کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9425672 1295886 2005 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The role of 5-HT1A receptors in the proliferation and survival of progenitor cells in the dentate gyrus of the adult hippocampus and their regulation by corticoids
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی علوم اعصاب (عمومی)
پیش نمایش صفحه اول مقاله
The role of 5-HT1A receptors in the proliferation and survival of progenitor cells in the dentate gyrus of the adult hippocampus and their regulation by corticoids
چکیده انگلیسی
These experiments explore the role of 5-HT1A receptors in the regulation of cell proliferation in the dentate gyrus of the intact and adrenalectomized adult rat. Depleting 5-HT with p-chlorophenylalanine (300mg/kg initially followed by 100mg/kg/day) or stimulating 5-HT1A receptors with 8-OH-DPAT (1mg/kg or 2mg/kg, s.c. injections twice daily) for 14 days had no effect on cell proliferation as measured by Ki-67 or BrdU (5-bromo-3-deoxyuridine) immunocytochemistry in the dentate gyrus. However, combined treatment with p-chlorophenylalanine followed by 8-OH-DPAT significantly increased cell proliferation compared with p-chlorophenylalanine alone. Micro-injection of the 5-HT neurotoxin 5,7-dihydroxytryptamine into the fimbria-fornix (3.0μg/side) and the cingulate bundle (1.8μg/side) depleted hippocampal 5-HT locally but did not change cell proliferation 3 weeks after the surgery. However, 8-OH-DPAT (1mg/kg, twice daily) stimulated cell proliferation in the dentate gyrus of hippocampal 5-HT-depleted rats compared with controls. These results suggest that 5-HT1A modulates cell proliferation in the hippocampus by a direct post-synaptic effect. Previous studies demonstrate that adrenalectomy increases hippocampal 5-HT1A receptor expression and binding, and thus we investigated whether the effect of adrenalectomy on cell proliferation and survival was dependent on the activity of the 5-HT1A receptors. In contrast to the null effect following twice-daily s.c. injection, 8-OH-DPAT (2.0mg/kg/day) delivered by s.c. osmotic pumps increased proliferation in intact rats. The 5-HT1A antagonist WAY-100635 (1.5mg/kg/day also delivered by osmotic pump) by itself did not alter cell proliferation, confirming that reduced serotonin activity does not change proliferation, but blocked the effect of 8-OH-DPAT. However, WAY-100635 could not block the stimulating action of adrenalectomy cell proliferation. 5-HT1A mRNA expression was not altered in the hippocampus by adrenalectomy. Thus, the effect of adrenalectomy on cell proliferation and survival is not 5-HT1A dependent, despite the interaction between 5-HT1A and corticosterone.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Neuroscience - Volume 135, Issue 3, 2005, Pages 803-813
نویسندگان
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