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We present an accurate simulation of the Raman spectrum of the carbon dioxide molecule in the 1150–1500 cm−1 spectral range, comparing the results obtained using the three polyad schemes found in the literature of this molecule. The description of the molecule with the algebraic U1(2)×U(3)×U2(2) local model encompasses both stretching and bending degrees of freedom. A detailed analysis of the Hamiltonian interactions for the three polyad schemes provides fittings with root mean square deviations in the range 0.14–0.20 cm−1, involving 19 parameters taking into account the 178 experimental term energies found in the literature. Using a limited subset of 9 experimental transition moments, we optimize 5 partial derivatives of the mean polarizability and simulate the Raman spectrum of CO2 for the three polyad schemes. Comparing the calculated results with the experimental spectrum, we obtain an overall good agreement for the three polyads. However, an inspection in detail of the spectrum seems to show a slight preference for polyad P212 albeit not due to the interaction characterizing the polyad but due to anharmonic effects and energy distribution. Finally, we assess the effect of the Fermi resonance over CO2 Raman line intensities. [ABSTRACT FROM AUTHOR]

Background and Purpose: Pharmacological strategies aimed to facilitate neuronal renewal in the adult brain, by promoting endogenous neurogenesis, constitute promising therapeutic options for pathological or traumatic brain lesions. We have previously shown that non-tumour-promoting PKC-activating compounds (12-deoxyphorbols) promote adult neural progenitor cell (NPC) proliferation in vitro and in vivo, enhancing the endogenous neurogenic response of the brain to a traumatic injury. Here, we show for the first time that a diterpene with a lathyrane skeleton can also activate PKC and promote NPC proliferation.Experimental Approach: We isolated four lathyranes from the latex of Euphorbia plants and tested their effect on postnatal NPC proliferation, using neurosphere cultures. The bioactive lathyrane ELAC (3,12-di-O-acetyl-8-O-tigloilingol) was also injected into the ventricles of adult mice to analyse its effect on adult NPC proliferation in vivo.Key Results: The lathyrane ELAC activated PKC and significantly increased postnatal NPC proliferation in vitro, particularly in synergy with FGF2. In addition ELAC stimulated proliferation of NPC, specifically affecting undifferentiated transit amplifying cells. The proliferative effect of ELAC was reversed by either the classical/novel PKC inhibitor Gö6850 or the classical PKC inhibitor Gö6976, suggesting that NPC proliferation is promoted in response to activation of classical PKCs, particularly PKCß. ELAC slightly increased the proportion of NPC expressing Sox2. The effects of ELAC disappeared upon acetylation of its C7-hydroxyl group.Conclusions and Implications: We propose lathyranes like ELAC as new drug candidates to modulate adult neurogenesis through PKC activation. Functional and structural comparisons between ELAC and phorboids are included. [ABSTRACT FROM AUTHOR]

Summary: The nucleus incertus (NI) in the pontine tegmentum sends ascending projections to the midbrain, hypothalamus, amygdala, basal forebrain, hippocampus, and prefrontal cortex, and has a postulated role in modulating several forebrain functions. A substantial population of GABAergic NI neurons expresses the neuropeptide, relaxin‐3, which acts via the Gi/o‐protein‐coupled receptor, RXFP3, present throughout the forebrain target regions. Broad and specific manipulations of these systems by activation or inhibition of the NI or modulating RXFP3 signaling have revealed key insights into the likely influence of the NI/relaxin‐3/RXFP3 system on modalities including arousal, feeding, stress responses, anxiety and addiction, and attention and memory. This range of actions corresponds to a likely impact of NI/(relaxin‐3) projections on multiple integrated circuits, but makes it difficult to draw conclusions about a generalized function for this network. This review will focus on the key physiological process of oscillatory theta rhythm and the neural circuits that promote it during behavioral activation, highlighting the ability of NI and relaxin‐3/RXFP3 signaling systems to modulate these circuits. A better understanding of these mechanisms may provide a way to therapeutically adjust malfunction of forebrain activity present in several pathological conditions. [ABSTRACT FROM AUTHOR]

This work is concerned with the excited state quantum phase transitions (ESQPTs) defined in Ann. Phys. 323, 1106 (2008). In many-body models that exhibit such transitions, the ground state quantum phase transition (QPT) occurs in parallel with a singularity in the energy spectrum that propagates to higher energies as the control parameter increases beyond the QPT critical point. The analysis of the spectrum has been a main tool for the detection of these ESQPTs. Studies of the effects of this transition on the system dynamics are more limited. Here, we extend our previous works and show that the evolution of an initial state with energy close to the ESQPT critical point may be extremely slow. This result is surprising, because it may take place in systems with long-range interactions, where the dynamics is usually expected to be very fast. A timely example is the one-dimensional spin-1/2 model with infinite-range Ising interaction studied in experiments with ion traps. Its Hamiltonian has a U(2) algebraic structure. More generally, the slow dynamics described here occurs in two-level bosonic or fermionic models with pairing interactions and a [ABSTRACT FROM AUTHOR]