98 Are the Androids Dreaming Yet?

98 Are the Androids Dreaming Yet? , ee Einstein’s Brain of the brain. Whether this is related to his highly creative thinking or just random chance is unknown, but it’s an interesting data point in our quest to understand creativity and intelligence. Looking through a microscope, the wrinkly grey matter is composed of 30 trillion neurons; small whitish cells sprouting filaments that wrap around each other like the tentacles of an octopus. The tentacles, and there can be as many as 10,000 per cell, are known as dendrites and spread out to nearly touch other neurons. At the other end of the neuron is a single axon. The gaps between the end of an axon and the next neuron’s dendrites are called synapses, about one-tenth of the width of a human hair and varied in structure. When a nerve ‘fires, an electrical pulse spreads out along the axon to the end and crosses the synapses to other brain cells. This electrical pulse is not like the flow of current in a wire: neurons don't conduct electricity. It is more akin to dominoes falling in a line. Ion gates in the walls of the neuron open, letting potassium ions flow out. As the gates open in one section, the next section is triggered and so on. Thus, electrical signals ripple out along the axon. As the electrical signals cross the synapses they either excite or inhibit the firing of adjacent neurons. There is a lot more structure to a neuron than was once thought. The textbook model is of a sequence of ion sacks stacked end to end rather like plant cells, but neurons have a far more complex structure. Bundles of actin and tubulin form a skeleton in the neuron and the neuron metabolizes ATP to recharge its firing mechanism. Neurons behave far more like small animals than inanimate plant cells. HOUSE_OVERSIGHT_015788