The venom of the fish-eating marine mollusc, Conus geographus, contains several neurotoxic peptides having different targets. A novel peptide has recently been isolated from the venom of C. geographus by Drs B. M. Olivera and W. R. Gray and colleagues in our department (in preparation). We report here that this peptide, designated omega CgTX (omega C. geographus toxin), irreversibly blocks nerve stimulus-evoked release of transmitter at the frog skeletal neuromuscular junction. Experiments indicate that the toxin acts by preventing action potential. Consistent with this is the demonstration that omega CgTX also irreversibly attenuates the Ca2+ component of the action potential in dorsal root ganglion (DRG) neurones from embryonic chick. omega CgTX thus provides a unique and potentially powerful probe for exploring the presynaptic terminal.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1038/308282a0 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Exploring the relaxation effects of Coptis chinensis and berberine on the lower esophageal sphincter: potential strategies for LES motility disorders.
BMC Complement Med Ther
December 2024
Department of Pediatrics, E-Da Hospital, I-Shou University, No. 1, Yi-Da Road, Yan-Chao District, Kaohsiung City, 82445, Taiwan, R.O.C..
Article Synopsis
- Esophageal achalasia is a condition that affects the lower esophageal sphincter (LES), leading to symptoms like difficulty swallowing, chest pain, and weight loss, with traditional treatments providing limited relief.
- This study investigates the effectiveness of Traditional Chinese Medicine, specifically Coptis chinensis and its active component berberine, in promoting LES relaxation as a potential alternative treatment.
- Results indicate that both C. chinensis extract and berberine significantly relax the LES by activating potassium channels, suggesting further research is warranted for their therapeutic use in esophageal disorders like achalasia.
Multiple layers of diversity govern the cell type specificity of GABAergic input received by mouse subicular pyramidal neurons.
J Physiol
September 2024
Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, USA.
The subiculum is a key region of the brain involved in the initiation of pathological activity in temporal lobe epilepsy, and local GABAergic inhibition is essential to prevent subicular-originated epileptiform discharges. Subicular pyramidal cells may be easily distinguished into two classes based on their different firing patterns. Here, we have compared the strength of the GABAa receptor-mediated inhibitory postsynaptic currents received by regular- vs.
View Article and Find Full Text PDFNew insights into the characterization of the mechanism of action of hyoscine butylbromide in the human colon ex vivo.
Eur J Pharmacol
June 2024
Universitat Autònoma de Barcelona, Department of Cell Biology, Physiology and Immunology, Barcelona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Barcelona, Spain. Electronic address:
Introduction: Hyoscine butylbromide (HBB) is one of the most used antispasmodics in clinical practice. Recent translational consensus has demonstrated a similarity between human colonic motor patterns studied ex vivo and in vivo, suggesting ex vivo can predict in vivo results. It is unclear whether the mechanism of action of antispasmodics can predict different use in clinical practice.
View Article and Find Full Text PDFUrsolic acid inhibits the synaptic release of glutamate and prevents glutamate excitotoxicity in rats.
Eur J Pharmacol
January 2024
School of Medicine, Fu Jen Catholic University, No.510, Zhongzheng Rd., Xinzhuang Dist, New Taipei City, 24205, Taiwan; Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan, 33303, Taiwan. Electronic address:
The present study evaluated the effect of ursolic acid, a natural pentacyclic triterpenoid, on glutamate release in rat cortical nerve terminals (synaptosomes) and its neuroprotection in a kainic acid-induced excitotoxicity rat model. In cortical synaptosomes, ursolic acid produced a concentration-dependent inhibition of evoked glutamate release with a half-maximum inhibition of release value of 9.5 μM, and calcium-free medium and the P/Q -type Ca channel blocker, ω-agatoxin IVA, but not ω-conotoxin GVIA, an N-type Ca channel blocker, prevented the ursoloic acid effect.
View Article and Find Full Text PDFP/Q type (Ca2.1) Calcium Channel Blocker ω-Agatoxin IVA Alters Cleaved Caspase-3 and BDNF Expressions in the Rat Brain and Suppresses Seizure Activity.
Mol Neurobiol
April 2024
Department of Biophysics, Meram Faculty of Medicine, University of Konya-NE, Konya, Turkey.
High-voltage-gated calcium channels have pivot role in the cellular and molecular mechanisms of various neurological disorders, including epilepsy. Similar to other calcium channels, P/Q-type calcium channels (Ca2.1) are also responsible for vesicle release at synaptic terminals.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!