El blog de Rubén Carvajal Santana

June 22, 2014 Researchers discover how neurons equalize between excitation and inhibition. Researchers at the University of California, San Diego School of Medicine have discovered a fundamental mechanism by which the brain maintains its internal balance . The mechanism, described in the June 22 advanced online publication of the journal Nature , involves the brain’s most basic inner wiring and the processes that control whether a neuron relays information to other neurons or suppresses the transmission of information. Specifically, the scientists have shown that there is a constant ratio between the total amount of pro-firing stimulation that a neuron receives from the hundreds or thousands of excitatory neurons that feed into it, and the total amount of red-light stop signaling that it receives from the equally numerous inhibitory neurons. This constant ratio, called the E/I ration , was known to exist for individual neurons at a given time. This study goes a s...

El cerebelo ayuda a control de movimiento, el equilibrio y otras funciones motoras. Un nuevo estudio en Nature Comunications revela que un gen conocido como Snf2h es clave para el desarrollo del cerebelo. Los científicos en el Instituto de investigación del Hospital de Ottawa eliminaron este gen en ratones en etapas tempranas del desarrollo y descubireron que el gen funciona como regulador principal en las células madre neurales. Sus cerebelos eran sólo un tercio del tamaño estándar, y los ratones tenían problemas para caminar. Cuando los investigadores evaluaron la expresión génica en los ratones, descubrieron que, sin Snf2h como un regulador maestro, la expresión génica se volvió errática. Los científicos esperan ampliar sus conocimientos sobre cómo estos reguladores moldean el desarrollo del cerebro. Leer más: http://bit.ly/UZJ4vI artículo: Snf2h-mediated chromatin organization and histone H1 dynamics govern cerebellar morphogenesis and neural maturation. Nature Comm...

Crossing Blood-Brain Barrier Could Open Up New Treatment Options for Alzheimer’s, Cancer June 20, 2014  | by  Lisa Winter photo credit:  Marvin 101 via Wikimedia Commons The blood-brain barrier (BBB) is just as it sounds: an incredibly selective permeable membrane that separates blood from the brain. While this does a great job of keeping the brain healthy and preventing contaminants in the blood from affecting the brain,  it also makes it more difficult to use medications to target neurological disorders . Only a few types of drugs can make it through, and they usually come with a host of nasty side effects. However, a group of researchers are about to  begin clinical trials  on a technique that uses MRI-guided ultrasound to open up the BBB in order to give access to drugs that could treat diseases like cancer, Alzheimer’s, and Parkinson’s. The research will use 10 patients who have been diagnosed with cancerous brain tumors . A paper from res...

Left Brain vs. Right: It's a Myth, Research Finds By Christopher Wanjek, Columnist   |   September 03, 2013 12:21pm ET It's the foundation of myriad personality assessment tests, self-motivation books and team-building exercises – and it's all bunk. Popular culture would have you believe that logical, methodical and analytical people are left-brain dominant, while the  creative and artistic types  are right-brain dominant. Trouble is, science never really supported this notion. Now, scientists at the University of Utah have debunked the myth with an analysis of more than 1,000 brains . They found no evidence that people preferentially use their  left or right brain . All of the study participants — and no doubt the scientists — were using their entire brain equally, throughout the course of the experiment. A paper describing this study appeared in August in the journal PLOS ONE. [ 10 Things You Didn't Know About the Brain ] ...

Patterns of connections between brain cells could determine vulnerability to stress, depression by Bethany Brookshire 4:57pm, June 3, 2014 Neurons like this one (green) can become active in times of stress . A new study in mice shows that the connections a neuron develops could make the difference between shrugging off stress and entering a depressive episode. We all respond to stress in different ways. Some of us work harder. Others drink more or eat our feelings. Sometimes we experience sleep loss, heart palpitations or sweats. When the stress dissipates, many of us go back to our daily lives, none the worse for wear. We are resilient. But some people find that stress is a first step on the way to a major depressive episode. It’s not quite clear what’s different between people who go back to normal after stress, and those who descend into depression. “One of the most important questions is, how do th...

Researchers confirm cellular basis for memory by implanting and erasing fear into the brains of rats using fibre optics.   Ewen Callaway 02 June 2014 Sadegh Nabavi and Sina Alizadeh By controlling rats' brain cells they had genetically engineered to respond to light, researchers were able to create fearful memories of events that never happened — and then to erase those memories again. Neuroscientists can breathe a collective sigh of relief. Experiments have confirmed a long-standing theory for how memories are made and stored in the brain. Researchers have created and erased frightening associations in rats' brains using light, providing the most direct demonstration yet that the strengthening and weakening of connections between neurons is the basis for memory. “This is the best evidence so far available, period,” says Eric Kandel, a neuroscientist at Columbia University in New York. Kandel, who shared the 2000 Nobel...

Un grupo de científicos estimuló el área ventral tegmental (VTA ) - una región del cerebro involucrada en la memoria , el aprendizaje, y la recompensa - en macacos , haciendo que estos fueran capaces de cambiar la imagen que los monos veían en el experimento . Los investigadores del Hospital General de Massachusetts (MGH ) y la Universidad de Lovaina en Bélgica implantaron microelectrodos en el VTA de macacos para estimular las neuronas en esa región. Los monos fueron entrenados para mirar a una de dos imágenes con una recompensa de jugo. Luego , los investigadores aplicaron una estimulación suave para la VTA cuando los monos miraban la imagen no preferida, para ver si ellos estarían dispuestos a pasar su preferencia debido a la "recompensa" del VTA estimulado en vez del jugo , y así lo hicieron. El trabajo, publicado en la revista Current Biology , demuestra por primera vez que las neuronas de VTA juegan un ...