title: Histamine H3receptor activation stimulates calcium mobilization in a subpopulation of rat striatal neurons in primary culture, but not in synaptosomes.
abstract: The histamine H3receptor (H3R) is abundantly expressed in the Central Nervous System where it regulates several functions pre and postsynaptically. H3Rs couple to Gαi/oproteins and trigger or modulate several intracellular signaling pathways, including the cAMP/PKA pathway and the opening of N- and P/Q-type voltage-gated Ca2+channels. In transfected cells, activation of the human H3R of 445 amino acids (hH3R445) results in phospholipase C (PLC) stimulation and release of Ca2+from intracellular stores. In this work we have studied whether H3R activation induces Ca2+mobilization from intracellular stores in native systems, either isolated nerve terminals (synaptosomes) or neurons in primary culture. In rat striatal synaptosomes H3R activation induced inositol 1,4,5-trisphosphate (IP3) formation but failed to increase the intracellular calcium concentration ([Ca2+]i). In striatal primary cultures H3R activation resulted in IP3formation and increased the [Ca2+]iin 18 out of 70 cells that responded with an elevation in the [Ca2+]ito membrane depolarization with KCl (100 mM) as evaluated by microfluorometry. Confocal microscopy studies corroborated the increase in [Ca2+]i induced by H3R activation in a fraction of those cells that were responsive to membrane depolarization. These results indicate that H3R activation stimulates the PLC/IP3/Ca2+pathway but only in a subpopulation of striatal neurons.
authors.affiliation: Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del IPN, Av. IPN 2508, Zacatenco, 07360, México, D.F., México.
authors.forename: Nayeli
authors.initials: N
authors.lastname: Rivera-Ramírez
authors.affiliation: Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del IPN, Av. IPN 2508, Zacatenco, 07360, México, D.F., México.
authors.forename: Wilber
authors.initials: W
authors.lastname: Montejo-López
authors.affiliation: Departamento de Bioquímica, Centro de Investigación y de Estudios Avanzados del IPN, Av. IPN 2508, Zacatenco, 07360, México, D.F., México.
authors.forename: María-Cristina
authors.initials: MC
authors.lastname: López-Méndez
authors.affiliation: Departamento de Bioquímica, Centro de Investigación y de Estudios Avanzados del IPN, Av. IPN 2508, Zacatenco, 07360, México, D.F., México.
authors.forename: Agustín
authors.initials: A
authors.lastname: Guerrero-Hernández
authors.affiliation: Departamento de Biología Celular, Instituto Nacional de Perinatología, Montes Urales 800, 11000, México, D.F., México.
authors.forename: Anayansi
authors.initials: A
authors.lastname: Molina-Hernández
authors.affiliation: Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del IPN, Av. IPN 2508, Zacatenco, 07360, México, D.F., México.
authors.forename: Ubaldo
authors.initials: U
authors.lastname: García-Hernández
authors.affiliation: Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del IPN, Av. IPN 2508, Zacatenco, 07360, México, D.F., México. Electronic address: jaarias@fisio.cinvestav.mx.
authors.forename: José-Antonio
authors.initials: JA
authors.lastname: Arias-Montaño
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D000697:Central Nervous System Stimulants / Q000378:metabolism; D003342:Corpus Striatum / Q000378:metabolism*; D008297:Male; D009474:Neurons / Q000378:metabolism*; D017208:Rats, Wistar; D018100:Receptors, Histamine H3 / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D013574:Synaptosomes / Q000378:metabolism*
chemical_list: D000697:Central Nervous System Stimulants; D018100:Receptors, Histamine H3; D002118:Calcium
keywords: Calcium mobilization; H(3) receptor; Histamine; Primary culture; Striatum; Synaptosomes