Search results for " calcium channel"

Linoleic acid induces calcium signaling, Src kinase phosphorylation, and neurotransmitter release in mouse CD36-positive gustatory cells.

2008

We have recently demonstrated that the cells expressing CD36, localized apically on the taste buds of mouse lingual circumvallate papillae, act as gustatory cells. In the present study we isolated these CD36-positive cells from mouse circumvallate papillae and investigated intracellular signaling events, triggered by a long-chain polyunsaturated fatty acid, i.e. linoleic acid (LA). LA induced increases in free intracellular calcium concentrations, [Ca(2+)](i), by recruiting calcium from endoplasmic reticulum pool via inositol 1,4,5-triphosphate production followed by calcium influx via opening of store-operated calcium (SOC) channels. LA also induced phosphorylation of Src-protein-tyrosine …

Persistent activity in layer 5 pyramidal neurons following cholinergic activation of mouse primary cortices

2011

Persistent spiking activity is thought to be a cellular process involved in working memory. We have been interested in whether persistent activity also exists in cortical areas which are not involved in this memory process. To study the possible presence and the mechanisms of persistent activity in layer 5 pyramidal cells of the mouse primary somatosensory, visual and motor cortices, we used patch-clamp and calcium imaging techniques. A combination of cholinergic receptor activation and suprathreshold depolarization or sufficient extracellular stimulation leads to either a subthreshold afterdepolarization or suprathreshold persistent activity in these cortices. There is a continuum of respo…

The electrophysiology of adenosine in the mammalian central nervous system

1991

Adaptive Mechanisms of Somatostatin-Positive Interneurons after Traumatic Brain Injury through a Switch of α Subunits in L-Type Voltage-Gated Calcium…

2021

Abstract Unilateral traumatic brain injury (TBI) causes cortical dysfunctions spreading to the primarily undamaged hemisphere. This phenomenon, called transhemispheric diaschisis, is mediated by an imbalance of glutamatergic versus GABAergic neurotransmission. This study investigated the role of GABAergic, somatostatin-positive (SST) interneurons in the contralateral hemisphere 72 h after unilateral TBI. The brain injury was induced to the primary motor/somatosensory cortex of glutamate decarboxylase 67–green fluorescent protein (GAD67-GFP) knock-in mice at postnatal days 19–21 under anesthesia in vivo. Single GFP+ interneurons of the undamaged, contralateral cortex were isolated by fluores…

Evaluation and synthesis of 7-arylhydroxymethyltriazolopyridines as potential cardiovascular agents

2002

7-Arylhydroxymethyltriazolopyridines 3a-c and 4a-d were synthesized by regioselective lithiation of [1,2,3]triazolo[1,5-a]pyridines 1 and 2 and subsequent trapping of the 7-lithioderivatives formed using aryl aldehydes as electrophiles. The structural relationship between compounds 3a-c and 4a-d and arylethanolamines suggested their consideration as potential cardiovascular agents. A preliminary evaluation as vascular smooth muscle relaxants was carried out. These compounds did not act as α1-adrenoceptor antagonists and were unable to block calcium entry through voltage-dependent calcium channels. Abarca Gonzalez, Belen, Belen.Abarca@uv.es ; Ballesteros Campos, Rafael, Rafael.Ballesteros@uv…

Activation of TRPC6 calcium channels by diacylglycerol (DAG)-containing arachidonic acid: A comparative study with DAG-containing docosahexaenoic acid

2006

We synthesized a diacylglycerol (DAG)-containing arachidonic acid, i.e., 1-stearoyl-2-arachidonyl-sn-glycerol (SAG), and studied its implication in the modulation of canonical transient receptor potential sub-type 6 (TRPC6) channels in stably-transfected HEK-293 cells. SAG induced the influx of Ca(2+), and also of other bivalent cations like Ba(2+) and Sr(2+), in these cells. SAG-evoked Ca(2+) influx was not due to its metabolites as inhibitors of DAG-lipase (RHC80267) and DAG-kinase (R50922) failed to inhibit the response of the same. To emphasise that SAG exerts its action via its DAG configuration, but not due to the presence of stearic acid at sn-1 position, we synthesized 1-palmitoyl-2…

Separation of presynaptic Cav2 and Cav1 channel function in synaptic vesicle exo- and endocytosis by the membrane anchored Ca2+ pump PMCA

2021

Significance Synaptic vesicle (SV) release from presynaptic terminals requires nanometer precise control of action potential (AP)–triggered calcium influx through voltage-gated calcium channels (VGCCs). SV recycling also depends on calcium signals, though in different spatiotemporal domains. Mechanisms for separate control of SV release and recycling by AP-triggered calcium influx remain elusive. Here, we demonstrate largely independent regulation of release and recycling by two different populations of VGCCs (Cav2, Cav1), identify Cav1 as one of potentially multiple calcium entry routes for endocytosis regulation, and show functional separation of simultaneous calcium signals in the nanome…

COVID-19, Cation Dysmetabolism, Sialic Acid, CD147, ACE2, Viroporins, Hepcidin and Ferroptosis: A Possible Unifying Hypothesis.

2022

Background: iron and calcium dysmetabolism, with hyperferritinemia, hypoferremia, hypocalcemia and anemia have been documented in the majority of COVID-19 patients at later/worse stages. Furthermore, complementary to ACE2, both sialic acid (SA) molecules and CD147 proved relevant host receptors for SARS-CoV-2 entry, which explains the viral attack to multiple types of cells, including erythrocytes, endothelium and neural tissue. Several authors advocated that cell ferroptosis may be the core and final cell degenerative mechanism. Methods: a literature research was performed in several scientific search engines, such as PubMed Central, Cochrane Library, Chemical Abstract Service. More than 5…

Association of Whirlin with Cav1.3 (α1D) Channels in Photoreceptors, Defining a Novel Member of the Usher Protein Network

2010

Contains fulltext : 88383.pdf (Publisher’s version ) (Closed access) PURPOSE: Usher syndrome is the most common form of hereditary deaf-blindness. It is both clinically and genetically heterogeneous. The USH2D protein whirlin interacts via its PDZ domains with other Usher-associated proteins containing a C-terminal type I PDZ-binding motif. These proteins co-localize with whirlin at the region of the connecting cilium and at the synapse of photoreceptor cells. This study was undertaken to identify novel, Usher syndrome-associated, interacting partners of whirlin and thereby obtain more insights into the function of whirlin. METHODS: The database of ciliary proteins was searched for proteins…

Choice and Outcomes of Rate Control versus Rhythm Control in Elderly Patients with Atrial Fibrillation: A Report from the REPOSI Study

2018

Background: Among rate-control or rhythm-control strategies, there is conflicting evidence as to which is the best management approach for non-valvular atrial fibrillation (AF) in elderly patients. Design: We performed an ancillary analysis from the ‘Registro Politerapie SIMI’ study, enrolling elderly inpatients from internal medicine and geriatric wards. Methods: We considered patients enrolled from 2008 to 2014 with an AF diagnosis at admission, treated with a rate-control-only or rhythm-control-only strategy. Results: Among 1114 patients, 241 (21.6%) were managed with observation only and 122 (11%) were managed with both the rate- and rhythm-control approaches. Of the remaining 751 patie…