Adaptation Physiology



Professor: Satoshi Matsuo
Associate Professor: Takeshi Inoue
Assistant Professor: Felix Ojeiru Ezomo

Features of our Division

Adaptation physiology is a field of study that analyzes various biological phenomena induced by changes in the internal and external environment, to promote health and prevent disease. The research interests of our division are space physiology (adaptation to microgravity), circulatory physiology (adaptation to ischemia), neurophysiology (mechanisms of the central nervous system), exercise physiology (adaptation to physical exercise), and the physiology of aging (adaptation to aging).
We welcome students with an interest in sport, but students who are not interested in sport are also very welcome!

Areas of Research Interest


Effects of microgravity on the circulatory system
Weightlessness is one of the most important factors affecting human function in space. The body is comprised of 60% water. In microgravity environments, body fluid shifts to the upper body. This shift causes problems such as space motion sickness, facial swelling, and nasal congestion. We examine the adaptive responses to microgravity in the human body with special reference to circulatory system. Our work focuses on deconditionings in microgravity environments and countermeasures against them. These studies are imperative for the development of comfortable space travel in the future.

Visual-motor transformations
How does the brain transform sensory inputs into motor outputs? Answering this question is important for understanding information processing in the brain. We conduct research into the neural mechanisms underlying orienting movement as an example of visual-motor transformation. Our objective is to elucidate the mechanisms underlying the generation of normal and pathological orienting movements.

Neural regulation of respiration
It is well known that the respiratory rhythm is generated in the brainstem, and can be changed by changes in the internal and external environment. However, the neural mechanisms involved in generating respiratory rhythms and patterns are currently unclear. We discovered respiration-related neurons in the medullary raphe nuclei, which have different firing patterns. We examine how these neurons play a role in generating respiratory movements. We aim to develop a neural network model that can explain the generation of respiratory rhythms and patterns.

Vestibular autonomic system and Development of vestibular rehabilitation device
Changes in somatosensory inputs, including vision vestibular and proprioception, due to changes in the environmental perturbation induce short-term adaptation of motor output and circulatory response. The repetition of the perturbation results in appropriate mid- to long-term adaptation for the body. We are interested in not only the mechanism of the adaptation of each sensory input using various perturbations, but also the change of sensory weighting for each sensory receptor and its clinical application.


Even slight changes in environmental conditions affect homeostasis, growth, reproduction, and survival of creatures, and therefore organisms sense environmental conditions and accordingly decide survival strategies. The mechanisms of the environmental adaptations, which are regulated by complex physiological and neural processes, remain poorly understood despite their importance for health maintenance and disease prevention, as well as animal ethology and evolution. The mechanisms and physiological process of the environmental adaptations in organisms consist of multiple levels such as the molecular level, the cellular level, the tissue level, the organ level, and the individual level. Therefore, we systematically analyze the biological system using advanced analysis technologies.

 A novel model animal
- planarian -
To systematically analyze the mechanisms regulating the environmental responses from the molecular level to the individual level, we have established a novel model organism. Planarians (phylum Platyhelminthes) are renowned as immortal creatures that can be regenerated no matter how much the body is cut. Besides, the planarian belongs to an evolutionarily basal group of animals possessing a central nervous system, and it exhibits robust behaviors in response to environmental stimuli. The planarian brain is a simple, nevertheless incredibly sophisticated, that consists of several structural domains defined by a complex set of genes and neural networks. Furthermore, the combination of behavioral assays quantifying many parameters and RNAi to knockdown neuron-specific genes can demonstrate that neural networks in planarians strictly regulate distinct behaviors via the corresponding sensory organs and brain neurons in response to specific environmental stimuli. Therefore, planarians are an ideal model for understanding the basic mechanisms of brain function and can serve as a basis for research to investigate the causes of human diseases and contribute to health maintenance and disease prevention.

 The mechanisms to integrate various physiological functions and adapt to the environment
- Morphology follows Function -
The physiological functions and the morphology of the organisms are surprisingly diverse in the animal kingdom. However, much remain to be understood about the relationship between physiological function and morphology. We have recently discovered that morphological features impact efficiencies in multiple environmental responses. "Form follows function" is the word of an architect Louis Sullivan, but in the very organisms, the morphology and the function are strongly linked. We aim to clarify the mechanism of physiological function by analyzing from both views of the morphology and the function.


Adaptability to physical exercise and Development of rehabilitation device
We research biological responses to physical exercise, focusing on changes in thermal, circulatory and respiratory regulation during exercise. These studies aim to develop new exercise programs for the rehabilitation and maintenance of health. These programs have to be customized according to individual abilities, because exercise elicits different biological responses between individuals.