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Transsynaptic Tracing of Sensory‐Motor Connections in the Gut‐Brain Axis
Author(s) -
Parker Coltan G,
Grako Megan,
Berish Brooks,
Dailey Megan J
Publication year - 2018
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2018.32.1_supplement.lb462
Subject(s) - sensory system , retrograde tracing , neuroscience , biology , nucleus , small intestine , anatomy , endocrinology
The neural gut‐brain axis consists of distinct sensory and motor neurons. Sensory neurons innervating the small intestine transmit meal‐related information to the brain, while motor neurons to the small intestine regulate motility and secretion. Previous research has only partially mapped the brain regions directly connected to the gut‐brain axis, and no research has yet investigated sensory‐motor overlap in those brain regions. Here we used transsynaptic viral tracing to identify the brain regions directly connected to the small intestine and quantify the extent of sensory‐motor overlap in those regions. Because transsynaptic tracing has not been done between the brain and small intestine, we needed to first characterize the viral transmission pattern. A motor‐tracing virus (PRV‐152) was injected to the duodenal wall of adult male Sprague‐Dawley (SD) rats (N=4). Viral transmission was allowed for 3, 4, or 5 days. Brains were processed and virus labeled cells were quantified per nucleus. Progressive viral transmission revealed, for the first time, the sequence of brain regions directly connected to the small intestine through the motor gut‐brain axis. Next, we combined PRV‐152 with a sensory tracing virus (H129 #424) in order to identify sensory‐motor overlap. Both viruses were injected to the duodenal wall of adult male SD rats (N=6). Viral transmission was allowed for 5 days. Brains were processed, and single‐ and double‐labeled cells were quantified per nucleus. We found consistent single‐ and double‐labeled populations across brain regions of the gut‐brain axis, suggesting multiple distinct parallel pathways that persist through the axis. This is the first study to reveal the sensory‐motor organization of the gut‐brain axis, and is a step toward phenotyping the neuronal subpopulations involved in gut‐brain axis control. Further work toward generating a phenotypic map of the axis could enable targeted manipulation of specific gut‐brain axis functions. Support or Funding Information This work was supported by USDA Hatch (to MJD) ILLU‐538‐926 This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .