Korshunov Kirill S, Blakemore Laura J, Trombley Paul Q
Department of Biological Science, Florida State University, Tallahassee, FL, United States.
Program in Neuroscience, Florida State University, Tallahassee, FL, United States.
Front Cell Neurosci. 2020 Aug 31;14:275. doi: 10.3389/fncel.2020.00275. eCollection 2020.
In the central nervous system, dopamine is well-known as the neuromodulator that is involved with regulating reward, addiction, motivation, and fine motor control. Yet, decades of findings are revealing another crucial function of dopamine: modulating sensory systems. Dopamine is endogenous to subsets of neurons in the retina and olfactory bulb (OB), where it sharpens sensory processing of visual and olfactory information. For example, dopamine modulation allows the neural circuity in the retina to transition from processing dim light to daylight and the neural circuity in the OB to regulate odor discrimination and detection. Dopamine accomplishes these tasks through numerous, complex mechanisms in both neural structures. In this review, we provide an overview of the established and emerging research on these mechanisms and describe similarities and differences in dopamine expression and modulation of synaptic transmission in the retinas and OBs of various vertebrate organisms. This includes discussion of dopamine neurons' morphologies, potential identities, and biophysical properties along with their contributions to circadian rhythms and stimulus-driven synthesis, activation, and release of dopamine. As dysregulation of some of these mechanisms may occur in patients with Parkinson's disease, these symptoms are also discussed. The exploration and comparison of these two separate dopamine populations shows just how remarkably similar the retina and OB are, even though they are functionally distinct. It also shows that the modulatory properties of dopamine neurons are just as important to vision and olfaction as they are to motor coordination and neuropsychiatric/neurodegenerative conditions, thus, we hope this review encourages further research to elucidate these mechanisms.
在中枢神经系统中，多巴胺作为一种神经调质广为人知，它参与调节奖赏、成瘾、动机和精细运动控制。然而，数十年来的研究结果揭示了多巴胺的另一个关键功能：调节感觉系统。多巴胺是视网膜和嗅球（OB）中某些神经元亚群的内源性物质，在那里它能增强视觉和嗅觉信息的感觉处理。例如，多巴胺调节使视网膜中的神经回路能够从处理暗光过渡到处理日光，使嗅球中的神经回路能够调节气味辨别和检测。多巴胺通过这两种神经结构中的众多复杂机制来完成这些任务。在这篇综述中，我们概述了关于这些机制的已有的和新出现的研究，并描述了多巴胺在各种脊椎动物的视网膜和嗅球中表达及对突触传递调节的异同。这包括对多巴胺能神经元的形态、潜在身份、生物物理特性的讨论，以及它们对昼夜节律和刺激驱动的多巴胺合成、激活和释放的贡献。由于帕金森病患者可能会出现其中一些机制的失调，因此也对这些症状进行了讨论。对这两个不同的多巴胺群体的探索和比较表明，尽管视网膜和嗅球在功能上有所不同，但它们非常相似。这也表明多巴胺能神经元的调节特性对视觉和嗅觉的重要性与对运动协调以及神经精神/神经退行性疾病的重要性相当，因此，我们希望这篇综述能鼓励进一步的研究来阐明这些机制。
