新型视网膜神经节细胞光感受器参与介导光对多巴胺能无长突细胞活动的调节

多巴胺是中枢神经系统中重要的一种神经递质,它参与包括感觉、运动和其它高级脑行为活动的形成和调节;因此,多巴胺的缺乏会导致多种神经系统疾病如巴金森氏综合症和老年痴呆,但是,有关多巴胺释放调节的机制仍然不清楚。释放多巴胺的神经元分布在几个脑区,在这些脑区中,视网膜是研究多巴胺神经元最容易入手的部位。视网膜多巴胺神经元属于一种特殊的无长突细胞,它的多巴胺的释放受外界光和机体内生物钟的调节。借助转基因技术和膜片钳电生理学方法,我们最近几年深入研究了光和生物钟对视网膜多巴胺神经元功能活动调节的机制,其中包括发现了光通过激活新型的黑素视蛋白神经节细胞光感受器来调节视网膜多巴胺细胞的活动。这些进展对我们了解多巴胺和多巴胺神经元的生物学特性及其在疾病的作用具有重要的参考价值。

Melanopsin ganglion cells mediate light regulation of dopaminergic cell activity in the mammalian retina

Dopamine is a key neurotransmitter in the CNS and plays vital roles in sensory,motor control,cognition,and motivation.As a result,dopamine deficiency leads to a variety of neurodegenerative diseases such as Pakinson’s and Alzheimer’s diseases.The most accessible dopaminergic neurons of the CNS are located in the vertebrate retina.These neurons are a specialized subpopulation of amacrine cells.It is well known that dopamine release from retinal dopaminergic neurons is regulated by light and biological circadian clock;however,the mechanisms involved are poorly understood.We have sought to understand these mechanisms by taking advantage of genetic approach in combination with patch clamp technique.In particular,we have discovered that light regulates activity of retinal dopaminergic cell through activation of recently discovered melanopsin ganglion cells.The findings reviewed here have provided valuable information for understanding the role of dopamine and neurobiology of dopaminergic neurons in normal and diseased states.