A New Species of Sexually Dimorphic Brittle Star of the Genus Ophiodaphne (Echinodermata: Ophiuroidea).

We describe a new species of sexually dimorphic brittle star, Ophiodaphne spinosa, from Japan associated with the irregular sea urchin, Clypeaster japonicus based on its external morphology, and phylogenetic analyses of mitochondrial COI (cytochrome c oxidase subunit I). Females of this new species of Ophiodaphne are characterized mainly by the presence of wavy grooves on the surface of the radial shields, needle-like thorns on the oral skeletal jaw structures, and a low length-to-width ratio of the jaw angle in comparison with those of type specimens of its Ophiodaphne congeners: O. scripta, O. materna, and O. formata. A tabular key to the species characteristics of Ophiodaphne is provided. Phylogenetic analyses indicate that the new species of Ophiodaphne, O. scripta, and O. formata are monophyletic. Our results indicate that the Japanese Ophiodaphne include both the new species and O. scripta, and that there are four Ophiodaphne species of sexually dimorphic brittle stars with androphorous habit.

[Mechanisms of memory bridging past and present].

The human mind develops through history within the passing of time. Thus, what determines the passing of time in the human mind? For example, when you are asked about yourself 10 years before now, you are able to answer by tracing back through your own experiences. You will be confident of your answer as far as you rely on your memory. Therefore, your personal memory is critical for the passage of time; however, how memory that allows for mental time travel is formed or maintained in the brain is largely unknown. This type of memory may exist only in humans. In this article, we review past studies on memories that emerge from time information in human and experimental animals.

N-methyl-D-aspartate receptors and protein synthesis are necessary for reinstatement of conditioned fear.

Conditioned fear is extinguished if a conditioned animal receives the conditioned stimulus without an unconditioned stimulus. The extinguished fear response can be reinstated after the animal experiences a mild unconditioned stimulus. Although extensive studies on the neuronal circuitry and neurochemical mechanisms leading to fear acquisition and extinction have been carried out, few studies have focused on reinstatement. In this study, we investigated the effects of N-methyl-D-aspartic acid receptor (NMDAR) antagonists, protein synthesis inhibitors, cannabinoid receptor type 1 (CB1R) antagonists, and benzodiazepine on reinstatement of conditioned fear in mice. An intraperitoneal injection of the NMDAR antagonist MK-801 or the protein synthesis inhibitor anisomycin before the reminder shock attenuated fear reinstatement tested the next day. However, anisomycin had no effect on fear reinstatement tested 2 h after the reminder shock. CB1R antagonists, SR141716, and a benzodiazepine, diazepam, had no effect on fear reinstatement. These results suggested that NMDAR and protein synthesis-dependent plasticity contributed toward the reinstatement of conditioned fear and that protein synthesis was involved in consolidation of reinstated fear.

Mn(III)-initiated facile oxygenation of heterocyclic 1,3-dicarbonyl compounds.

The Mn(III)-initiated aerobic oxidation of heterocyclic 1,3-dicarbonyl compounds, such as 4-alkyl-1,2-diphenylpyrazolidine-3,5-diones, 1,3-dialkylpyrrolidine-2,4-diones, 3-alkyl-1,5-dimethylbarbituric acids, and 3-butyl-4-hydroxy-2-quinolinone gave excellent to good yields of the corresponding hydroperoxides, which were gradually degraded by exposure to the metal initiator after the reaction to afford the corresponding alcohols. The synthesis of 30 heterocyclic 1,3-dicarbonyl compounds, the corresponding hydroperoxides and the 10 alcohols, their characterization, and the limitations of the procedure are described. In addition, the mechanism of the hydroperoxidation and the redox decomposition of the hydroperoxides are discussed.