The Regulatory Effects of Lateral Hypothalamus Area GABAB Receptor on Gastric Ischemia-Reperfusion Injury in Rats

Regulation of the central amygdala on intestinal motility and behavior via the lateral hypothalamus in irritable bowel syndrome model mice

BACKGROUND

Impaired bidirectional communication between the gastrointestinal tract and the central nervous system (CNS) is closely related to the development of irritable bowel syndrome (IBS). Studies in patients with IBS have also shown significant activation of the hypothalamus and amygdala. However, how neural circuits of the CNS participate in and process the emotional and intestinal disorders of IBS remains unclear.

METHODS

The GABAergic neural pathway projecting from the central amygdala (CeA) to the lateral hypothalamus (LHA) in mice was investigated by retrograde tracking combined with fluorescence immunohistochemistry. Anxiety, depression-like behavior, and intestinal motility were observed in the water-immersion restraint stress group and the control group. Furthermore, the effects of the chemogenetic activation of the GABAergic neural pathway of CeA-LHA on behavior and intestinal motility, as well as the co-expression of orexin-A and c-Fos in the LHA, were explored.

KEY RESULTS

In our study, Fluoro-Gold retrograde tracking combined with fluorescence immunohistochemistry showed that GABAergic neurons in the CeA were projected to the LHA. The microinjection of the gamma-aminobutyric acid (GABA) receptor antagonist into the LHA relieved anxiety, depression-like behavior, and intestinal motility disorder in the IBS mice. The chemogenetic activation of GABAergic neurons in the CeA-LHA pathway led to anxiety, depression-like behavior, and intestinal motility disorder. In addition, GABAergic neurons in the CeA-LHA pathway inhibited the expression of orexin-A in the LHA, and orexin-A was co-expressed with GABAA receptors.

CONCLUSIONS & INFERENCES

The CeA-LHA GABAergic pathway might participate in the occurrence and development of IBS by regulating orexin-A neurons.

Gluten-free grains: Importance, processing and its effect on quality of gluten-free products

Gluten-enteropathy affects a significant number of people, making gluten a major concern in the food industry. With medical advancements, the diagnosis of allergies is becoming easier, and people who are allergic to gluten are recommended a complete gluten-free diet. Since wheat provides a major part of the energy and nutrition in the diet, its elimination affects nutrition intake of allergic population. Food scientists are working to formulate products using protein-rich gluten-free grains with quality attributes at par with gluten-containing products. Focused research has been done to provide nutrition and a variety of food to people suffering from gluten-related disorders. Efforts are being made to remove the gluten from the wheat and other gluten-containing grains, while applying different processing/treatments to enhance the properties of gluten-free grains. Hence, the present review summarizes the importance, processing, and products of different gluten-free grains. It also highlights the digestibility of gluten-free grains with clinical trials and gluten elimination strategies for gluten-containing grains.

Autophagy-lysosome dysfunction is involved in gastric ischemia-reperfusion injury by promoting microglial activation in the paraventricular nucleus

The hypothalamic paraventricular nucleus (PVN) is a specific center in the brain that regulates gastric mucosal injury following gastric ischemia-reperfusion (GI-R) injury. This study aimed to investigate whether autophagy-lysosome dysfunction in the PVN tissues of GI-R rats is involved in the gastric injury, and the underlying molecular mechanisms. The rat model of GI-R was established by clamping the celiac artery for 30 min and reperfusion for different hours (1, 3, and 6 h). The gastric injury was evaluated by hematoxylin and eosin staining of the stomach and the gastric mucosal index. The autophagy-lysosome dysfunction in the PVN was evaluated by the protein levels of LC3 II and Beclin-1 (markers for autophagosome activity) and the activity of acid phosphatase (a representative lysosomal enzyme). Immunohistochemical staining of ionized calcium-binding adaptor molecule 1 in the PVN was performed to evaluate microglial activation. Reactive oxygen species (ROS) content and phosphorylated γ-aminobutyric acid B receptor (p-GABA_B R) expression in the PVN were also examined. The results revealed that, in GI-R rats, the shorter the reperfusion duration, the more severe the gastric mucosal damage. The autophagy-lysosome dysfunction exhibited by GI-R rats further enhanced microglial activation, ROS production, p-GABA_B R expression, and gastric injury. In addition, activating microglial cells increased ROS production, p-GABA_B R expression, and gastric injury in GI-R rats, while inhibiting microglial activation resulted in the opposite results. Taken together, autophagy-lysosome dysfunction induced by GI-R aggravated the gastric injury by inducing microglia activation.

Neuromechanism of acupuncture regulating gastrointestinal motility

Acupuncture has been used in China for thousands of years and has become more widely accepted by doctors and patients around the world. A large number of clinical studies and animal experiments have confirmed that acupuncture has a benign adjustment effect on gastrointestinal (GI) movement; however, the mechanism of this effect is unclear, especially in terms of neural mechanisms, and there are still many areas that require further exploration. This article reviews the recent data on the neural mechanism of acupuncture on GI movements. We summarize the neural mechanism of acupuncture on GI movement from four aspects: acupuncture signal transmission, the sympathetic and parasympathetic nervous system, the enteric nervous system, and the central nervous system.

The Roles of GABA in Ischemia-Reperfusion Injury in the Central Nervous System and Peripheral Organs

Ischemia-reperfusion (I/R) injury is a common pathological process, which may lead to dysfunctions and failures of multiple organs. A flawless medical way of endogenous therapeutic target can illuminate accurate clinical applications. γ-Aminobutyric acid (GABA) has been known as a marker in I/R injury of the central nervous system (mainly in the brain) for a long time, and it may play a vital role in the occurrence of I/R injury. It has been observed that throughout cerebral I/R, levels, syntheses, releases, metabolisms, receptors, and transmissions of GABA undergo complex pathological variations. Scientists have investigated the GABAergic enhancers for attenuating cerebral I/R injury; however, discussions on existing problems and mechanisms of available drugs were seldom carried out so far. Therefore, this review would summarize the process of pathological variations in the GABA system under cerebral I/R injury and will cover corresponding probable issues and mechanisms in using GABA-related drugs to illuminate the concern about clinical illness for accurately preventing cerebral I/R injury. In addition, the study will summarize the increasing GABA signals that can prevent I/R injuries occurring in peripheral organs, and the roles of GABA were also discussed correspondingly.