Figure 6. Effects of TLR2 stimulation on colonic motility and neurogenesis.

A-C are representative photomicrographs of colonic myenteric ganglion after immunostaining with the neuronal marker HuC/D (green) and nNOS (red); nuclei are stained with DAPI (blue); (A) Representative image of normal colonic myenteric ganglion containing nitrergic neurons (arrow). (B) Ampicillin reduced the total number of enteric neurons in a ganglion and reduced proportions of nitrergic neurons within the ganglion. (C) Concurrent treatment with LTA and ampicillin preserved the number of enteric neurons as well as proportions of nitrergic neurons (arrow) within myenteric ganglion. (D) Grouped results of WGTT under various conditions shows that WGTT is preserved in the ampicillin-LTA group. (E) Grouped results of mean number of total neurons and nitrergic neurons under various conditions shows preserved number of all neurons and nitrergic neurons in the ampicillin-LTA group. F-H are representative photomicrographs of colonic myenteric ganglion of Nestin-creER^T2:tdTomato mice after tamoxifen induction and after immunostaining with the neuronal marker HuC/D (green). Top panels and bottom panels show different magnifications; (F) In ampicillin-treated mice, number of neurons expressing tdTomato (arrow) after tamoxifen induction is reduced, suggesting reduced neurogenesis. (G) Concurrent treatment with LTA and Ampicillin reverses this effect and increases the number of neurons expressing tdTomato (arrow), suggesting increased neurogenesis from Nestin⁺ ENPCs. (H) tdTomato⁺ neurons (arrow) within the myenteric plexus ganglion of control mice, showing neurogenesis from Nestin⁺ ENPCs at steady state. (I) Grouped results of mean number of tdTomato–expressing neurons (newly formed neurons from ENPCs) under different conditions (* p<0.05). Scale bar is 10 μm.