Morphological, molecular, and functional characterization of mouse glutamatergic myenteric neurons.
Morphological, molecular, and functional characterization of mouse glutamatergic myenteric neurons.
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小鼠谷氨酸肌间神经元的形态、分子和功能特征。
DOI：
10.1152/ajpgi.00200.2023
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发表时间：
2024
期刊：
影响因子：
--
通讯作者：
Feng,Bin
中科院分区：
文献类型：
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作者：
Liu,Jia;Zhang,Shaopeng;Emadi,Sharareh;Guo,Tiantian;Chen,Longtu;Feng,Bin
肠神经系统（ENS）的功能在很大程度上独立于中枢神经系统（CNS）。谷氨酸是中枢神经系统和感觉传入神经中的主要神经递质，但不是ENS中的主要神经递质。小鼠远端结肠和直肠（结肠直肠）中只有一小部分（约2%）肌间神经元呈囊泡谷氨酸转运体2（VGLUT 2）阳性，其结构和功能尚未确定。在这里，我们通过腺相关病毒稀疏标记，单细胞mRNA测序（scRNA-seq）和GCaMP 6 f钙成像系统地表征了VGLUT 2阳性肠神经元（VGLUT 2-EN）。我们的研究结果表明，大多数VGLUT 2-EN（29/31，93.5%）表现出Dogiel I型形态，具有单个外突轴突;大多数轴突（26/29，89.7%）长度在4和10 mm之间，每个轴突穿过19至34个肌间神经节。这些解剖学特征排除了VGLUT 2-EN作为内在初级传入或运动神经元。对52个VGLUT 2-EN进行的scRNA-seq表明与常规下行中间神经元不同的表达谱。扁平结直肠的离体GCaMP 6 f记录表明，几乎所有的VGLUT 2-EN（215个中的181个，84.2%）通过烟碱胆碱能神经传递被结直肠牵拉间接激活。总之，VGLUT 2-EN是一组功能独特的肠神经元，具有穿过多个肌间神经节的单个外突长轴突，并通过结直肠机械牵拉间接激活。这方面的知识将提供一个坚实的基础，为后续研究的潜在相互作用VGLUT 2-EN与外源性结直肠传入通过aminamatergic neurontransmission.NEW & NOTEWORTHWe揭示，VGLUT 2阳性肠神经元（EN），虽然构成了一小部分的总EN，均匀表达在肌间神经节，与轻微的浓度在中间区域之间的结肠和直肠。通过解剖、分子和功能分析，我们证明了VGLUT 2-EN通过烟碱胆碱能传递被有害的环向结肠直肠牵拉间接激活，表明它们参与了机械内脏伤害感受。https://ajpgi.podbean.com/e/got-guts-the-micro-version-characterize-mouse-glutamatergic-myenteric-neurons/
The enteric nervous system (ENS) functions largely independently of the central nervous system (CNS). Glutamate, the dominant neurotransmitter in the CNS and sensory afferents, is not a primary neurotransmitter in the ENS. Only a fraction (∼2%) of myenteric neurons in the mouse distal colon and rectum (colorectum) are positive for vesicular glutamate transporter type 2 (VGLUT2), the structure and function of which remain undetermined. Here, we systematically characterized VGLUT2-positive enteric neurons (VGLUT2-ENs) through sparse labeling with adeno-associated virus, single-cell mRNA sequencing (scRNA-seq), and GCaMP6f calcium imaging. Our results reveal that the majority of VGLUT2-ENs (29 of 31, 93.5%) exhibited Dogiel type I morphology with a single aborally projecting axon; most axons (26 of 29, 89.7%) are between 4 and 10 mm long, each traversing 19 to 34 myenteric ganglia. These anatomical features exclude the VGLUT2-ENs from being intrinsic primary afferent or motor neurons. The scRNA-seq conducted on 52 VGLUT2-ENs suggests different expression profiles from conventional descending interneurons. Ex vivo GCaMP6f recordings from flattened colorectum indicate that almost all VGLUT2-EN (181 of 215, 84.2%) are indirectly activated by colorectal stretch via nicotinic cholinergic neural transmission. In conclusion, VGLUT2-ENs are a functionally unique group of enteric neurons with single aborally projecting long axons that traverse multiple myenteric ganglia and are activated indirectly by colorectal mechanical stretch. This knowledge will provide a solid foundation for subsequent studies on the potential interactions of VGLUT2-EN with extrinsic colorectal afferents via glutamatergic neurotransmission.NEW & NOTEWORTHYWe reveal that VGLUT2-positive enteric neurons (EN), although constituting a small fraction of total EN, are homogeneously expressed in the myenteric ganglia, with a slight concentration at the intermediate region between the colon and rectum. Through anatomic, molecular, and functional analyses, we demonstrated that VGLUT2-ENs are activated indirectly by noxious circumferential colorectal stretch via nicotinic cholinergic transmission, suggesting their participation in mechanical visceral nociception.Listen to this article’s corresponding podcast at https://ajpgi.podbean.com/e/got-guts-the-micro-version-characterize-mouse-glutamatergic-myenteric-neurons/.