Download Are genes or environment more influential to serotonin levels?

 Are genes or environment more influential to serotonin levels? Low serotonin can be genetically inherited because there are certain genes that are responsible for the occurrence of this condition. On the other hand, low serotonin may also be acquired due to several reasons. One of the causes for this condition is a very long period of constant stress. Another reason that is responsible for the decreased level of serotonin is a poor and unhealthy diet without amino acids, vitamins and minerals. There are also cases when digestive disorders cause malabsorption of the vital nutrient, which has for the consequence the low level of serotonin. Furthermore, insufficient exposure to sunlight, hormonal imbalance, particularly low progesterone levels in women, excessive consuming of alcohol and nicotine and drug abuse are also some of the causes for the occurrence this condition. It is also considered that exposure to toxic heavy metals, certain chemicals and plastics can lead to serotonin deficiency. The main warning symptoms of this condition are sleep disorders, such as sleepiness, tiredness, fatigue and weakness. Furthermore, people with low serotonin levels may experience anxiety and depression, problems with concentration and memory, and low self-­‐esteem. Moreover, constant urge for sugary foods, negative thoughts, irritability, panics and phobias are also some of the warning signs of the decreased levels of this neurotransmitter. -­‐ Many studies have found that low serotonin levels in adults are linked to aggression, alcohol abuse and mental illness. But evidence to date doesn't indicate whether low serotonin causes the problems or the problems cause low serotonin. That's why Suomi, Dee Higley, PhD, and their colleagues at the National Institutes of Health (NIH) Primate Center in Poolesville, Md., study the link between behavior, serotonin and environment in rhesus monkeys. They've found that 5 percent to 10 percent of monkeys in wild and laboratory populations are unusually impulsive and aggressive. These monkeys also have the lowest levels of serotonin compared with the rest of the population. Like most researchers, Suomi and Higley estimate amounts of serotonin by measuring the concentration of the serotonin metabolite 5-­‐hydroxyindoleacetic acid (5-­‐HIAA) in the fluid surrounding the spine and brain. Monkeys with low 5-­‐HIAA demonstrate impulsive behaviors in late childhood: Their play bouts often build into fights and their peers shun them. In the lab, they're antisocial, inappropriately aggressive and will drink to intoxication if given access to alcohol. (Normally, monkeys will only drink moderately). In the wild, these monkeys seek out danger, often making risky leaps between trees that other monkeys would never attempt, said Higley, an intramural researcher at the National Institute on Alcohol Abuse and Alcoholism (NIAAA). These traits can have dire consequences. Male rhesus monkeys typically leave their home troupe at puberty and find their way into another group. But troupes oust impulsive males well before adolescence. They tend to become loners, unable to win acceptance into another troupe, are unsuccessful at mating and often die within a year, said Suomi. It is possible that there are specific genes which may be responsible for the level of production of 5-­‐HIAA. Some of these males may pass on their genes but, if 5-­‐HIAA concentration is an inherited trait, it more likely comes through the mother, said Higley. Females with low serotonin are also impulsive, aggressive and disliked, but more often reproduce. They also make poor mothers, and recent research in the lab indicates that a poor rearing environment can affect behavior and 5-­‐HIAA concentrations, said Higley. 'Just because a trait runs in families, doesn't mean it can't be influenced by the environment,' said Higley. 'Our research is a prime example that low serotonin is likely a mix of genetics and environment.' In a recent study, Higley, Suomi and NIAAA scientific director Markku Linnoila, PhD, found that monkeys raised without their mothers-­‐-­‐with only their peers for support-­‐-­‐had low 5-­‐HIAA, compared with mother-­‐reared monkeys. They measured the differences as early as 14 days of age and into adulthood. Peer-­‐reared monkeys were also socially inept and excessively aggressive-­‐-­‐more so than mother-­‐reared monkeys with low 5-­‐HIAA. These finding indicate that a poor rearing environment can aggravate behaviors already caused by low 5-­‐HIAA, the researchers concluded in Alcohol, Clinical and Experimental Research (Vol. 20, No. 4, 643-­‐649). They are now investigating whether an exceptionally good rearing environment-­‐-­‐one spent with an attentive, highly caring mother-­‐-­‐
can eliminate problems associated with low 5-­‐HIAA. SOURCE: From the APA Monitor, April, 1997, By Beth Azar SOURCE http://ic.steadyhealth.com/low_serotonin_levels.html