Brain/MINDS: brain-mapping project in Japan

There is an emerging interest in brain-mapping projects in countries across the world, including the USA, Europe, Australia and China. In 2014, Japan started a brain-mapping project called Brain Mapping by Integrated Neurotechnologies for Disease Studies (Brain/MINDS). Brain/MINDS aims to map the structure and function of neuronal circuits to ultimately understand the vast complexity of the human brain, and takes advantage of a unique non-human primate animal model, the common marmoset (Callithrix jacchus). In Brain/MINDS, the RIKEN Brain Science Institute acts as a central institute. The objectives of Brain/MINDS can be categorized into the following three major subject areas: (i) structure and functional mapping of a non-human primate brain (the marmoset brain); (ii) development of innovative neurotechnologies for brain mapping; and (iii) human brain mapping; and clinical research. Brain/MINDS researchers are highly motivated to identify the neuronal circuits responsible for the phenotype of neurological and psychiatric disorders, and to understand the development of these devastating disorders through the integration of these three subject areas.     

Influence of Triacylglycerol Composition on the Emulsification Capacity of Oils

The emulsification capacity of several edible oils was determined in an aqueous system of bovine serum albumin. The relative emulsification capacity of corn, soybean, sesame, palm, palm kernel and coconut oils was 1.00, 0.99, 0.93, 0.90, 0.82 and 0.77, respectively. The emulsification capacity of straight mixed oils lay close to the mean value of that of the component oils. The capacity of mixed oils was decreased by 30～60% by interesterification. Monoacid triacylglycerols had a very low capacity in comparison with edible oils. By interesterification, the emulsification capacity of a mixture of trioleoylglycerol and trioctanoylglycerol was increased and approached the level of interesterified mixed edible oils.     

Functional role of Rho-kinase in ameloblast differentiation

During tooth development, inner enamel epithelial (IEE) cells differentiate into enamel-secreting ameloblasts, a polarized and elongated cellular population. The molecular underpinnings of this morphogenesis and cytodifferentiation, however, are not well understood. Here, we show that Rho-associated coiled-coil-containing protein kinase (ROCK) regulates ameloblast differentiation and enamel formation. In mouse incisor organ cultures, inhibition of ROCK, hindered IEE cell elongation and disrupted polarization of differentiated ameloblasts. Expression of enamel matrix proteins, such as amelogenin and ameloblastin, and formation of the terminal band structure of actin and E-cadherin were also perturbed. Cultures of dental epithelial cells revealed that ROCK regulates cell morphology and cell adhesion through localization of actin bundles, E-cadherin, and β-catenin to cell membranes. Moreover, inhibition of ROCK promoted cell proliferation. Small interfering RNA specific for ROCK1 and ROCK2 demonstrated that the ROCK isoforms performed complementary functions in the regulation of actin organization and E-cadherin-mediated cell-cell adhesion. Thus, our results have uncovered a novel role for ROCK in amelogenesis.     

Collapsin response mediator protein 4 affects the number of tyrosine hydroxylase‐immunoreactive neurons in the sexually dimorphic nucleus in female mice

In the sexually dimorphic anteroventral periventricular nucleus (AVPV) of the hypothalamus, females have a greater number of tyrosine hydroxylase‐immunoreactive (TH‐ir) and kisspeptin‐immunoreactive (kisspeptin‐ir) neurons than males. In this study, we used proteomics analysis and gene‐deficient mice to identify proteins that regulate the number of TH‐ir and kisspeptin‐ir neurons in the AVPV. Analysis of protein expressions in the rat AVPV on postnatal day 1 (PD1; the early phase of sex differentiation) using two‐dimensional fluorescence difference gel electrophoresis followed by MALDI‐TOF‐MS identified collapsin response mediator protein 4 (CRMP4) as a protein exhibiting sexually dimorphic expression. Interestingly, this sexually differential expressions of CRMP4 protein and mRNA in the AVPV was not detected on PD6. Prenatal testosterone exposure canceled the sexual difference in the expression of Crmp4 mRNA in the rat AVPV. Next, we used CRMP4‐knockout (CRMP4‐KO) mice to determine the in vivo function of CRMP4 in the AVPV. Crmp4 knockout did not change the number of kisspeptin‐ir neurons in the adult AVPV in either sex. However, the number of TH‐ir neurons was increased in the AVPV of adult female CRMP4‐KO mice as compared with the adult female wild‐type mice. During development, no significant difference in the number of TH‐ir neurons was detected between sexes or genotypes on embryonic day 15, but a female‐specific increase in TH‐ir neurons was observed in CRMP4‐KO mice on PD1, when the sex difference was not yet apparent in wild‐type mice. These results indicate that CRMP4 regulates the number of TH‐ir cell number in the female AVPV. © 2013 Wiley Periodicals, Inc. Develop Neurobiol 73: 502–517, 2013