کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4352489 1298117 2008 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
On the role of calcium and potassium currents in circadian modulation of firing rate in rat suprachiasmatic nucleus neurons: Multielectrode dish analysis
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی علوم اعصاب (عمومی)
پیش نمایش صفحه اول مقاله
On the role of calcium and potassium currents in circadian modulation of firing rate in rat suprachiasmatic nucleus neurons: Multielectrode dish analysis
چکیده انگلیسی
The master circadian clock of mammals in the suprachiasmatic nucleus (SCN) of the hypothalamus entrains to a 24-h daily light-dark cycle and regulates circadian rhythms. The SCN is composed of multiple neurons with cell autonomous clocks exhibiting robust firing rhythms with a high firing rate during the subjective day. The membrane target(s) of the cellular clock responsible for circadian modulation of the firing rate in SCN neurons still remain unclear. Previously, L-type Ca2+ currents and fast delayed rectifier (FDR) K+ currents have been suggested to contribute directly to circadian modulation of electrical activity. Using long-term continuous recording of activity from dispersed rat SCN neurons in multielectrode dish and ionic channel blockers, we tested these hypotheses. Neither an L-type Ca2+ current blocker (20 μM of nifedipine for 2 days) nor an FDR current blocker (500 μM of 4-aminopyridine (4-AP) for 4 days) suppressed the circadian modulation of firing rate. A specific blocker of Na+ persistent current (5 μM of riluzole for 1 day followed by 10 μM during the next day) reversibly suppressed firing activity in a dose-dependent manner. These data indicate that neither nifedipine-sensitive Ca2+ current(s) nor 4-AP-sensitive K+ current(s) are key membrane targets for circadian modulation of electrical firing rate in SCN neurons.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Neuroscience Research - Volume 62, Issue 1, September 2008, Pages 51-57
نویسندگان
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