Cagampang F R, Piggins H D, Sheward W J, Harmar A J, Coen C W
Anatomy and Human Biology, Division of Biomedical Sciences, King's College London, London WC2R 2LS, UK.
Brain Res. 1998 Nov 30;813(1):218-22. doi: 10.1016/s0006-8993(98)01044-0.
A receptor for pituitary adenylate cyclase activating polypeptide (PACAP), denoted as PAC1, is expressed in the suprachiasmatic nuclei (SCN). Since the circadian clock demonstrates phase-dependent sensitivity to PACAP, we have used in situ hybridization histochemistry to examine whether PAC1 mRNA is differentially expressed in the rat SCN across the 24-h cycle. There was a significant variation in PAC1 mRNA within the SCN and supraoptic nuclei during the light-dark cycle and in constant darkness, with peaks at the middle of both the real and subjective day and night; no significant variation was observed in the cingulate cortex. The results suggest that the phase-dependent actions of PACAP on the clock may involve phase-specific changes in the availability of PAC1 receptors within the SCN.
一种名为PAC1的垂体腺苷酸环化酶激活多肽（PACAP）受体在视交叉上核（SCN）中表达。由于昼夜节律时钟显示出对PACAP的相位依赖性敏感性，我们使用原位杂交组织化学来检查PAC1 mRNA在大鼠SCN中是否在24小时周期内存在差异表达。在明暗周期和持续黑暗条件下，SCN和视上核内的PAC1 mRNA存在显著变化，在实际和主观的白天和黑夜中间出现峰值；在扣带回皮质中未观察到显著变化。结果表明，PACAP对时钟的相位依赖性作用可能涉及SCN内PAC1受体可用性的相位特异性变化。
