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. Overview A neuron is a specialized type of cell found in the bodies of all eumetozoans. Although neurons are very diverse and there are exceptions to nearly every rule, it is convenient to begin with a schematic description of the structure and function of a "typical" neuron. Polarity
Diffusion MRI Diffusion MRI (or dMRI) is a magnetic resonance imaging (MRI) method which came into existence in the mid-1980s. It allows the mapping of the diffusion process of molecules, mainly water, in biological tissues, in vivo and non-invasively. Molecular diffusion in tissues is not free, but reflects interactions with many obstacles, such as macromolecules, fibers, membranes, etc. Water molecule diffusion patterns can therefore reveal microscopic details about tissue architecture, either normal or in a diseased state. The first diffusion MRI images of the normal and diseased brain were made public in 1985. Since then, diffusion MRI, also referred to as diffusion tensor imaging or DTI (see section below) has been extraordinarily successful. Its main clinical application has been in the study and treatment of neurological disorders, especially for the management of patients with acute stroke. Diffusion Given the concentration and flux where D is the diffusion coefficient. .
Khan Academy - BRAINTEASERS Multitasking: This Is Your Brain On Media From Rasmussen College, Multitasking: This Is Your Brain On Media is a cool infographic design that looks at some of the research behind multitasking. New reports find that multi-taskers are “lousy at everything that’s necessary for multi-tasking.” Considering the amount of time people spend with around-the-clock access to TV, the Internet and mobile devices, it’s not surprising.This infographic looks at the causes and effects of multi-tasking. From a design perspective, I like the clean look with a simple color palate that is easy on the eyes. The statistics in the Media Addiction section could have been visualized to make them easier to comprehend. I love the brain diagrams. Found on Infographics Journal
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’. – closely packed neuron cell bodies form the grey matter of the brain. Cerebellum – responsible for psychomotor function, the cerebellum co-ordinates sensory input from the inner ear and the muscles to provide accurate control of position and movement. Brainstem – found at the base of the brain, it forms the link between the cerebral cortex, white matter and the spinal cord. Other important areas in the brain include the basal ganglia, thalamus, hypothalamus, ventricles, limbic system, and the reticular activating system. Neurons
Functional magnetic resonance imaging Researcher checking fMRI images Functional magnetic resonance imaging or functional MRI (fMRI) is a functional neuroimaging procedure using MRI technology that measures brain activity by detecting associated changes in blood flow. This technique relies on the fact that cerebral blood flow and neuronal activation are coupled. When an area of the brain is in use, blood flow to that region also increases. The primary form of fMRI uses the Blood-oxygen-level dependent (BOLD) contrast, discovered by Seiji Ogawa. The procedure is similar to MRI but uses the change in magnetization between oxygen-rich and oxygen-poor blood as its basic measure. FMRI is used both in the research world, and to a lesser extent, in the clinical world. Overview The fMRI concept builds on the earlier MRI scanning technology and the discovery of properties of oxygen-rich blood. History Three studies in 1992 were the first to explore using the BOLD contrast in humans. Physiology
Morality Quiz/Test your Morals, Values & Ethics - Your Morals.Org Musicians use both sides of their brains more frequently. A colleague pointed me to this interesting (to me, because I'm a pianist) work by Sohee Park's laboratory at Vanderbilt. Their central finding is that professionally trained musicians more effectively use divergent thinking (the ability to come up with new solutions to open-ended, multifaceted problems, or thinking 'outside of the box'). Creative thinking was tested both with written word association test and by asking subjects to make up new functions for a variety of household objects. Brain activity was measured by near infrared spectroscopy (NIRS), a noninvasive neuroimaging method that allows in-vivo measurement of changes in the concentrations of oxygenated hemoglobin and deoxygenated hemoglobin in the cortex. Empirical studies of creativity have focused on the importance of divergent thinking, which supports generating novel solutions to loosely defined problems.