Serotonin 2A receptor

Monoamine oxidase inhibition Serotonin reuptake inhibition Norepinephrine reuptake inhibition Dopamine reuptake inhibition a2-Adrenergic receptor blockade Serotonin-2A receptor blockade Serotonin-2C receptor blockade Serotonin-3 receptor blockade op-Adrenergic receptor blockade Histamine-1 receptor blockade Muscarinic cholinergic receptor blockade... 

Lin, C. H., Tsai, S. J., Yu, Y. W. etal. (1999). No evidence for association of serotonin-2A receptor variant (102T/C) with schizophrenia or clozapine response in a Chinese population. Neuroreport 10, 57-60. 

Minov, C., Baghai, T.C., Schule, C. etal. (2001). Serotonin-2A-receptor and -transporter polymorphisms lack of association in patients with major depression. Neurosci. Lett., 303, 119-22. 

Inayama Y, Yoneda H, Sakai T, Ishida T, Nonomura Y, Kono Y et al. Positive association between a DNA sequence variant in the serotonin 2A receptor gene and schizophrenia. Am J Med Genet 1996 67[1] 103 105. 

Segman RH, Heresco-Levy U, Finkel B, Goltser T, Shalem R, Schlafman M et al. Association between the serotonin 2A receptor gene and tardive dyskinesia in chronic schizophrenia. Mol Psychiatry 2001 6(2) 225-229. 

Levitan, R. D., Masellis, M., Basile, V. S., et al. (2002) Polymorphism of the serotonin-2A receptor gene (HTR2A) associated with childhood attention deficit hyperactivity disorder (ADHD) in adult women with seasonal affective disorder. J. Ajfect. Disord. 71, 229-233. 

Vaquero, L. C., Baca-Garda, E., az-Hemandez, M., et al. (2006) Association between the T102C polymorphism of the serotonin-2A receptor gene and schizophrenia. Prog. Neuropsychopharmacol. Biol. Psychiatry. 30, 1136-1138. 

Chen, R. Y., Sham, P., Chen, E. Y., et al. (2001) No association between T102C polymorphism of serotonin-2A receptor gene and clinical phenotypes of Chinese schizophrenic patients. Psychiatry Res. 105, 175-185. 

Czerskl, P. M.,Leszczynska-Rodziewicz, A., Dmitrzak-Weglarz,M.,et al. (2003) Association analysis of serotonin 2A receptor gene T102C polymorphism and schizophrenia. World J. Biol. Psychiatry. 4, 69-73. 

Pandey GN, Pandey SC, Dwivedi Y, et al. Platelet serotonin-2A receptors a potential biological marker for suicidal behavior. Am J Psychiatry 1995 156 850-855. 

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. 

Some of the tricyclic antidepressants also have the ability to block serotonin 2A receptors, which may contribute to the therapeutic actions of those agents with this property. Blockade of serotonin 2A receptors is discussed in Chapter 7. Tricyclic antidepressants also block sodium channels in the heart and brain, which can cause cardiac arrhythmias and cardiac arrest in overdose, as well as seizures. 

Several antidepressants share the ability to block serotonin 2A receptors as well as serotonin reuptake. In fact, some of the tricyclic antidepressants, such as amitriptyline, nortriptyline, doxepine, and especially amoxapine, have this combination of actions at the serotonin synapse. Since the potency of blockade of serotonin 2A receptors varies considerably among the tricyclics, it is not clear how important this action is to the therapeutic actions of tricyclic antidepressants in general. 

Another antidepressant, namely trazodone, also has significant sedating properties. This may be due to its serotonin 2A antagonist properties, which may act to induce and restore slow-wave sleep (Fig. 7—14). Trazodone can be used safely with most other psychotropic drugs and so is a popular choice when a patient must take another medication that disrupts sleep, such as an SSRI. Other sedating antidepressants that block serotonin 2A receptors include mirtazapine and nefazodone. These agents are occasionally also used for their sedative-hypnotic properties. 

Serotonin 2A antagonism not only reverses dopamine 2 antagonism but causes a net increase in dopamine activity in the mesocortical dopamine pathway, where the balance between serotonin and dopamine is different from that in the nigrostriatal dopamine pathway. That is, unlike the nigrostriatal dopamine pathway, in which dopamine 2 receptors predominate, there is a preponderance of serotonin 2A receptors over dopamine 2 receptors in many parts of the cerebral cortex. Thus, in the mesocortical dopamine pathway, atypical antipsychotics with SDA properties have a more profound effect in blocking densely populated cortical serotonin 2A receptors, thereby increasing DA release, than in blocking thinly populated cortical D2 recep-... 

Hallucinogens are thought to have important actions as partial agonists at serotonin-2A receptors. True or False. 

Though psilocybin is known as a natural hallucinogen and has a reputation of being gentler than LSD, it is still known to cause panic attacks, bad trips, and to precipitate mental illness in some people. In 1998, a study at the Psychiatric University Hospital in Zurich, Switzerland, demonstrated that psilocybin produces a psychosis-like syndrome in healthy humans that is similar to early schizophrenia. The study showed that psilocybin-induced psychosis was due to serotonin-2A receptor activation and was not dependent on dopamine stimulation. 

Tsai SJ, et al. Serotonin-2A receptor polymorphism (102T/C) in mood disorders. Psychiatry Res 1999 87(2-3) 233-237. 

Du L, et al. Association of polymorphism of serotonin 2A receptor gene with suicidal ideation in major depressive disorder. Am J Med Genet 2000 96(1) 56-60. 

Ranade SS, et al. Linkage and association between serotonin 2A receptor gene polymorphisms and bipolar I disorder. Am J Med Genet 2003 121B(l) 28-34. 

Maeshima T, Shutoh F, Hamada S, et al. Serotonin 2A receptor-like immunoreactivity in rat cerebellar Purkinje cells. Neurosci Lett 1998 252 72-74. 

Ikemoto K, Nishimura A, Okado N, Mikuni M, Nishi K, Nagatsu I. Human midbrain dopamine neurons express serotonin 2A receptor an immunohistochemical demonstration. Brain Res 2000 853 377-380. 

Bray NJ, Buckland PR, Hall H, Owen MJ, O Donovan MC. The serotonin-2A receptor gene locus does not contain common polymorphism affecting mRNA levels in adult brain. Mol Psychiatry 2004 9(1) 109—114. 

Pralong D, Tomaskovic-Crook E, Opeskin K, Copolov D, Dean B. 2000. Serotonin(2A) receptors are reduced in the planum temporale from subjects with schizophrenia. Schi-zophr Res 44(1) 35-45. 

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