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Neuron

Neuron
All neurons are electrically excitable, maintaining voltage gradients across their membranes by means of metabolically driven ion pumps, which combine with ion channels embedded in the membrane to generate intracellular-versus-extracellular concentration differences of ions such as sodium, potassium, chloride, and calcium. Changes in the cross-membrane voltage can alter the function of voltage-dependent ion channels. If the voltage changes by a large enough amount, an all-or-none electrochemical pulse called an action potential is generated, which travels rapidly along the cell's axon, and activates synaptic connections with other cells when it arrives. Neurons do not undergo cell division. In most cases, neurons are generated by special types of stem cells. A type of glial cell, called astrocytes (named for being somewhat star-shaped), have also been observed to turn into neurons by virtue of the stem cell characteristic pluripotency. Overview[edit] Anatomy and histology[edit]

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Brain Atlas - Introduction The central nervous system (CNS) consists of the brain and the spinal cord, immersed in the cerebrospinal fluid (CSF). Weighing about 3 pounds (1.4 kilograms), the brain consists of three main structures: the cerebrum, the cerebellum and the brainstem. Cerebrum - divided into two hemispheres (left and right), each consists of four lobes (frontal, parietal, occipital and temporal). The outer layer of the brain is known as the cerebral cortex or the ‘grey matter’. It covers the nuclei deep within the cerebral hemisphere e.g. the basal ganglia; the structure called the thalamus, and the ‘white matter’, which consists mostly of myelinated axons. – closely packed neuron cell bodies form the grey matter of the brain.

Decision-Making and Control in the Brain Damage to the brain's frontal lobe is known to impair one's ability to think and make choices. And now scientists say they've pinpointed the different parts of this brain region that preside over reasoning, self-control and decision-making. Researchers say the data could help doctors determine what specific cognitive obstacles their patients might face after a brain injury. For the study, neuroscientists at the California Institute of Technology (Caltech) examined 30 years worth of data from the University of Iowa's brain lesion patient registry and mapped brain activity in almost 350 people with lesions in their frontal lobes. They linked these maps with data on how each patient performed in certain cognitive tasks.

The Brain: A Body Fit for a Freaky-Big Brain Aiello and Wheeler noted that this dramatic increase in brain size would seem to have required a dramatic increase in metabolism—the same way that adding an air-conditioning system to a house would increase the electricity bill. Yet humans burn the same number of calories, scaled to size, as other primates. Somehow, Aiello and Wheeler argued, our ancestors found a way to balance their energy budget. As they expanded their brains, perhaps they slimmed down other organs.

10% of the Brain Myth Let me state this very clearly: There is no scientific evidence to suggest that we use only 10% of our brains. Let's look at the possible origins of this "10% brain use" statement and the evidence that we use all of our brain. UCSB scientists discover how the brain encodes memories at a cellular level (Santa Barbara, Calif.) –– Scientists at UC Santa Barbara have made a major discovery in how the brain encodes memories. The finding, published in the December 24 issue of the journal Neuron, could eventually lead to the development of new drugs to aid memory. The team of scientists is the first to uncover a central process in encoding memories that occurs at the level of the synapse, where neurons connect with each other. How mapping neurons could reveal how experiences affect mental wiring This article was taken from the July 2012 issue of Wired magazine. Be the first to read Wired's articles in print before they're posted online, and get your hands on loads of additional content by subscribing online. No road, no trail can penetrate this forest. The long and delicate branches of its trees lie everywhere, choking space with their exuberant growth. No sunbeam can fly a path tortuous enough to navigate the narrow spaces between these entangled branches.

Buddhism and the Brain Credit: Flickr user eschipul Over the last few decades many Buddhists and quite a few neuroscientists have examined Buddhism and neuroscience, with both groups reporting overlap. I’m sorry to say I have been privately dismissive. Researchers show that memories reside in specific brain cells Our fond or fearful memories — that first kiss or a bump in the night — leave memory traces that we may conjure up in the remembrance of things past, complete with time, place and all the sensations of the experience. Neuroscientists call these traces memory engrams. But are engrams conceptual, or are they a physical network of neurons in the brain? In a new MIT study, researchers used optogenetics to show that memories really do reside in very specific brain cells, and that simply activating a tiny fraction of brain cells can recall an entire memory — explaining, for example, how Marcel Proust could recapitulate his childhood from the aroma of a once-beloved madeleine cookie.

The Brain's Highways: Mapping the Last Frontier Frontiers are in short supply. No explorer will again catch that first glimpse of the Pacific Ocean with “wild surmise,” take the first steps on the moon, or arrive first at the Challenger deep – the remotest corners of the earth are now tourist attractions. Even in science, great mysteries have fallen – life itself has gone from being the subject of metaphysical speculation about vital substances to the biophysical understanding of cellular processes. Uncharted territories, both physical and metaphorical, are hard to find.

Online papers on consciousness Search tips There are three kinds of search you can perform: All fields This mode searches for entries containing all the entered words in their title, author, date, comment field, or in any of many other fields showing on OPC pages. Imagining the Future Invokes Your Memory I REMEMBER my retirement like it was yesterday. As I recall, I am still working, though not as hard as I did when I was younger. My wife and I still live in the city, where we bicycle a fair amount and stay fit.

Cooperative Neural Networks Suggest How Intelligence Evolved Working together can hasten brain evolution, according to a new computer simulation. When programmed to navigate challenging cooperative tasks, the artificial neural networks set up by scientists to serve as mini-brains "learned" to work together, evolving the virtual equivalent of boosted brainpower over generations. The findings support a long-held theory that social interactions may have triggered brain evolution in human ancestors. "It is the transition to a cooperative group that can lead to maximum selection for intelligence," said study researcher Luke McNally, a doctoral candidate at Trinity College Dublin.

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