Did a Copying Mistake Build Man's Brain? A copying error appears to be responsible for critical features of the human brain that distinguish us from our closest primate kin, new research finds. When tested out in mice, researchers found this "error" caused the rodents' brain cells to move into place faster and enabled more connections between brain cells. When any cell divides, it first copies its entire genome. During this process, it can make errors. The cell usually fixes errors in the DNA. But when they aren't fixed, they become permanent changes called mutations, which are sometimes hurtful and sometimes helpful, though usually innocuous. One type of error is duplication, when the DNA-copying machinery accidentally copies a section of the genome twice. The researchers scanned the human genome for these duplications, and found that many of them seem to play a role in the developing brain. [10 Fun Facts About the Brain] The second, more recent, duplication seems to be incomplete, with only part of the gene being duplicated.
RC circuit A resistor–capacitor circuit (RC circuit), or RC filter or RC network, is an electric circuit composed of resistors and capacitors driven by a voltage or current source. A first order RC circuit is composed of one resistor and one capacitor and is the simplest type of RC circuit. RC circuits can be used to filter a signal by blocking certain frequencies and passing others. The two most common RC filters are the high-pass filters and low-pass filters; band-pass filters and band-stop filters usually require RLC filters, though crude ones can be made with RC filters. Introduction There are three basic, linear passive lumped analog circuit components: the resistor (R), the capacitor (C), and the inductor (L). This article relies on knowledge of the complex impedance representation of capacitors and on knowledge of the frequency domain representation of signals. Natural response The simplest RC circuit is a capacitor and a resistor in series. Complex impedance where and As or . per
The pioneers | Spectrum California became the first U.S. state to legalize medical marijuana, mainly for adults with severe chronic illness such as cancer or AIDS. Since California’s decision in 1996, 24 states and the District of Columbia (Washington, D.C.) have followed, and since 2012, four states and Washington, D.C., have legalized recreational use of the drug. So far, only Pennsylvania specifically permits medical marijuana use for autism, but in the past few years, parents of children with epilepsy across the nation have adopted this approach. Much of this enthusiasm stemmed from the widespread media coverage in 2013 of Charlotte’s Web, a marijuana strain with high levels of CBD. Around that time, Karlee was at her wits’ end. Giving her son marijuana was not an easy decision for Karlee. With her prescription in hand, Karlee was able to visit a for-profit medical dispensary that sells marijuana oils and tinctures — marijuana extracts steeped in alcohol.
Neurons, Synapses, Action Potentials, and Neurotransmission - The Mind Project Function of neurons Because our main interest lies in exploring how information processing occurs in the brain, we are going to ignore glia. But before we see how neurons process information (and what that means), you need to know a few things about the structure of neurons. Structure of neurons While there are as many as 10,000 specific types of neurons in the human brain, generally speaking, there are three kinds of neurons: motor neurons (for conveying motor information), sensory neurons (for conveying sensory information), and interneurons (which convey information between different types of neurons). Neuronal signaling Conduction Neurotransmission The following animation illustrates the difference between these two kinds of synapses. Copyright: 2008 You've reached the end of this component.
The Split Brain Experiments : Games from Nobelprize.org Lists of Nobel Prizes and Laureates The Split Brain Experiments Play the Split Brain Experiments About the game The split brain experiments revealed that the right and left hemisphere in the brain are good at different things. The Nobel Prize The 1981 Nobel Prize in Physiology or Medicine was awarded for discoveries in the 1960s concerning differences in the right and left brain hemispheres. Read More Background to the Split Brain Experiments » Share this: Share on facebook Share on google_plusone_share Share on twitter More Sharing Services Share on email To cite this pageMLA style: "The Split Brain Experiments". Recommended: The Legacy of Alfred Nobel On 27 November 1895 Alfred Nobel signed his last will in Paris. Play the Blood Typing Game Try to save some patients and learn about human blood types! Unlocking the Secrets of Our Cells Discover the 2012 awarded research on stem cells and cell signalling. Contact E-mail us Press Sitemap A-Z Index Frequently Asked Questions Terms Follow Follow us: Follow us:
Kirchhoff's circuit laws Both of Kirchhoff's laws can be understood as corollaries of the Maxwell equations in the low-frequency limit. They are accurate for DC circuits, and for AC circuits at frequencies where the wavelengths of electromagnetic radiation are very large compared to the circuits. Kirchhoff's current law (KCL) The current entering any junction is equal to the current leaving that junction. i2 + i3 = i1 + i4 This law is also called Kirchhoff's first law, Kirchhoff's point rule, or Kirchhoff's junction rule (or nodal rule). The principle of conservation of electric charge implies that: The algebraic sum of currents in a network of conductors meeting at a point is zero. Recalling that current is a signed (positive or negative) quantity reflecting direction towards or away from a node, this principle can be stated as: n is the total number of branches with currents flowing towards or away from the node. This formula is valid for complex currents: Uses Kirchhoff's voltage law (KVL) Assuming
Role for Fatty Acid Metabolism in Preclinical AD? Action Points Note that this observational study found an association between higher levels of docosahexaenoic acid and lower levels of cerebral amyloidosis.Be aware that the study was focused on individuals with significant vascular risk factors and may not be generalizable to the population at large. Limited seafood intake may increase the risk of brain amyloid deposition and Alzheimer's disease (AD), according to new research. Greater levels of the essential fatty acid docosahexaenoic (DHA) were associated with less cerebral amyloidosis, larger brain volumes, and better cognitive measures in cognitively healthy patients, Hussein N. In 61 older participants enrolled in the Aging Brain Study, serum DHA levels (the percentage of total fatty acids) were 23% lower in those with significantly more cerebral amyloidosis than in those without (0.97 versus 1.25). In an accompanying editorial, Joseph F. So what's a clinician to do? Reviewed by F.
THE BRAIN FROM TOP TO BOTTOM A presynaptic neuron has several specialized structures that distinguish it from a postsynaptic neuron. The terminal button of the presynaptic neuron’s axon contains mitochondria as well as microtubules that transport the neurotransmitters from the cell body (where they are produced) to the tip of the axon. (click on 2. Axonal Transport) This terminal button also contains spherical vesicles filled with neurotransmitters. These neurotransmitters are secreted into the synaptic gap by a process called exocytosis, in which the vesicles’ membranes fuse with that of the presynaptic button. The synaptic gap that the neurotransmitters have to cross is very narrow–on the order of 0.02 micron. Across the gap, the neurotransmitters bind to membrane receptors: large proteins anchored in the cell membrane of the post-synaptic neuron.
Brainbow: See the brain in different lights A subset of neurons found in the mouse’s retina. To a large extent the brain remains a mystery. In comparison to Astronomy, Neuroscietist and author of Portraits of the Mind, Carl Schoonover believes we are at the stage stargazing was before the invention of the telescope.He says, “We are still seeing very small parts of things, we have some interesting and great tools that in their own way are very powerful but we don’t yet have the defining tools we need to look at the brain.” Golgi’s Stain Drawing of a dog’s olfactory bulb by Camillo Golgi. Despite our lack of an overall understanding of the mind, in the last 140 years significant advances have been made. This technique was put to great use by a man considered by many to be the father of modern neuroscience, Santiago Ramón y Cajal. What our brain does is effortlessly, automatically and extremely quickly organize that information and it is an open question how that works Green fluorescent protein Brainbow Watch Carl Shoonover’s TED talk:
Ohm's law V, I, and R, the parameters of Ohm's law. where I is the current through the conductor in units of amperes, V is the potential difference measured across the conductor in units of volts, and R is the resistance of the conductor in units of ohms. More specifically, Ohm's law states that the R in this relation is constant, independent of the current. The law was named after the German physicist Georg Ohm, who, in a treatise published in 1827, described measurements of applied voltage and current through simple electrical circuits containing various lengths of wire. In physics, the term Ohm's law is also used to refer to various generalizations of the law originally formulated by Ohm. where J is the current density at a given location in a resistive material, E is the electric field at that location, and σ is a material dependent parameter called the conductivity. History Ohm's law was probably the most important of the early quantitative descriptions of the physics of electricity. Scope
The New Drug That Could Treat Alzheimer's - Introducing NTRX-07 In Brief Five million people, in the US alone, could be significantly helped by a new drug to treat Alzheimer's Disease. There have been many recent breakthroughs in the study and treatment of nuerodegenerative disorders. From medication to gene therapy, new solutions are continually popping up to instill greater hope. Targeting Inflammation New developments and research into treating Alzheimer’s disease are always welcome. “This drug may reduce inflammation in the brain, which is linked to Alzheimer’s disease,” says lead researcher Mohamed Naguib of Cleveland Clinic. “NTRX-07 uses a different mechanism than many other Alzheimer’s drugs currently available, as it targets the cause of the disease, not just the symptoms,” Naguib explains. Restoring Memory and Lives During tests on mice bred to show neurodegenerative issues similar to Alzheimer’s, NTRX-07 showed memory-restoring abilities.
The art of mindreading: Empathy or rational inference? The ability to infer what another person is thinking is an essential tool for social interaction and is known by neuroscientists as "Theory of Mind" (ToM), but how does the brain actually allow us to do this? We are able to rationally infer what someone knows, thinks, or intends, but we are also able to "slip into their shoes" and infer how they feel, and it seems that the brain processes these different types of information in different ways, as confirmed by a new report in the June 2010 issue of Elsevier's Cortex. Prof. Elke Kalbe and colleagues from the Institute of Neuroscience and Medicine at the Research Centre Juelich and the Neurological University Clinic Cologne, Germany, studied a group of male volunteers as they performed a computerized task, which assessed their abilities in both emotional and rational inference. Coauthor Prof.
Why is it Impossible to Stop Thinking, to Render the Mind a Complete Blank? Why is it impossible to stop thinking, to render the mind a complete blank? —, via email Barry Gordon, professor of neurology and cognitive science at the Johns Hopkins University School of Medicine, replies: Forgive your mind this minor annoyance because it has worked to save your life—or more accurately, the lives of your ancestors. Most likely you have not needed to worry whether the rustling in the underbrush is a rabbit or a leopard, or had to identify the best escape route on a walk by the lake, or to wonder whether the funny pattern in the grass is a snake or dead branch. Constant thinking is what propelled us from being a favorite food on the savanna—and a species that nearly went extinct—to becoming the most accomplished life-form on this planet. For these reasons, we benefit from having a brain that works around the clock, even if it means dealing with intrusive thoughts from time to time.