目的:大脑功能和生理可塑性对于应对动态环境挑战至关重要。有节奏的多巴胺信号通路,调节情绪,奖励和学习,显示了季节性模式,在黑暗季节,多巴胺合成能力较高,多巴胺转运蛋白数量较低。然而,多巴胺受体信号的季节性变化仍有待表征。
方法:基于健康人脑[11C]raclopridePET扫描的历史数据库(n=291,224男性和67女性),我们调查了D2/3多巴胺受体信号的季节性模式.扫描时的白天长度用作放射性示踪剂的大脑区域不可移位结合的预测因子,同时控制年龄和性别。
结果:日长与纹状体中D2/3多巴胺受体的可用性呈负相关。最大的影响是在左尾状,基于原始样本,每4.26小时(即,1个标准差)日长的增加与受体可利用性的平均下降2.8%(95%CI-0.042~-0.014)相关.
结论:随季节变化的D2/3受体信号也可能是情绪季节性的基础,喂养,和激励过程。我们的发现表明,在未来对大脑多巴胺信号传导的研究中,特别是在高纬度地区,应考虑季节性的影响。
OBJECTIVE: Brain functional and physiological plasticity is essential to combat dynamic environmental challenges. The rhythmic dopamine signaling pathway, which regulates emotion, reward and learning, shows seasonal patterns with higher capacity of dopamine synthesis and lower number of dopamine transporters during dark seasons. However, seasonal variation of the dopamine receptor signaling remains to be characterized.
METHODS: Based on a historical database of healthy human brain [11C]raclopride PET scans (n = 291, 224 males and 67 females), we investigated the seasonal patterns of D2/3 dopamine receptor signaling. Daylength at the time of scanning was used as a predictor for brain regional non-displaceable binding of the radiotracer, while controlling for age and sex.
RESULTS: Daylength was negatively correlated with availability of D2/3 dopamine receptors in the striatum. The largest effect was found in the left caudate, and based on the primary sample, every 4.26 h (i.e., one standard deviation) increase of daylength was associated with a mean 2.8% drop (95% CI -0.042 to -0.014) of the receptor availability.
CONCLUSIONS: Seasonally varying D2/3 receptor signaling may also underlie the seasonality of mood, feeding, and motivational processes. Our finding suggests that in future studies of brain dopamine signaling, especially in high-latitude regions, the effect of seasonality should be considered.