Faculty of Life Sciences, University of Manchester, Manchester, UK.
Trends Neurosci. 2013 Oct;36(10):610-9. doi: 10.1016/j.tins.2013.06.006. Epub 2013 Jul 19.
The human brain comprises approximately 100 billion neurons that express a diverse, and often subtype-specific, set of neurotransmitters and voltage-gated ion channels. Given this enormous complexity, a fundamental question is how is this achieved? The acquisition of neurotransmitter phenotype was viewed as being set by developmental programs 'hard wired' into the genome. By contrast, the expression of neuron-specific ion channels was considered to be highly dynamic (i.e., 'soft wired') and shaped largely by activity-dependent mechanisms. Recent evidence blurs this distinction by showing that neurotransmitter phenotype can be altered by activity and that neuron type-specific ion channel expression can be set, and perhaps limited by, developmental programs. Better understanding of these early regulatory mechanisms may offer new avenues to avert the behavioral changes that are characteristic of many mental illnesses.
人类大脑由大约 1000 亿个神经元组成，这些神经元表达出多种多样的、通常具有亚型特异性的神经递质和电压门控离子通道。鉴于这种巨大的复杂性，一个基本问题是如何实现这一点？神经递质表型的获得被认为是由基因组中“硬连线”的发育程序设定的。相比之下，神经元特异性离子通道的表达被认为是高度动态的（即“软连线”），并且主要受活动依赖性机制的影响。最近的证据表明，神经递质表型可以通过活动来改变，并且神经元类型特异性离子通道的表达可以由发育程序来设定，甚至可能受到其限制，这使得这种区分变得模糊。更好地理解这些早期的调控机制可能为避免许多精神疾病所特有的行为变化提供新的途径。
