Back to Search
Start Over
Morphological, molecular, and functional characterization of mouse glutamatergic myenteric neurons.
- Source :
- American Journal of Physiology: Gastrointestinal & Liver Physiology; Mar2024, Vol. 326 Issue 3, pG279-G290, 12p
- Publication Year :
- 2024
-
Abstract
- 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 (scRNAseq), 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. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 01931857
- Volume :
- 326
- Issue :
- 3
- Database :
- Complementary Index
- Journal :
- American Journal of Physiology: Gastrointestinal & Liver Physiology
- Publication Type :
- Academic Journal
- Accession number :
- 176323689
- Full Text :
- https://doi.org/10.1152/ajpgi.00200.2023