The role of amygdala neuropsin/serpinb6 pathway in the regulation of gastric hypersensitivity and anxiety by electroacupuncture

Global trends in research related to functional dyspepsia and anxiety or depression over the past two decades: a bibliometric analysis

Background and purpose

Functional dyspepsia (FD) is a prevalent global disorder of the upper digestive tract characterized by functional impairment. It often coexists with anxiety/depression, significantly impairing occupational productivity and overall quality of life. This study aimed to identify emerging patterns and prominent themes within FD and anxiety/depression research through bibliometric analysis to help explore new innovative avenues for investigating this type of FD.

Methods

A comprehensive review of literature encompassing FD and anxiety/depression was conducted using the Science Citation Index Extension of the Web of Science Core Collection from 2003 to 2023. Information extracted comprised "Full Record and Cited References." Bibliometric analysis of relevant publications, including country, institution, author, journal, citations, and keywords, was conducted using CiteSpace, VOSviewer, and Bibliometrix package in R and Excel.

Results

Studies related to FD and anxiety/depression have demonstrated an ascending trajectory since 2003. Our bibliometric analysis identified 338 studies published by 2023. NEUROGASTROENTEROLOGY AND MOTILITY emerged as the most prolific journal, while GASTROENTEROLOGY retained pre-eminence within the top 10 published journals. China emerged as the most prolific country, with two institutions within the top 10 in terms of volume of publications. The Mayo Clinic stood as the foremost institution in terms of publication volume, with the Chengdu University of Traditional Chinese Medicine exhibiting robust collaborative engagement. Eminent author influence was attributed to Talley NJ of Newcastle University, Australia. Clusters of extensively cited papers and prevalent keywords delineate the status and trend of FD and anxiety/depression research. This encompasses FD, anxiety, depression, sleep disorders, and functional gastrointestinal disorders. Furthermore, the timeline view map or trend-term analysis suggested that duodenal low-grade inflammation ("duodenal eosinophilia" and "mast cells") might be a new concern associated with FD and anxiety/depression.

Conclusion

Employing bibliometric analysis, this study revealed prevalent focal areas and new trends within FD and anxiety/depression research. These insights serve as valuable guidance for scholars seeking to delve into new research avenues.

A central amygdala input to the dorsal vagal complex controls gastric motility in mice under restraint stress

Background/aims: Psychological and physiological stress can cause gastrointestinal motility disorders. Acupuncture has a benign regulatory effect on gastrointestinal motility. However, the mechanisms underlying these processes remain unclear. Methods: Herein, we established a gastric motility disorder (GMD) model in the context of restraint stress (RS) and irregular feeding. The activity of emotional center-central amygdala (CeA) GABAergic neurons and gastrointestinal center-dorsal vagal complex (DVC) neurons were recorded by electrophysiology. Virus tracing and patch clamp analysis of the anatomical and functional connection between the CeA^GABA → dorsal vagal complex pathways were performed. Optogenetics inhibiting or activating CeA^GABA neurons or the CeA^GABA → dorsal vagal complex pathway were used to detect changes in gastric function. Results: We found that restraint stress induced delayed gastric emptying and decreased gastric motility and food intake. Simultaneously, restraint stress activated CeA GABAergic neurons, inhibiting dorsal vagal complex neurons, with electroacupuncture (EA) reversing this phenomenon. In addition, we identified an inhibitory pathway in which CeA GABAergic neurons project into the dorsal vagal complex. Furthermore, the use of optogenetic approaches inhibited CeA^GABA neurons and the CeA^GABA → dorsal vagal complex pathway in gastric motility disorder mice, which enhanced gastric movement and gastric emptying, whereas activation of the CeA^GABA and CeA^GABA → dorsal vagal complex pathway mimicked the symptoms of weakened gastric movement and delayed gastric emptying in naïve mice. Conclusion: Our findings indicate that the CeA^GABA → dorsal vagal complex pathway may be involved in regulating gastric dysmotility under restraint stress conditions, and partially reveals the mechanism of electroacupuncture.

Analysis of brain signal change response in amygdala evoked by skin pressure stimulus

BACKGROUND

It was well known that the human body would produce an uncomfortable sensation when the fabric exerted a certain amount of pressure irritation on the skin. The amygdala had long been thought to be the source of negative emotion perception. However, up to now, the brain signal changes in the amygdala evoked by skin exposure pressure had not been known.

MATERIALS AND METHODS

In this work, a series of gradually increasing contact pressure stimulus from boneless corsets was repeatedly applied to the body's waist and abdomen, and the technology of functional magnetic resonance imaging (fMRI) was adopted to detect the brain response synchronously.

RESULTS

The results shown that both subjective comfort score and percent signal changes (PSCs) of amygdala decreased with the increase of skin contact pressure. When the skin pressure applied to the waist and abdomen of the human body exceeded about 1 kPa, blood oxygen level dependent signal in the amygdala was negatively activated. Besides, the degree of response of PSCs was intense than subjective evaluation, and the standard deviations of PSCs between individuals were much smaller than subjective evaluations.

CONCLUSION

It was suggested that skin contact pressure stimulus caused the attention of the amygdala brain area. The greater the stimulus, the higher the attention, but such attention was caused by negative activation of the amygdala induced by skin discomfort. In addition, skin comfort representation based on brain perception was superior to subjective representation due to its higher response sensitivity and antipsychological interference ability.