Depolarizing stimuli cause persistent and selective loss of orexin in rat hypothalamic slice culture
スポンサーリンク
概要
- 論文の詳細を見る
A hypothalamic neuropeptide orexin (hypocretin) is a critical regulator of physiological processes including sleep/wakefulness and feeding. Using organotypic slice culture of rat hypothalamus, we found that exposure to elevated extracellular concentration of K+ (+10-30 mM) for 24-72 h led to a substantial decrease in the number of neurons immunoreactive for orexin and a co-existing neuropeptide dynorphin-A. In contrast, the same treatment affected neither the number of melanin-concentrating hormone-immunoreactive neurons nor the number of total neurons. A substantial decrease of orexin-immunoreactive neurons was also induced by 72 h treatment with 1-10 μM veratridine, a Na+ channel activator. The effect of elevated K+ was only partially reversible, and that of veratridine was virtually irreversible, although the decrease in orexin immunoreactivity was not associated with signs of cell damage assessed by propidium iodide uptake and Hoechst 33342 nuclear staining. In addition, the level of preproorexin mRNA did not decrease during treatment with elevated K+ or veratridine. After treatment with elevated K+ and veratridine, c-Fos immunoreactivity appeared in orexin-immunoreactive neurons but not in melanin-concentrating hormone-immunoreactive neurons, suggesting selective excitation of orexin neurons. However, the amount of orexin released extracellularly was paradoxically decreased by treatment with elevated K+ and veratridine. Overall, these characteristics of orexin neurons may be taken into consideration to understand the behaviors of these neurons under physiological and pathophysiological conditions.
論文 | ランダム
- フィラー,金,ヒアルロン酸によるトラブル (特集 最近のトピックス2010) -- (皮膚科医のための臨床トピックス)
- 薬物療法--有用性と副作用対策を中心に 関節注入療法 (関節リウマチ(第2版)--寛解を目指す治療の新時代) -- (関節リウマチの治療)
- 白内障手術における着色ディスコビスクの臨床使用
- 血清由来タンパク質SHAPとヒアルロン酸との共有結合複合体は,炎症におけるヒアルロン酸の機能実体か? 複合体の発見,構造,形成機構,機能について
- 血中SHAP 濃度の疾患マーカーとしての有用性—ヒアルロン酸に比較して