Leng Gareth
Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.
Endocr Connect. 2018 Dec 1;7(12):R275-R285. doi: 10.1530/EC-18-0367.
The brain hosts a vast and diverse repertoire of neuropeptides, a class of signalling molecules often described as neurotransmitters. Here I argue that this description entails a catalogue of misperceptions, misperceptions that feed into a narrative in which information processing in the brain can be understood only through mapping neuronal connectivity and by studying the transmission of electrically conducted signals through chemical synapses. I argue that neuropeptide signalling in the brain involves primarily autocrine, paracrine and neurohormonal mechanisms that do not depend on synaptic connectivity and that it is not solely dependent on electrical activity but on mechanisms analogous to secretion from classical endocrine cells. As in classical endocrine systems, to understand the role of neuropeptides in the brain, we must understand not only how their release is regulated, but also how their synthesis is regulated and how the sensitivity of their targets is regulated. We must also understand the full diversity of effects of neuropeptides on those targets, including their effects on gene expression.
大脑中存在着大量多样的神经肽，这是一类常被描述为神经递质的信号分子。在此我认为，这种描述存在一系列误解，这些误解促成了一种观点，即大脑中的信息处理只能通过绘制神经元连接图谱以及研究电传导信号通过化学突触的传递来理解。我认为，大脑中的神经肽信号传导主要涉及自分泌、旁分泌和神经激素机制，这些机制不依赖于突触连接，并且它不仅完全依赖于电活动，还依赖于类似于经典内分泌细胞分泌的机制。与经典内分泌系统一样，要理解神经肽在大脑中的作用，我们不仅必须了解它们的释放是如何调节的，还必须了解它们的合成是如何调节的以及它们靶标的敏感性是如何调节的。我们还必须了解神经肽对这些靶标的全部多样效应，包括它们对基因表达的影响。
