掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.neuroscience.2020.06.004

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Medical Association of Nippon Medical School  

Background: Photoreceptors differentiated from somatic cells are a useful tool for transplantation and drug screening. We previously showed that photosensitive cells are differentiated from human fibroblasts by direct reprogramming. In induced pluripotent stem (iPS) cells or embryonic stem (ES) cells, the properties of differentiated cells differ among the source of cell lines. However, whether or not the properties of the photosensitive cells produced by direct reprogramming are controlled by the origin of the cell line remains unknown. Methods: We compared the morphological and physiological properties of photosensitive cells induced by two fibroblast cell lines. Results: The differentiated cells had larger somas and more primary processes than the non-infected cells in both cell lines. The degree of morphological change was statistically different between the two cell lines. In addition, physiological responses to light differed between the two cell lines. An outward current (photoreceptor-like response) was observed in both cell lines, while an inward current (intrinsically photosensitive retinal ganglion cell-like response) was observed only in one cell line under light stimulation. Conclusions: These results suggest that photosensitive cells produced from different cell lines by direct reprogramming might express different phenotypes.

DOI： 10.1272/jnms.2018_85-17

Scopus

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ENDOCRINE SOC  

In rodents, GnRH neurons are diffusely distributed from the medial septum through to the medial preoptic area and control gonadal functions through the pituitary. The activity of GnRH neurons is regulated by a variety of bioactive substances, including the inhibitory peptide somatostatin. In the present study, we focused on somatostatin because intracerebroventricular injection of somatostatin inhibits the LH surge in rats and reduces LH secretion in ewes. Somatostatin also decreases GnRH release from rat hypothalamic slices. In mice, somatostatin is also thought to suppress GnRH neuronal activity through contact on the soma of GnRH neurons. However, similar data are missing in rats. Moreover, rat GnRH neurons receive only a few synaptic inputs. In this study, we assessed the morphological relationship between GnRH and somatostatin neurons. Confocal microscopy on the sections from the medial septum through medial preoptic area revealed about 35 close contacts per rat between the GnRH and somatostatin neuronal fibers in the organum vasculosum of the lamina terminalis region. No contact of somatostatin fibers on the GnRH neuronal somata was observed. Multicell RT-PCR for somatostatin receptor mRNA in rat GnRH neurons was also performed, which revealed moderate expression of somatostatin receptor subtypes 1-5. In addition, patch clamp experiments were carried out in acute slice preparations. Somatostatin suppressed neuronal firing in cells recorded in a cell-attached configuration and also induced whole-cell outward currents in GnRH neurons. These findings suggest that somatostatin directly inhibits the activity of rat GnRH neurons through volume transmission in the organum vasculosum of the lamina terminalis region. (Endocrinology 153: 806-814, 2012)

DOI： 10.1210/en.2011-1374

Web of Science

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER TOKYO  

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 Ca2+ currents. In this study, oligo-cell RT-PCR was carried out to identify subtypes of the alpha(1) subunit of voltage-gated Ca2+ channels in adult rat GnRH neurons. GnRH neurons expressed mRNAs for all five types of voltage-gated Ca2+ channels. For T-type Ca2+ 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 Ca2+ currents with fast inactivation kinetics (similar to 20 ms at -30 mV) and a time constant of recovery from inactivation of similar to 0.6 s. These results indicate that rat GnRH neurons express subtypes of the alpha(1) subunit for all five types of voltage-gated Ca2+ channel, and that alpha(1H) was the dominant subtype in T-type Ca2+ channels.

DOI： 10.1007/s12576-010-0085-z

Web of Science

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記述言語：英語   出版者・発行元：WILEY-BLACKWELL  

Gonadotrophin-releasing hormone (GnRH) neurones represent the final output neurones in the neuroendocrine system for the control of reproduction. To understand the reproductive neuroendocrine system, an investigation of the intrinsic and extrinsic properties of GnRH neurones is essential. In this review, we focus on the intrinsic properties and summarise our recent findings of ion channels expressed in rat GnRH neurones. Rat GnRH neurones express all four types of high voltage-activated Ca(2+)channel (L, N, P/Q, R) and the low voltage-activated Ca2+ channel (T). GnRH neurones also express two types of Ca2+-activated K+ [K(Ca)] channel: the small conductance Ca2+-activated K+ (SK) channel and the large conductance Ca2+- and voltage-activated K+ (BK) channel. The activities of these Ca2+ and K(Ca) channels regulate cell excitability and cellular calcium homeostasis.

DOI： 10.1111/j.1365-2826.2009.01849.x

Web of Science

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記述言語：日本語  

J-GLOBAL

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記述言語：日本語  

J-GLOBAL

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記述言語：日本語  

J-GLOBAL

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記述言語：日本語  

J-GLOBAL

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記述言語：日本語  

J-GLOBAL

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