The development of biologically realistic models of brain microcircuits and regions constitutes currently a very relevant topic in computational neuroscience. One of the main challenges of such models is the passage between different scales, going from the microscale (cellular) to the meso (microcircuit) and macroscale (region or whole-brain level), while keeping at the same time a constraint on the demand of computational resources. In this paper we introduce a multiscale modeling framework for the hippocampal CA1, a region of the brain that plays a key role in functions such as learning, memory consolidation and navigation.
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June 2024
Under normal conditions the principal cells of the striatum, medium spiny neurons (MSNs), show structured cell assembly activity patterns which alternate sequentially over exceedingly long timescales of many minutes. It is important to understand this activity since it is characteristically disrupted in multiple pathologies, such as Parkinson's disease and dyskinesia, and thought to be caused by alterations in the MSN to MSN lateral inhibitory connections and in the strength and distribution of cortical excitation to MSNs. To understand how these long timescales arise we extended a previous network model of MSN cells to include synapses with short-term plasticity, with parameters taken from a recent detailed striatal connectome study.
View Article and Find Full Text PDFThe core-level electron excitation and ionization spectra of glycolaldehyde have been investigated by photoabsorption and photoemission spectroscopy at both carbon and oxygen -edges; the valence ionization spectra were also recorded by photoelectron spectroscopy in the UV-vis region. The spectra are interpreted by means of ab initio calculations based on the equation-of-motion coupled cluster singles and doubles (EOM-CCSD) and coupled cluster singles, doubles, and perturbative are in good agreement with the experimental results, and many of the observed features are assigned. The photoabsorption spectra are not only dominated by transitions from core-level orbitals to unoccupied π and σ orbitals but also show structures due to Rydberg transitions.
View Article and Find Full Text PDFExtraction-site alveolar remodeling is a major concern due to negative volumetric hard and soft tissue changes that inevitably limit rehabilitation options and diminish esthetic outcomes. Surgical techniques employed to minimize alveolar dimensional changes are not always predictable. Utilizing a socket shield with an immediate surgical implant procedure helps maintain a thin portion of the root in the vestibular area and thus minimizes bone resorption, especially at the coronal cortical aspect.
View Article and Find Full Text PDFThis work shows how the N 1s photoemission (PE) spectrum of self-associated melamine molecules in aqueous solution has been successfully rationalized using an integrated computational approach encompassing classical metadynamics simulations and quantum calculations based on density functional theory (DFT). The first approach allowed us to describe interacting melamine molecules in explicit waters and to identify dimeric configurations based on π-π and/or H-bonding interactions. Then, N 1s binding energies (BEs) and PE spectra were computed at the DFT level for all structures both in the gas phase and in an implicit solvent.
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