1,720,996 research outputs found
The Capsaicin-dependent current in dorsal root ganglion neurones is enhanced by PKC activation
No full textcGMP gated channel, exchanger and phototransduction in isolated rod outer segments
No full textThe experiments described in this paper show that the isolated rod outer segment recorded in whole-cell is an ideal preparation to study in situ the guanosine 3':5'-cyclic monophosphate (cGMP) gated channels, the enzymes involved in phototransduction and the Na+-Ca2+,K+ exchanger. In particular, the role on phototransduction of intracellular Ca2+, Ca2+i, and the existence of possible modulation of Ca2+ movements across the plasma membrane were analyzed. It was found that the reduction of [Ca2+]i stimulates the GC without affecting the basal PDE activity: this regulation plays a key role in shaping the photoresponse kinetics and the low frequency noise of dark current. The Ca2+i homeostasis is entirely controlled by the exchangers, which Ca2+ extrusion rate was found to be driven exclusively by the electrochemical gradients of the cotransported ions, and by the Ca2+ entry through the cGMP gated channels, which were found to be modulated by nucleotide triphosphates
Regolare la rabbia: quale strategia? Uno studio preliminare
No full textRiassunto
La regolazione emotiva è una capacità di fondamentale importanza per il funzionamento ottimale dell'individuo che nell'ultimo ventennio ha catturato l'attenzione degli studiosi portando ad un incremento degli studi sul tema. Pochi articoli si sono concentrati sullo studio della regolazione della rabbia, emozione primaria tanto importante quanto rappresentata nella quotidianità. Lo studio qui presentato, prendendo spunto dal lavoro di Sheppes e colleghi (2011), ha voluto indagare il modo in cui due strategie, reinterpretazione e soppressione, vengono scelte per gestire la rabbia provata. I risultati indicano che la soppressione è la strategia più utilizzata per regolare questa emozione. Le implicazioni di questi risultati vengono discusse alla luce delle recenti scoperte sulla regolazione emozionale.
Abstract
In the present paper, we present results from an experiment about the regulation of anger in a sample of 26 volunteers (f=14, mean age=24.9, mean education=17.4). In a social interaction task, participants were presented with verbal stimuli either anger provoking or emotionally neutral associated with neutral faces of simulated participants. After each anger provoking and neutral situation they were asked to rate the level of perceived anger and to choose between three different options to regulate the emotion: reappraisal, suppression or no strategy. Results indicate that participants correctly perceived anger provoking stimuli and that suppression was the most used strategy for anger regulation. Notably, previous studies using self-reported measures, reported that reappraisal was the most effective strategy to regulate anger. This study thus expands previous findings and point toward the direction of a shift toward suppression based strategies when confronted with real social interactions that elicit anger
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Specific PKC-epsilon Translocation and sensitisation of the heat-dependent current by bradykinin in nociceptive neurones
No full text
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Abnormal pain sensation in mice lacking the prokineticin receptor PKR2: interaction of PKR2 with transient receptor potential TRPV1 and TRPA1
Full text linkThe amphibian Bv8 and the mammalian prokineticin 1 (PROK1) and 2 (PROK2) are new chemokine-like protein ligands acting on two G protein-coupled receptors, prokineticin receptor 1 (PKR1) and 2 (PKR2), participating to the mediation of diverse physiological and pathological processes. Prokineticins (PKs), specifically activating the prokineticin receptors (PKRs) located in several areas of the central and peripheral nervous system associated with pain, play a fundamental role in nociception. In this paper, to improve the understanding of the prokineticin system in the neurobiology of pain, we investigated the role of PKR2 in pain perception using pkr2 gene-deficient mice. We observed that, compared to wildtype, pkr2-null mice were more resistant to nociceptive sensitization to temperatures ranging from 46 to 48 °C, to capsaicin and to protons, highlighting a positive interaction between PKR2 and the non-selective cation channels TRPV1. Moreover, PKR2 knock-out mice showed reduced nociceptive response to cold temperature (4 °C) and to mustard oil-induced inflammatory hyperalgesia, suggesting a functional interaction between PKR2 and transient receptor potential ankyrin 1 ion (TRPA1) channels. This notion was supported by experiments in dorsal root ganglia (DRG) cultures from pkr1 and–pkr2-null mice, demonstrating that the percentage of Bv8-responsive DRG neurons which were also responsive to mustard oil was much higher in PKR1−/− than in PKR2−/− mice. Taken together, these findings suggest a functional interaction between PKR2 and TRP channels in the development of hyperalgesia. Drugs able to directly or indirectly block these targets and/or their interactions may represent potential analgesics
Ion channels gated by heat
Full text linkAll animals need to sense temperature to avoid hostile environments and to regulate their internal homeostasis. A particularly obvious example is that animals need to avoid damagingly hot stimuli. The mechanisms by which temperature is sensed have until recently been mysterious, but in the last couple of years, we have begun to understand how noxious thermal stimuli are detected by sensory neurons. Heat has been found to open a nonselective cation channel in primary sensory neurons, probably by a direct action. In a separate study, an ion channel gated by capsaicin, the active ingredient of chili peppers, was cloned from sensory neurons. This channel (vanilloid receptor subtype 1, VR1) is gated by heat in a manner similar to the native heat-activated channel, and our current best guess is that this channel is the molecular substrate for the detection of painful heat. Both the heat channel and VR1 are modulated in interesting ways. The response of the heat channel is potentiated by phosphorylation by protein kinase C, whereas VR1 is potentiated by externally applied protons. Protein kinase C is known to be activated by a variety of inflammatory mediators, including bradykinin, whereas extracellular acidification is characteristically produced by anoxia and inflammation. Both modulatory pathways are likely, therefore, to have important physiological correlates in terms of the enhanced pain (hyperalgesia) produced by tissue damage and inflammation. Future work should focus on establishing, in molecular terms, how a single ion channel can detect heat and how the detection threshold can be modulated by hyperalgesic stimuli
- …
