The mammalian habenula consists of the medial and lateral habenulae. Recent behavioral and electrophysiological studies suggested that the lateral habenula plays a pivotal role in controlling motor and cognitive behaviors by influencing the activity of dopaminergic and serotonergic neurons. Despite the functional significance, manipulating neural activity in this pathway remains difficult because of the absence of a genetically accessible animal model such as zebrafish. To address the level of lateral habenula conservation in zebrafish, we applied the tract-tracing technique to GFP (green fluorescent protein)-expressing transgenic zebrafish to identify habenular neurons that project to the raphe nuclei, a major target of the mammalian lateral habenula. Axonal tracing in live and fixed fish showed projection of zebrafish ventral habenula axons to the ventral part of the median raphe, but not to the interpeduncular nucleus where the dorsal habenula projected. The ventral habenula expressed protocadherin 10a, a specific marker of the rat lateral habenula, whereas the dorsal habenula showed no such expression. Gene expression analyses revealed that the ventromedially positioned ventral habenula in the adult originated from the region of primordium lateral to the dorsal habenula during development. This suggested that zebrafish habenulae emerge during development with mediolateral orientation similar to that of the mammalian medial and lateral habenulae. These findings indicated that the lateral habenular pathways are evolutionarily conserved pathways and might control adaptive behaviors in vertebrates through the regulation of monoaminergic activities.

Small-diameter fibroin-based vascular grafts have excellent long-term patency. Bone marrow-derived cells contribute to vascular remodeling after graft implantation. Fibroin might be a promising material to engineer vascular prostheses for small arteries.

The amino acid sequence of a single polypeptide chain, B-4, from fowl feather barbs has been determined. The B-4 chain was found to consist of 96 amino acid residues and to have a molecular weight of 10206 in the S-carboxymethylated form. The N terminus of this protein was an N-acetylserine residue. The B-4 protein contained seven S-carboxymethylcysteine residues, six of which are located in the N-terminal region (residues 1 -26), and other one in C terminus. The central region of the peptide chain was rich in hydrophobic residues. There were homologous amino acids at 66 positions in the sequences of the feather keratins of fowl, emu and silver gull. The variation (substitution, deletion and insertion) in sequence was found to be localized in both terminal sections of the polypeptide chain.The B-4 protein structure was predicted to contain fi-sheet (about 30 %), turn and random-coil-like structure, and no a-helix. P-Sheet structure is mostly located in the central region (residues 22-70). On the other hand, both terminal regions are almost devoid of secondary structure.Feather proteins are solubilized in the presence of denaturant by cleavage of disulfide cross-linkages of cystine residues with oxidant or reductant [l -31. Although soluble feather keratins from various birds have been reported to be relatively homogeneous with respect to molecular weight (about 10000) [4,S], they are at the same time heterogeneous by electrophoresis and chromatography and contain slightly different components [6,7]. It was found that an extract of emu feather gave the simplest electrophoretic pattern and that from silver gull was the next simplest. Thus single polypeptide chains were isolated from feather of these two avian species [8]. The present authors have reported on isolation and characteristics of soluble proteins from fowl feather barbs and calamus [9-111. From these studies it has been found that the components of each feather keratin are almost identical in amino acid composition except for cystine and/or amide content. O'Donnell [12] and O'Donnell and Inglis [13] determined amino acid sequences of the proteins from emu and silver gull feather calami, respectively. It was found that a central section, about 60-residues long, of the polypeptide chain contained predominantly hydrophobic residues and was free of S-carboxymethylcysteine, while both terminal sections were rich in S-carboxymethylcysteine. Fraser et al. estimated from infrared spectra data that about 30 % of the polypeptide chain in seagull feather rachis had an antiparallel pleated sheet conformation [14].The ultimate purposes of the present study were to elucidate (a) the whole structure of feather keratin and (b) the relation between the feather keratin sequence and the evolutionary developments in Aves. In this paper, the amino acid sequence of the main component of fowl feather barbs is reported. The sequence is compared with those of emu and silver gull feather calami.Abbreviations. Dansyl, 1-dimethylaminonaphthalene-5-sulphonyl; HPLC, high-performan...

Background: Cichlid fishes in Lake Tanganyika exhibit remarkable diversity in their feeding habits. Among them, seven species in the genus Perissodus are known for their unique feeding habit of scale eating with specialized feeding morphology and behaviour. Although the origin of the scale-eating habit has long been questioned, its evolutionary process is still unknown. In the present study, we conducted interspecific phylogenetic analyses for all nine known species in the tribe Perissodini (seven Perissodus and two Haplotaxodon species) using amplified fragment length polymorphism (AFLP) analyses of the nuclear DNA. On the basis of the resultant phylogenetic frameworks, the evolution of their feeding habits was traced using data from analyses of stomach contents, habitat depths, and observations of oral jaw tooth morphology.

Aims-To clarify the features of the background electroencephalographic (EEG) activities in clinically well preterm infants born at less than 27 weeks gestation and to outline their chronological changes with increasing postconceptional age (PCA). Methods-EEGs of clinically well premature infants born at less than 27 weeks gestation were recorded during the early postnatal period. The infants were separated into three groups according to their PCA at the time of EEG recording (21-22 weeks PCA, 23-24 weeks PCA, and 25-26 weeks PCA). The mean and maximum duration of interburst intervals (IBIs), the mean duration of bursts, and the percentage of continuous and discontinuous patterns in each PCA group were evaluated. Results-There were three infants at 21-22 weeks PCA, seven at 23-24 weeks PCA, and five at 25-26 weeks PCA. Eighteen EEG recordings were obtained. The mean and maximum IBI duration decreased with increasing PCA. The percentage of continuous patterns increased with increasing PCA. Conversely, the percentage of discontinuous patterns decreased with increasing PCA. Conclusions-In premature infants born at less than 27 weeks gestation, the characteristics of the background EEG activities were similar to those of older premature infants. These changes reflect the development of the central nervous system in this period.