title: [Isoforms of the human histamine H3 receptor: Generation, expression in the central nervous system and functional implications].
abstract: Histamine plays a significant role as a neuromodulator in the human central nervous system. Histamine-releasing neurons are exclusively located in the tuberomammillary nucleus of the hypothalamus, project to all major areas of the brain, and participate in functions such as the regulation of sleep/wakefulness, locomotor activity, feeding and drinking, analgesia, learning, and memory. The functional effects of histamine are exerted through the activation of four G protein-coupled receptors (H1, H2, H3 and H4), and in the central nervous system the first three receptors are widely expressed. The H3 receptor (H3R) is found exclusively in neuronal cells, where it functions as auto- and hetero-receptor. One remarkable characteristic of the H3R is the existence of isoforms, generated by alternative splicing of the messenger RNA. For the human H3R, 20 isoforms have been reported; although a significant number lack those regions required for agonist binding or receptor signaling, at least five isoforms appear functional upon heterologous expression. In this work we review the evidence for the generation of human H3R isoforms, their expression, and the available information regarding the functionality of such receptors.
authors.affiliation: Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados (Cinvestav), México, D.F., México.
authors.forename: Ana Maricela
authors.initials: AM
authors.lastname: García-Gálvez
authors.affiliation: Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados (Cinvestav), México, D.F., México.
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Arias-Montaño
mesh_terms: D002490:Central Nervous System / Q000378:metabolism* / Q000502:physiology*; D015870:Gene Expression; D006801:Humans; D020033:Protein Isoforms; D018100:Receptors, Histamine H3 / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology*
chemical_list: D020033:Protein Isoforms; D018100:Receptors, Histamine H3