El blog de Rubén Carvajal Santana

Neuroscientists connect neural activity and blood flow in new brain stimulation technique UC Berkeley News By Sarah Yang, Media Relations | 27 September 2007 BERKELEY – Neuroscientists at the University of California, Berkeley, have for the first time measured the electrical activity of nerve cells and correlated it to changes in blood flow in response to transcranial magnetic stimulation (TMS), a noninvasive method to stimulate neurons in the brain. Their findings, reported in the Sept. 28 issue of the journal Science , could substantially improve the effectiveness of brain stimulation as a therapeutic and research tool. Illustration of the visual cortex during transcranial magne...

The Most Important Psychology Experiment That's Never Been Done By Brandon Keim September 25, 2007 | 4:57:29 PM What's the most important psychology experiment that hasn't been done? The British Psychological Society asked this question of leading psychologists and bloggers, and is collecting the responses on their blog. One of the more interesting, suggested by Susan Blackmore: watching death. The most important experiment that’s never been done is to take fMRI or PET scans of people as they die; either those who really do go on to die, or those who suffer clinical death but are resuscitated. If this were done we would be able to test theories about how NDEs and mystical experiences are generated in the dying brain, and answer questions about the timing of the experiences. Perhaps even this would not resolve the final question once and for all, but it would certainly bring us a lot closer to knowing what happens when we die. And why has it n...

September 19, 2007 Molecular biology Whether a man smells sweet or stinky is in the odorant receptor of the beholder Sophie L. Rovner Genetic differences determine whether a component of male body odor smells like sweat, vanilla, or nothing at all, according to newly published research. The component is androstenone, a steroid derived from testosterone that is present in sweat. To some people, androstenone smells pleasant, with a sweet, floral, or vanilla-like scent. Others find the compound's odor offensive and liken it to sweat or urine. A third group can't even smell the compound. The wide variability in people's perception of androstenone is due in large part to slight genetic variations that affect the odorant receptor OR7D4, report Leslie B. Vosshall , an associate professor who heads Rockefeller University's Laboratory of Neurogenetics & Behavior; Hiroaki Matsunami...

Why Stuff Stinks: Secret Sniffed Out By Dave Mosher , LiveScience Staff Writer posted: 21 September 2007 08:36 am ET Our noses can quickly distinguish a pleasant smell and a stench, but until now the chemical cues that help us make such decisions had not been understood. Researchers have found that heavier, more spread-out molecules tend to smell worse than lighter, more compact molecules, although exceptions to the rule exist. The finding can be used to predict how good or bad a molecule smells before anyone takes a whiff of it. Rehan Khan, a neuroscientist at the University of California in Berkeley, thinks evolution selected for pleasantness of smell as a gut reaction to guide us through our environments. "People can tell you right away whether something smells bad or good, but they're bad at naming the scent," Khan said. "Evolution probably latched onto the most efficient cues, like how the eye uses the wavelength of light to pick out colo...

How We Smell By Corey Binns , Special to LiveScience posted: 22 May 2006 08:37 am ET Your nose is one powerful protrusion. Whether it's a big honker or a little button, if it is working correctly you can sense a skunk from only 0.000,000,000,000,071 of an ounce of offensive spray. Animals can trace even tinier trails. Male luna moths, for example, track females from 5 miles away. Such nosiness is important for the survival of almost all creatures: to find food, avoid being eaten, and pick proper mates. It warns us about rotten milk, a burning house, or an unhappy skunk, and can turn our attention to attractive potential dates . Nosing around Despite its value, scientists knew little about how we sensed scents before the 2004 Nobel Prize winners took a jab at it. Know Your Noses Guess who these famous honkers belong to, then click to see the full pictures. (Hint: None of these is attached to Gerard Depard...

De acuerdo a un estudio aparecido en el Journal of Neuroscience ( Jing Zhao, Anthony N. Moore, John B. Redell, and Pramod K. Dash ) el brócoli puede ayudar en la protección del cerebro. La conclusión se obtuvo de un estudio realizado con una molécula llamada sulforaphane , que se encuentra presente en el brócoli, que ayuda a incrementar la actividad de la barrera hematoencefálica cuando ésta se encuentra dañada. El estudio se hizo en animales de laboratorio pero pudiese extrapolarse a humanos. La función principal de la barrera hematoencefálica e s proteger al cerebro al prevenir la entrada de sustancias químicas peligrosas que se encuentren en la sangre. La forma como funciona el sulforaphane es atenuando la pérdida de las proteínas citoprotectivas de la barrera hematoe ncefálica que son las que mantienen la integridad de la misma. Estas proteínas suelen declinar después de una lesión. El sulforaphane además de disminuir la pérdida de estas proteínas al incrementar la actividad d...

Explorando la neurobiología de la política, científicos en la universidad de Nueva York y UCLA parecieran haber encontrado que los liberales toleran la ambigüedad y el conflicto mejor que los conservadores debido a la forma como funcionan sus cerebros. En un experimento divulgado el en la revista Nature Neuroscience ( 9 September 2007; | doi:10.1038/nn1979) , Amodio y colaboradores, de la universidad de Nueva York y UCLA sugieren que la orientación política pareciera estar relacionada con las diferencias en cómo el cerebro procesa la información. Los conservadores tenderían a ser más estructurados y persistentes en sus juicios mientras que los liberales serían más abiertos a las nuevas experiencias. El estudio encontró que esos rasgos no se confinan a las situaciones políticas sino también a las decisiones diarias. Los resultados parecen demostrar que “hay dos estilos cognoscitivos -- un estilo liberal y un estilo conservador,” dijo el Dr. Marco Iacoboni, neurólogo de UCLA. Los parti...