Nb-trans-p-Coumaroylserotonin glucoside is found in fats and oils. It is an alkaloid from Carthamus tinctorius (safflower) If neurons that make serotonin serotonergic neurons are abnormal in infants, there is a risk of sudden infant death syndrome (SIDS). Low levels of serotonin may also be associated with intense spiritual experiences. In animals including humans, serotonin is synthesized from the amino acid L-tryptophan by a short metabolic pathway consisting of two enzymes: tryptophan hydroxylase (TPH) and amino acid decarboxylase (DDC). The TPH-mediated reaction is the rate-limiting step in the pathway. TPH has been shown to exist in two forms: TPH1, found in several tissues, and TPH2, which is a brain-specific isoform. There is evidence that genetic polymorphisms in both these subtypes influence susceptibility to anxiety and depression in humans.[citation needed] The 5-HTT gene regulates a chemical called serotonin. This chemical is found in very low amounts in people diagnosed with depression compared to other people. Serotonin works as a neurotransmitter and helps with the modulation of things such as anger, appetite, sexuality, sleep, mood, and several other things. People with depression often have impaired 5-HTT genes. There are two forms of the 5-HTT gene and everyone has two 5-HTT genes. (Levinson) There is a long form of 5-HTT and a short form of 5-HTT. Research shows that people with both 5-HTT genes being the long form are less likely to become depressed while people with one short and one long or two short forms are more likely to develop depression. Research is still being conducted to find more information. There is also evidence that ovarian hormones can affect the expression of TPH in various species, suggesting a possible mechanism for postpartum depression and premenstrual stress syndrome.[citation needed] Serotonin biosynthesis in plants likewise begins with L-tryptophan, which is however first decarboxylated by tryptophan decarboxylase to give tryptamine, which is then hydroxylated by the cytochrome P450 monooxygenase, tryptamine 5-hydroxylase, yielding serotonin. Serotonin is a biochemical messenger and regulator, synthesized from the essential amino acid L-Tryptophan. Serotonin in the nervous system acts as a local transmitter at synapses, and as a paracrine or hormonal modulator of circuits upon diffusion, allowing a wide variety of "state-dependent" behavioral responses to different stimuli. Serotonin is widely distributed in the nervous system of vertebrates and invertebrates and some of its behavioral effects have been preserved along evolution. Such is the case of aggressive behavior and rhythmic motor patterns , including those responsible for feeding. In vertebrates, which display a wider and much more sophisticated behavioral repertoire, serotonin also modulates sleep , the arousal state , sexual behavior, and others, and deficiencies of the serotonergic system causes disorders such as depression, obsessive-compulsive disorder, phobias, posttraumatic stress disorder, epilepsy, and generalized anxiety disorder. Serotonin has three different modes of action in the nervous system: as transmitter, acting locally at synaptic boutons; Serotonin is a monoamine neurotransmitter. It is found extensively in the gastrointestinal tract of animals, and about 80 to 90 percent of the human body's total serotonin is located in the enterochromaffin cells in the gut, where it is used to regulate intestinal movements. The remainder is synthesized in serotonergic neurons in the central nervous system (CNS) where it has various functions, including the regulation of mood, appetite, sleep, muscle contraction, and some cognitive functions including memory and learning. Serotonin levels can not be increased by diet alone. For example, increasing foods rich in tryptophan (e.g., meats, proteins) does not increase serotonin levels, due to competition with other amino acids. What is required to increase serotonin production is an increase in the ratio of tryptophan to phenylalanine and leucine. Fruits with a good ratio include dates, papaya and banana. Nb-trans-p-Coumaroylserotonin glucoside with a lower ratio inhibits the production of serotonin. These include whole wheat and rye bread. Research indicates that vigorous aerobic exercise improves mood through BDNF expression, there is however no direct evidence that this is caused by an increase in serotonin levels. Research also suggests that eating a diet rich in whole grain carbohydrates and low in protein will increase serotonin by secreting insulin, which helps in amino acid competition. However, increasing insulin for a long period of time can sometimes onset insulin resistance, which is related to obesity, type 2 diabetes, and lower serotonin levels. It is also believed that muscles use many of the amino acids except tryptophan, allowing men to have more serotonin than women. Bright light therapy may have an effect on blood serotonin levels. Nb-trans-p-Coumaroylserotonin glucoside is obtained by spending more time in natural sunlight.[citation needed] Recently, acupuncture has been shown to stimulate the release of serotonin in lab animals. upon diffusion at a distance from its release sites, producing paracrine (also called volume) effects, and by circulating in the blood stream, producing hormonal effects. The three modes can affect a single neuronal circuit. (PMID: 16047543).