title: Histamine responses of large neostriatal interneurons in histamine H1 and H2 receptor knock-out mice.
abstract: Histamine (HA) is an important neuro-modulator, contributing to a variety of physiological responses in the mammalian central nervous system (CNS). However there is little information about the cell/signaling mechanism underlying its role. In the present study, we characterized HA responses in single large neostriatal neurons acutely dissociated from wild type (WT) and HA receptor knock-out (KO) mice, with a particular emphasis on identifying the role of HA receptor subtypes. HA (10 microM) and a selective H(2) receptor agonist dimaprit (1 microM) both evoked an inward current in H(1)-KO mice, and HA and a selective H(1) receptor agonist HTMT (10 microM) both evoked an inward current in H(2)-KO mice. In the H(1) and H(2) double (H(1/2)) KO mice, there was no response to either the application of HA or the selective H(1), H(2) receptor agonists. Hence we have confirmed that the targeted genes were indeed absent in these KO mice and that both receptor subtypes contribute to HA's excitatory actions. Furthermore the HA-induced inward currents were mediated by a decrease in current through K(+) channels. In addition, we observed the effects of methamphetamine (METH) on the locomotor activity of WT and HA receptor KO mice, and found that METH-induced behavioral sensitization is evident in H(1/2)-KO mice, but not in H(1)- or H(2)-KO mice. These observations suggest that suppressive roles of HA on methamphetamine-induced behavioral sensitization would be mediated through both H(1) and H(2) receptors in the CNS including neostriatum.
authors.affiliation: Research Division for Life Sciences, Kumamoto Health Science University, Kumamoto 861-5598, Japan.
authors.forename: Sachie
authors.initials: S
authors.lastname: Ogawa
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Yanai
authors.forename: Takeshi
authors.initials: T
authors.lastname: Watanabe
authors.forename: Zhi-Ming
authors.initials: ZM
authors.lastname: Wang
authors.forename: Hironari
authors.initials: H
authors.lastname: Akaike
authors.forename: Yushi
authors.initials: Y
authors.lastname: Ito
authors.forename: Norio
authors.initials: N
authors.lastname: Akaike
mesh_terms: D000818:Animals; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000494:pharmacology; D004594:Electrophysiology / Q000379:methods; D006632:Histamine / Q000008:administration & dosage / Q000494:pharmacology*; D017442:Histamine Agonists / Q000008:administration & dosage / Q000494:pharmacology; D007274:Injections, Intraperitoneal; D007395:Interneurons / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D008694:Methamphetamine / Q000008:administration & dosage / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D017072:Neostriatum / Q000166:cytology / Q000378:metabolism; D018408:Patch-Clamp Techniques / Q000379:methods; D011969:Receptors, Histamine H1 / Q000172:deficiency* / Q000235:genetics; D011970:Receptors, Histamine H2 / Q000172:deficiency* / Q000235:genetics
chemical_list: D000697:Central Nervous System Stimulants; D017442:Histamine Agonists; D011969:Receptors, Histamine H1; D011970:Receptors, Histamine H2; D008694:Methamphetamine; D006632:Histamine