Separation of Channels Subserving Approach and Avoidance/Escape at the Level of the Basal Ganglia and Related Brainstem Structures.

The basal ganglia have the key function of directing our behavior in the context of events from our environment and/or our internal state. This function relies on afferents targeting the main input structures of the basal ganglia, entering bids for action selection at the level of the striatum or signals for behavioral interruption at the level of the subthalamic nucleus, with behavioral reselection facilitated by dopamine signaling. Numerous experiments have studied action selection in relation to inputs from the cerebral cortex.

Multivalued Memory via Freezing of Super-Hard Magnetic Domains in a Quasi 2D-Magnet.

The design of high-density non-volatile memories is a long-standing dream, limited by conventional storage "0" or "1" bits. An alternative paradigm exists in which regions within candidate materials can be magnetized to intermediate values between the saturation limits. In principle, this paves the way to multivalued bits, vastly increasing storage density.

The Subthalamic Nucleus: A Hub for Sensory Control via Short Three- Lateral Loop Connections with the Brainstem?

The subthalamic nucleus (STN) is classically subdivided into sensori-motor, associative and limbic regions, which is consistent with the involvement of this structure in not only motor control, but also in cognitive and emotional tasks. However, the function of the sensory inputs to the STN's sensori-motor territory is comparatively less well explored, although sensory responses have been reported in this structure. There is still a paucity of information regarding the characteristics of that subdivision and its potential functional role in basal ganglia processing and more widely in associated networks.

Influence of Polymorphism on the Magnetic Properties of CoTeO Spinel.

This study presents the influence of polymorphism on the magnetic properties of CoTeO. This compound with a spinel-like structure [Co][CoTe]O was synthesized into two polymorphs: one disordered within a cubic 3̅ structure, where Co and Te ions are randomly distributed on the octahedral B sites [the disordered polymorph can also be presented as an inverse spinel of the formula Co(CoTe)O] and the other ordered with a cubic 432 structure where Co and Te ions are ordered on the B sites. The macroscopic magnetic measurements showed that both polymorphs present a ferrimagnetic ordering, below ∼40 K, and a second transition is also observed at 27 K for the ordered polymorph.

Glioma Associated Microglia/Macrophages Distribution is Conserved in Glioblastoma Regrowth: A Morphometric Study.

We compared the morphological aspect of glioblastoma-associated microglia/macrophages cells in 15 paired recurrent glioblastomas to check the ability of glioblastoma to recreate its microenvironment. The absolute number of GAMs is lower in normal tissue (21/mm) than in the isolated tumor cells area (100-112/mm) than in the solid tumor area (212-220/mm) ( < 0.01).

Strong Magnetic Anisotropy of Epitaxial PrVO Thin Films on SrTiO Substrates with Different Orientations.

We have probed the structural and magnetic properties of PrVO (PVO) thin films grown on the (001)-, (110)-, and (111)-oriented SrTiO (STO) substrates. By changing the substrate orientation, the film out-of-plane orientation can be tuned to [110], [100]/[010], and [011]/[311], with different in-plane crystallographic variants. Accommodation of these variants on the different substrates implies different strain states, which have direct influence on the magnetic properties of PVO films.

A basal ganglia-like cortical-amygdalar-hypothalamic network mediates feeding behavior.

The insular cortex (INS) is extensively connected to the central nucleus of the amygdala (CEA), and both regions send convergent projections into the caudal lateral hypothalamus (LHA) encompassing the parasubthalamic nucleus (PSTN). However, the organization of the network between these structures has not been clearly delineated in the literature, although there has been an upsurge in functional studies related to these structures, especially with regard to the cognitive and psychopathological control of feeding. We conducted tract-tracing experiments from the INS and observed a pathway to the PSTN region that runs parallel to the canonical hyperdirect pathway from the isocortex to the subthalamic nucleus (STN) adjacent to the PSTN.

Cascading transitions toward unconventional charge density wave states in the quasi-two-dimensional monophosphate tungsten bronze PWO.

Single crystals of the = 8 member of the low-dimensional monophosphate tungsten bronzes (PO)(WO) family were grown by chemical vapour transport technique and the high crystalline quality obtained allowed a reinvestigation of the physical and structural properties. Resistivity measurements revealed three anomalies at = 258 K, = 245 K and = 140 K, never observed until now. Parallel X-ray diffraction investigations showed a specific signature associated with three structural transitions, the appearance of different sets of satellite reflections below , and .

Textured Manganite Films Anywhere.

New paradigms are required in microelectronics when the transistor is in its downscaling limit and integration of materials presenting functional properties not available in classical silicon is one of the promising alternatives. Here, we demonstrate the possibility to grow LaSrMnO (LSMO) functional materials on amorphous substrates with properties close to films grown on single-crystalline substrates using a two-dimensional seed layer. X-ray diffraction and electron backscatter diffraction mapping demonstrate that the CaNbO nanosheet (NS) layer induces epitaxial stabilization of LSMO films with a strong out-of-plane (001) texture, whereas the growth of LSMO films on uncoated glass substrates exhibits a nontextured polycrystalline phase.

Metamagnetic Transitions versus Magnetocrystalline Anisotropy in Two Cobalt Arsenates with 1D Co Chains.

We have investigated two original hydrated cobalt arsenates based on Co octahedral edge-sharing chains. Their different magnetocrystalline anisotropies induce different types of metamagnetic transitions: spin-flop versus spin-flip. In both compounds, a strong local anisotropy (Ising spins) is favored by the spin-orbit coupling present in the CoO octahedra, while ferromagnetic (FM) exchanges predominate in the chains.

Deciphering local complex order by HAADF in a disordered mixed polyanion iron oxide: SrFe[Fe(SO)(CO)]O.

A layered iron compound involving two divalent polyanions (carbonate and sulfate anions) was synthesized by solid state chemistry in a closed ampule in the form of a ceramic. The Sr4Fe2[Fe0.5(SO4)0.

Revealing a novel nociceptive network that links the subthalamic nucleus to pain processing.

Pain is a prevalent symptom of Parkinson's disease, and is effectively treated by deep brain stimulation of the subthalamic nucleus (STN). However, the link between pain and the STN remains unclear. In the present work, using in vivo electrophysiology in rats, we report that STN neurons exhibit complex tonic and phasic responses to noxious stimuli.

Stairlike Aurivillius Phases in the Pseudobinary BiNbO-ABiNbO (A = Ba and Sr) System: A Comprehensive Analysis Using Superspace Group Formalism.

We report the possibility of extending the so-called stairlike Aurivilius phases in the pseudobinary BiNbO-ABiNbO (A = Ba and Sr) over a wide range of compositions. These phases are characterized by a discontinuous stacking of [BiO] slabs and perovskite blocks, leading to long-period intergrowths stabilized as a single phase. When analyses from precession electron diffraction tomography and X-ray and neutron powder diffraction are combined, the monoclinic incommensurately modulated structure with q = αa* + γc* previously proposed for the ABiNbO composition could be generalized to the BiNbO-ABiNbO (A = Ba and Sr) compounds.

Combining Multiscale Approaches for the Structure Determination of an Iron Layered Oxysulfate: SrFeO(SO).

The new iron layered oxysulfate SrFeO(SO) has been prepared by a solid-state reaction in closed ampules into the form of ceramics and single crystals. Its atomic structure has been solved by means of spectroscopy, diffraction techniques, and high-resolution electron microscopy. SrFeO(SO) is a layered structure that derives from the Ruddelsden-Popper (RP) phases with the layer stacking sequence SrO/SrFeO/SrFe(SO)O/SrFeO.

Comprehensive Study of Oxygen Storage in YbFeO (x ≤ 0.5): Unprecedented Coexistence of FeO Polyhedra in One Single Phase.

The multiferroic LuFeO was recently proposed as a promising material for oxygen storage due to its easy reversible oxidation into LuFeO. We have investigated the similar scenario in YbFeO, leading to a slightly greater oxygen storage (OSC) capacity of 1434 μmol O/g. For the first time, the structural model of LnFeO was fully understood by high-resolution microscopy images, and synchrotron and neutron diffraction experiments, as well as maximum entropy method.

Preferred Orientation Contribution to the Anisotropic Normal State Resistivity in Superconducting Melt-Cast Processed Bi₂Sr₂CaCu₂O.

We describe how the contribution of crystallographic texture to the anisotropy of the resistivity of polycrystalline samples can be estimated by averaging over crystallographic orientations through a geometric mean approach. The calculation takes into account the orientation distribution refined from neutron diffraction data and literature values for the single crystal resistivity tensor. The example discussed here is a melt-cast processed Bi₂Sr₂CaCu₂O (Bi-2212) polycrystalline tube in which the main texture component is a <010> fiber texture with relatively low texture strength.

Chemical Strain Engineering of Magnetism in Oxide Thin Films.

Transition metal oxides having a perovskite structure form a wide and technologically important class of compounds. In these systems, ferroelectric, ferromagnetic, ferroelastic, or even orbital and charge orderings can develop and eventually coexist. These orderings can be tuned by external electric, magnetic, or stress field, and the cross-couplings between them enable important multifunctional properties, such as piezoelectricity, magneto-electricity, or magneto-elasticity.

Unusual Relaxor Ferroelectric Behavior in Stairlike Aurivillius Phases.

New ferroelectric layered materials were found in the pseudobinary system Bi5Nb3O15-ABi2Nb2O9 (A= Ba, Sr and Pb). Preliminary observations made by transmission electron microscopy indicate that these compounds exhibit a complex incommensurately modulated structure. A (3 + 1)D structural model is obtained using ab initio phasing by charge flipping based on the analysis of precession electron diffraction tomography data.

Common Building Motifs in Ba2Fe3(PO4)4·2H2O, BaFe3(PO4)3, and Na3Fe3(PO4)4: Labile Fe(2+)/Fe(3+) Ordering and Charge-Dependent Magnetism.

Two new mixed-valence Fe(2/3+) barium phosphates have been synthesized in hydrothermal conditions and characterized: Ba2Fe(2.66+)3(PO4)4·2H2O (compound 1, ratio Fe(3+)/Fe(2+) = 2:1, orthorhombic space group Pbca, a = 6.71240(10) Å, b = 10.

Kondo effect goes anisotropic in vanadate oxide superlattices.

We study the transport properties in SrVO3/LaVO3 (SVO/LVO) superlattices deposited on SrTiO3 (STO) substrates. We show that the electronic conduction occurs in the metallic LVO layers with a galvanomagnetism typical of a 2D Fermi surface. In addition, a Kondo-like component appears in both the thermal variation of resistivity and the magnetoresistance.

Magnetodielectric Effect in Crystals of the Noncentrosymmetric CaOFeS at Low Temperature.

Single crystals of the stoichiometric iron calcium oxysulfide CaOFeS have been grown by a solid-state reaction. Structural analysis of CaOFeS at room temperature by combining single-crystal X-ray diffraction data and transmission electron microscopy leads to a stoichiometric hexagonal noncentrosymmetric P63mc layered structure isostructural to CaOZnS. It is built from alternating layers made of FeOS3 tetrahedra sharing sulfur apexes and stacked with Ca(2+) planes.

Structural analysis of strained LaVO3 thin films.

While structure refinement is routinely achieved for simple bulk materials, the accurate structural determination still poses challenges for thin films due on the one hand to the small amount of material deposited on the thicker substrate and, on the other hand, to the intricate epitaxial relationships that substantially complicate standard x-ray diffraction analysis. Using both electron and x-ray diffraction, we analyze the crystal structure of epitaxial LaVO3 thin films grown on (1 0 0)-oriented SrTiO3. Transmission electron microscopy study reveals that the thin films are epitaxially grown on SrTiO3 and points to the presence of 90° oriented domains.

Two components for one resistivity in LaVO3/SrTiO3 heterostructure.

A series of 100 nm LaVO3 thin films have been synthesized on (0 0 1)-oriented SrTiO3 substrates using the pulsed laser deposition technique, and the effects of growth temperature are analyzed. Transport properties reveal a large electronic mobility and a non-linear Hall effect at low temperature. In addition, a cross-over from a semiconducting state at high-temperature to a metallic state at low-temperature is observed, with a clear enhancement of the metallic character as the growth temperature increases.

Reversible topochemical exsolution of iron in BaFe(2+)2(PO4)2.

BaFe(2+) 2 (PO4 )2 was recently prepared and identified as the first 2D-Ising ferromagnetic oxide with an original reentrant structural transition driven by high-spin Fe(2+) ions arranged in honeycomb layers. Both long-term air exposure and moderate temperature (T>375 °C) leads to topochemical oxidation into iron-depleted compounds with mixed Fe(2+) /Fe(3+) valence. This process is unique, as the exsolution is effective even from single crystal with preservation of the initial crystallinity, and the structure of the deficient BaFe2-x (PO4 )2 (x View Article and Find Full Text PDF