Program in Neuroscience, University of Arizona, Gould-Simpson Building, Tucson, AZ, 85721, United States; Department of Neuroscience, University of Arizona, Gould-Simpson Building, Tucson, AZ, 85721, United States.
Department of Neuroscience, University of Arizona, Gould-Simpson Building, Tucson, AZ, 85721, United States.
Behav Brain Res. 2019 Mar 15;360:103-112. doi: 10.1016/j.bbr.2018.12.004. Epub 2018 Dec 3.
Dopamine (DA) is an important neuromodulator of motor control across species. In zebra finches, DA levels vary in song nucleus Area X depending upon social context. DA levels are high and song output is less variable when a male finch sings to a female (female directed, FD) compared to when he is singing by himself (undirected, UD). DA modulates glutamatergic input onto cortico-striatal synapses in Area X via N-methyl-d-aspartate (NMDA) and DA receptor mechanisms, but the relationship to UD vs. FD song output is unclear. Here, we investigate the expression of molecular markers of dopaminergic and glutamatergic synaptic transmission (tyrosine hydroxylase - TH, alpha-synuclein - α-syn) and plasticity (NMDA 2B receptor - GRIN2B) following singing (UD vs. FD) and non-singing states to understand the molecular mechanisms driving differences in song output. We identified relationships between protein levels for these biomarkers in Area X based on singing state and the amount of song, measured as the number of motifs and time spent singing. UD song amount drove increases in TH, α-syn, and NMDA 2B receptor protein levels. By contrast, the amount of FD song did not alter TH and NMDA 2B receptor expression. Levels of α-syn showed differential expression patterns based on UD vs. FD song, consistent with its role in modulating synaptic transmission. We propose a molecular pathway model to explain how social context and amount of song are important drivers of molecular changes required for synaptic transmission and plasticity.
多巴胺（DA）是跨物种运动控制的重要神经调节剂。在斑马雀中，根据社会环境的不同，DA 水平在歌曲核区 X 中发生变化。与雄性雀独自歌唱相比（无导向，UD），当雄性雀向雌性歌唱时（有导向，FD），DA 水平较高，歌唱输出的变化较小。DA 通过 N-甲基-D-天冬氨酸（NMDA）和 DA 受体机制调节皮质纹状体突触的谷氨酸能输入，但与 UD 与 FD 歌唱输出的关系尚不清楚。在这里，我们研究了在歌唱（UD 与 FD）和非歌唱状态下，多巴胺能和谷氨酸能突触传递（酪氨酸羟化酶 - TH、α-突触核蛋白 - α-syn）和可塑性（NMDA 2B 受体 - GRIN2B）的分子标记物的表达，以了解驱动歌唱输出差异的分子机制。我们根据歌唱状态和歌唱量（以模式数量和歌唱时间衡量），确定了 Area X 中这些生物标志物的蛋白水平之间的关系。UD 歌唱量增加了 TH、α-syn 和 NMDA 2B 受体蛋白水平。相比之下，FD 歌唱量并没有改变 TH 和 NMDA 2B 受体的表达。α-syn 的水平根据 UD 与 FD 歌曲表现出不同的表达模式，这与其在调节突触传递中的作用一致。我们提出了一个分子途径模型，以解释社会环境和歌唱量如何成为突触传递和可塑性所需的分子变化的重要驱动因素。
