A series of Cp*Rh-based functional metallarectangles have been synthesized from metallaligands. Enlargement of one linker leads to the isolation of two novel Borromean link architectures. All these complexes are intact in solution, as evident from ESI-MS spectroscopic analysis. Arising from the combination of open Cu centers and favorable cavity space, {(Cp*Rh)4(bpe)2[Cu(opba)·2MeOH]2}4(OTf)·6MeOH shows extraordinary catalytic abilities with high efficiency and wide substrate selectivity in the acyl-transfer reaction.

No abstract

The present study aims to define the role of postsynaptic density (PSD)-95 in the regulation of dopamine (DA) receptor function. We found that PSD-95 physically associates with either D1 or D2 DA receptors in co-transfected HEK-293 cells. Stimulation of DA receptors altered the association between D1 receptor and PSD-95 in a time-dependent manner. Functional assays indicated that PSD-95 co-expression did not affect D1 receptor-stimulated cAMP production, Gs-protein activation or receptor desensitization. However, PSD-95 accelerated the recovery of internalized membrane receptors by promoting receptor recycling, thus resulting in enhanced resensitization of internalized D1 receptors. Our results provide a novel mechanism for regulating DA receptor recycling that may play an important role in postsynaptic DA functional modulation and synaptic neuroplasticity.

Interlocked molecules are a type of supramolecules whose sub-components are held together not by covalent bonds but non-covalent interactions. Examples include rotaxanes, catenanes, Solomon links, ring-in-ring complexes, molecular Borromean rings, molecular knots and interlocked cages. The design and manufacture of these architectures is mainly based on self-assembly and templatedirected methodologies. Inspired by the successful utilization of coordination-driven assembly in metallasupramolecular systems, the metallacyclic assembly of interlocked superstructures is developing rapidly and as such makes a fascinating topic for reviewing. In this review we will focus on the metal-directed synthesis of the different types of interlocked superstructures, as well as their functional applications.

Neuronal oscillations have been suggested to play an important role in information processing in the brain. Using spectral analysis, we have recently shown that the repetitive burst-like firing in many dopamine (DA) neurons in the ventral tegmental area (VTA) can be described as a slow oscillation (SO) in firing rate. In this study, we examined whether DA neurons in the adjacent substantia nigra (SN) also display a SO. DA neurons were recorded extracellularly using the cells/track technique in chloral hydrate-anesthetized rats. Spectral analysis showed that firing patterns of SN DA neurons exhibited a SO similar to that observed in VTA DA neurons. The amplitude of the SO, however, was much reduced in the SN compared with that in the VTA and so was the number of DA neurons qualified as high-SO cells. In high-SO DA neurons, the amplitude of the SO was strongly correlated with the degree of bursting, and this correlation was observed in both the VTA and SN. In low-SO cells, however, the SO was more significantly correlated with the variability of firing than with firing rate and bursting. Since the generation of the SO depends on afferent inputs to DA neurons, a better understanding of its difference between the SN and VTA may provide important insights into the neural networks that control DA neurons in the two areas.

The emergence of supramolecular chemistry has led to the discovery of a rising number of macrocycles and cages with a range of functionalities. Most of these supramolecular aggregates are metal coordination networks, whereas pure organic assemblies are less developed. Organic macrocycles and cages have the advantages of chemical robustness, processability in organic solvents, and suitability for pilot-scale applications. They are constructed primarily from covalent bonds, with irreversible and reversible bond types. We herein highlight the use of different versatile bonding approaches in engineering these soft materials, as well as their emerging applications, such as gas storage, thin films, liquid crystals, and catalysis.

In vivo voltammetric measurements of striatal extracellular DOPAC concentrations and of striatal DA release in combination with post-mortem analysis of striatal catechols were performed in the rat to study the effects on the nigro-striatal neurons of a Chinese neuroleptic, l-tetrahydropalmatine (l-THP), which is known to block post-synaptic dopaminergic receptors. l-THP injected at doses that cause sedation in rats and mice (5-10 mg/kg) induced a marked increase in post-mortem DOPAC levels (+250%), while no significant effect was observed on postmortem DA levels. The extracellular DOPAC concentration was increased to 155 +/- 9% of the control value after l-THP administration (1 mg/kg, IP). Further, an injection of l-THP (1 mg/kg, IP) induced an increase in extracellular DA concentration (220% of the basal value), reversed the decrease in extracellular DA concentration induced by apomorphine (0.05 mg/kg, SC) and enhanced the effects of the electrical stimulation of the nigro-striatal pathway. These results confirm that l-THP acts on the nigro-striatal neurons as a dopaminergic antagonist that can block both post- and presynaptic receptors.

Dopamine (DA) profoundly modulates excitatory synaptic transmission and synaptic plasticity in the brain. In the present study the effects of SKF83959, the selective agonist of phosphatidylinositol (PI)-linked D(1) -like receptor, on the excitatory synaptic transmission were investigated in rat hippocampus. SKF83959 (10-100 μM) reversibly suppressed the field excitatory postsynaptic potential (fEPSP) elicited by stimulating the Schaffer's collateral-commissural fibers in CA1 area of hippocampal slices. However, the inhibition was not blocked by the D(1) receptor antagonist SCH23390, the D(2) receptor antagonist raclopride, the 5-HT(2A/2C) receptor antagonist mesulergine, or the α(1) -adrenoceptor antagonist prazosin. In addition, SKF83959 inhibited the afferent volley and significantly reduced the paired-pulse facilitation ratios. In dissociated hippocampal CA1 pyramidal neurons, SKF83959 had no detectable effect on glutamate-induced currents but potently inhibited voltage-activated Na(+) current (IC50 value = 26.9 ± 1.0 μM), which was not blocked by SCH23390 or by intracellular dialysis of GDP-β-S. These results demonstrate that SKF83959 suppressed the excitatory synaptic transmission in hippocampal CA1 area, which was independent of D(1) -like receptor. The mechanism underlying the effect could be mainly inhibition of Na(+) channel in the afferent fibers. The suppression of excitatory synaptic transmission and the Na(+) channel by SKF83959 may contribute to its therapeutic benefits in Parkinson's disease.