Biology 302 Discussion (Professor Anthony ONLY)

Article Critique

http://www.independent.co.uk/news/science/virus-that-makes-humans-more-stupid-discovered-9849920.html.

Posted on November 9, 2014 by the UK Independent

1. Summary/Background Information

This study expands upon claims by American scientists that they have accidentally discovered a virus that infects the brains of humans and affects their cognitive abilities, a nice way of saying that it makes people “more stupid.” The algae virus, called ATCV-1, which had never before been observed in healthy people, was found to have a modest but measurable effect on various cognitive functions including visual processing and spatial awareness. The study shows that the virus is apparently quite common in humans and can have a detrimental effect on brain function, memories, and immune response through the suppression of the brain’s normal impulses.

By means of oropharyngeal samples obtained from healthy adults, the unexpected result was the identification of DNA sequences that are homologous to ATCV-1, which was not previously known to infect humans. In addition, a mouse model was later used to confirm the relationship between the algae ATCV-1 and cognitive functions. The scientists found indications that exposure to ATCV-1 can be responsible for changes in gene expression within the brain while also providing evidence that viruses in the environment not thought to infect humans can have biological effects.

While an unrelated study into throat microbes was being undertaken, scientists at Johns Hopkins Medical School and the University of Nebraska stumbled upon the discovery. To their surprise, the researchers found that the throats of healthy individuals contained DNA that matched the DNA of a virus known to infect green algae. They tested a field of 90 participants for the study, the findings of which were published in the Proceedings of the National Academy of Sciences, and found 40 of them to test positive for the algae virus. During tests that were designed to measure the speed and accuracy of visual processing they found that those who tested positive performed worse while also achieving lower scores in tasks designed to measure attention.

The findings of this research show that there some microbes, even in an otherwise healthy human body, are capable of altering the gene expression of brain cells, which can have a negative effect on cognitive functions. ATCV-1 alters gene expression relating to "...synaptic plasticity, learning, memory formation, and the immune response to viral exposure,” according to the study abstract. This is despite the fact that most of the trillions of bacteria, viruses and fungi that we possess are harmless.

2. Discussion of the Science

The goal of the study was to study the biological effects of the wide range of microorganisms within human mucosal surfaces, which are largely unknown.

As a method to identify novel microbes in viruses, the scientists were using large-scale metagenomic sequencing in order to study large DNA viruses called chloroviruses which are known to infect certain eukaryotic green algae but have not been previously shown to infect humans. An apparent link to the algae itself was ruled out early in the study when it was found that ATCV-1 doesn’t restrict itself to swimmers. The unexpected result was the discovery of found sequences that are homologous to the chlorovirus Acanthocystis turfacea chlorella virus 1 (ATCV-1) in a metagenomic analysis of DNA once it was extracted from human oropharyngeal samples. The adult participants in the study, who were found to be free from psychiatric disorders and serious illnesses, were subject to measures of cognitive functioning through means of providing samples which were obtained by throat swabs. In samples obtained from 40 of the 92 individuals (43.5%), the presence of ATCV-1 DNA was confirmed and a modest statistically significant decrease in the performance on cognitive assessments of visual processing and visual motor speed was detected.

A model that prescribed the inoculation of 9-to-11 week old mice was then used in order to further explore the effects of ATCV-1. This model revealed that several cognitive domains, including those affecting recognition memory and sensory-motor gating, were adversely affected upon the introduction of the virus into the intestinal tract. The procedure also resulted in the altered expression of genes within the hippocampus which are meant to support the processes aiding synaptic plasticity, learning, memory formation, and the immune system’s response to viral exposure. As reported by Healthline, “In the mice, the virus broke through the blood/brain barrier and changed the activity of some genes in the brain. The genes affect neurotransmitters, including dopamine, as well as inflammation.”

3. Opinion

Having knowledge that a virus is capable of altering the function and expression of our brain cells and that the microorganisms we carry are not necessarily innocuous can obviously be very advantageous for humanity. Any knowledge of an organism that can affect behavior and cognitive abilities is worth looking into but within this study there are also concerns that a rather small sample size was employed.

It is intriguing to think that some of the characteristics that define individuals from one another are the result of the various microorganisms that are ingrained in us and profoundly affect the way that the brain interacts with our genes. Apparently, in nearly half the population not all of human behavior patterns are entirely subject to DNA in the set of genes each inherits from parents.

What I personally would like to see the scientists do as a follow-up to this study is to target specific individuals who have been identified by their peers as “brilliant” in every way except for those involving cognitive skills and memory to see how many of them are unknowingly affected with this virus. We’ve heard of students who are tremendous achievers in academia but who also have trouble at times remembering very simple things like the directions to their home or how to tie their shoes. We may also have heard of successful people who can solve any complicated problem put in front of them with ease and yet can’t remember what they ate for dinner last night. Just as the behavior of many can be explained by the presence of mild cases of autism or Asperger’s Syndrome, perhaps an untreated algae virus that obstructs the brain’s relationship with cognition is a problem for many people.

4. Real World Application

On many levels, the achievement of this study is simply that it introduced a hypothesis that is worth looking at closely. There are numerous questions that remain apart from the legitimate question of whether a sample size of 90 people hailing from a common geographical area is enough to make a sound judgment. One obstacle that is yet to be close to being solved is, how does one acquire-or for that matter, avoid-this virus? It is perhaps even more intriguing to consider how long this virus has been present within and among mankind or how it ever got from algae to people. But should further study reveal the answers to these inquiries, science could provide a means of improving the memory and problem-solving abilities of entrepreneurs, students, and perhaps most importantly, scientists who may not realize that they are not reaching their fullest potential due to an inhibiting virus that potential affects roughly 40% of the populace. A positive identification of ATCV-1 and its treatment, leading to its eventual eradication, could serve as a potential boon to human productivity throughout the world.

References:

Tufft, B. (2014). Virus that 'makes humans more stupid' discovered. Retrieved from HYPERLINK http://www.independent.co.uk/news/science/virus-that-makes-humans-more-stupid-discovered-9849920.html.

Van Etten, J (2014). Chlorovirus ATCV-1 is part of the human oropharyngeal virome and is associated with changes in cognitive functions in humans and mice. Retrieved from HYPERLINK http://www.pnas.org/content/111/45/16106.abstract