Brain Imaging sheds light on the physical nature of addiction control

Does a custom tailored program for getting a person to stop smoking work better than a one-size-fits all generic program? A new study published in Nature: Neuroscience seems to think so. Using brain imaging and statistics the study produces strong data that could result in radical changes to how we treat addicts.

Researchers have determined that using individually tailored method to induce smokers to quit has proven more effective than generic non-personalized treatment. Researchers used MRI brain scans to measure which part of the brain was activated while the participant was thinking about him or herself and used that data to predict how likely a participant was to quit smoking. What they found was that increased activity in certain parts of the brain was associated with introspective thinking was also linked with increased likelihood of quitting. The activation around these regions that are associated with thinking about one’s self showed a treatment that caused the patient to think about the personal impact of smoking to be more effective than a one size fits all approach. This finding has implications not just for research on smokers but for all treatment that involves self improvement whether that is weight loss or substance abuse. The link between introspective thinking, certain specific brain activity, and the resultant positive behavioral change had never been analyzed in a study before until now.

It has long been suggested that a tailored approach to patients with a behavioral problem was more effective than a generic one (as evidenced by the recent increase in high end “luxury” recovery centers such as this one in Malibu), however, the physical reasons for why this is the case have still been mostly unknown. While scanning the participants brains while exposing them to various messaging the researchers have finally shed some light on the physical underpinnings of this phenomenon. The messages ranged from neutral (“Sighted in the Pacific Ocean, the world's tallest sea wave was 112 feet.”) to untailored (“Many smokers quit because they are tired of spending money on cigarettes.”) to specific tailored messages (“You feel like your sister will help you stay on track once you quit.”) When subjected to this third type of message, the areas of the brain thought to be associated with thinking about one’s self – the prefrontal cortex and precuneus regions - showed significantly more activity.

Your brain when you look in the mirror

The researchers did not stop at merely identifying the relevant portions of the brain activated by custom tailored messaging, however. They then used this data to reliably predict which participants quit smoking 4 months later and which did not. In the third portion of the study the participants completed an intervention course – some tailored, others generic – and were given anti-smoking books as well as a 10 week supply of nicotine patches. When the researcher’s followed up 4 months later, they found those that exhibited the strongest responses in their prefrontal cortex were the mostly likely to have quit smoking. For the first time researchers have shed some light on the physical reasons why these personalized approaches work so well. This find paves the way for further research into an area that could have profound implications for behavioral science – particularly addiction control.

What shouldn’t get lost in the science behind this discovery is the fact that according to the CDC smoking is the single most preventable cause of disease, disability, and death in the United States with over 443,000 people dying annually. This discovery opens the door to a wealth of new research into the very best way to combat the plague of addiction. Without fully understanding the underlying physical characteristics of addiction – and more importantly – addiction control, one cannot truly solve the problem.

References:

Chua, Hannah F., S. S. Ho, Agnes J. Jasinska, Thad A. Polk, Robert C. Welsh, Israel Liberzon, and Victor J. Strecher. "Self-related Neural Response to Tailored Smoking-cessation Messages Predicts Quitting." Nature Neuroscience (2011). Web. 15 Mar. 2011.

When a drug becomes a medicine...

Have you ever wondered what our world would be like if the answer to solving the mysteries of a severe disease such as cancer or an inflammatory disease was within the components of an illegal drug that most sick patients cannot obtain? Most people often associate a negative response to the word drug anytime they hear it or see it. This is because the only information people have received about this drug is negative. What these people do not realize though is that there are also positive impacts that this drug can have on our people and world. This drug has many different names but is most commonly known as marijuana.

Marijuana is from the hemp plant Cannabis Sativa. There are several components of this plant that are active when this drug is used. The main active chemical is called delta-9-tetrahydrocannabinol or THC for short. Marijuana is most commonly smoked, resulting in THC getting into the bloodstream, which carries the chemical to the brain and other organs of our bodies.

Recent studies have increased the concentration of medical interest in new anti-inflammatory therapies. Researchers have begun to test the effects that components of cannabinoids, any of the chemical compounds that are the active principles of marijuana, would have on immune functions. They have found out that these components of cannibinoids, such as THC, can change immune functions and they therefore have the possibility for treating inflammatory diseases.

Atherosclerosis is a chronic inflammatory disease in which a combination of fatty deposits and inflammation leads to ‘plaques’ that obstruct coronary arteries, and is the primary cause of heart disease and stroke in Western countries. This disease can occur after plaque ruptures, which result in blood clots, and thrombosis (formation of a blood clot). Current treatments for atherosclerosis use medicines that lower plasma cholesterol concentration and that lower blood pressure. These current treatments have proven to have a positive effect on atherosclerosis patients but atherosclerosis is still the number one cause of heart disease and stroke in Western countries. Immunosuppressive and anti-inflammatory effects of cannabinoids have been reported lately and these newer therapies are of great interest to the medical world. Researchers specifically experimented the effects that THC would have on this particular inflammatory disease.

Figure 1 –Representative cryosections showing CB2 receptor expression (pink staining) in human coronary atherosclerotic lesion.

Based on research from other successful treatments using cannibinoids, receptors for THC were identified on several types of immune cells. There are two different receptors, CB1 and CB2, but the CB2 receptor is found primarily on cells of the immune system. The CB2 receptor is what makes the positive effects of cannabinoids on immune cells possible. Researchers found that CB2 receptors were in fact in atherosclerotic plaques of human and mouse diseased arteries, but there were no CB2 receptors observed in non-diseased arteries. CB2 receptors are shown by macrophages (white blood cells that take in foreign material) and T lymphocytes (white blood cells that play a role in cell-mediated immunity) within atherosclerotic lesions. This suggests that cannabinoid elements may be a valuable, positive feature to the treatment of atherosclerosis.

Figure 2—The cannabinoid receptor CB2 is expressed on macrophages and T lymphocytes within plaques.

Researchers examined the effects of THC on rodents who have advanced atherosclerosis. The mice were given a high-cholesterol diet for five weeks, and then THC was given to them orally for the next 6 weeks. The dose of THC given to the mice was 1 mg kg ^-1. It was observed that after the high-cholesterol diet, atherosclerotic lesions were visible within the mice. After the 11-weeks of research, the THC- treated mice showed a major decrease of the disease progression. To make sure the anti-atherosclerotic effect of THC was made possible through the CB2 receptor, the researchers performed more experiments using THC without the presence of the CB2 receptor. Without a CB2 receptor, the atherosclerotic lesions could not be abolished.

In conclusion, after this particular experiment THC was found to have the potential to treat atherosclerosis. This can only mean that cannabinoids should be considered a medicine or cure for this particular disease. The only drawback is that this drug is illegal in several places and most people still have a negative opinion of marijuana. If people start to realize the potential marijuana has to be a medicine, then hopefully more studies will be done to treat other severe diseases. Hopefully soon, the world will realize that this drug is in fact, a medicine.

Works Cited:

Steffens, Sabine, and Niels R. Veillard, et al. “Low dose oral cannibinoid therapy reduces progression of atherosclerosis in mice.” Nature 434 (2005): 782-786. Print.

Other links relating to blog:

http://www.medicalmarijuanablog.com/

S.O.S Save Our Species

We have all heard about extinctions of the tropical world and species. But do we really know how serious it actually is and how it can affect our planet in the long run? Mammals, amphibians, and birds are slowly disappearing due to many environmental factors. Logging, agriculture, habitat loss, and urban movement can all cause problems for our native species disappearing. I don’t know about you, but I don’t want to see panda bears, polar bears, or tigers disappearing in our near future. The zoo would be a ghost town without them. They are what make this world of animal life so unique. I can’t imagine a zoo without polar bears, tigers, or even chimpanzees. They are what attract people to the zoo. However, researchers have found five “environmental synergisms”, which is the interaction of many elements and then when they are combined, their total effect is much greater than the individual effect would be, and that are affecting the disappearance of our species.

What people do not realize is that there are several other factors that can affect our wildlife and our species. Hunting, fire, and invasive species in new territories can ruin wildlife for many, causing them to migrate into a new environment that may not fit their needs. From research found by William F. Laurance and Diana C. Useche, it is said that due to the rise of climate change it can sometimes conflict with other threats. What has always been hard for researchers to predict with all of these threats is how big of an impact they can make on the environment and the species that lie within them. William F. Laurance and Diana C. Useche, part of the Smithsonian Tropical Research Institute, research the many threats that could be used against extinct species and species that could become extinct. Through this, they came up with five synergisms that could affect large tropical ecosystems and their species.

What really is a synergism and how does it affect the environment?

Synergisms have become a very popular topic in the science area especially dealing with the extinction of species. Synergisms are like a disease, something that almost can’t be stopped to save these species and their wildlife. Through research, it is believed that synergisms could be linked with chemical pollutants that could ultimately affect human and wildlife health. Myers, is a researcher, who believed that environmental synergisms could lead to the extinction of many wildlife species. He added that fire, drought, pollution, and fragmentation could also make an impact on the lives of these species. To give you an idea of how many synergisms there are out there and how it can affect the environment, the International Union for Conversation of Nature researchers narrowed some information they gathered and made it into a chart to give a clearer view on how it can affect our wildlife and species. The number one threat that would affect amphibians, birds and mammals would be agriculture. According to the chart, 17.0 mammals would be extinct, 10.0 birds, and 26.6 amphibians. There is no time period given in which these animals would become extinct, but it is just an estimation of how many species would become extinct. The threat is livestock, wood, and pulp plantations would eventually ruin these plants and species. However, it was interesting to see that roads, energy, and disturbance could cause a huge threat to these species. Some of the main threats that we would think of that were on the chart were hunting, climate, pollution, invaders, and agriculture. All of these have dangerous affects that could potentially have very harmful effects to these species.



(Photo by W.F.I)
Above is a picture that was taken in logged forest in central Africa.



What is the biggest threat to species?

The largest threat to species by far is hunting and agriculture. This may not be surprising to many, however, other threats popped to my mind first such as climate change. It is said that there is a connection between forest loss, fragmentation, and hunting. For example, species that live in small forests that are fragmented are more likely to be susceptible to hunters. Think back to any friends or family members you have that go out in the small country woods hunting for deer, peasants, or even quail. The woods and forests they go into are fragmented with species inclined to being caught by their hunters. One land use that is used everywhere is the combination of hunting and logging. Logging and hunting has become a problem in many forests today. It is growing especially across the tropics and what is even worse about the whole situation is that these hunters are going into the only last surviving forests in the tropics that contain many wonderful species that exist in our world today. Some of the forests in which these hunters are going may sound familiar to you such as the Amazon, which we have all heard about of some sort, the Congo Basin, New Guinea, and Borneo.

It is not the largest threat to species, but logging and fire can pose a dangerous threat to the land of the species. Natural fires have been affected by logging which can cause debris in the forest’s understory. The understory can be affected majorly by logging. Logging lets in sunlight and wind, which can damage the understory of the forest. This can be very dangerous not only for the environment of the forest but also for the species that live within the forest. Some animals are very sensitive by smoke of the fire which can cause a decline in the species or even a disappearance.



Figure 4. Incidence of surface fires (as revealed by 14years of satellite imagery) near forest edges in eastern Amazonia (adapted from Cochrane & Laurance 2002).
Above is a chart which shows the fire frequency and how much forest land it burns.







It is sad to think that we have people in our world today that are still going through some of last surviving forests and are destroying them by logging, hunting, or even starting forest fires. What can we do to stop this? Will there ever be an ending to this? Or when will it get to the point where so many species are extinct there is nothing we can do about it? Logging, hunting, agriculture, pathogens, climate change, and habitat change are all synergisms that are harmful to our environment. What I want to know is when will people come to their senses and let the species live their lives? S.O.S: Save our Species!


Works Cited
1). Laurance, William F., and Diana C. Useche. “Environmental Synergisms and Extinctions of Tropical Species”. Conservation Biology 23.6 (2009): 1427-1437. Academic Search Premier. EBSCO Web. 16 Mar. 2011.

Do your genes make you dizzy?

Tibetans and Andeans evolutionarily evolved to live at high altitudes

Only a few days ago I went hiking in Colorado’s tall Front Range Mountains. Man, was I in for a doozy! Coming from Raleigh, North Carolina, where the elevation is a mere 315 feet (or 96 meters), I was warned of the symptoms that may occur as I stepped off the airplane in Colorado Springs, elevation 1,893.5 m. To acclimate myself to the high altitude a friend suggested we first travel to the nearest mountaintop: Pikes Peak, elevation 4,302 m. As we neared the top in our rent-a-van, I notice that I was breathing faster, which made me lightheaded and fatigued. As my head pounded, I asked myself: How do people live up here? Are they born with superpowers?

Yes, genetic superpowers! Anthropologist and cardiologist at the Case Western Reserve University in Ohio study Tibetan and Andean populations because they have evolved to cope with the continual stress of high-altitude-living. Evidence of Darwin’s theory of natural selection happens every day in these two very separate regions of the world. Exhibit A:

Hearty, healthy babies.

A study by Cynthia Beall shows that because of generations of adaptive genes, mothers on both continents have heavier babies due to a successful increase of oxygen delivered to their uterus and placenta during pregnancy. This is a great accomplishment because in altitudes as high as the Tibetan Plateau (average 4,500m) oxygen is hard to come by.

Lowlanders, like me, on the other hand travel to such elevations in constant fear of altitude sickness. Climbers and mountaineers all over the world can relate. In fear of altitude sickness, and potentially fatal conditions like pulmonary hypertension, these adventurers take a combination of drug-store-bought Diamox (to relieve blood pressure) and Viagra (to dilate blood vessels). Diamox however is a diuretic and can lead to dehydration, whereas Viagra tends to mainly affect just a localized area. ;)

Altitude sickness, called “high-altitude hypoxia” by the medical world, is very common in lowlanders. High-altitude hypoxia is a term that refers to the human response to less than normal amounts of oxygen in the atmosphere. Incidentally for lowlanders their physiological response doesn’t make much sense. The body kicks into survival mode, realizing the need for oxygen. Quickly, blood vessels constrict in order to efficiently direct the available oxygen to the most important places in the body. Exhaustively, your body demands that you take more and more breaths to deliver the same amount of oxygen to your bloodstream. Though as you climb in altitude, atmospheric pressures drops, meaning that there is less available oxygen in the air. The resulting lowlander is apt to look and function like a modern day Frankenstein. It can take weeks, and even months, to acclimate to these high-altitude conditions.

Dr. Michael Callahan, program manager at the Defense Advanced Research Projects Agency (DARPA), recognizes the need for function at high altitudes. Employed and funded by the US Department of Defense, Callahan’s knows that researching ways to speed up the acclimatization process could immediately aid our troops involved in mountain warfare abroad. Understanding exactly where adaptations can be made is highly important for research.

Beall’s study revealed that Andeans and Tibetans (at ~3,700m) accomplish healthy reproduction using two different pathways of evolution. While similarly maintaining regular basal metabolic rates (minimum amt energy needed to regulate body temp, heart rate, breathing), upholding maximal oxygen uptake and common range of oxygen delivery to organs; these populations breathed at different rates, their blood flowed at different rates and the had differing levels of hemoglobin in their blood. Hemoglobin is important because it acts like velcro to oxygen, carrying it into the mitochondria of each cell for energy production.

On exposure to high altitude, Tibetans retained the (lowlander) trait of increased ventilation, which sustained persistent levels of hypoxic stress. Yet, because of less velcroed hemoglobin there were lesser amounts of the oxygen content in their blood. Nevertheless, they consistently displayed low blood pressure.

According to Jonathan Stamler, cardiologist and funded DARPA researcher at the Case Western, nitric oxide that binds to hemoglobin helps regulate blood vessel dilation, which “helps explain the healthy blood flow of Tibetan highlanders.” DARPA has released pilot experiments that demonstrate that by inhaling eythl nitric oxide, one can improve their blood oxygenation.

Andeans on the other hand breathe slower and receive greater intake of oxygen into their blood. Due to greater amounts of a protein called Erythropoietin, a builder-block that boosts hemoglobin, their blood pressure is consistently well above average. Thus, they are all prone to cases pulmonary hypertension from day one.

Erythropoietin is infamously known as the performance-enhancing drug abused in the Tour de France. What happens if these adaptations become available to a larger audience?

Scientists all around the world are coming closer and closer to alienating the specific genes that are associated with these adapted traits. But as climbers continue to climb, troops to scale and Tibetans to breath, we all must remember the motivation behind our ascent. What will happen if humans adapt to living at all altitudes?

References:

Beall, Cynthia M. "Two Routes to Functional Adaptation: Tibetan and Andean High-altitude Natives." PNAS 104.May (2007): 8655-8660. Print.

Borrell, Brendan. "Mountains to Climb." Nature Medicine 16.11 (2010): 1176-1179. Print.

The Real Differences between Men and Women

The age old gender investigation into the psychological differences between men and woman's sexuality is placed under a microscope.

Letitia Anne Peplau’s research into the differences between men and women’s sexuality provides facts which are easily observed in most heterosexual relationships. In an interesting twist, Peplau extends this quite common investigation to the male or female dynamics in homosexual relationships. The aspects through which Peplau explores these gender differences are sexual desire, sexuality and relationships, sexuality and aggression, and sexual plasticity. Much of the mostly empirical or statistical evidence gathered tends to suggest that the consistent differences in sexuality found in men and women in heterosexual relationships transcends also into the dynamics of homosexual relationships.

Sexual Desire

The amount or intensity of interest in sexual objects or activities is known as a person’s sexual desire. Through many empirical experiences society has come to deem men as having more or greater sexual desire than women. Peplau, in her study, has used frequency of masturbation as a way to quantify a person’s sexual desire as it relies almost completely on the person’s self and not on a partner. The statistics of the study showed that male participants not only started masturbation at an earlier age than female participants but also do so more often. Empirically, it was also found that in heterosexual couples, men preferred to have sex more often than their partners. This, understandably, was found to cause some disagreements about sexual frequency. In homosexual couples, sexual desire was found to be of more equality between partners. Studies show that lesbian couples are likely to have less sex than the average heterosexual couple, while gay couples are likely to have more sex.

Sexuality and Relationships

Also a common cliché in society is the concept that women tend to require a committed emotional relationship from which a sexual one should derive. When asked to define sexual desire women are more likely to place emphasis on the emotional attachment in contrast to men who express more the longing for physical rather than emotional pleasure. Additionally, men tend to consider premarital and extramarital sex more acceptable than women. When a group of young men and women were asked to recount sexual dreams, there was a noticeable difference in the main focuses of the dreams. Women’s tended to be more focused a person that they knew and already had an emotional relationship with. Men, on the other hand, involved strangers or multiple sex partners and focus much more on the sexual acts and organs. In homosexual cases, many of the same gender roles are found. Sexual promiscuity is much more likely to be found in gay males than with lesbians. Additionally gay men in homosexual relationships are more likely to cheat on their partner by having sex with a man outside of the relationship.

Sexuality and Aggression

Aggression is much more closely linked to sexuality with men than with women. When asked to characterize dimensions of their own sexuality, both men and women seem to take some aspect of passion into respect, rating themselves either very passionate or not very passionate. One aspect, however, that was unique to the men’s responses related to aggression. Men seem (proud) to take specifically into account their aggressiveness, power and experience where women put no importance of a similar concept. In support of this, studies show that men are much more asserted than women in heterosexual relationships. In the beginning of a relationship, men are more likely to initiate physically intimate behaviour. On average, men initiate sex twice more than females do in a relationship. Although women do have many strategies to get men to have sex with them, they do not often include violence and physical force. Rape is primarily conducted by males. This is seen not only in stranger or acquaintance coercive sex but also in heterosexual relationships. This supports the theory that aggression or violence is connected to sexuality mostly in men than in women.

Sexual Plasticity

A woman’s sexual beliefs and behaviour are more malleable than those of men. A woman’s view on sex can be more easily shaped through cultural, societal and situational factors. This is, however, a likely occurrence since many findings suggest that sex is much more mechanical or physical for men than for women. Emotions vary much more than mechanical or physical needs/desires do. A prime example of this is ones sexual tendencies following a breakup. Where a woman could easily go for months without sexual encounters or masturbation after a breakup, men are more likely to turn to frivolous promiscuity. An additional sign of malleability is suggested in a study which provides evidence which states that 25% of 18- to 25-year-old women who initially identified themselves as lesbian or bisexual changed their sexual preference during the next 5 years. Such results were not as prevalent in studies of gay men.

All in all this research into gender differences in human sexuality help to shed light on the specific patterns of sexual interactions. Peplau’s investigation was of particular interest because of the transcendence of these illuminations to describe not only heterosexual relationships, but to homosexual relationships. In the psychology of sexual studies, it is important to obtain separate analysis of males and females before a proper understanding of sexuality on a whole can be reached.

Useful Links:

· http://www.npr.org/blogs/thetwo-way/2010/03/older_men_like_sex_more_than_o.html

· http://www.psychologytoday.com/blog/the-how-and-why-sex-differences/201101/how-can-there-still-be-sex-difference-even-when-there-is

· http://www.nytimes.com/2011/03/18/education/18sex.html?_r=1&scp=1&sq=gender%20differences%20sex&st=cse

Works Cited:

Human Sexuality: How Do Men and Women Differ?

Letitia Anne Peplau

Current Directions in Psychological Science
Vol. 12, No. 2 (Apr., 2003), pp. 37-40

Thanks for the Memories! Nicotine's Plot Against Cognition

We all know that adolescence is that high peak in life where we feel completely invincible and are open to try many things; this is why adolescence is also known as the “experimental stage.” Adolescents are easily influenced by their peers and sometimes fall subject to drug abuse and it is a period marked by intense vulnerability. One of the most common abuses is smoking in which about 30% of adolescents that experiment with it become established smokers. Everyone knows that smoking can cause several types of cancers, but did you know that adolescent smokers also risk damaging their cognition and attention span?

Cognition

What exactly is cognition and how is it possible that smoking can have such negative effects on it? Cognition is a broad term that refers to thinking, remembering, judging, knowing, and problem-solving. Imagination and perception are also higher-level functions of the brain categorized under cognitive behaviors.

This diagram provides a quick overview of how cognition works:



The Prefrontal Cortex

The brain has a very intricate way of communication. Nerves constantly send signals back and forth across the brain and to the rest of the body. What researchers have found is that when exposing the body to nicotine, a stimulant found in tobacco products, during adolescence there is interference and the signals are not quite making it to their terminals. This in turn causes problems with attention span and other areas associated with the prefrontal cortex. The prefrontal cortex, or PFC, is the area of the brain responsible for personality, decision making, social behavior, and cognitive behaviors.

Here’s a video that shows how important the PFC is during the adolescence stage and how it continues developing up until the mid-twenties.

As odd as it may sound, nicotine exposure during adolescence does impair the way you think, how much attention you pay, and even how you behave. Since the nerves do not receive the signals under the influence of nicotine, normal brain function is not possible and communication is reduced.

The Experiment

Researchers at VU University in Amsterdam conducted an experiment on three groups of rats. One group was given nicotine treatments from the start of the adolescence and the other was given a simple saline solution. The third group was given nicotine only during adulthood. The experiment was conducted on rats because their brain functions are consistent with those of the human brain, therefore the results could easily be applied to humans as well. Prior to the exposure of nicotine, the adolescent rats experienced “normal adolescent” behavior. It’s kind of an entertaining thought to see rats making impulsive decisions and falling for “peer pressure.”

Remember how the brain communicates? The brain uses nerves to transmit signals - you can think of them as messengers. These messengers are constantly communicating with other messengers in order to process different actions such as moving an arm or mental processes such as thinking. In order to successfully send a message there must be a terminal receptor that receives the final signal. Inside these terminal receptors are metabotropic glutamate receptors (mGluR2). Try saying that ten times fast! The receptors are responsible for controlling excess glutamate, a chemical that plays an important role in learning and memory, release.

What researchers found in the experiment was that nicotine was severely decreasing mGluR2 which led to deficits in cognitive behaviors. The decrease in mGluR2 can be seen in the wider gaps between each interval in which the rats were stimulated (Fig. B). These tests were conducted after the adolescent rats were taken of their treatments (approximately five weeks before they reached adulthood) in order to see the full effect that nicotine had on their cognition.




During this abstinence, researchers noticed that impulsive behaviors were still present but so were other problems: the rats were having many issues with their attention spans. When compared to the rats only exposed to nicotine during adulthood the results were extremely different. The adult rats were only experiencing some behavioral changes unlike the adolescent rats that were losing their minds. Since the PFC is still developing during adolescence, alterations made to it can lead to negative results in adulthood. The alterations in mGluR2 were significant enough to make an impact because the receptors are directly linked to cognitive behaviors, so disturbances during development can only end with irreversible consequences in the future. Does this mean that smoking in adulthood is “better” than smoking during adolescence? Not necessarily, but this shows how vulnerable the stage of adolescence can be. Because adolescence is a major stage in human development, bad habits that start early often lead to dire consequences.


The Results

Researchers found that nicotine did in fact lower mGluR2 activity which caused the cognitive disturbances simply because the signals were not being received. Nicotine served as a barrier in adolescent rats and the results included increase in impulsivity, impaired attention span, and other defects in cognitive behaviors. When compared to the third group of rats that were only treated with nicotine during adulthood, the adolescent rats were showing lasting effects that the adult rats were not.

One important thing to note is that when researchers increased mGluR2 levels in the adolescent rats the symptoms were not expressed as much, but this was not a “cure” because they still showed poor cognitive activity in adulthood.

Moral of the story for adolescents, think before you choose to be a part of the 30% "experimenters" that become smokers so that maybe you can still have the ability to think, focus, and remember when you are an adult.

Reference

Mansvelder, Pattij, Spijker. “Lasting synaptic changes underlie attention deficits caused by nicotine exposure during adolescence.” Nature Neuroscience: Brief Communication doi:10.1038/nn.2770 (2011): n. pag. Web. 20 March 2011.

Interesting Links

http://www.landesbioscience.com/curie/chapter/683/

http://www.psychologytoday.com/blog/the-skeptical-brain/201012/attention-and-the-hemispheres