A novel task to evaluate irony comprehension and its essential elements in Spanish speakers.

An ironic statement transmits the opposite meaning to its literal counterpart and is one of the most complex communicative acts. Thus, it has been proposed to be a good indicator of social communication ability. Prosody and facial expression are two crucial paralinguistic cues that can facilitate the understanding of ironic statements. The primary aim of this study was to create and evaluate a task of irony identification that could be used in neuroimaging studies. We independently evaluated three cues, contextual discrepancy, prosody and facial expression, and selected the best cue that would lead participants in fMRI studies to identify a stimulus as ironic in a reliable way. This process included the design, selection, and comparison of the three cues, all of which have been previously associated with irony detection. The secondary aim was to correlate irony comprehension with specific cognitive functions. Results showed that psycholinguistic properties could differentiate irony from other communicative acts. The contextual discrepancy, prosody, and facial expression were relevant cues that helped detect ironic statements; with contextual discrepancy being the cue that produced the highest classification accuracy and classification time. This task can be used successfully to test irony comprehension in Spanish speakers using the cue of interest. The correlation of irony comprehension with cognitive functions did not yield consistent results. A more heterogeneous sample of participants and a broader battery of tests may be needed to find reliable cognitive correlates of irony comprehension.

Valoración de la severidad en enfermedades degenerativas articulares temporomandibulares mediante tomografía computarizada Cone Beam / Assessment of the severity of temporomandibular articular degenerative diseases through Cone Beam imaging

RESUMEN: Introducción: Muchos estudios han demostrado que las enfermedades degenerativas articulares Temporomandibulares (EDATM) provocan dolor, alteran la función modificando las estructuras esqueletales que se traducen en asimetrías faciales. La valoración imagenológica contribuye a un adecuado diagnóstico con el objetivo de optimizar la evaluación morfológica de las articulaciones temporomandibulares. Metodología: Se realizó una búsqueda electrónica en las bases de datos de PubMed, Google Scholar y SciELO. La estrategia de búsqueda se realizó utilizando una combinación de términos con el objetivo de analizar la valoración de las características imagenológicas y de volumen condilar. Resultados y Discusión: De un total de 9807 artículos se seleccionaron 18 que cumplían con los requisitos. Se han propuesto muchas categorías para clasificar la severidad imagenológica de la EDATM sumado al advenimiento de softwares y reconstrucciones tridimensionales que han propuesto categorías a través de algoritmos matemáticos y de superposición de imagen que son un gran aporte para el diagnóstico, la toma decisiones en la elección del plan de tratamiento y en el seguimiento. Conclusiones: La valoración de la severidad de las EDATM son claves para que la investigación clínica permita esclarecer los procesos que se relacionan con el objeto de valorar la progresión de esta enfermedad.

ABSTRACT: Introduction: Many studies have shown that Temporomandibular degenerative joint diseases (TMDJD) cause pain, alter function by modifying skeletal structures that result in facial asymmetries. Imaging evaluation contributes to an adequate diagnosis with the aim of optimizing the morphological evaluation of the temporomandibular joints. Methodology: An electronic search was performed in the PubMed, Google Scholar and SciELO databases. The search strategy was performed using a combination of terms in order to analyze the assessment of imaging characteristics and condylar volume. Results and Discussion: From a total of 9807 articles, 18 were selected that met the requirements. Many categories have been proposed to classify the imaging severity of the TMDJD added to the advent of software and three-dimensional reconstructions that have proposed categories through mathematical algorithms and image superposition that are a great contribution to diagnosis, decision-making and choice of the treatment plan and follow-up. Conclusions: The assessment of the severity of TMDJD is key for clinical research in order to clarify the processes that are related to assessing the progression of this disease.

BCG-induced cytokine release in bladder cancer cells is regulated by Ca2+ signaling.

Bacillus Calmette-Guérin (BCG) is widely used in the clinic to effectively treat superficial urinary bladder cancer. However, a significant proportion of patients who fail to respond to BCG risk cystectomy or death. Though more than 3 million cancer treatments with BCG occur annually, surprisingly little is known about the initial signaling cascades activated by BCG. Here, we report that BCG induces a rapid intracellular Ca2+ (calcium ion) signal in bladder cancer cells that is essential for activating the transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and for synthesizing and secreting proinflammatory cytokines, including interleukin 8 (IL-8). A similar Ca2+ response was observed when cells were exposed to the supernatant of BCG. Studying cellular molecular mechanisms involved in the BCG signaling event, we found pivotal roles for phospholipase C and the Toll-like receptor 4. Further assessment revealed that this signaling pathway induces synthesis of IL-8, whereas exocytosis appeared to be controlled by global Ca2+ signaling. These results shed new light on the molecular mechanisms underlying BCG treatment of bladder cancer, which can help in improving therapeutic efficacy and reducing adverse side effects.

Publisher Correction: Experimental orthotopic transplantation of a tissue-engineered oesophagus in rats.

This corrects the article DOI: 10.1038/ncomms4562.

Glycosylation controls sodium-calcium exchanger 3 sub-cellular localization during cell cycle.

The Na+/Ca2+ exchanger (NCX) is a membrane antiporter that has been identified in the plasma membrane, the inner membrane of the nuclear envelope and in the membrane of the endoplasmic reticulum (ER). In humans, three genes have been identified, encoding unique NCX proteins. Although extensively studied, the NCX's sub-cellular localization and mechanisms regulating the activity of different subtypes are still ambiguous. Here we investigated the subcellular localization of the NCX subtype 3 (NCX3) and its impact on the cell cycle. Two phenotypes, switching from one to the other during the cell cycle, were detected. One phenotype was NCX3 in the plasma membrane during S and M phase, and the other was NCX3 in the ER membrane during resting and interphase. Glycosylation of NCX3 at the N45 site was required for targeting the protein to the plasma membrane, and the N45 site functioned as an on-off switch for the translocation of NCX3 to either the plasma membrane or the membrane of the ER. Introduction of an N-glycosylation deficient NCX3 mutant led to an arrest of cells in the G0/G1 phase of the cell cycle. This was accompanied by accumulation of de-glycosylated NCX3 in the cytosol (that is in the ER), where it transported calcium ions (Ca2+) from the cytosol to the ER. These results, obtained in transfected HEK293T and HeLa and confirmed endogenously in SH-SY5Y cells, suggest that cells can use a dynamic Ca2+ signaling toolkit in which the NCX3 sub-cellular localization changes in synchrony with the cell cycle.

Ca2+/Calmodulin-Dependent Protein Kinase II and Androgen Signaling Pathways Modulate MEF2 Activity in Testosterone-Induced Cardiac Myocyte Hypertrophy.

Testosterone is known to induce cardiac hypertrophy through androgen receptor (AR)-dependent and -independent pathways, but the molecular underpinnings of the androgen action remain poorly understood. Previous work has shown that Ca2+/calmodulin-dependent protein kinase II (CaMKII) and myocyte-enhancer factor 2 (MEF2) play key roles in promoting cardiac myocyte growth. In order to gain mechanistic insights into the action of androgens on the heart, we investigated how testosterone affects CaMKII and MEF2 in cardiac myocyte hypertrophy by performing studies on cultured rat cardiac myocytes and hearts obtained from adult male orchiectomized (ORX) rats. In cardiac myocytes, MEF2 activity was monitored using a luciferase reporter plasmid, and the effects of CaMKII and AR signaling pathways on MEF2C were examined by using siRNAs and pharmacological inhibitors targeting these two pathways. In the in vivo studies, ORX rats were randomly assigned to groups that were administered vehicle or testosterone (125 mg⋅kg-1⋅week-1) for 5 weeks, and plasma testosterone concentrations were determined using ELISA. Cardiac hypertrophy was evaluated by measuring well-characterized hypertrophy markers. Moreover, western blotting was used to assess CaMKII and phospholamban (PLN) phosphorylation, and MEF2C and AR protein levels in extracts of left-ventricle tissue from control and testosterone-treated ORX rats. Whereas testosterone treatment increased the phosphorylation levels of CaMKII (Thr286) and phospholambam (PLN) (Thr17) in cardiac myocytes in a time- and concentration-dependent manner, testosterone-induced MEF2 activity and cardiac myocyte hypertrophy were prevented upon inhibition of CaMKII, MEF2C, and AR signaling pathways. Notably, in the hypertrophied hearts obtained from testosterone-administered ORX rats, both CaMKII and PLN phosphorylation levels and AR and MEF2 protein levels were increased. Thus, this study presents the first evidence indicating that testosterone activates MEF2 through CaMKII and AR signaling. Our findings suggest that an orchestrated mechanism of action involving signal transduction and transcription pathways underlies testosterone-induced cardiac myocyte hypertrophy.

GSK-3ß/NFAT Signaling Is Involved in Testosterone-Induced Cardiac Myocyte Hypertrophy.

Testosterone induces cardiac hypertrophy through a mechanism that involves a concerted crosstalk between cytosolic and nuclear signaling pathways. Nuclear factor of activated T-cells (NFAT) is associated with the promotion of cardiac hypertrophy, glycogen synthase kinase-3ß (GSK-3ß) is considered to function as a negative regulator, mainly by modulating NFAT activity. However, the role played by calcineurin-NFAT and GSK-3ß signaling in testosterone-induced cardiac hypertrophy has remained unknown. Here, we determined that testosterone stimulates cardiac myocyte hypertrophy through NFAT activation and GSK-3ß inhibition. Testosterone increased the activity of NFAT-luciferase (NFAT-Luc) in a time- and dose-dependent manner, with the activity peaking after 24 h of stimulation with 100 nM testosterone. NFAT-Luc activity induced by testosterone was blocked by the calcineurin inhibitors FK506 and cyclosporine A and by 11R-VIVIT, a specific peptide inhibitor of NFAT. Conversely, testosterone inhibited GSK-3ß activity as determined by increased GSK-3ß phosphorylation at Ser9 and ß-catenin protein accumulation, and also by reduction in ß-catenin phosphorylation at residues Ser33, Ser37, and Thr41. GSK-3ß inhibition with 1-azakenpaullone or a GSK-3ß-targeting siRNA increased NFAT-Luc activity, whereas overexpression of a constitutively active GSK-3ß mutant (GSK-3ßS9A) inhibited NFAT-Luc activation mediated by testosterone. Testosterone-induced cardiac myocyte hypertrophy was established by increased cardiac myocyte size and [3H]-leucine incorporation (as a measurement of cellular protein synthesis). Calcineurin-NFAT inhibition abolished and GSK-3ß inhibition promoted the hypertrophy stimulated by testosterone. GSK-3ß activation by GSK-3ßS9A blocked the increase of hypertrophic markers induced by testosterone. Moreover, inhibition of intracellular androgen receptor prevented testosterone-induced NFAT-Luc activation. Collectively, these results suggest that cardiac myocyte hypertrophy induced by testosterone involves a cooperative mechanism that links androgen signaling with the recruitment of NFAT through calcineurin activation and GSK-3ß inhibition.

Wnt/ß-Catenin Stimulation and Laminins Support Cardiovascular Cell Progenitor Expansion from Human Fetal Cardiac Mesenchymal Stromal Cells.

The intrinsic regenerative capacity of human fetal cardiac mesenchymal stromal cells (MSCs) has not been fully characterized. Here we demonstrate that we can expand cells with characteristics of cardiovascular progenitor cells from the MSC population of human fetal hearts. Cells cultured on cardiac muscle laminin (LN)-based substrata in combination with stimulation of the canonical Wnt/ß-catenin pathway showed increased gene expression of ISL1, OCT4, KDR, and NKX2.5. The majority of cells stained positive for PDGFR-α, ISL1, and NKX2.5, and subpopulations also expressed the progenitor markers TBX18, KDR, c-KIT, and SSEA-1. Upon culture of the cardiac MSCs in differentiation media and on relevant LNs, portions of the cells differentiated into spontaneously beating cardiomyocytes, and endothelial and smooth muscle-like cells. Our protocol for large-scale culture of human fetal cardiac MSCs enables future exploration of the regenerative functions of these cells in the context of myocardial injury in vitro and in vivo.

Fuentes de estrés percibidas y rendimiento académico de estudiantes de odontología chilenos / Perceived sources of stress and academic performance of Chilean dental students

Objetivo: Evaluar la influencia de distintas fuentes de estrés en el rendimiento académico de estudiantes de odontología de la Universidad de Chile. Sujetos y métodos: Se utilizó el cuestionario de estrés en el ambiente dental (DESQ) modificado de 25 preguntas, que se aplicó al 60% de los estudiantes de cada año. Se compararon distintas fuentes de estrés percibidas entre los cursos. La prueba r de Pearson se utilizó para determinar la influencia de las fuentes de estrés en el rendimiento académico. Resultados: Una muestra de 302 estudiantes respondió el cuestionario. Entre los resultados se identificó que las principales fuentes de estrés en todos los cursos eran las calificaciones y los exámenes, el miedo a fallar en un curso o un año y la falta de tiempo para relajarse. Un factor de estrés importante para los cursos superiores fue la atmósfera negativa creada por los supervisores clínicos. La carga de trabajo presentó una correlación negativa con el rendimiento académico, mientras que la práctica preclínica y clínica mostraron una correlación positiva. Conclusiones: El cuarto año parece ser el más estresante. El contacto temprano con los pacientes y una mejor planificación curricular y administración deben ponerse en práctica para evitar el aumento del estrés de la formación clínica

Aim: To assess the influence of perceived sources of stress amongst University of Chile dental students on their academic performance. Subjects and methods: In this research was used a modified Dental Environment Stress Questionnaire (DESQ) consisting of 25 questions was applied to 60% of students of each year. Tests were applied to compare perceived sources of stress between courses. The Pearson r test was used to determine the influence of stress sources on academic performance. Results: A sample of 302 students answered the questionnaire. In results, the main sources of stress in all courses were grades and examinations, fear of failing a course or a year and lack of time to relax. An important stressor for higher courses was the negative atmosphere created by clinical supervisors. Workload showed a negative correlation with academic performance, and preclinical and clinical training showed a positive correlation. Conclusions: The fourth year seems being the most stressful. Earlier contact with patients and an improvement in curriculum planning and administration should be put in practice to avoid the increased stress of the clinical training

Sublethal caspase activation promotes generation of cardiomyocytes from embryonic stem cells.

Generation of new cardiomyocytes is critical for cardiac repair following myocardial injury, but which kind of stimuli is most important for cardiomyocyte regeneration is still unclear. Here we explore if apoptotic stimuli, manifested through caspase activation, influences cardiac progenitor up-regulation and cardiomyocyte differentiation. Using mouse embryonic stem cells as a cellular model, we show that sublethal activation of caspases increases the yield of cardiomyocytes while concurrently promoting the proliferation and differentiation of c-Kit+/α-actininlow cardiac progenitor cells. A broad-spectrum caspase inhibitor blocked these effects. In addition, the caspase inhibitor reversed the mRNA expression of genes expressed in cardiomyocytes and their precursors. Our study demonstrates that sublethal caspase-activation has an important role in cardiomyocyte differentiation and may have significant implications for promoting cardiac regeneration after myocardial injury involving exogenous or endogenous cell sources.

An integrated mechanism of cardiomyocyte nuclear Ca(2+) signaling.

In cardiomyocytes, Ca(2+) plays a central role in governing both contraction and signaling events that regulate gene expression. Current evidence indicates that discrimination between these two critical functions is achieved by segregating Ca(2+) within subcellular microdomains: transcription is regulated by Ca(2+) release within nuclear microdomains, and excitation-contraction coupling is regulated by cytosolic Ca(2+). Accordingly, a variety of agonists that control cardiomyocyte gene expression, such as endothelin-1, angiotensin-II or insulin-like growth factor-1, share the feature of triggering nuclear Ca(2+) signals. However, signaling pathways coupling surface receptor activation to nuclear Ca(2+) release, and the phenotypic responses to such signals, differ between agonists. According to earlier hypotheses, the selective control of nuclear Ca(2+) signals by activation of plasma membrane receptors relies on the strategic localization of inositol trisphosphate receptors at the nuclear envelope. There, they mediate Ca(2+) release from perinuclear Ca(2+) stores upon binding of inositol trisphosphate generated in the cytosol, which diffuses into the nucleus. More recently, identification of such receptors at nuclear membranes or perinuclear sarcolemmal invaginations has uncovered novel mechanisms whereby agonists control nuclear Ca(2+) release. In this review, we discuss mechanisms for the selective control of nuclear Ca(2+) signals with special focus on emerging models of agonist receptor activation.

A novel dihydropyridine with 3-aryl meta-hydroxyl substitution blocks L-type calcium channels in rat cardiomyocytes.

RATIONALE: Dihydropyridines are widely used for the treatment of several cardiac diseases due to their blocking activity on L-type Ca(2+) channels and their renowned antioxidant properties. METHODS: We synthesized six novel dihydropyridine molecules and performed docking studies on the binding site of the L-type Ca(2+) channel. We used biochemical techniques on isolated adult rat cardiomyocytes to assess the efficacy of these molecules on their Ca(2+) channel-blocking activity and antioxidant properties. The Ca(2+) channel-blocking activity was evaluated by confocal microscopy on fluo-3AM loaded cardiomyocytes, as well as using patch clamp experiments. Antioxidant properties were evaluated by flow cytometry using the ROS sensitive dye 1,2,3 DHR. RESULTS: Our docking studies show that a novel compound with 3-OH substitution inserts into the active binding site of the L-type Ca(2+) channel previously described for nitrendipine. In biochemical assays, the novel meta-OH group in the aryl in C4 showed a high blocking effect on L-type Ca(2+) channel as opposed to para-substituted compounds. In the tests we performed, none of the molecules showed antioxidant properties. CONCLUSIONS: Only substitutions in C2, C3 and C5 of the aryl ring render dihydropyridine compounds with the capacity of blocking LTCC. Based on our docking studies, we postulate that the antioxidant activity requires a larger group than the meta-OH substitution in C2, C3 or C5 of the dihydropyridine ring.

Experimental orthotopic transplantation of a tissue-engineered oesophagus in rats.

A tissue-engineered oesophageal scaffold could be very useful for the treatment of pediatric and adult patients with benign or malignant diseases such as carcinomas, trauma or congenital malformations. Here we decellularize rat oesophagi inside a perfusion bioreactor to create biocompatible biological rat scaffolds that mimic native architecture, resist mechanical stress and induce angiogenesis. Seeded allogeneic mesenchymal stromal cells spontaneously differentiate (proven by gene-, protein and functional evaluations) into epithelial- and muscle-like cells. The reseeded scaffolds are used to orthotopically replace the entire cervical oesophagus in immunocompetent rats. All animals survive the 14-day study period, with patent and functional grafts, and gain significantly more weight than sham-operated animals. Explanted grafts show regeneration of all the major cell and tissue components of the oesophagus including functional epithelium, muscle fibres, nerves and vasculature. We consider the presented tissue-engineered oesophageal scaffolds a significant step towards the clinical application of bioengineered oesophagi.

New insights into IGF-1 signaling in the heart.

Insulin-like growth factor 1 (IGF-1) signaling regulates contractility, metabolism, hypertrophy, autophagy, senescence, and apoptosis in the heart. IGF-1 deficiency is associated with an increased risk of cardiovascular disease, whereas cardiac activation of IGF-1 receptor (IGF-1R) protects from the detrimental effects of a high-fat diet and myocardial infarction. IGF-1R activates multiple pathways through its intrinsic tyrosine kinase activity and through coupling to heterotrimeric G protein. These pathways involve classic second messengers, phosphorylation cascades, lipid signaling, Ca(2+) transients, and gene expression. In addition, IGF-1R triggers signaling in different subcellular locations including the plasma membrane, perinuclear T tubules, and also in internalized vesicles. In this review, we provide a fresh and updated view of the complex IGF-1 scenario in the heart, including a critical focus on therapeutic strategies.

Role of heterotrimeric G protein and calcium in cardiomyocyte hypertrophy induced by IGF-1.

In the heart, insulin-like growth factor-1 (IGF-1) is a peptide with pro-hypertrophic and anti-apoptotic actions. The pro-hypertrophic properties of IGF-1 have been attributed to the extracellular regulated kinase (ERK) pathway. Recently, we reported that IGF-1 also increases intracellular Ca(2+) levels through a pertussis toxin (PTX)-sensitive G protein. Here we investigate whether this Ca(2+) signal is involved in IGF-1-induced cardiomyocyte hypertrophy. Our results show that the IGF-1-induced increase in Ca(2+) level is abolished by the IGF-1 receptor tyrosine kinase inhibitor AG538, PTX and the peptide inhibitor of Gßγ signaling, ßARKct. Increases in the activities of Ca(2+) -dependent enzymes calcineurin, calmodulin kinase II (CaMKII), and protein kinase Cα (PKCα) were observed at 5 min after IGF-1 exposure. AG538, PTX, ßARKct, and the dominant negative PKCα prevented the IGF-1-dependent phosphorylation of ERK1/2. Participation of calcineurin and CaMKII in ERK phosphorylation was discounted. IGF-1-induced cardiomyocyte hypertrophy, determined by cell size and ß-myosin heavy chain (ß-MHC), was prevented by AG538, PTX, ßARKct, dominant negative PKCα, and the MEK1/2 inhibitor PD98059. Inhibition of calcineurin with CAIN did not abolish IGF-1-induced cardiac hypertrophy. We conclude that IGF-1 induces hypertrophy in cultured cardiomyocytes by activation of the receptor tyrosine kinase activity/ßγ-subunits of a PTX-sensitive G protein/Ca(2+) /PKCα/ERK pathway without the participation of calcineurin.

Intracellular calcium release modulates polycystin-2 trafficking.

BACKGROUND: Polycystin-2 (PC2), encoded by the gene that is mutated in autosomal dominant polycystic kidney disease (ADPKD), functions as a calcium (Ca(2+)) permeable ion channel. Considerable controversy remains regarding the subcellular localization and signaling function of PC2 in kidney cells. METHODS: We investigated the subcellular PC2 localization by immunocytochemistry and confocal microscopy in primary cultures of human and rat proximal tubule cells after stimulating cytosolic Ca(2+) signaling. Plasma membrane (PM) Ca(2+) permeability was evaluated by Fura-2 manganese quenching using time-lapse fluorescence microscopy. RESULTS: We demonstrated that PC2 exhibits a dynamic subcellular localization pattern. In unstimulated human or rat proximal tubule cells, PC2 exhibited a cytosolic/reticular distribution. Treatments with agents that in various ways affect the Ca(2+) signaling machinery, those being ATP, bradykinin, ionomycin, CPA or thapsigargin, resulted in increased PC2 immunostaining in the PM. Exposing cells to the steroid hormone ouabain, known to trigger Ca(2+) oscillations in kidney cells, caused increased PC2 in the PM and increased PM Ca(2+) permeability. Intracellular Ca(2+) buffering with BAPTA, inositol 1,4,5-trisphosphate receptor (InsP3R) inhibition with 2-aminoethoxydiphenyl borate (2-APB) or Ca(2+)/Calmodulin-dependent kinase inhibition with KN-93 completely abolished ouabain-stimulated PC2 translocation to the PM. CONCLUSIONS: These novel findings demonstrate intracellular Ca(2+)-dependent PC2 trafficking in human and rat kidney cells, which may provide new insight into cyst formations in ADPKD.

Local control of nuclear calcium signaling in cardiac myocytes by perinuclear microdomains of sarcolemmal insulin-like growth factor 1 receptors.

RATIONALE: The ability of a cell to independently regulate nuclear and cytosolic Ca(2+) signaling is currently attributed to the differential distribution of inositol 1,4,5-trisphosphate receptor channel isoforms in the nucleoplasmic versus the endoplasmic reticulum. In cardiac myocytes, T-tubules confer the necessary compartmentation of Ca(2+) signals, which allows sarcomere contraction in response to plasma membrane depolarization, but whether there is a similar structure tunneling extracellular stimulation to control nuclear Ca(2+) signals locally has not been explored. OBJECTIVE: To study the role of perinuclear sarcolemma in selective nuclear Ca(2+) signaling. METHODS AND RESULTS: We report here that insulin-like growth factor 1 triggers a fast and independent nuclear Ca(2+) signal in neonatal rat cardiac myocytes, human embryonic cardiac myocytes, and adult rat cardiac myocytes. This fast and localized response is achieved by activation of insulin-like growth factor 1 receptor signaling complexes present in perinuclear invaginations of the plasma membrane. The perinuclear insulin-like growth factor 1 receptor pool connects extracellular stimulation to local activation of nuclear Ca(2+) signaling and transcriptional upregulation through the perinuclear hydrolysis of phosphatidylinositol 4,5-biphosphate inositol 1,4,5-trisphosphate production, nuclear Ca(2+) release, and activation of the transcription factor myocyte-enhancing factor 2C. Genetically engineered Ca(2+) buffers--parvalbumin--with cytosolic or nuclear localization demonstrated that the nuclear Ca(2+) handling system is physically and functionally segregated from the cytosolic Ca(2+) signaling machinery. CONCLUSIONS: These data reveal the existence of an inositol 1,4,5-trisphosphate-dependent nuclear Ca(2+) toolkit located in direct apposition to the cell surface, which allows the local control of rapid and independent activation of nuclear Ca(2+) signaling in response to an extracellular ligand.