Role of Basal Ganglia in Sleep–Wake Regulation: Neural Circuitry and Clinical Significance

Researchers over the last decade have made substantial progress toward understanding the roles of dopamine and the basal ganglia (BG) in the control of sleep–wake behavior. In this review, we outline recent advancements regarding dopaminergic modulation of sleep through the BG and extra-BG sites. Our main hypothesis is that dopamine promotes sleep by its action on the D2 receptors in the BG and promotes wakefulness by its action on D1 and D2 receptors in the extra-BG sites. This hypothesis implicates dopamine depletion in the BG (such as in Parkinson's disease) in causing frequent nighttime arousal and overall insomnia. Furthermore, the arousal effects of psychostimulants (methamphetamine, cocaine, and modafinil) may be linked to the ventral periaquductal gray (vPAG) dopaminergic circuitry targeting the extra-BG sleep–wake network

Neuronal activity (c-Fos) delineating interactions of the cerebral cortex and basal ganglia

The cerebral cortex and basal ganglia (BG) form a neural circuit that is disrupted in disorders such as Parkinson’s disease. We found that neuronal activity (c-Fos) in the BG followed cortical activity, i.e., high in arousal state and low in sleep state. To determine if cortical activity is necessary for BG activity, we administered atropine to rats to induce a dissociative state resulting in slow-wave electroencephalography but hyperactive motor behaviors. Atropine blocked c-Fos expression in the cortex and BG, despite high c-Fos expression in the sub-cortical arousal neuronal groups and thalamus, indicating that cortical activity is required for BG activation. To identify which glutamate receptors in the BG that mediate cortical inputs, we injected ketamine [N-methyl-d-aspartate (NMDA) receptor antagonist] and 6-cyano-nitroquinoxaline-2, 3-dione (CNQX, a non-NMDA receptor antagonist). Systemic ketamine and CNQX administration revealed that NMDA receptors mediated subthalamic nucleus (STN) input to internal globus pallidus (GPi) and substantia nigra pars reticulata (SNr), while non-NMDA receptor mediated cortical input to the STN. Both types of glutamate receptors were involved in mediating cortical input to the striatum. Dorsal striatal (caudoputamen, CPu) dopamine depletion by 6-hydroxydopamine resulted in reduced activity of the CPu, globus pallidus externa (GPe), and STN but increased activity of the GPi, SNr, and putative layer V neurons in the motor cortex. Our results reveal that the cortical activity is necessary for BG activity and clarifies the pathways and properties of the BG-cortical network and their putative role in the pathophysiology of BG disorders

2-Methyl-1,2,3,4-tetra­hydro­isoquinolin-6-yl N-phenyl­carbamate

In the mol­ecule of the title compound, C17H18N2O2, the piperidine ring adopts a half-chair form. The two benzene rings are individually planar and make a dihedral angle of 53.90°. The crystal structure is stabilized by inter­molecular N—H⋯N hydrogen bonds and π–π stacking inter­actions (centroid–centroid distance = 3.962 Å)

On the Abundance of Potassium in Metal-Poor Stars

Based on extensive statistical-equilibrium calculations, we performed a non-LTE analysis of the K {\sc i} 7699 equivalent-width data of metal-deficient stars for the purpose of clarifying the behavior of the photospheric potassium abundance in disk/halo stars. While the resulting non-LTE abundance corrections turned out to be considerably large, amounting to 0.2--0.7 dex, their effect on the [K/Fe] vs. [Fe/H] relation is not very important, since these corrections do not show any significant metallicity dependence. Hence, we again confirmed the results of previous LTE studies, that [K/Fe] shows a gradual systematic increase toward a lowered metallicity up to [K/Fe] $\sim$ 0.3--0.5 at [Fe/H] $\sim$ -1 to -2, such as in the case of $\alpha$ elements.Comment: 16 pages (including 2 tables and 4 figures), to appear in PASJ, Vol.54, No.2 (using the style file pasj00.cls

(6aS,11aR,11cS)-8-Sulfanylidene-2,3,5,6,6a,7,11,11a,11b,11c-decahydro-3a,7a-diaza-1H,4H-benzo[de]anthracen-3a-ium chloride hemihydrate

The title compound, C15H23N2S+·Cl−·0.5H2O, was prepared from (6aS,11aR,11cS)-2,3,5,6,6a,7,11,11a,11b,11c-deca­hydro-3a,7a-diaza-1H,4H-benzo[de]anthracene-8-one (sophocarpine) and Lawesson’s reagent. The thione-substituted ring is in an envelope conformation and the three other six-membered rings are in chair conformations. In the crystal, anions and cations are linked by N—H⋯Cl and weak C—H⋯Cl hydrogen bonds. One 0.5-occupancy solvent water mol­ecule lies on a twofold rotation axis and another 0.25-occupancy solvent water mol­ecule is in a general position. The H atoms of these water mol­ecules were not located or included in the refinement

(Dimethyl sulfoxide-κO)[3-hydr­oxy-2-hydroxy­methyl-2-(3-meth­oxy-2-oxido­benzyl­ideneamino-κ2 O 2,N)propanolato-κO]dioxomolybdenum(VI). Corrigendum

Corrigendum to Acta Cryst. (2006), E62, m1994–m1996

Spiniform phase-encoded metagratings entangling arbitrary rational-order orbital angular momentum

Quantum entanglements between integer-order and fractional-order orbital angular momentums (OAMs) have been previously discussed. However, the entangled nature of arbitrary rational-order OAM has long been considered a myth due to the absence of an effective strategy for generating arbitrary rational-order OAM beams. Therefore, we report a single metadevice comprising a bilaterally symmetric grating with an aperture, creating optical beams with dynamically controllable OAM values that are continuously varying over a rational range. Due to its encoded spiniform phase, this novel metagrating enables the production of an average OAM that can be increased without a theoretical limit by embracing distributed singularities, which differs significantly from the classic method of stacking phase singularities using fork gratings. This new method makes it possible to probe the unexplored niche of quantum entanglement between arbitrarily defined OAMs in light, which could lead to the complex manipulation of microparticles, high-dimensional quantum entanglement and optical communication. We show that quantum coincidence based on rational-order OAM-superposition states could give rise to low cross-talks between two different states that have no significant overlap in their spiral spectra. Additionally, future applications in quantum communication and optical micromanipulation may be found