Neurogenesis in the Human Brain

Nick Ciborowski

There is a common belief floating around amongst the people of our society today and it is that our brains do not recreate new brain cells throughout our lives. People believe that they have a set number of brain cells from when they are born and they will never regenerate over time. And while there has been no legitimate evidence (involving humans) to prove our bodies can produce new brain cells throughout our lives, there have been discoveries and theories recently, in the field of neurogenesis, that have been turning heads in the scientific community. Biologists like Michael Kaplan and Joseph Altman were among the first to explore the realm of possibility of neurogenesis in the brain.

Initially, it was discovered that neurogenesis occurred in the brains of birds and later on, mammals like monkeys. Experiments were performed on monkeys and they revealed that new neurons were formed in the cerebral cortex. The latter discovery made many scientists believe that neurogenesis could in fact occur in humans as well. Scientists believe that neurogenesis occurs more effectively under certain conditions. They think that exercise and an “enriched environment” encourage neurogenesis. However, there can be adverse effects on neurogenesis as well. High stress levels as well as aging are a few factors that can be detrimental to the neurogenesis process. So even though it is still an unclear what the future will hold in the field of neurogenesis, we do know that new discoveries are just beyond the horizon.

People Use Only 10% of Their Brains

There is a common saying that people only use 10% of their brains. This is a common misconception. It has been proven that every part of the brain has a known function. This misunderstanding arose sometime in the early 1900’s when researchers either discovered that only about 10% of the neurons in the brain are firing at any given time. Either that or only 10% of brain function was able to be mapped at that time in scientific history.

            Another possible origin of this misconception is that only 10% of total brain cells are neurons. The rest of the cells in the brain are called glial cells, which do not function the same way neurons do. On a lighter note, Some New Age proponents propagate this belief by asserting that the "unused" ninety percent of the human brain is capable of exhibiting psychic powers and can be trained to perform psychokinesis and extra-sensory perception.

References:http://en.wikipedia.org/wiki/Human_brain#Common_misconceptions

Are You a Righty or a Lefty?

Alexis Gorin
Farah Laiwalla
Engineering Biomedical Systems (BI920-3B)
Tuesday, July 22, 2008

To start a conversation, a common icebreaker is "Are you right-brained or left-brained?" making the asker associate a few characteristics to your character in 5 seconds based on whichever two words you choose. While certain abilities , such as verbal language, can be associated to either the left or right side of the brain, the right brain has been shown to be able to carry out verbal language, though to a lesser extent. Other than the left brain's superior ability to carry out verbal language, both sides of the brain are similarly able to carry out each ability with only a small difference of either the right or left being the better processor (Two Brains for the Price of One).

Left and right brain interaction to control a mental ability is also necessary, to the point that one can only be unable to perform a mental ability if both sides of the brain are damaged (Two Brains for the Price of One). Using the language example from before, it has been found that while left brain controls grammar and pronunciation, the right controls the pitch of the voice, both producing the ability to verbally speak (Brain Mythology). So next time someone asks whether you are a righty or a lefty, say your both, or just show them how you write, whichever you prefer.

"Two Brains for the Price of One? ." PsyBlog. PsyBlog. 23 Jul 2008 http://www.spring.org.uk/2008/03/two-brains-for-price-of-one.php.

"Brain Mythology." Brain Fitness Channel. 2008. Posit Science Corporation. 23 Jul 2008 http://bfc.positscience.com/brain/brain_mythology.php.

Stryke three for the stryker artificial hip

Stryker industries was sent warning letters from the FDA pertaining to the quality of it's product, the stryker artificial hip. These problems resulted in the neccesity of more surgery to correct the problem caused by the device. The problems included too much residual components left on the device upon packaging, which I imagine would not be very biofriendly. Another problem, invovled the devices design itself, causing fractures and squeaking noises, though I imagine that most people getting hip replacements don't really realize the latter.
All in all I wouldn't call this product a very successful one. Such a thing can and did marr Stryker industries' reputation, as they lost considerable amounts of stock. This raises the question of, why such carelessness? Where in the design process or manufacturing process was there such a reckless abandon? Better yet, why didn't the FDA realize this problem before clearing it? I don't really have the answers as I don't posses open contact with Stryker industries, who would probably lie about how the problem developed, or the FDA, who would probably lie about how they let the problem slip during testing.


http://www.healthsquare.com/news/news-200039.htm

Myth: Sleepy After Thanksgiving Dinner

Sleepy After Thanksgiving Dinner

 

The drowsiness that many people experience after a Thanksgiving feast is not a result of the turkey alone. Instead, it is the carbohydrate rich meal that accompanies the turkey that causes people to feel sleepy. The amino acid tryptophan can be metabolized to produce serotonin, a neurotransmitter that causes a calming effect and regulates sleep. Tryptophan is found in high levels in protein rich foods, such as turkey. Yet the amount of the amino acid present in turkey is not nearly high enough to have immediate effects, and similar concentrations of tryptophan are found in other foods that do not cause any affects. Contrary to popular belief, it is the carbohydrates consumed during a meal that cause drowsiness.

Once the tryptophan is in the bloodstream, it is competing with many other amino acids to take the journey across the blood-brain barrier. When carbohydrates are consumed, the pancreas secretes insulin, which causes the competing amino acids to leave the bloodstream and enter the muscle cells. This increases the relative concentration of tryptophan in the bloodstream and allows more of it to reach the brain and become serotonin. Basically, any carbohydrate rich diet that has some protein in it can cause the familiar sleepy feeling after a meal.

 

http://chemistry.about.com/od/holidaysseasons/a/tiredturkey.htm

http://wiki.answers.com/Q/Why_does_eating_turkey_on_Thanksgiving_make_you_sleepy

Mozart Mania

Myth: Playing music such as Mozart to babies increases intelligence

Fact: Research has found that the “Mozart Effect” does not exist

The Mozart effect is defined as the “increase in brain development that occurs in children under age 3 when they listen to the music of Wolfgang Amadeus Mozart” (Skeptics’ Dictionary). The concept originated in 1993 when two physicists, Rauscher and Shaw, conducted an experiment. After a group of college students listened to Mozart, they exhibited a short-term spatial-temporal reasoning enhancement. However, despite multiple efforts, similar results were not replicated. Several years later in 1997, Rauscher and Shaw performed another experiment that uncovered the power of Mozart’s music to enhance children’s reasoning abilities:

“The experiment included three groups of preschoolers: one group received private piano/keyboard lessons and singing lessons; a second group received private computer lessons; and a third group received no training. Those children who received piano/keyboard training performed 34% higher on tests measuring spatial- temporal ability than the others. These findings indicate that music uniquely enhances higher brain functions required for mathematics, chess, science and engineering” (Neurological Research, February 1997).

The discovery of this experiment launched a new industry, especially in the media. The Mozart effect sparked books, tapes, CDs, and programs that were not backed by extensive scientific evidence. The research of one experiment published in a scientific journal became an automatic truth. The media jumped on the bandwagon while distorting and exaggerating the not-so-scientific findings.

The experiment conducted was only a fluke. While some kids did have high scores, others scored unusually low. Current research has not found any links to the Mozart effect. However, this does not mean music and the brain do no share a connection. With additional research and more controlled experiments the link between intelligence and music may be discovered.

Ego Development:
http://www.egodevelopment.com/10-debunked-myths-myths-about-our-brain/

The Skeptics' Dictionary:
http://www.skepdic.com/mozart.html

Head Injuries and Brain Cell Loss

Can a blow to the head actually lead to brain cell loss? The fact that brain cells can be lost due to head injuries is often overlooked by many when the injury is not severe. A traumatic head injury, such as a major concussion, can lead to the disconnection of some brain cells, which in turn causes cell death. Similar to how the affects of an injury can vary the seriousness of a concussion also varies. The brain basically floats inside the skull while immersed in spinal fluid. Although the skull is able to protect the brain from external trauma, it cannot absorb the impact of the force. The brain could hit the inner wall of the skull following a blow to the head, leading to bruising in the brain.
A minor concussion, or a weaker blow to the head, can leave a person vulnerable for more serious injury. Athletes who play contact sports are often prone to concussions. The dangers of a minor concussion come from the athlete continuing play with an injury that has not fully healed. The chances of the injury becoming critical are increased enough that another blow can cause rapid swelling of the brain and death.
A hit to the head can cause microscopic damage that is not visible on a CT scan, but still contains some bruising and bleeding. Many neurologists have been concerned that repeated injuries may cause problems later in life. While the injuries may appear to have healed, there can be a loss of brain cells. The loss of some brain cells may lead to additional harm to other brain cells. When it comes to the head, a person can never be too careful. There is a reason why doctors stress that athletes take time off when a head injury is involved.
References:
http://www.sciencedaily.com/releases/2008/03/080303190628.htm
http://query.nytimes.com/gst/fullpage.html?res=9500E5DC123EF932A35756C0A96E958260 http://www.neurosurgerytoday.org/what/patient_e/concussion.asp