Our research theme is development of new photoreaction using photoinduced electron transfer and its application to syntheses of functional materials. In present, we are working on (1) investigation of photochemical syntheses of indole derivatives which are considered to the important alkaloids widely found in nature, and (2) development of efficient photochemical synthetic methods for quinone imine dyes and their application. Because these target compounds indicate characteristic redox behavior, we also consider applying them to functional materials such as an OLED material while adopting their expected physical properties evaluated by quantum chemical calculation.

The kinds of polymers are relatively a few, which are used as plastics, rubber, and gels for daily life, since they exhibit versatile properties by hierarchical structure control ranging from nano- to micro-meter scales. In our laboratory, we focus to develop new polymeric materials by the hierarchical structure control and reveal the relationship between the mechanism and structure by microscope, scattering, and spectroscopy methods.

I’m working on migration behavior of elements in hydrosphere from a chemical view.

【Elucidation of mechanism of solid-liquid interfacial reaction】
One of the factors affecting migration behavior of elements in environment (especially in hydrosphere) is “adsorption of dissolved species on soil”. In recent years, it has been reported that various reactions to the adsorbed species occur. I’m trying to elucidate the mechanism of the reaction.

【Elucidation of nature of dissolved species in hydrosphere】
The dissolved species in hydrosphere is complex because several dissolved species coexists. I’m trying to elucidate the nature of the complicated dissolved species with theoretical calculation.

Transient absorption spectroscopy measures the changes in the absorbance of short-lived species generated by photo-irradiation, and gives us the information about dynamic processes in materials or chemical compounds. Rate constants are also determined by measuring time-profiles of the concentration of excited molecules.
By using this method, we can investigate molecular dynamics after photo-irradiation.

Developing efficient organic photovoltaic cell devices have been increasingly important in the growing needs for inexpensive renewable energy. The molecular designs for organic photovoltaic materials required delocalized pi-electron systems and utility elements. To develop novel pi-electron systems for organic photovoltaic materials, we synthesized some novel donor/acceptor arrays with aromatic bisimide units, and measured their properties and self-assembly abilities. Recently, we also synthesized some N-atom containing pi-electron systems and revealed their photophysical properties and structures.

We investigate various biological characteristics such as genetics, morphology, physiological reproduction, and nutrition of wild animals, especially small mammals, through breeding and preservation of their breeding stock (e.g., suncus and voles). To elucidate the diverse biosystems in humans and other animals, we aim to create unique animal resources that enable us to obtain knowledge that is difficult to obtain with common laboratory animals (e.g., mice and rats) and to improve their added value.

Hepatocyte growth factor (HGF) was originally identified as an hepatotrophic factor. During the past 30 years, we provided evidence to show that HGF plays an essential role for regeneration of several types of organs, including kidney, lung, hearts and neural tisses, using animal models of intractable disorders. HGF elicits unique biological activities, such as mitogen, motogen and morphgen via activating c-Met/HGF-receptor tyrosine kinase as shown below. Of note, a loss in HGF production is responsible for manifestation of acute and chronic organdiseases. This is the reason why HGF supplemental therapy produces benefit effects against the progression of acute and chronic organ diseases.

The coypu (Myocastor coypus) is a large-sized rodent introduced from South America, and has been designated as a specific alian species since 2005 by Japanese government. However, the knowledge of its biological charateristics necessary for pest control is scanty. Thus, we are coducting related research on the coypu from various angles. We have revealed that the coypu has a high level of learning capability. It also has a high physical potential, such as climbing over a fence about 70 centimeters tall. In the historical aspect, we have also revealed that the background for the spread of the species in Japan has not been as has been told before. There was a nationwide campaign for promotion of the propagation of the coypu for meat production increase in the WWII postwar food shortage period.

The final goal of our research is to converse with ants. Ants have long been thought to engage in detailed communication using chemical substances such as pheromones. However, our researchis revealing that acoustic signals are also important toos of communication.We conducte detailed analyses of organs such as “ears” and “sound-producing organs”. It will be able to control the behavior of ants like leaf-cutting ants, which are significant damage against human society.

We have been collaborating with various stakeholders such as the Fukuoka City, Fukuoka Prefecture, and the Ministry of the Environment to control invasive alien ant species such as the red imported fire ant, the yellow crazy ant, and Argentine ant. In Okayama Prefcture, there have been reported of the little fire ant (Wasmannia auropunctata) at Mizushima Port, and we will continue to control and manage these ants.

By using silk produced by silworms, which domesticated in China 6,000 years ago, and the silks spun by black Japanese weaver ant in Okinawa, we conduct research to create new fabric sheets. We hope that as this research progresses, the black Japanese weaver ant can be a symbolic relationship with humans as the fourth demesticated insect.

Primates (precisely non-human primates), are the animal group that shares the most similarities with humans. They show high levels of intelligence and social skills. Additionally, many primate species live in tropical and subtropical regions and are considered keystone species that play a fundamental role in maintaining tropical ecosystems. Researching the society and ecology of primates can provide us with valuable insights into the evolution and nature of humans. This knowledge can help us better understand ourselves, as well as contribute to the conservation of biodiversity and the resolution of global environmental issues. My work involves studying the society and ecology of primates and other large and medium-sized mammals, mainly through field observations. I also examine human society from a zoological perspective and its evolution. Currently, my team and I are conducting long-term field research and conservation activities to protect wild gorillas in the tropical forests of Central Africa. We also conduct educational and animal welbeing activities in zoos and perform behavior observation research on Japanese macaques in Japan.

We focus on the ecology of wild animals, including endangerd species, and their function in the ecosystem using direct observation or research tools such as camera trap. We explore better conservation methods and way for a sustainable coexistence with people.

Mammanlian reproductive status changes during postnatal development and aging. It can also be altered by environmental cues, stress or dysfunction of related organs. My research aims to clarify the factors and the mechanism which affect reproductive functions by using histological analysis on hypothalamic-pituitary-gonadal axis and measuring reproductive hormones. I am also working to establish methods to monitor reproductive status of wild animals by measuring steroid hormones in hair.

Japanese quail are the second most reared animal in the world poultry industry (meat and egg production), after chickens. Although suitable environments to improve productivity of domestic quail have been studied, not much is known about their biological characteristics, such as whether they are monogamous or polygamous, how females and males are involved in child rearing, and how they select partners. A better understanding of these issues will contribute to further improvement of quail productivity, and we are conducting behavioral and genetic research by actually raising and observing quail.
We also conduct population genetic and phylogeographic studies to understand how wild animals adapt to and live in their habitats, with focuses on wild animals.

There are many diseases associated with hard tissue, such as osteoporosis, osteoarthritis and periodontal disease, and their patients have increased with the advent of an aging society. In this laboratory, for the treatment of these diseases, we are developing regenerative research on hard tissue (bone, cartilage, teeth) by setting three keyword; growth factors, extracellular microenvironment and stem cell.

Epithelial cells in spheroids formed through three-dimensional culture exhibit a quiescent state. Our research aims artificial interventions to control cell proliferation and differentiation during spheroid formation. Additionally, aiming for the standardization of cell culture techniques, we are advancing the development of a assessment system utilizing recorded videos.

Clostridium perfringens is a bacterium that causes gas gangrene and food poisoning. a-toxin (phospholipase C) is a pathogenic factor in gas gangrene. We showed which amino acids in the C-terminal domain of the αsubunit (αCTD) of RNA polymerase interact with the phased A-tracts DNA upstream of the promoter of a-toxin gene. The autolytic enzyme autolysin of C. perfrignes was identified as one of the fibronectin-binding proteins. In addition, through joint research, we were able to determine the three-dimensional structure of CppA, a pili-constituting protein.

We found that vagal hyperactivity produced by ventromedial hypothalamic (VMH) lesions stimulated cell proliferation of rat pancreatic islet B through a cholinergic receptor mechanism. Previously, we developed a new technique regarding high-quality RNA extraction from rat pancreas for cDNA microarray analysis, and thereby, we found that VMH lesions may change the expression of cell proliferation-related genes and neuron-related genes in a rat pancreas, using DNA microarray and real-time polymerase chain reaction. We believes that these new gene network analysis will lead to Diabetes MellitusTreatment or Pancreatic Cancer.

Proteins exert their functions by adopting specific three-dimensional structures. Molecular chaperones are known to be involved in the process of achieving proper protein folding, which is crucial for the formation of these three-dimensional structures. We are focusing on a specific molecular chaperone known as heat shock protein and investigating its role in the brain. Through our research, we have revealed a connection between heat shock protein and depressive-like symptoms. Currently, we are further expanding this research to explore the relationship between depression and protein misfolding abnormalities.
Additionally, we are studying the impact of heat shock protein expression on memory, sensation, as well as its effects on allergies such as rhinitis.

1. We investigate the role of calcitonin-gene relate peptide (CGRP) which is a potent peptide vasodilator and can function in the transmission of pain on mice behavior. Recently, we have demonstrated that intracerebroventricular administration of CGRP induced anti-depressant effect in 15-day restraint stressed mice. This anti-depressant effect is associated with a massive nerve growth factor production in hippocampus. We are now investigating whether the fear memory associated with the exogenous CGRP in mice.

2. We also exploring the effect of CGRP on atherosclerosis in apoE knockout mice which has on CGRP. ApoE knockout mice, which develop atherosclerosis lesion in short time.

Infectious diseases caused by bacteria begin with the attachment (Binding) of bacteria to the host. We use <ｉ>Clostridium perfringens, one of the pathogenic bacteria, as wound infection model. We are studying host-pathogen interaction from the following viewpoints.

1. Interaction between fibronectin and fibronectin binding protein (Fbps) of <ｉ>C. perfringens
2. The effect of Fbps on dermatopontin (DPT)-induced fibronectin fibrosis.
3. Fbps functions as a peptidoglycan hydrolyzing enzyme
4. The effect of Fbps on wound healing