Monday, February 23, 2015

BRAIN SWITCHES

In the last post, we discussed certain dream theories.  One thing about the brain that is fascinating is that it is the most complex organ in the human body, and the least understood.

For example, did you know certain brain activities can be turned on and off like a light switch?

It has to do with stimulating or deactivating certain areas of the brain associated with a certain aspect of life.

Researchers know the control center for thirst is somewhere in the hypothalamus,  an almond-sized section of the human brain that regulates a number of our basic functions (hunger, sex drive, temperature). But recently, neuroscientists identified two specific populations of neurons in the hypothalamus of mice that control the impulse to hydrate, and they wanted to know what happens when they’re activated. By using a process called optogenetics,  they manipulated these cells to make them sensitive to certain wavelengths of light. Then, fiber-optic cables were implanted in the brains of mice that when illuminated, turned the corresponding neurons on or off. They found that one group of thirst neurons “evokes intense drinking behavior” when activated. How intense? Mice drank up to eight percent of their body weight in water when these neurons were switched on. That’s the equivalent of a human drinking a gallon and a half of water in ten minutes. The second group of neurons reduces the desire to drink, even when the animal is deprived of water.

Using the same optogenetics technique, scientists found the brain cells  that control hunger. When these cells are activated in mice, the rodents are compelled to stuff themselves well beyond the point of being full. But when they’re shut down, the mice ignore food, even when they should be hungry.
 
Consciousness and self-awareness are defining characteristics of human life. But these traits can be turned off and on like a light switch in a lab setting. At George Washington University, researchers accidentally flipped the switch while using electrodes to stimulate different parts of the brain in an epileptic woman.  When they stimulated a section called the claustrum,  the patient lost consciousness, but she didn’t pass out. Instead she sat motionless with a blank stare and showed no response to cues around her. She snapped out of her trance when the stimulation stopped, and had no memory of the lapse.

Other studies have shown the human brain may switch off self-awareness when we’re stressed, without any help from researchers. In 2006, neurobiologists from the Weizmann Institute of Science in Rehovot, Israel observed that when humans are forced to focus on a difficult task (particularly under a strict deadline), the area of our brains associated with introspection, the cortex, becomes quiet, and we go into a sort of robotic mode until the task is done. This ability could have evolved for purposes of self-defense.

Pain can be eased with certain drugs, but many treatments come with side effects like dependency and tolerance. Saint Louis University researchers found a way to treat chronic pain caused by nerve damage, including the physical agony caused by chemotherapy and bone cancer. By turning on the “A3 adenosine receptor” in the brain and spinal cord, they were able to block pain caused by nerve damage in rodents, without any of the side effects associated with drug treatments.

Beyond just physical traits, researchers have looked into emotional components to brain activity. What if we could reduce the human urge to fight? New York University researchers  zoomed in on the hypothalamus, the previously-mentioned hub of bodily functions, to look at the specific neurons that fire during acts of physical violence. By stimulating those neurons using optogenetics, they were able to turn male mice into vicious fighters that attacked anything in their vicinity—including inanimate objects, and both male and female mice. But then the team could also calm them, quelling their violent urges by silencing these neurons. 

These vast different research projects tend to lend some real world perspective on the fictional forays into science with the DHARMA compounds. Turning on and off brain switches have vast potential and power to those who control it.