Dopamine and glutamate release in the dorsolateral caudate putamen following withdrawal from cocaine self-administration in rats

Evidence suggests that cocaine addiction may involve progressive neuroadaptive changes in the dorsolateral caudate putamen (dlCPu). While cocaine seeking following abstinence from chronic self-administration requires intact dlCPu function, in vivo neurotransmitter release in the dlCPu has not been investigated. The current study measured dlCPu dopamine (DA) and glutamate (GLU) release during drug seeking following limited or extended abstinence, as well as in response to a cocaine priming injection alone. Male, Sprague–Dawley rats self-administered cocaine (0.2 mg/50 μl infusion, i.v.) for 10 days (2 h/day). In vivo microdialysis occurred in the self-administration chamber after 1 and 14 days of abstinence (Experiment 1). A separate set of animals that completed self-administration as well as drug naïve controls received a cocaine priming injection (20 mg/kg) during concurrent microdialysis (Experiment 2). DA release increased during drug seeking in the self-administration context at both 1 and 14 days post abstinence. In contrast, GLU release only increased after 1 day of abstinence. Furthermore, animals with a cocaine self-administration history showed enhanced DA and GLU release following cocaine challenge as compared to drug naïve controls. These results indicate that chronic cocaine self-administration enhances dlCPu DA and GLU under both drug-paired context and drug-primed conditions.Fil: Gabriele, Amanda. Medical University Of South Carolina; Estados UnidosFil: Pacchioni, Alejandra Maria. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Laboratorio de Toxicología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: See, Ronald E.. Medical University Of South Carolina; Estados Unido

Accuracy of dielectric-dependent hybrid functionals in the prediction of optoelectronic properties of metal oxide semiconductors: a comprehensive comparison with many-body GW and experiments

Understanding the electronic structure of metal oxide semiconductors is crucial to their numerous technological applications, such as photoelectrochemical water splitting and solar cells. The needed experimental and theoretical knowledge goes beyond that of pristine bulk crystals, and must include the effects of surfaces and interfaces, as well as those due to the presence of intrinsic defects (e.g. oxygen vacancies), or dopants for band engineering. In this review, we present an account of the recent efforts in predicting and understanding the optoelectronic properties of oxides using ab initio theoretical methods. In particular, we discuss the performance of recently developed dielectric-dependent hybrid functionals, providing a comparison against the results of many-body GW calculations, including G 0 W 0 as well as more refined approaches, such as quasiparticle self-consistent GW. We summarize results in the recent literature for the band gap, the band level alignment at surfaces, and optical transition energies in defective oxides, including wide gap oxide semiconductors and transition metal oxides. Correlated transition metal oxides are also discussed. For each method, we describe successes and drawbacks, emphasizing the challenges faced by the development of improved theoretical approaches. The theoretical section is preceded by a critical overview of the main experimental techniques needed to characterize the optoelectronic properties of semiconductors, including absorption and reflection spectroscopy, photoemission, and scanning tunneling spectroscopy (STS)

Photoluminescence dispersion as a probe of structural inhomogeneity in silica

We report time-resolved photoluminescence spectra of point defects in amorphous silicon dioxide (silica), in particular the decay kinetics of the emission signals of extrinsic Oxygen Deficient Centres of the second type from singlet and directly-excited triplet states are measured and used as a probe of structural inhomogeneity. Luminescence activity in sapphire ($\alpha$-Al$_2$O$_3$) is studied as well and used as a model system to compare the optical properties of defects in silica with those of defects embedded in a crystalline matrix. Only for defects in silica, we observe a variation of the decay lifetimes with emission energy and a time dependence of the first moment of the emission bands. These features are analyzed within a theoretical model with explicit hypothesis about the effect introduced by the disorder of vitreous systems. Separate estimations of the homogenous and inhomogeneous contributions to the measured emission linewidth are obtained: it is found that inhomogeneous effects strongly condition both the triplet and singlet luminescence activities of oxygen deficient centres in silica, although the degree of inhomogeneity of the triplet emission turns out to be lower than that of the singlet emission. Inhomogeneous effects appear to be negligible in sapphire

Cerium-doped zirconium dioxide, a visible-light-sensitive photoactive material of third generation

The dispersion of small amounts of Ce4+ ions in the bulk of ZrO2 leads to a photoactive material sensitive to visible light. This is shown by monitoring with EPR the formation and the reactivity of photogenerated (lambda > 420 nm) charge carriers. The effect, as confirmed by DFT calculations, is due to the presence in the solid of empty 4f Ce states at the mid gap, which act as intermediate levels in a double excitation mechanism. This solid can be considered an example of a third-generation photoactive material

Competing Interactions in the Self-Assembly of NC-Ph-3-CN Molecules on Cu(111)

We report on low-temperature scanning tunneling microscopy and spectroscopy measurements on NC-Ph-3-CN molecules adsorbed at 300 K on a Cu(111) surface. Upon cooling, the molecules form chain and honeycomb structures, incorporating Cu adatoms supplied by the substrate as metal linkers. In these assemblies, the molecules align along two main directions, with a relative abundance that depends on the coordination number and on the bond length. We show spectroscopic data about the unoccupied molecular orbitals and investigate the patterns obtained by depositing different amounts of molecules. Comparison of these results with the ones obtained for NC-Ph-5-CN molecules on the same substrate enables us to establish a hierarchy of the different interaction forces at work in the system

Temperature-dependent self-assembly of NC–Ph5–CN molecules on Cu(111)

We present the results of temperature-dependent self-assembly of dicarbonitrile-pentaphenyl molecules (NC-Ph-5-CN) on Cu(111). Our low-temperature scanning tunneling microscopy study reveals the formation of metal-organic and purely organic structures, depending on the substrate temperature during deposition (160-300 K), which determines the availability of Cu adatoms at the surface. We use tip functionalization with CO to obtain submolecular resolution and image the coordination atoms, enabling unequivocal identification of metal-coordinated nodes and purely organic ones. Moreover, we discuss the somewhat surprising structure obtained for deposition and measurement at 300 K. (C) 2015 AIP Publishing LLC

Anxiety-Related Disorders

Anxiety is a common experience, a physiologic mechanism that lets us cope with a stressor, but if it occurs without a stimulus or it is exaggerated and general functioning is impaired, it becomes pathological. Treating anxiety disorders requires pharmacotherapy to lower anxiety levels and psychological therapies to learn to cope with stressors adaptively. Obsessive-compulsive disorder (OCD) has been considered as part of the Anxiety Disorders chapter up to the fourth edition of the DSM (DSM IV-TR), while from the fifth edition (DSM-5) it is placed in a separate chapter. The nosographic autonomy of this disorder depends on the fact that the anxious manifestations, even if present, would be secondary and dependent on the obsessive contents. A group of conditions related to OCD from a clinical, epidemiological, and sometimes aetiopathological perspective is included in the DSM chapter about “obsessive-compulsive and related disorders”. After a traumatic experience, one person physiologically develops a limited-in-time reaction. In some cases, more pronounced depressive, anxious, intrusive, and/or dissociative symptoms occur. The biological basis for trauma-related disorders is not fully understood, but insights so far have let us choose pharmacological treatments alongside with psychotherapy in order to control symptoms and elaborate the traumatic experience