Aggression serotonin system

The clinical implications of such data point to a relationship between abnormalities in the central serotonin system and self-injurious behavior. These findings have led to an interest in developing specific drugs that alter 5-HT activity to treat suicidality, impulsivity, and aggressivity independent of any specific psychiatric disorder. Central serotonin function can be enhanced by agents such as lithium and various serotonin reuptake inhibitors. Recent studies have found that the use of such agents is associated with reductions in the likelihood of suicide attempts and completions in both patients with major depression and those with cluster... 

Gammie SC, Nelson RJ (1999) Maternal aggression is reduced in neuronal nitric oxide synthase-deficient mice. J Neurosci 19 8027-8035 Caspar P, Cases O, Maroteaux L (2003) The developmental role of serotonin news from mouse molecular genetics. Nat Rev Neurosci 4 1002-1012 Gobbi G, Murphy DL, Lesch K, Blier P (2001) Modifications of the serotonergic system in mice lacking serotonin transporters an in vivo electrophysiological study. J Pharmacol Exp Ther 296 987-995... 

Most of the serotonin in the brain is in the brainstem, specifically in the raphe nuclei considerable amounts also are present in areas of the hypothalamus, the limbic system, and the pituitary gland. Current evidence indicates that serotonin is involved in the regulation of several aspects of behavior, including sleep, pain perception, depression, sexual activity, and aggressiveness. Some of the most important antidepressant agents are believed to prevent the reuptake of serotonin (see Chapter 33). Serotonin also may be involved in temperature regulation and in the hypothalamic control of the release of pituitary hormones. 

Kravitz, E.A. (2000) Serotonin and aggression insights gained from a lobster model system and speculations on the role of amine neurons in a complex behavior. / Comp Physiol A 186 221-238. 

In children who drink juices containing aspartame, hypersensitivity has been observed and an increased tendency toward aggressive behavior has been observed. It has been found that aspartame intake leads to doubling phenylalanine concentration in the central nervous system. Also an increase in tyrosine has been observed, followed by a decrease of tryptophan—a serotonine precursor. Low CNS serotonine in children has been found to be responsible for neurosis symptoms. 

Laborit, H. Correlations between Protein and Serotonin Synthesis during Various Activities of the Central Nervous System (slow and desynchronized sleep, learning and memory, sexual activity, morphine tolerance, aggressiveness, and pharmacological action of sodium gamma-hydroxybutyrate). Research Communications in Chemical Pathology and Pharmacology 3 (1) (1972) 58-81. 

Regulation of mood, sleep, and aggression have all been shown to involve the serotoninergic system (17-19), and most antidepressant drugs currently being used inhibit 5-HT reuptake and/or act on 5-HT receptors (of which there are several subtypes). 5-HT is produced centrally from the amino acid tryptophan, and depressed mood can be induced experimentally by acute tryptophan depletion in healthy individuals. This effect is accentuated in those with a family history of depression (18-21). Similarly, depressive relapse can be initiated in individuals treated with MAO inhibitors or selective serotonin reuptake (SSRI) inhibitors by depleting tryptophan (22, 23). 

A number of reviews have described the important role that serotonin, a derivative of tryptophan, plays within the central nervous system.22-24 Also, Chapter 7 reviewed the importance of serotonin in selected diseases of the central nervous system. Serotonin neurons participate in a wide range of behaviors, including sleep, feeding, aggression, locomotor activity, and pain sensitivity.25 Dietary manipulations that alter brain tryptophan levels can, in animals and in humans, affect many of these behaviors. Several examples of these effects are cited. 

The symptoms of premenstrual syndrome (PMS), also called premenstrual dysphoric disorder, include depressed mood, anxiety, affective lability, and anger or irritability.79 Since low serotonin levels are thought to be involved in the etiology of depression, aggression, and impulsivity,80 specific serotonin reuptake inhibitors have been tested in PMS. The SSRI fluoxetine was found to be better than placebo.81 Since chronic treatment with SSRIs can influence many neuron systems other than serotonin,82 Steinberg et al.83 designed a study using tryptophan, relatively specific for its effect on serotonin, on the effects of symptoms of PMS. In a randomized controlled clinical trial, 37... 

Serotonin (5-hydroxytryptamine 5-HT) is involved in the regulation of the cardiovascular and respiratory systems, sleep, aggression, sexual behavior, food intake, anxiety, mood, motor output, neuroendocrine secretion, nociception, and analgesia. 

Serotonin has been linked to aggressive behavior as a result of activation of the limbic system (olfactory bulb, amygdala, and hypothalamus), the prefrontal cortex, and a region of the periaqueductal gray (Wood et al., 2006). 

---