Objective: To examine the effect of acetylcholine (ACh) on the electric activities of pain-excitation neurons (PEN) and pain-inhibitation neurons (PIN) in the hippocampal CA1 area of normal rats or morphinistic rats, and to explore the role of ACh in regulation of pain perception in CA1 area under normal condition and morphine addiction.
Methods: The trains of electric impulses applied to sciatic nerve were set as noxious stimulation. The discharges of PEN and PIN in the CA1 area were recorded extracellularly by glass microelectrode. We observed the influence of intracerebroventricular (i.c.v.) injection of ACh and atropine on the noxious stimulation-evoked activities of PEN and PIN in the CA1 area.
Results: Noxious stimulation enhanced the electric activity of PEN and depressed that of PIN in the CA1 area of both normal and addiction rats. In normal rats, ACh decrease the pain-evoked discharge frequency of PEN, while increased the frequency of PIN. These effects reached the peak value at 4 min after injection of ACh. In morphinistic rats, ACh also inhibited the PEN electric activity and potentialized the PIN electric activity, but the maximum effect appeared at 6 min after administration. The ACh-induced responses were significantly blocked by muscarinic receptor antagonist atropine.
Conclusion: Cholinergic neurons and muscarinic receptors in the hippocampal CA1 area are involved in the processing of nociceptive information and they may play an analgesia role in pain modulation. Morphine addiction attenuated the sensitivity of pain-related neurons to the noxious information.
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http://dx.doi.org/10.1007/s12264-007-0048-4 | DOI Listing |
Nan Fang Yi Ke Da Xue Xue Bao
December 2024
Innovation and Transformation Center, Fujian University of Traditional Chinese Medicine, Fuzhou 350122, China.
Objectives: To explore the neuroprotective mechanism of electroacupuncture at the acupoints and in rats with cerebral ischemia-reperfusion (IR) injury.
Methods: Forty-eight male SD rats were equally randomized into sham operation group, cerebral IR model group, acupoint electroacupuncture group and non-acupoint acupuncture group. In the latter 3 groups, cerebral focal ischemic injury was induced using the Longa method; in the two electroacupuncture groups, electroacupuncture was performed either at the acupoints and or at non-acupoint sites for 7 days.
Behav Pharmacol
December 2024
Neuroscience Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences.
Exposure to stressful conditions such as forced swim stress (FSS) induces antinociception. Previous reports determined that dopamine receptors in the CA1 hippocampal area are important in chronic pain processing. Considering that neural mechanisms behind acute and chronic pain differ significantly, in this study, we have investigated the role of dopamine receptors within the CA1 region in the FSS-induced antinociceptive response in the acute pain induced by the tail-flick test in the rat.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Department of Laboratory Medicine and Pathobiology and Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
Introduction: Limited research has extensively analyzed neurodegenerative disease-related protein deposition patterns in the hippocampus.
Methods: This study examined the distribution of proteins in hippocampal subregions across major neurodegenerative diseases and explored their relation to each other. The area density of phosphorylated tau (p-tau), amyloid beta (Aβ), α-synuclein, and phosphorylated TDP-43 protein deposits together with pyramidal cell density in each hippocampal subregion, including CA1-4, prosubiculum (ProS), and subiculum was assessed in 166 cases encompassing various neurodegenerative diseases.
Brain Behav
December 2024
Neuroscience Institute, Georgia State University, Atlanta, Georgia, USA.
Purpose: Perineuronal nets (PNNs) are extracellular matrix proteoglycans surrounding neurons and glia. It has been suggested that PNNs are involved in the pathophysiology of multiple CNS illnesses, including stress-related neuropsychiatric disorders like schizophrenia, major depressive disorder, and anxiety disorders.
Method: Before examining the putative role of PNNs in stress-related responses, we described for the first time the anatomical distribution in Syrian hamsters (Mesocricetus auratus), an excellent model organism for studying social stress and circadian rhythms.
Mol Biol (Mosk)
December 2024
Institute of Medical Genetics, Tomsk National Research Medical Center, Russian Academy of Sciences, Tomsk, 634050 Russia.
Atherosclerosis and aneurysm of the aorta are relatively common pathological conditions that remain asymptomatic for a long period of time and have life-threatening and disabling complications. DNA methylation profiling in several regions (a dilated area, a nondilated area, and an atherosclerotic plaque) of the ascending aorta was carried out in patients with aortic aneurysm. DNA methylation was analyzed by reduced representation bisulfite sequencing (RRBS).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!