Nicotine acetylcholine (ACh) receptors (nAChRs) are ligand-gated ion channels that are widely expressed throughout the central nervous system. It is well established that presynaptic, alpha7-containing nAChRs modulate glutamate release in several brain areas, and that this modulation requires extracellular calcium. However, the intracellular mechanisms consecutive to nAChR opening are unclear. Recent studies have suggested a role for presynaptic calcium stores in the increase of neurotransmitter release following nAChR activation. Using the minimal stimulation protocol at low-probability Schaffer collateral synapses in acute hippocampal slices from neonatal rats, we show that nicotine acting on presynaptic alpha7 nAChRs persistently upregulates glutamate release. We tested the role of calcium stores in this potentiation. First, we examined the relationship between calcium stores and glutamate release. We found that bath application of SERCA pump inhibitors (cyclopiazonic acid and thapsigargin), as well as an agonist of ryanodine receptors (ryanodine 2 microM) increases the probability of glutamate release at CA3-CA1 synapses, decreases the coefficient of variation and the paired-pulse ratio, indicating that presynaptic activation of calcium-induced calcium release can modulate glutamatergic transmission. Next, we investigated whether blocking calcium release from internal stores could alter the effect of nicotine. Preincubation with thapsigargin (10 microM), cyclopiazonic acid (30 microM), or with a high (blocking) concentration of ryanodine (100 microM) for 30 min to 5 h failed to block the effect of nicotine. However, after preincubation in ryanodine, nicotine-elicited potentiation was significantly shortened. These results indicate that at immature Schaffer collateral-CA1 synapses, activation of presynaptic calcium stores is not necessary for but contributes to nicotine-elicited increase of neurotransmitter release.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/hipo.20271 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Fabrication and characterization of 3D-printed polymeric-based scaffold coated with bioceramic and naringin for a potential use in dental pulp regeneration (in vitro study).
Int Endod J
January 2025
Restorative and Aesthetic Dentistry Department, College of Dentistry, University of Baghdad, Baghdad, Iraq.
Aim: 3D-printed scaffolds loaded with healing directed agents could be employed for better treatment outcome in regenerative dentistry. The aim of this study was to fabricate and characterize simple 3D-printed poly lactic acid (PLA) scaffolds coated with nanoHydroxyapatite (nHA), Naringin (NAR), or their combination, and testing their morphological, chemical, mechanical, antibacterial, biocompatible and bioactive properties.
Methodology: Two variants pore sizes, 300 and 700 μm, of 3D-printed PLA disc scaffolds measuring (10 × 1 mm) were fabricated.
Widespread occurrence and relevance of phosphate storage in foraminifera.
Nature
January 2025
SUGAR, X-star, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan.
Foraminifera are ubiquitous marine protists that intracellularly accumulate phosphate, an important macronutrient in marine ecosystems and in fertilizer potentially leaked into the ocean. Intracellular phosphate concentrations can be 100-1,000 times higher than in the surrounding water. Here we show that phosphate storage in foraminifera is widespread, from tidal flats to the deep sea.
View Article and Find Full Text PDFNovel Protective Role for Gut Microbiota-derived Metabolite PAGln in Doxorubicin-induced Cardiotoxicity.
Cardiovasc Drugs Ther
January 2025
Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, 410011, Hunan, China.
Purpose: Doxorubicin (Dox) is a classic anthracycline chemotherapy drug with cause cumulative and dose-dependent cardiotoxicity. This study aimed to investigate the potential role and molecular mechanism of phenylacetylglutamine (PAGln), a novel gut microbiota metabolite, in Dox-induced cardiotoxicity (DIC).
Methods: DIC models were established in vivo and in vitro, and a series of experiments were performed to verify the cardioprotective effect of PAGln.
Transcriptional determinants of goal-directed learning and representational drift in the parahippocampal cortex.
Cell Rep
January 2025
Department of Biology, Boston University, Boston, MA 02215, USA; Center for Neurophotonics, Boston University, Boston, MA 02215, USA; Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA; Center for Systems Neuroscience, Boston University, Boston MA 02215, USA. Electronic address:
Article Synopsis
- Task learning involves forming and storing associations between stimuli and outcomes in memory, but individual neuron representations can change over time.
- Researchers used two-photon calcium imaging and spatial transcriptomics to study neuron activity and gene expression in the perirhinal cortex during task training.
- Deleting brain-derived neurotrophic factor disrupted gene expression and task learning, while prolonged training reduced representational drift and strengthened existing memory representations, highlighting key cellular mechanisms in memory stability.
Clinically Deployable Electro-Immunosensing Device Comprising Bioactive Glass-MWCNT for Alkaline Phosphatase Detection in Human Serum Samples.
ACS Appl Bio Mater
January 2025
School of Biochemical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005, India.
Bone is a dynamic tissue that serves several purposes in the human body, including storing calcium, forming blood cells, and protecting and supporting the body's organs. Alkaline phosphatase (ALP) is secreted into the circulation by osteoblasts, the cells responsible for making bone. It attaches to the surface of osteoblast cells or matrix vesicles.
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!