The six-layered neocortex permits complex information processing in all mammalian species. Because its homologous region (the pallium) in nonmammalian amniotes has a different architecture, the ability of neocortical progenitors to generate an orderly sequence of distinct cell types was thought to have arisen in the mammalian lineage. This study, however, shows that layer-specific neuron subtypes do exist in the chick pallium. Deep- and upper-layer neurons are not layered but are segregated in distinct mediolateral domains in vivo. Surprisingly, cultured chick neural progenitors produce multiple layer-specific neuronal subtypes in the same chronological sequence as seen in mammals. These results suggest that the temporal sequence of the neocortical neurogenetic program was already inherent in the last common ancestor of mammals and birds and that mammals use this conserved program to generate a uniformly layered neocortex, whereas birds impose spatial constraints on the sequence to pattern the pallium.

Supported Au nanoparticles (NPs) prepared by colloid deposition method were well characterized, and their catalytic performance was tested for chemoselective reduction of a nitro group of substituted nitroaromatics by H 2 . Systematic studies on the effects of NPs size and support show small size of Au NPs, and acid-base sites of supports are required for high activity. The Au/Al 2 O 3 catalyst with Au particle size of 2.5 nm selectively hydrogenates a nitro group in the presence of various other reducible functional groups, and it shows higher intrinsic activity than the state-of-the-art catalyst (Au NPs on TiO 2 ). In situ FTIR studies provide a reaction mechanism, which explains fundamental reasons of the observed structure-activity relationship. Cooperation of the acid-base pair site on Al 2 O 3 and the coordinatively unsaturated Au atoms on the Au NPs are responsible for the H 2 dissociation to yield a H + /Hpair at the metal/support interface. High chemoselectivity could be attributed to a preferential transfer of the H + /Hpair to the polar bonds in the nitro group as well as a preferential adsorption of nitroaromatics on the catalyst through the nitro group.

Neural circuitry formation depends on the molecular control of axonal projection during development. By screening with fluorophore-assisted light inactivation in the developing mouse brain, we identified cartilage acidic protein–1B as a key molecule for lateral olfactory tract (LOT) formation and named it LOT usher substance (LOTUS). We further identified Nogo receptor–1 (NgR1) as a LOTUS-binding protein. NgR1 is a receptor of myelin-derived axon growth inhibitors, such as Nogo, which prevent neural regeneration in the adult. LOTUS suppressed Nogo-NgR1 binding and Nogo-induced growth cone collapse. A defasciculated LOT was present in lotus-deficient mice but not in mice lacking both lotus- and ngr1. These findings suggest that endogenous antagonism of NgR1 by LOTUS is crucial for normal LOT formation.

A single-atom-sized gold wire was successfully observed in real time by a newly developed defocus-image modulation processing electron microscope. Because of phase retrieval processing with spherical aberration correction, the single-atom strand wire was observed with high contrast and without contrast blurring. By carefully looking at the atomic distance, the contrast, and the dynamic behavior of the wire, we recognized that there are two stages of the wire. In the first stage the wire maintained the atomic distance in the bulk crystal, but in the second stage the wire showed the atomic distance of the nearest-neighbor atoms with weaker contrast. The gold wire was rather stable for a few seconds under strong electron beam illumination.