Neuroscience Graduate Program, Baylor College of Medicine, Houston, United States.
Department of Neuroscience, Baylor College of Medicine, Houston, United States.
Elife. 2023 Feb 3;12:e80100. doi: 10.7554/eLife.80100.
The locus coeruleus (LC) houses the vast majority of noradrenergic neurons in the brain and regulates many fundamental functions, including fight and flight response, attention control, and sleep/wake cycles. While efferent projections of the LC have been extensively investigated, little is known about its local circuit organization. Here, we performed large-scale multipatch recordings of noradrenergic neurons in adult mouse LC to profile their morpho-electric properties while simultaneously examining their interactions. LC noradrenergic neurons are diverse and could be classified into two major morpho-electric types. While fast excitatory synaptic transmission among LC noradrenergic neurons was not observed in our preparation, these mature LC neurons connected via gap junction at a rate similar to their early developmental stage and comparable to other brain regions. Most electrical connections form between dendrites and are restricted to narrowly spaced pairs or small clusters of neurons of the same type. In addition, more than two electrically coupled cell pairs were often identified across a cohort of neurons from individual multicell recording sets that followed a chain-like organizational pattern. The assembly of LC noradrenergic neurons thus follows a spatial and cell-type-specific wiring principle that may be imposed by a unique chain-like rule.
蓝斑含有大脑中绝大多数去甲肾上腺素能神经元,调节许多基本功能,包括战斗和逃跑反应、注意力控制以及睡眠/觉醒周期。尽管蓝斑的传出投射已得到广泛研究,但对其局部回路组织知之甚少。在这里,我们对成年小鼠蓝斑中的去甲肾上腺素能神经元进行了大规模多贴附记录,以分析其形态-电特性,同时检查它们的相互作用。蓝斑去甲肾上腺素能神经元是多样的,可以分为两种主要的形态-电类型。虽然在我们的制备中没有观察到蓝斑去甲肾上腺素能神经元之间的快速兴奋性突触传递,但这些成熟的 LC 神经元通过缝隙连接连接,其连接速率与早期发育阶段相似,与其他脑区相当。大多数电连接形成于树突之间,仅限于同一类型的神经元之间的狭窄间隔对或小簇。此外,在来自单个多细胞记录集的单个神经元群体中,经常会识别出两个以上电耦联的细胞对,这些细胞对遵循链状组织模式。因此,LC 去甲肾上腺素能神经元的组装遵循空间和细胞类型特异性布线原则,这可能是由独特的链状规则决定的。