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The World in our Head
Cartography has been of grave importance to the human race ever since the advent of man. The geological features of any entity have been noted since the age of cave men. From the times of cave drawings and mythological imagination of maps, today technological advances have made us capable of getting the most accurate views of the whole planet on a 1024x768 flat screen. The intrinsic curiosity of man has led to the use of aerial photography and satellite imagery which has helped increase the relative precision of the exact placement of physical features and lands. Today we have world maps, maps of countries, cities, villages and buildings giving the exact coordinates of any part we want to see. It has made the understanding of demographics of planet Earth more comprehensible and made possible different forms of travel such as air and water. If such advances can be made in the field of geology, how would biology not be affected? For years on end, neuroscientists and biologists have been using various methods to form a similar map for a smaller entity though almost as, if not more complex than the world: The Brain.
Picture an atlas made up of millions of neural connections. The 4 lobes are the continents; each different region of the brain can be characterized as a country, and the main neuron bundles as the official facilitating bodies, invigilating the work of all the other parts – kind of like our own personal United Nations. The neural circuits are like the individual governing bodies of each country and each individual part of the neuron is a different committee of this government body. Finally, the transmission path of the neurons forms the roads and highways of the region and facilitates communication. At the start of the 20th century, a German neuro-anatomist, Korbinian Brodmann, parceled the human cortex into nearly 50 different areas by looking at the structure and organization of sections of brain under a microscope. His findings had been used for about a century to map the brain. Today, his framework is being modified and new ways of mapping the brain are being found.
The most basic overview of getting the map is kind of like an overview of the world map, showing just the continents and minor boundaries segregating certain areas. This can be easily achieved through processes such as computer axial tomography (CAT scan), Magnetic resonance imaging (MRI) and diffusion tensor-MRI (DTI). These techniques produce images of the brain. To get better knowledge of the brain and to examine brain activity, more complex and in-depth techniques are used. EEG (electroencephalography) is like a software, which gives the coordinates of a feasible region. It indicates electrically active locations in the brain using detectors placed on a cap. Similarly, PET scans (Positron emission tomography) and fMRI’s (functional MRI) give images of radioactive markers and brain activities in different situations. PhMRI (Pharmalogical MRI) shows brain activity as drugs are administered.
Now that we have characterized our brain as a new form of a world, the question arises- what is the point of this laborious effort? The answer to this question would be quite obvious; It helps us understand the brain more intimately which in turns helps neuroscientists plan surgeries in a safe manner.
Neurosurgeons use brain mapping to locate neurological diseases and fix the exact problem through various medical procedures. Brain imaging also helps diagnose various neuro-degenerative diseases such as Parkinson’s and Alzheimer’s. The scans show drops in brain chemicals or areas of the brain, which may have shrunk to indicate tissue loss. Doctors use this information to understand the progress of a disease and fix up a suitable treatment plan.
Neuroscientists and psychologists together have formed various observations by compiling their readings and understood how we learn and adapt through these methods. It gives them a better idea of where one region ends and the next begins, for a closer understanding of behavior-brain correspondence.
Numerous techniques and softwares are being created to further explore the arcane brain. Katrin Amunts is developing one such technique, which uses polarized light to reconstruct three-dimensional structures of nerve fibers in brain tissue. Another technique called Clarity, developed in the lab of Karl Deisseroth, a neuroscientist and bioengineer at Stanford University, allows scientists to directly see the structures of neurons and circuitry in an intact brain! Brain mapping is most definitely the auspicious future of neurosciences. Through the course of further research and inventions of new techniques, neuroscience may indeed conquer many threatening diseases. And so, the importance of maps is once again restored.