I’m not sure if my readership is large enough for this question to be fruitful but I figured it can’t hurt to ask.

Everyone knows the brain forms new connections all the time. It is one of the few fundamental ideas in neuroscience every person knows, regardless of if you are an neuroscientist or restaurant waitress. And yet I’m having a very hard time finding more information on the subject. Currently, synapses in DN are permanent. Each phenotype grows its web of connections and then retains them with no change until death. This is clearly wrong and on my list of things to change but I’m not sure how the process occurs in our brains.

I believe the term used to describe the process is synaptogenesis. But I’m not sure the rules that govern synaptogenesis. What makes one neuron connect to another? Do neurons clump together based on similar shared neurotransmitters? Do they have a geographical preference for connections? Are there external factors that direct dendrite growth? Or is it just plain random?

Furthermore, people talk about losing weak connections. What makes a neuron decide “You know what, this connection is too weak for my liking, I’m going to drop it”? Is there an internal counter of some sort that monitors synapse firing, dropping the connection when it gets too low? Can a synapse get dropped even if it fires often?

A common fallacy people seem to have is that the capabilities of the human brain is unlimited. The human brain for sure is extremely powerful and amazingly flexible, but not infinite. Higher intelligence and specialization comes at the cost of losing general perceptual abilities.

A study from the University of Massachusetts at Amherst showed that infants 6 months in age were capable of differentiating equally well between two human faces and two monkey faces. Nine-month old infants, however, could only differentiate between two human faces. They had lost their ability to differentiate the two different monkey faces.

The study also demonstrated that 6 month old infants could tell the difference between sounds from nearly every language while older 9 month old infants had lost this ability. It is little wonder that prevailing wisdom suggests teaching second or third languages is most efficient during childhood.

According to Scott, “what is most intriguing about these findings is that they collectively suggest that typical perceptual specialization and development is characterized by the gradual decline of abilities, not just gaining new ones.” Coincident with this decline, the brain is experiencing an exuberance of synaptic connections, followed by the pruning of these connections to adult levels.

I would assume this narrowing of perception is the same concept at work as the filtering mechanism that prevents background noise from becoming overwhelming. Your auditory system automatically filters out most background noise and other sounds that don’t concern you or your safety. If this system weren’t in place, one would quickly become overwhelmed with too much stimulus.

Similarly, I would guess infants “specialize” their recognition systems for the same reason. If you aren’t exposed to monkeys every day, and thus do not require the ability to differentiate between two monkey faces, there is no reason your brain will continue to use precious brain real estate for a skill never used. In this light, infants are perhaps one of the most impressive phenomena in existence. They are supremely capable of learning anything because they are aware of every stimuli. Their brains have not specialized in anything and are therefore aware of everything.

Imagine hearing and being cognitively aware of every sound, sight and smell in your environment. I know I would quickly go crazy. But infants do this on a daily basis until they learn what input is important and what can be ignored. Impressive indeed.

Straight from the department of “We didn’t see that one coming”, new research suggests that removing ovaries before menopause may lead to memory and movement problems.

Researchers found that women who had one or both ovaries removed before menopause were nearly two times more likely to develop cognitive problems or dementia compared to women who did not have the surgery. In addition, those women who were younger when their ovaries were removed were more likely to develop dementia than women who were older when their ovaries were removed.

“It’s possible that estrogen has a protective effect on the brain and that a lack of estrogen due to ovary removal may increase a woman’s risk of developing memory problems,” said study author Walter A. Rocca, MD, MPH, with the Mayo Clinic in Rochester, MN, and member of the American Academy of Neurology.

Not a neuroscience article but undeniably cool nonetheless: One species’ entire genome discovered inside another’s

Scientists at the University of Rochester and the J. Craig Venter Institute have discovered a copy of the entire genome of a bacterial parasite residing inside the genome of its host species.

Werren doesn’t believe that the Wolbachia “intentionally” insert their genes into the hosts. Rather, it is a consequence of cells routinely repairing their damaged DNA. As cells go about their regular business, they can accidentally absorb bits of DNA into their nuclei, often sewing those foreign genes into their own DNA.

“Such transfers have happened before in the distant past” notes Werren. “In our very own cells and those of nearly all plants and animals are mitochondria, special structures responsible for generating most of our cells’ supply of chemical energy. These were once bacteria that lived inside cells, much like Wolbachia does today. Mitochondria still retain their own, albeit tiny, DNA, and most of the genes moved into the nucleus in the very distant past. Like wolbachia, they have passively exchanged DNA with their host cells. It’s possible wolbachia may follow in the path of mitochondria, eventually becoming a necessary and useful part of a cell.

“In a way, wolbachia could be the next mitochondria,” says Werren. “A hundred million years from now, everyone may have a wolbachia organelle.”

Edit: Here is a fascinating article looking at the endosymbiotic properties of another small organism. Very interesting.

This is in response to a question posed by Dave over at Cognitive Daily. Dave cited a quote from a book he was reading:

Meaning is rooted in agency (the ability to act and choose), and agency depends on embodiment. In fact, this is a hard-won lesson that the artificial intelligence community has finally begun to grasp after decades of frustration: Nothing truly intelligent is going to develop in a bodiless mainframe. In real life there is no such thing as disembodied consciousness.

Discussion was then opened up regarding the plausibility of the above statement. The resulting comments quickly turned into the classic debate of “what is intelligence?” To be fair, I have no good answer to this, but I don’t believe this matters. In fact, I believe trying to define intelligence is detrimental to understanding how intelligence came to be, and therefore, how to create it.

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Garlic is one of those foods you constantly hear about. One day it is saving your heart. Another day it is boosting your immune system. Romans ate it for courage, I eat it for taste. Many people avoid it for its smell. You may even cry over it.

But your neurons will thank you the most for eating it. A recent study from the Medical University of South Carolina reveals that garlic is an excellent means of killing brain tumors. More details after the jump.
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In between bouts of painting and drywalling, as well as class and much needed napping, I’ve been able to get some more work done on Distributed Neuron. The code is fulfilling all my wildest dreams (except that one involving a beach and Jessica Alba…). It is very flexible and easy to update/manage. The time put into planning and designing a coherent layout is starting to payoff as I add features and more functionality.

Done

There are a slew of minor updates, best listed as bullet points:

-I recently implemented growth hormones as mentioned here.

-A simulation class has been built to manage the logistical details of running a simulation (physical dimensions, health blobs, location of organism, physics, etc).

-The client code is now autonomous, meaning it can recover itself from crashes as well as load new experiment/trial parameters when one trial finishes.

-Mutation has been completed on the entire genotype. Mutation is controllable by a value in the experimental parameters table, which is unaffected by mutation. This is so I can slow down or speed up mutation at will.

To Do

Oh but there is still much to do. In the next few days I am going to write up the initial fitness function. After this function is written I can begin some limited runs to create a starter population. Next on the drawing board is implementation of crossover mutation (sex FTW!) and running more lengthy trials to make sure the whole operation works.

If at that point I haven’t hit anything catastrophic, the next step is to work on the network code and start the server code. Which I’m not looking forward to but it is a necessary evil. So much to do, so little time!

Ahh, good ol’ Piracetam. If you haven’t heard about Piracetam, you are probably living in the United States (it isn’t very popular over here). Piracetam is a drug that falls into the nebulous category of nootropics. Nootropics are drugs that supposedly improve cognitive function. Not just the cognitive function of individuals with brain damage but also perfectly normal people like you and me. There has been much debate over the benefits of nootropics. Scientists are interested in piracetam to help cure diseases while common people are interested in boosting their performance.

In this spotlight I’ll be focusing on studies revolving around Piracetam’s, the first and classical nootropic. Piracetam has been used to treat a myriad of diseases with varying levels of success. More details, including my own personal tale, after the jump.
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The key to long life will most likely be found in those that live the longest. Scientists at Albert Einstein College of Medicine of Yeshiva University have taken this idea to heart and have been working on the Longevity Gene Study. It was theorized that individuals who live a long time must possess some beneficial genes that “buffer” against more harmful genotypes.

The study gathered over 1200 individuals all of Ashkenazi Jewsish descent. Since these individuals originated from a founder group of about 30,000 people, the genetic diversity is fairly small. This makes it easier to identify genes that confer longevity to their owners.

More after the jump.
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Bloggers for Peer-Reviewed Research Reporting is now hosting a contest for their icon. Winners of the contest receive free subscription to Seed Magazine, a ScienceBlogs coffee mug, and a copy of Natalie Angier’s The Canon.

If you have artistic skills, check out the contest. Details regarding the dimensions and design can be found at the contest page.