastadons, the dinosaurs and the first anphibians In humans, the olds parts of the brain oversee emotion and help build memories They control heart rate and breathing They also form intimate connections with the new brain The cortex, though less than a ¼ inch thick, The cortex is the brain's crowing glory Among its roles, the cortex is our reality check It filters and orders the outside world for us and allows to see, touch, hear, and speak The cortex is also the human thinking cap All our plans, thoughts and ideas originate in this layer The cortex is packed with nerve cells About 2/3 of all our neurons operate here A piece of cortex tissue, no larger than a pinhead can house 30,000 of these cells Each neuron has a job: to communicate with other neurons the brain works by forming networks among these cells The long, spiny branches of the networks create a neuron forest of astounding intricacy Neurons use these communication lines to talk to each other with electric and chemical signals Here under microscope are two neurons linking up Though it may look like they fused together neurons don't actually touch each other A closer look reveals that a tiny gap called called the synapse, separates their branches this is where one message passes from one neuron to the next The message comes from here: small sacs that store chemical molecules When stimulated, these sacs release their molecules which cross the cell membrane into the synaptic gap An electric zap allows this to happen Meantime the receiving neuron has special welcome sites for the incoming molecules These receptor sites bind with the molecules When they do, special gates open up The gates let in a flood of charged particles: sodium and potassium ions which start up a new electrical signal in the receiving neuron This simple chain of events: an electrical zap followed by chemical changes, followed by another zap is the basis of all brain activity It's how neurons speak to eachother Here then is the key to the brain's complexity There are 100 billion neurons in the brain each neuron, like a bit player in a grand production processes its information, then hooks up with as much as 50 thousand other neurons to send and to receive messages 100 billion neurons x 50 thousand connections It's this complexity that allows us to think imaginitively On their own, neurons aren't very bright But put 100 billion of them together in a small space and let them all start talking to each other and you start to get brainstorms The trillions of neuron networks, like an improvisational orchestra, create new ideas and connect different thoughts in a whimsical and sometimes inspired fashion It's this impromptu ability to create new things in our brains that allows us to progress That quite simply takes us from here to here