Neuroscience

Most basically speaking, neuroscience is the study of the brain and nervous systems. The central nervous system consists of the brain and spinal cord. The peripheral nervous system is made up of the neurons that connect the spinal cord to muscles, as well as the neurons that transmit sensory information such as touch from our body to our spinal cord, which will then process that information or send it to the brain for further processing. The peripheral nervous system can be further broken down into the somatic and the autonomic nervous systems. The somatic nervous system is that which we can voluntarily control, such as movement. The autonomic, or ‘automatic’ nervous system, contains the sympathetic and parasympathetic nervous systems, as well as an additional nervous system, the enteric nervous system. This latter nervous system chiefly governs all things digestive in the body.

Neuroscience is concerned with all aspects of the nervous system, including its development, maintenance, pathology and degeneration, aging, learning, and memory. Therefore, neuroscientists are members of a large number of other fields such as neurobiology, neurochemistry, neuro-physics, neuronal modeling via computers or electrical engineering, psychology, neuro-immunology, neuro-oncology, and more. It is much more than simply studying the brain; neuroscience incorporates the brain's interactions with the rest of the body, as well as with its environment. The study of the function and pathology of the five senses is part of neuroscience. Additionally, a growing field in the early twenty-first century is the study of the inter-relations between the brain, nutrition, and our state of health, including our immune system.

Much study can be carried out using humans in research; however, many fascinating discoveries were and are made using model organisms, each one particularly suited to a facet of neuroscience. A great amount of neuroscience research is done using model organisms. Some model organisms in use include cell culture, planarians, mice, rats, cats, bats, frogs, nonhuman primates, and songbirds. Much of what neuroscientists take as fact now came from meticulous investigations on the squid giant axon. The axon is the part of the neuron that sends an electrical signal from the neuron's cell body, down to its target cell. In humans, axons are typically on the order of tens of micrometers in diameter; in contrast, the squid giant axon can measure greater than one millimeter in diameter. Thus, to study the electrical properties of a human axon, extremely small electrodes are needed; these electrodes need not be so small for the squid. The squid therefore was a crucial model organism for early neuroscientists who investigated the electrical properties of an axon.

It hasn't always been known that the brain is the center of our thoughts. Ancient Egyptians and Greeks believed the heart to be the seat of our intelligence; then Hippocrates mused that the brain was involved, as it was central to the eyes, ears, and tongue. Finally the Roman physician Galen noted that Gladiators who had suffered brain trauma subsequently suffered from impaired mental function, and scientists accepted the brain as the seat of human intelligence.

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