| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Submitted on February 14, 2003
Accepted on August 6, 2003
1 Department of Physiology, Nippon Medical School (M.K., M.W., Y.S.), Tokyo 113-8602, Japan; Department of Biophysics and Biochemistry, School of Science, University of Tokyo (K.U-T.), Tokyo 113-0033, Japan
* To whom correspondence should be addressed. E-mail: mkato{at}nms.ac.jp.
Functional analysis of gonadotropin releasing hormone (GnRH) neurons is limited, although these neurons play an important role in neuroendocrine regulation. Therefore we decided to conduct cell physiological analysis of GnRH neurons. To identify GnRH neurons, we tagged the neurons with green fluorescence protein by a transgenic technique. A dispersed culture of GnRH neurons was prepared from the transgenic rats. After overnight culture, a perforated patch clamp was applied to the identified GnRH neurons to analyze the Ca2+ currents. In neonatal GnRH neurons, high voltage-activated Ca2+ currents were clearly observed but low voltage-activated Ca2+ current was negligible. Nimodipine (L-type channel blocker) and 
-conotoxin GVIA (N-type channel blocker) each attenuated the current by 
20%. The R-type channel blocker SNX-482 attenuated the current by 55%. Inhibition by P/Q-type channel blocker -agatoxin IVA was small. In GnRH neurons around puberty, however, both high and low voltage-activated Ca2+ currents were observed. Inhibitions by nifedipine, -conotoxin GVIA and SNX-482 were similar to that in the neonatal neurons, whereas the inhibition by -agatoxin IVA was clearly seen in 40-61% of GnRH neurons examined. These results indicate that GnRH neurons functionally express L-, N-, P/Q-, R- and T-type channels. Expressions of P/Q- and T-type channels are developmentally regulated.
This article has been cited by other articles:
 |
|
 |
|
  C. B. Roberts and K. J. Suter Emerging methodologies for the study of hypothalamic gonadotropin-releasing-hormone (GnRH) neurons Integr. Comp. Biol., May 17, 2008; (2008) icn039v1. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 I. Nishimura, K. Ui-Tei, K. Saigo, H. Ishii, Y. Sakuma, and M. Kato 17{beta}-Estradiol at Physiological Concentrations Augments Ca2+-Activated K+ Currents via Estrogen Receptor {beta} in the Gonadotropin-Releasing Hormone Neuronal Cell Line GT1-7 Endocrinology, February 1, 2008; 149(2): 774 - 782. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Rasier, A.-S. Parent, A. Gerard, M.-C. Lebrethon, and J.-P. Bourguignon Early Maturation of Gonadotropin-Releasing Hormone Secretion and Sexual Precocity after Exposure of Infant Female Rats to Estradiol or Dichlorodiphenyltrichloroethane Biol Reprod, October 1, 2007; 77(4): 734 - 742. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Zhang, M. A. Bosch, J. E. Levine, O. K. Ronnekleiv, and M. J. Kelly Gonadotropin-Releasing Hormone Neurons Express KATP Channels That Are Regulated by Estrogen and Responsive to Glucose and Metabolic Inhibition J. Neurosci., September 19, 2007; 27(38): 10153 - 10164. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. J. Spergel Calcium and Small-Conductance Calcium-Activated Potassium Channels in Gonadotropin-Releasing Hormone Neurons before, during, and after Puberty Endocrinology, May 1, 2007; 148(5): 2383 - 2390. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Qiu, M. A. Bosch, K. Jamali, C. Xue, M. J. Kelly, and O. K. Ronnekleiv Estrogen Upregulates T-Type Calcium Channels in the Hypothalamus and Pituitary J. Neurosci., October 25, 2006; 26(43): 11072 - 11082. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Arroyo, B. Kim, R. L. Rasmusson, G. Bett, and J. Yeh Hyperpolarization-Activated Cation Channels Are Expressed in Rat Hypothalamic Gonadotropin-Releasing Hormone (GnRH) Neurons and Immortalized GnRH Neurons Reproductive Sciences, September 1, 2006; 13(6): 442 - 450. [Abstract] [PDF]
|
|
|
|
 |
|
 M. Kato, N. Tanaka, S. Usui, and Y. Sakuma The SK channel blocker apamin inhibits slow afterhyperpolarization currents in rat gonadotropin-releasing hormone neurones J. Physiol., July 15, 2006; 574(2): 431 - 442. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Okubo, F. Sakai, E. L. Lau, G. Yoshizaki, Y. Takeuchi, K. Naruse, K. Aida, and Y. Nagahama Forebrain Gonadotropin-Releasing Hormone Neuronal Development: Insights from Transgenic Medaka and the Relevance to X-Linked Kallmann Syndrome Endocrinology, March 1, 2006; 147(3): 1076 - 1084. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. B. Roberts, J. A. Best, and K. J. Suter Dendritic Processing of Excitatory Synaptic Input in Hypothalamic Gonadotropin Releasing-Hormone Neurons Endocrinology, March 1, 2006; 147(3): 1545 - 1555. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Abe and E. Terasawa Firing Pattern and Rapid Modulation of Activity by Estrogen in Primate Luteinizing Hormone Releasing Hormone-1 Neurons Endocrinology, October 1, 2005; 146(10): 4312 - 4320. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 I. S. Parhar, T. Soga, S. Ogawa, S. Ogawa, D. W. Pfaff, and Y. Sakuma Nonmammalian gonadotropin-releasing hormone molecules in the brain of promoter transgenic rats PNAS, April 19, 2005; 102(16): 5880 - 5885. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Ueta, H. Fujihara, R. Serino, G. Dayanithi, H. Ozawa, K.-i. Matsuda, M. Kawata, J. Yamada, S. Ueno, A. Fukuda, et al. Transgenic Expression of Enhanced Green Fluorescent Protein Enables Direct Visualization for Physiological Studies of Vasopressin Neurons and Isolated Nerve Terminals of the Rat Endocrinology, January 1, 2005; 146(1): 406 - 413. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Haneda and Y. Oka Selective Modulation of Voltage-Gated Calcium Channels in the Terminal Nerve Gonadotropin-Releasing Hormone Neurons of a Teleost, the Dwarf Gourami (Colisa lalia) Endocrinology, October 1, 2004; 145(10): 4489 - 4499. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. K. Greenwood and R. D. Fernald Social Regulation of the Electrical Properties of Gonadotropin-Releasing Hormone Neurons in a Cichlid Fish (Astatotilapia burtoni) Biol Reprod, September 1, 2004; 71(3): 909 - 918. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Watanabe, Y. Sakuma, and M. Kato High Expression of the R-Type Voltage-Gated Ca2+ Channel and Its Involvement in Ca2+-Dependent Gonadotropin-Releasing Hormone Release in GT1-7 Cells Endocrinology, May 1, 2004; 145(5): 2375 - 2383. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Endocrinology | Endocrine Reviews | J. Clin. End. & Metab. |
| Molecular Endocrinology | Recent Prog. Horm. Res. | All Endocrine Journals |
