Interactions of GABAA receptor activation and light on Period mRNA expression in the suprachiasmatic nucleus
Interactions of GABAA receptor activation and light on Period mRNA expression in the suprachiasmatic nucleus
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DOI：
10.1177/0748730407310785
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发表时间：
2008-02-01
影响因子：
3.5
通讯作者：
Albers, H. Elliott
中科院分区：
文献类型：
--
作者：
Ehlen, J. Christopher;Novak, Colleen M.;Albers, H. Elliott
视交叉上核 (SCN) 中 γ-氨基丁酸 (GABA)(A) 受体的激活会在白天重置生物钟，并抑制光在夜间重置生物钟的能力。光在白天反过来会抑制 GABA 的相位重置作用。一些证据表明，SCN 中的周期 mRNA 变化是光与 GABA 之间相互作用的原因。在此，测试了光和 GABA(A) 受体通过改变 SCN 中周期 1 和/或周期 2 mRNA 的表达而相互作用的假设。 GABA(A) 激动剂蝇蕈醇在光脉冲之前、主观白天中期以及主观夜间早晚注射到 SCN 附近。通过原位杂交测量 SCN 中第 1 期和第 2 期 mRNA 的变化。光诱导的第一期 mRNA 在清晨和深夜被 GABA(A) 受体激活所抑制，而第二期 mRNA 仅在深夜受到抑制。在主观日期间，光对蝇蕈醇抑制1期mRNA杂交信号的能力没有影响。因此，光和 GABA(A) 受体激活会抑制彼此在主观白天和夜间诱导行为相移的能力。然而，只有在深夜，这些行为效应才与周期基因表达的变化相关。总之，我们的数据支持这样的假设：光和 GABA 的相互作用是这些刺激对周期 mRNA 的相反作用的结果，但仅限于主观夜间。
Activation of gamma-aminobutyric acid (GABA)(A) receptors in the suprachiasmatic nucleus (SCN) resets the circadian clock during the day and inhibits the ability of light to reset the clock at night. Light in turn acts during the day to inhibit the phase-resetting effects of GABA. Some evidence suggests that Period mRNA changes in the SCN are responsible for these interactions between light and GABA. Here, the hypothesis that light and the GABA(A) receptor interact by altering the expression of Period 1 and/or Period 2 mRNA in the SCN is tested. The GABA(A) agonist muscimol was injected near the SCN just prior to a light pulse, during the mid-subjective day and the early and late subjective night. Changes in Period 1 and Period 2 mRNA were measured in the SCN by in situ hybridization. Light-induced Period 1 mRNA was inhibited by GABA(A) receptor activation in the early and late subjective night, while Period 2 mRNA was only inhibited during the late night. During the subjective day, light had no effect on the ability of muscimol to suppress Period 1 mRNA hybridization signal. Thus, light and GABA(A) receptor activation inhibit each other's ability to induce behavioral phase shifts throughout the subjective day and night. However, only in the late night are these behavioral effects correlated with changes in Period gene expression. Together, our data support the hypothesis that the interacting effects of light and GABA are the result of the opposing actions of these stimuli on Period mRNA, but only during the subjective night.