Portal-systemic encephalopathy (PSE) is associated with an increased brain tissue turnover of serotonin (5-HT). Despite increased 5-HT metabolism, brain 5-HT release in rats with a portacaval shunt (PCS) seems to be unaltered. Although this may indicate that the overall 5-HT output is unaltered in PSE, it is also possible that the 5-HT release pattern might be altered in some way. In the present study, the potassium-evoked frontal neocortical release of 5-HT was studied in experimental chronic PSE. KCI (60 mM) produced marked increases in the 5-HT output compared with basal values both in PCS and sham rats. Simultaneously, the KCI challenge resulted in significant elevations in the 5-HT release of PCS compared with sham. In Ca2+-free medium, the difference between PCS and sham rats in the KCl-evoked release of 5-HT was abolished. In the presence of TTX (1 mM), both groups displayed increased extracellular 5-HT levels. Again, a difference with higher amplitude of the 5-HT release in PCS compared with sham was evident. It is concluded that in experimental chronic PSE an augmented neocortical 5-HT release compared with the normal in vivo situation is available. The possible mechanism(s) responsible for the difference in neocortical 5-HT output between PCS and sham-operated rats in response to the KCl-challenge is discussed.
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Int J Mol Sci
January 2025
Department of Anesthesiology and Pain Medicine, Hubei Key Laboratory of Geriatric Anesthesia and Perioperative Brain Health, Wuhan Clinical Research Center for Geriatric Anesthesia, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Chronic pain is a multidimensional experience that not only involves persistent nociception but is also frequently accompanied by significant emotional disorders, such as anxiety and depression, which complicate its management and amplify its impact. This review provides an in-depth exploration of the neurobiological mechanisms underlying the comorbidity of chronic pain and emotional disturbances. Key areas of focus include the dysregulation of major neurotransmitter systems (serotonin, gamma-aminobutyric acid, and glutamate) and the resulting functional remodeling of critical neural circuits implicated in pain processing, emotional regulation, and reward.
View Article and Find Full Text PDFJ Neural Transm (Vienna)
January 2025
Human Anatomy, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Via Roma 55, Pisa, 56100, PI, Italy.
Anorexia nervosa (AN) represents an eating disorder, which features the highest rate of mortality among all psychiatric disorders. The disease prevalence is increasing steadily, and an effective cure is missing. The neurobiology of the disease is largely unknown, and only a few studies were designed to disclose specific brain areas, where altered neural transmission may occur.
View Article and Find Full Text PDFExp Neurol
January 2025
Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China. Electronic address:
Depression is one of the most common non-motor symptoms in Parkinson's disease (PD) and the hyperactivity of the lateral habenula (LHb) may contribute to depression. The present study was performed to investigate the effects and mechanisms of group I metabotropic glutamate receptors (mGluRs) in the LHb on PD-related depressive-like behaviors. Unilateral 6-hydroxydopamine lesions of the substantia nigra pars compacta (SNc) were used to establish the PD rat model.
View Article and Find Full Text PDFJ Physiol Sci
January 2025
Center for Medical Sciences, International University of Health and Welfare, 324-8501, Otawara, Tochigi, Japan; Bio-Laboratory, Foundation for Advancement of International Science, 305-0821, Tsukuba, Ibaraki, Japan. Electronic address:
Previously, we found that serotonin (5-HT) release in the central nucleus of the amygdala (CeA) of anesthetized rats decreases in response to innocuous stroking of the skin, irrespective of stimulus laterality, but increases in response to noxious pinching applied to a hindlimb contralateral to the 5-HT measurement site. The aim of the present study was to determine whether intra-CeA 5-HT release responses to cutaneous stimulation were altered in an animal model of neuropathic pain induced by ligation of the left L5 spinal nerve. In anesthetized neuropathic pain model rats, stroking of the left hindlimb increased 5-HT release in the CeA, whereas stroking of the right hindlimb decreased it.
View Article and Find Full Text PDFBr J Pharmacol
January 2025
Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy.
Background And Purpose: Inflammatory bowel disease (IBD) patients display genetic polymorphisms in toll-like receptor 4 (TLR4) genes, contributing to dysregulate enteric nervous system (ENS) circuits with increased levels of 5-HT and alteration of the neuroimmune crosstalk. In this study, we investigated the impact of TLR4 signalling on mouse ENS dysfunction caused by dextran sulphate sodium (DSS)-induced ileitis.
Experimental Approach: Male C57BL/6J (wild-type [WT]) and TLR4 mice (10 ± 2 weeks old) received 2% DSS in drinking water for 5 days and then were switched to 3-day regular drinking water.
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