γ oscillations are associated with higher brain functions such as memory, perception and consciousness. Disruption of γ oscillations occur in various neuro-psychological disorders such as schizophrenia. Nicotinic acetylcholine receptors (nAChR) are highly expressed in the hippocampus, however, little is known about the role on hippocampal persistent γ oscillation. This study examined the effects of nicotine and selective nAChR agonists and antagonists on kainate-induced persistent γ oscillation in rat hippocampal slices. Nicotine enhanced γ oscillation at concentrations of 0.1–10 μM, but reduced it at a higher concentration of 100 μM. The enhancement on γ oscillation can be best mimicked by co-application of α4β2- and α7- nAChR agonist and reduced by a combination of nAChR antagonists, DhβE and MLA. However, these nAChR antagonists failed to block the suppressing role of nicotine on γ. Furthermore, we found that the NMDA receptor antagonist D-AP5 completely blocked the effect of nicotine. These results demonstrate that nicotine modulates γ oscillations via α7 and α4β2 nAChR as well as NMDA activation, suggesting that nAChR activation may have a therapeutic role for the clinical disorder such as schizophrenia, which is known to have impaired γ oscillation and hypo-NMDA receptor function.

Background Intestinal fibrosis is considered an inevitable consequence of chronic inflammatory bowel disease (IBD), leading to stricture formation and need for surgery. During the process of fibrogenesis, extracellular matrix (ECM) components critically regulate the function of mesenchymal cells. We characterized the composition and function of the ECM in fibrostenosing Crohn’s disease (CD) and control tissues. Methods Decellularized full thickness intestinal tissue platforms were tested using three different protocols and ECM composition in different tissue phenotypes was explored by proteomics and validated by quantitative polymerase chain reaction (qPCR) and immunohistochemistry. Primary human intestinal myofibroblasts (HIMF) treated with Milk Fat Globule-Epidermal growth factor 8 (MFGE8) were evaluated regarding mechanism of their anti-fibrotic response, and the action of MFGE8 was tested in experimental intestinal fibrosis. Results We established and validated an optimal decellularization protocol for intestinal IBD tissues. Matrisome analysis revealed elevated MFGE8 expression in CD strictured tissue (CDs), which was confirmed at the mRNA and protein levels. Treatment with MFGE8 inhibited ECM production in normal control (NL) HIMF but not CDs HIMF. Next generation sequencing (NGS) uncovered functionally relevant integrin-mediated signaling pathways, and blockade of integrin αvβ5 and focal adhesion kinase rendered HIMF non-responsive to MFGE8. MFGE8 prevented and reversed experimental intestinal fibrosis in vitro and in vivo. Conclusion MFGE8 displays anti-fibrotic effects, and its administration may represent a future therapeutic approach for prevention of IBD-induced intestinal strictures.