Neurobiology Section, Division of Biological Sciences, Kavli Institute for Brain and Mind, University of California San Diego, La Jolla, California 92093, USA.
Dev Neurobiol. 2012 Jan;72(1):22-32. doi: 10.1002/dneu.20909.
The transmitter phenotype of a neuron has long been thought to be stable for the lifespan. Much as eyes have one color and do not change it over time, neurons have been thought to have one neurotransmitter and retain it for their lifetime. Both principles, exclusivity and stability, are challenged by recent data. More and more neurons in different regions of the brain appear to coexpress two or more neurotransmitters. Moreover, the profile of neurotransmitter expression of a given neuron has been shown to change over time, both during development and in response to changes in activity. The present review summarizes recent studies of this neurotransmitter phenotype plasticity (NPP). Homeostatic mechanisms of plasticity are aimed at maintaining the system within a functional range. They appear to be critical for optimal network operations and have been thought to operate largely by regulating intrinsic excitability, synapse number and synaptic strength. NPP provides a new and unexpected level of regulation of network homeostasis. We propose that it provides the basis for NT coexpression and discuss emerging issues and new questions for further studies in coming years.
长期以来，人们一直认为神经元的发射型是稳定的，可以维持其整个生命周期。就像眼睛只有一种颜色并且随着时间的推移不会改变一样，人们认为神经元只有一种神经递质，并在其一生中保持不变。这两个原则，即排他性和稳定性，都受到了最近数据的挑战。越来越多的证据表明，大脑不同区域的神经元似乎会共同表达两种或两种以上的神经递质。此外，给定神经元的神经递质表达谱已经被证明会随着时间的推移而发生变化，无论是在发育过程中还是在对活动变化的反应中。本综述总结了最近关于神经递质表型可塑性（NPP）的研究。可塑性的动态平衡机制旨在将系统维持在功能范围内。它们似乎对网络的最佳运作至关重要，并且被认为主要通过调节内在兴奋性、突触数量和突触强度来发挥作用。NPP 为网络动态平衡提供了一个新的、意想不到的调节水平。我们提出，它为 NT 共表达提供了基础，并讨论了未来几年进一步研究的新出现的问题和新问题。
