title: Voltage-gated Ca2+ channel mRNAs and T-type Ca2+ currents in rat gonadotropin-releasing hormone neurons.
abstract: Gonadotropin-releasing hormone (GnRH) neurons play a pivotal role in the neuroendocrine regulation of reproduction. We have previously reported that rat GnRH neurons exhibit voltage-gated Ca(2+) currents. In this study, oligo-cell RT-PCR was carried out to identify subtypes of the alpha(1) subunit of voltage-gated Ca(2+) channels in adult rat GnRH neurons. GnRH neurons expressed mRNAs for all five types of voltage-gated Ca(2+) channels. For T-type Ca(2+) channels, alpha(1H) was dominantly expressed in GnRH neurons. Electrophysiological analysis in acute slice preparations revealed that GnRH neurons from adult rats exhibited T-type Ca(2+) currents with fast inactivation kinetics (~20 ms at -30 mV) and a time constant of recovery from inactivation of ~0.6 s. These results indicate that rat GnRH neurons express subtypes of the alpha(1) subunit for all five types of voltage-gated Ca(2+) channel, and that alpha(1H) was the dominant subtype in T-type Ca(2+) channels.
authors.affiliation: Department of Physiology, Nippon Medical School, Sendagi 1, Bunkyo, Tokyo, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Tanaka
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Ishii
authors.forename: Chengzhu
authors.initials: C
authors.lastname: Yin
authors.forename: Makiko
authors.initials: M
authors.lastname: Koyama
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Sakuma
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Kato
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism* / Q000494:pharmacology; D009474:Neurons / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D055647:Rats, Transgenic; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D012333:RNA, Messenger; D007987:Gonadotropin-Releasing Hormone; D002118:Calcium