The question then was, "Do you get PTSD because you have a small hippocampus?" Or is a small hippocampus the result of stress?
The debate about which one comes first has been in the scientific community for some time. However, Designer Brain Blog wrote last year that stress can literally shrink and destroy your hippocampus--the brain region associated with memory and a study published in Science Direct supports this as they reported that loss of gray matter, "represents an acquired sign of PTSD consistent with stress-induced loss." The so-called neurotoxicity hypothesis also supports this view when it said that, "stress precedes volume reductions in the hippocampus in PTSD."
Robert Sapolsky at Stanford University suggests that stress may cause the death of neurons, Bruce McEwen at Rockefeller University said that stress can shrink neurons or lose their interconnectivity within the brain's network.
Stress is a normal survival instinct.
Compared to a relaxed state, stress can be good in the sense that it could pump up adrenaline to make you react with more power for a quick burst of energy for survival reasons, it could heighten memory functions, helps in immunity, less sensitivity to pain, etc..
The kind of stress that we should try to avoid is chronic type. Cortisol, the same hormone that is secreted by the adrenal glands to give you that "useful" kind of stress becomes your enemy when it floods your body and brain due to chronic stress.
Among the many negative effects of prolonged high levels of cortisol in the blood stream, About.com places "impaired cognitive performance" first on the list - why, it shrinks your brain.
It becomes very important then that relaxation should be given a higher level of importance and priority in one's day-to-day health practices. Meditation, proper diet, exercise, enough sleep, and many other expert-recommended health and relaxation regimens should be a part of everyone's daily routine.
Among the many measures at fighting stress, meditation may be the one that gives the most immediate and more lasting result. However, self-guided meditation is not as easy as it sounds-it could take years of commitment, discipline and constant practice to truly master the techniques. Fortunately, iMusic Zen Meditate could help with the learning currve. For more info, click here.
Scientists have known that a caloric-restricted diet (consumption of less than half the usual number of calories per day) can increase life span. The Okinawans, known to represent the highest percentage of people living past 100, can be the best examples of this: they embody hara hatchi bu, or eating only until they are 80% full. However, understanding the underlying biological mechanism that brings about this has eluded experts for more than seven decades.
It was in 2007 that scientists from the Salk Institute for Biological Studies claimed that they "finally have genetic evidence to unravel the underlying molecular program required for increased longevity in response to calorie restriction."
This discovery may have opened doors to the development of drugs that can mimic calorie restriction and reap life-prolonging health benefits, possibly without living or enduring the ascetism one may need to endure by limiting the amount of calorie to only half of what you usually enjoy.
Short-term trials on human subjects have shown that caloric-restricted diets may also result to some improvements in other areas of health such as blood sugar and insulin levels-inflammation and high insulin levels are both linked to cognitive problems. Studies in mice have shown that reduced insulin levels promote neurogenesis, or the continuous growth of neurons in the brain.
As demonstrated in a research of Suzanna Becker, of the Department of Psychology, Neuroscience, and Behavior at McMaster University in Ontario, "several computational theories have recently been suggested, including the idea that new neurons increase memory capacity." Separate researches also show that neurogenesis "reduce interference between memories, or add information about time to memories."
Here's the experiment:
50 healthy (normal to overweight) elderly subjects (mean age: 60.5 years) were grouped into three. The first group was subjected to caloric restriction (reduced calorie intake to 30%); the second group's diet was given a 20% increase in unsaturated fatty acid with no increase in total fat; and the third group served as the control.
At the end of three months, among the other changes noticed on the subjects, the caloric-restricted group showed improvement in recall ability, "and they also made fewer errors. Their memory improvement tended to be correlated with reductions in blood insulin and markers of inflammation (C-reactive protein and TNF-alpha). Memory did not change in the other two diet groups."
While we have written about it, studies about selectively erasing bad memories have been going on for years. LiveScience reported on this, August of 2006. Last year, science journals were also abuzz with the topic.
First, experts were able to pinpoint the region of the brain where pain or fear memories are stored: the lateral amygdala. The amygdala neurons produce CREB (cyclic adenosine monophosphate response element-binding protein) when the subject is exposed to pain or something scary.
The experiment first placed mice in fear training. It's your standard Pavlovian conditioned reflex training: a tone is played followed by a mild electric shock to the mouse. When the mouse is conditioned enough, everytime the tone is played, the mouse freezes (crouching) in fear.
To erase that fearful memory, the scientists zapped the CREB-making neurons. And the conditioned reflex -- the fear associated with the tone -- disappeared. The experiment also revealed that the effect is permanent. Further experiments also showed that zapping specific neurons associated with a particular fearful memory does not impair the subject's ability to form new memories. It can even relearn the tone-electric shock-fear conditioning. The exercise also did not affect other memories stored in the mouse's brain.
This new development presents endless possibilities in the understanding and manipulation of the human mind. One could easily say that instead of spending endless hours on a psychiatrist's couch, a zap in the brain sounds easier. Or is it?
In the tradition of sci-fi authors (George Orwell, H.G. Wells, Jules Vern, et. al.) who presage future scientific breakthroughs, the movie Eternal Sunshine of the Spotless Mind (2004), roughly illustrated this concept of selective erasure of memory. The character played by Jim Carrey wanted to erase the cause of his pain, his ex-girlfriend, from his memory.
Another sci-fi flick, Paycheck shown in threaters in 2003 starring Ben Affleck, runs around the idea of selectively erasing a memory after finishing each project, in lieu of signing a non-disclosure contract.
If you are thinking that this could solve your fear of spiders, or erase bad childhood memories, or erase a detrimental post-traumatic disorder,...listen to what Dr. Joe Tsien has to say: "First of all I should emphasize the methodology is not applicable to the human clinical situation yet...However, it does suggest molecular paradigms which we can explore to perhaps achieve the same kind of effects in humans-but those are probably years or decades away."
The hot topic in neuroscience today is: "Mind-zapping: to be, or not to be."
"Sex Chip" inserted in to brain can stimulate pleasure as intense as "devouring a delicious pastry."Posted February 2nd, 2009 by VTHron
Viagra, watch out. This "sex chip" will be able to stimulate pleasure centers in the brain which, according to Morten Kringelbach, senior fellow at Oxford University's department of psychiatry, can produce pleasure as intense as "devouring a delicious pastry."
Deep Brain Stimulation (DBS), was first officially used in the United States by neurosurgeons at Mayo Clinic for patients with essential tremor (tremor of the hands, head or neck and jaw, etc), Parkinson's disease and dystonia. This procedure has helped hudreds of patients. In recent months, researchers have been focusing at the orbitofrontal cortex -- the region of the brain associated with "feelings of pleasure derived from eating and sex" to help people suffering from anhedonia or the inability to experience pleasure derived from these activities.
The experts are optimistic about the efficacy of the procedure. Tipu Aziz, professor of neurosurgery at the John Radcliffe Hospital in Oxford said, "A few years ago, a scientist implanted such a device into the brain of a woman with a low sex drive and turned her into a very sexually active woman. She didn't like the sudden change, so the wiring in her head was removed."
Unlike transcranial direct current stimulation tDCS, which is actually non-intrusive, DBS requires an expensive surgical procedure (according to Mayo Clinic) that would insert an electrode to the brain. This electrode will then be connected by a wire to a heart pacemaker. While Aziz said that this surgical procedure could be intrusive and crude (causes bleeding in some patients), he predicts that a significant breakthrough in this technology is possible in ten years.
We have gone across several reports about this study... and no, shock treatment inside Arkham Asylum in Gotham City does not count, but Brainblogger.com also carried an interesting article about electroconvulsive therapy. The study involved 16 right-handed volunteers. Scalp electrodes with "weak, non-invasive direct currents were transmitted through their skulls to neurons in the motor cortex" for the tDCS --alright, it's not really "shock treatment" as how we perceived it to be.)
The result? "Significant improvements in motor function in the non-dominant hand were seen. Dual stimulation of the right and left motor cortex regions, resulted in improvement of scores by almost 25%. Stimulating only one motor region showed a smaller increase (16%)." MedscapeToday.com also reported that tDCS could improve the use of an individual's non-dominant hand.
The researchers are excited about the implications of this study in terms of helping stroke victims or those whose motor functions is reduced or lost. PS3 and X-Box gamers also have a lot to be excited about this. With the added dexterity, this could greatly boost anyone's Final Fantasy XIII game....even Batman: Arkham Asylum. All they have to do is zap their brains.
I ended up spending the rest of the day mouthing, "Who let the dogs out? who, who, who, who-who!" silently in my mind. I was going bonkers!
So what is brain itch?
Professor James Kellaris of the University of Cincinnati College of Business Administration explains how some of the songs get stuck in our head, "Certain songs have properties that are analogous to histamines that make our brain itch." The only way to scratch them is by repeating the tune over and over again.
In another research published in the journal Nature, a US team from Dartmouth College, in trying to explain how tunes get stuck in your head, asked volunteers to listen to parts of familiar and unfamiliar songs while monitoring their brain activities with fMRI or functional magnetic resonance imaging.
The study showed that certain parts of the brain, particularly the auditory cortex, had more activity even when the music had stopped. Incidentally, the participants also reported "hearing" the song part even when a silent gap was inserted into that part of the music. And this only happens to songs that are familiar to the participants.
David Kraemer, study team leader said, "We found that people couldn't help continuing the song in their heads, and when they did this, the auditory cortex remained active even though the music had stopped." In the forced gaps of a familiar music, a listener activates different parts of the auditory cortex, "going farther back in the processing stream," to fill in the blank.
This reminds me of my Uncle Harold who whistles "When the Saints Go Marching In" anytime he's fixing around the house; and he never seems to run out of something to do around the house the whole day --- everyday!
Another finding of the Dartmouth College team also showed that, "When you are recalling a particular song that will activate auditory brain regions but that may, in turn, lead to you having a very vivid visual memory as well. For example, you may picture yourself at the high school dance when you first heard the song."
This study aims to have a better understanding of how memories are formed and recalled could help us have a better grasp of the conditions that affect memory.
So how do you stop this brain itch? How do you shake Macarena off your head? Some swear "hearing" the song to the end would make it go away.
While our brain is similar to computers in the sense that it is wired like electrical circuitry, the difference lies in the fact that data or information is transmitted solely by electrical signals in computers while the brain employs both electric and chemical signals. Computers have fixed connections while our brain, on the other hand, continues to create new connections endlessly. This is a new finding in brain science explained by neuroplasticity.
Much unlike the computer, our brain can continually change its structure, add new brain cells, change connections. Neural connections may become more concentrated on one area (an F1 race driver develops more connections in areas related to improving his driving skills), and may create new connections to adapt to a new experience (or to fix itself).
There is a new finding however that could add to the brain's similarity to a computer, or at least how it operates: the presence of RAM-like behaving brain cells. These highly evolved individual brain cells or neurons found in the front part of the brain are found to "hold traces of memories by themselves for up to a minute, perhaps longer." These are the same memories that are processed and transmitted through a network of branches called dendrites. Imagine electrical sparks lighting up your brain, and "when millions of these brain cells communicate with each other at once, cognition occurs."
When neurons reorganize and connections are established and strengthened, permanent memories are stored. It does not happen instantaneously - it takes minutes or even hours to process these information to memory. Sleep or a 90-minute afternoon nap is one way of improving memory retention.
In a study that will be published in the upcoming issue of the journal Neurobiology of Aging, as reported in the January 8 edition of the CBC News, it has been proven that a healthy body means better blood flow to the brain, which translates to improved cognition. Marc Paulin at the University of Calgary said, "Being sedentary is now considered a risk factor for stroke and dementia."
Good Diet and Lots of Sunshine
Increasing your vitamin B12 intake could also prevent your brain from shrinking and protect you from memory loss or dementia.
On the other hand, vitamin D is ‘Mental Health Aid,' says a BBC News article. In a study conducted on 2,000 people aged 65 and over, they found out that the level of cognitive impairment is inversely proportional with vitamin D level; those with lower vitamin D have higher cognitive impairment.
Vitamin D can be found in oily fish, and vitamin D fortified milk, cereals and soya drinks. Incidentally, these types of foods are also good sources of vitamin B12.
You can also get vitamin D from sun exposure. It is important to note then that people living in the northern hemisphere, those living in countries with dark winters and less sunshine, would need more vitamin D supplements. Older people's skin also tends to absorb less sunshine so they would need to have more vitamin D from other sources.
You want to rush committing a new skill or knowledge to memory? Get a 90-minute daytime snooze and it might help: you get instant memory consolidation.
Here's the experiment as reported by LiveScience: participants are instructed to learn a complex thumb-tapping sequence. The participants are then divided into two groups; one group napped for an hour and the other stayed awake. The result? Those who took the afternoon siesta showed great improvement in their performance of the newly learned skill on the evening of that same day.
Further experiments also showed that a 90-minute snooze could lock in long-term memories faster. If we send this report to HR, do you think they'd start extending lunch breaks for catnaps?