The Interplay of Relational and Non-relational Processes in Sentence Production: The Case of Relative Clause Planning in Japanese and Spanish

Speech planning involves different steps in order to transform a conceptual message into speech. These include establishing structural relations among constituents (i.e., relational information), and selecting the appropriate lexical items to convey the intended message (non-relational elements). However, the precise way relational and non-relational information are computed when undertaking linguistic encoding is not clear. This paper explores how the pre-linguistic message undergoes linguistic encoding, and what kind of information (relational or non-relational) is prioritized in doing so. We analyze the production planning of Relative Clauses in Spanish (a head-initial language) and Japanese (a head-final language) by monolingual speakers, by means of the eye-tracking method while participants described colored pictures. Although in both Spanish and Japanese the structure under study is the same (with the same syntactic configuration), word order is entirely opposite between both languages. In Japanese, the head noun is not uttered until the end of the clause, thus making it possible to explore sentence planning in a structure where the syntactically most dominant element (the head noun, HN) is not the first element. Variables tested were type of relative clause, with either the agent or the patient as head noun, and the animacy of the agent and the patient of the event, the latter allowing the manipulation of the conceptual saliency of the elements involved. Results showed Japanese speakers focus extensively on the HN before directing their gazes to the element they are going to utter first, suggesting a speech planning process that prioritizes relational information, that is, structural scaffolding. Spanish monolinguals, in turn, showed a pattern in which both structural and linear information appear to be more closely related from the beginning. In both languages, the animacy of isolated elements had little effect on gaze patterns. Results point to a planning process that prioritizes structural relations over access to lexical elements in order in the planning of complex structures, with room for flexibility when the grammar of the language allows so

Modulation of ongoing cognitive processes by emotionally intense words

Abstract Contrary to what occurs with negative pictures, negative words are, in general, not capable of interfering with performance in ongoing cognitive tasks in normal subjects. A probable explanation is the limited arousing power of linguistic material. Especially intense words (insults and compliments), neutral personal adjectives, and pseudowords were presented to 28 participants while they executed a lexical decision task. Insults were associated with the poorest performance in the task and compliments with the best. Amplitude of the late positive component of the event-related potentials, originating at parietal areas, was maximal in response to compliments and insults, but latencies were delayed in response to the latter. Results suggest that intense emotional words modulate ongoing cognitive processes through both bottom-up (attentional capture by insults) and top-down (facilitation of cognitive processing by arousing words) mechanisms

Tetanus toxin Hc fragment induces the formation of ceramide platforms and protects neuronal cells against oxidative stress

Tetanus toxin (TeTx) is the protein, synthesized by the anaerobic bacteria Clostridium tetani, which causes tetanus disease. TeTx gains entry into target cells by means of its interaction with lipid rafts, which are membrane domains enriched in sphingomyelin and cholesterol. However, the exact mechanism of host membrane binding remains to be fully established. In the present study we used the recombinant carboxyl terminal fragment from TeTx (Hc-TeTx), the domain responsible for target neuron binding, showing that Hc-TeTx induces a moderate but rapid and sustained increase in the ceramide/sphingomyelin ratio in primary cultures of cerebellar granule neurons and in NGF-differentiated PC12 cells, as well as induces the formation of ceramide platforms in the plasma membrane. The mentioned increase is due to the promotion of neutral sphingomyelinase activity and not to the de novo synthesis, since GW4869, a specific neutral sphingomyelinase inhibitor, prevents neutral sphingomyelinase activity increase and formation of ceramide platforms. Moreover, neutral sphingomyelinase inhibition with GW4869 prevents Hc-TeTx-triggered signaling (Akt phosphorylation), as well as the protective effect of Hc-TeTx on PC12 cells subjected to oxidative stress, while siRNA directed against nSM2 prevents protection by Hc-TeTx of NSC-34 cells against oxidative insult. Finally, neutral sphingomyelinase activity seems not to be related with the internalization of Hc-TeTx into PC12 cells. Thus, the presented data shed light on the mechanisms triggered by TeTx after membrane binding, which could be related with the events leading to the neuroprotective action exerted by the Hc-TeTx fragment

Neurocognitive functioning in first-episode Bipolar Disorder: Relationship with functional status

Background The aim of this study was to assess if an association between neurocognitive deficits and psychosocial functioning exists in first-episode BD patients. Methods Twenty-five euthymic first-episode BD patients and thirty-seven healthy controls were recruited. History of suicide attempts, psychiatric comorbidities, pharmacological exposure, and previous depressive episodes were investigated. Performances on neurocognitive domains (verbal memory, attention, processing speed, and executive functions) as well as a measure of psychosocial functioning were used as outcomes. Results First-episode BD patients showed medium-to-large size deficits on measures of attention, processing speed, and executive functions. A significant association between verbal memory and psychosocial functioning at the moment of BD diagnosis was detected (beta coefficient −3.9, IC 95% −6.7 to −1.2, p < 0.01). Conclusions A relationship between cognitive performance at the moment of BD diagnosis and psychosocial functioning was detected. Possible therapeutic implications of this finding are discussed.Fil: Szmulewicz, Alejandro G.. Universidad Favaloro; Argentina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Valerio, Marina Paula. Gobierno de la Ciudad de Buenos Aires. Hospital de Emergencias Psiquiáicas "Torcuato de Alvear"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lomastro, Julieta. Gobierno de la Ciudad de Buenos Aires. Hospital de Emergencias Psiquiáicas "Torcuato de Alvear"; ArgentinaFil: Smith, José M.. Centro de Educaciones Médicas e Investigación Clínica "Norberto Quirno"; ArgentinaFil: Chiappe, Virginia. Gobierno de la Ciudad de Buenos Aires. Hospital de Emergencias Psiquiáicas "Torcuato de Alvear"; ArgentinaFil: Martino, Diego Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; Argentina. Universidad Favaloro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencias Cognitivas y Traslacional; ArgentinaFil: Igoa, Ana. Gobierno de la Ciudad de Buenos Aires. Hospital de Emergencias Psiquiáicas "Torcuato de Alvear"; Argentina. Universidad Favaloro; Argentin

Consequences of unilateral nigrostriatal denervation on the thalamostriatal pathway in rats

The position of the caudal intralaminar nuclei within basal ganglia circuitry has largely been neglected in most studies dealing with basal ganglia function. During the past few years, there has been a growing body of evidence suggesting that the thalamic parafascicular nucleus in rodents (PF) exerts a multifaceted modulation of basal ganglia nuclei, at different levels. Our aim was to study the activity of the thalamostriatal pathway in rats with unilateral dopaminergic depletion. The experimental approach comprised first unilateral delivery of 6-OHDA in the medial forebrain bundle. Thirty days post-lesioning, animals showing a clear asymmetry were then subjected to bilateral injection of Fluoro-Gold (FG) within the striatum. Subsequently, expression of the mRNA encoding the vesicular glutamate transporter 2 (vGLUT2) was detected within thalamostriatal-projecting neurons (FG-labeled) by in situ hybridization and the results were confirmed by laser-guided capture microdissection microscopy followed by real-time PCR. The data showed that there was a marked neuronal loss restricted to PF neurons projecting to the dopamine-depleted striatum. Moreover, PF neurons innervating the dopamine-depleted striatum were intensely hyperactive. These neurons showed a marked increase on the expression of vGLUT2 mRNA as well as for the mRNA encoding the subunit I of cytochrome oxidase as compared with those neurons projecting to the striatum with normal dopamine content. Thus, the selective neurodegeneration of PF neurons innervating the striatum together with the increased activity of the thalamostriatal pathway coexist after nigrostriatal denervation

Heterostructured Cobalt Silicide Nanocrystals: Synthesis in Molten Salts, Ferromagnetism, and Electrocatalysis

International audienceNanoscale heterostructures of covalent intermetallics should give birth to a wide range of interface-driven physical and chemical properties. Such a level of design however remains unattainable for most of these compounds, due to the difficulty to reach a crystalline order of covalent bonds at the moderate temperatures required for colloidal chemistry. Herein, we design heterostructured cobalt silicide nanoparticles to trigger magnetic and catalytic properties in silicon-based materials. Our strategy consists in controlling the diffusion of cobalt atoms into silicon nanoparticles, by reacting these particles in molten salts. By adjusting the temperature, we tune the conversion of the initial silicon particles toward homogeneous CoSi nanoparticles and core–shell nanoparticles made of a CoSi shell and a silicon-rich core. The increased interface-to-volume ratio of the CoSi component in the core–shell particles yields distinct properties compared to the bulk and homogeneous nanoparticles. First, the core–shell particles exhibit increased ferromagnetism, despite the bulk diamagnetic properties of cobalt monosilicide. Second, the core–shell nanoparticles act as efficient precatalysts for alkaline water oxidation, where the nanostructure is converted in situ into a layered cobalt silicon oxide/(oxy)hydroxide with high and stable oxygen evolution reaction (OER) electrocatalytic activity. This work demonstrates a route to design heterostructured nanocrystals of covalent intermetallic compounds and shows that these new structures exhibit very rich, yet poorly explored, interface-based physical properties and reactivity