Serotonin system receptors

Blier P, de Montigny C (1998) Possible serotonergic mechanisms underlying the antidepressant and anti-obsessive-compulsive disorder responses. Biol Psychiatry 44 313-323 Bonasera SJ, Tecott LH (2000) Mouse models of serotonin receptor function toward agenetic dissection of serotonin systems. Pharmacol Ther 88 133-142 Bonhoeffer T (1996) Neurotrophins and activity-dependent development of the neocortex. Curr Opin Nemobiol 6 119-126... 

S-HTjc, and 5-HTj receptors may be especially involved in the serotonin system s response in anxiety. Most interest has focused around 5-HTj, drugs (buspirone, ipsapirone, gepirone, tandospirone, flesinoxan, and others]. Some preclinical data indicate that antagonists at S-HTj, S-HTj, and 5-HT3 receptors may also exert anxiolytic activity, but so far these findings have not been consistently confirmed in clinical trials. 

Hjorth S Functional differences between ascending 5-HT systems, in Serotonin, CNS Receptors and Brain Function (Advances in the Biosciences, Vol 85). Edited by Bradley PB, Handley SL, Cooper SJ, et al. Oxford, England, Pergamon, 1992,... 

A rich library of tracers exists for the dopamine Systran and perhaps also the serotonin system however, little or nothing currently exists for the assessment of many other neurotransmitter systems in the brain, some of whose receptors have been identified only recently. Pharmaceutical and biotechnology industries are major sources not only of new compounds that target these sites as candidate therapeutics but also of compounds that may serve as radiotracers to evaluate these sites and the effects of disease and treatment. The incentive and raw materials for continued development of functional imaging of the human bram will depend on the establishment of sustained collaborations between academic and government research centers and the pharmaceutical industry. 

Vetulani J, Lebrecht V, Pile A. Enhancement of responsiveness of the central serotonergic system and serotonin-2 receptor density in rat frontal cortex by electroconvulsive treatment. EurJ Pharmacol 1981 76 81. 

One example of this is the super-family of receptors organized with seven transmembrane regions (Fig. 2—3). This is a structure common to many neurotransmitter receptors that use second-messenger systems and are slow in responding (e.g., serotonin-2A receptors and beta-2 adrenergic receptors). A description of the seven-transmembrane region superfamily of receptors will be amplified below in our discussion of receptors linked to second-messenger systems. 

In terms of the noradrenergic system, this chapter has described the locus co-eruleus as that part of the brain containing the noradrenergic neurons that mediate some of the symptoms of anxiety through alpha 2 and beta adrenergic receptors. Our discussion has also extended to the role of serotonin in anxiety, which appears to be key, yet quite complex and incompletely understood. One current theory developed in this chapter is the notion that anxiolytic drugs act as partial agonists at serotonin 1A receptors. 

Ondansetron antagonizes the action of serotonin at receptors in the upper gastrointestinal tract and in the chemoreceptor trigger zone of the central nervous system. Given intravenously (IV), it prevents vomiting completely for 24 h in 40% of patients treated with high doses (>100 mg/m2) of cisplatin and in 70 to 80% of patients treated with 50 to 100 mg/m2 of cisplatin or a combination of cyclophosphamide and doxorubicin. 

In aged animal models, chronic administration of ginkgo for 3-4 weeks led to modifications in central nervous system receptors and neurotransmitters. Receptor densities increased for muscarinic, 2, and 5-HTla receptors and decreased for B-adrenoceptors. Increased serum levels of acetylcholine and norepinephrine and enhanced synaptosomal reuptake of serotonin have also been reported. Additional mechanisms that may be involved include reversible inhibition of MAO-A and MAO-B, reduced corticosterone synthesis, inhibition of amyloid-beta fibril formation, and enhanced GABA levels. 

Stout BD, Clarke WP, Berg KA. Rapid desensitization of the serotonin(2C) receptor system effector pathway and agonist dependence. J Pharmacol Exp Ther 2002 302 957-962. 

Kia HK, Miquel MC, Brisorgueil MJ, et al. Immunocytochemical localization of serotonin(lA) receptors in the rat central nervous system. J Comp Neurol 1996 365 289-305. 

A major contribution of 5-HT2C receptors to the appetite-suppressant actions of central serotonin systems was indicated by a feeding and obesity phenotype in... 

The serotonin system of the brain, like other neuromodulatory systems, has its cell bodies centrally localized, projects its widely ramifying axons throughout the brain, and interacts with its postsynaptic targets via a wide array of receptors. The serotonin neurons are localized in the raphe nuclei of the brain stem and have three physical features that contribute... 

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