Study Projects
Our Aims
What is the goal of doing research and giving back to society?
Our laboratory focuses on elucidation of the regulatory mechanisms of body temperature and body fluids at the center of research.
I rarely notice, but my body temperature, body fluid volume and composition are constant. This is a very important regulatory system for our survival. Failure of this regulatory system is directly linked to death, such as heat stroke.
Body temperature is also related to the use of air conditioning in daily life, and is closely linked to changes in the urban environment such as the heat island phenomenon and global environmental issues such as global warming. It is also related to women’s chills.
In the laboratory, projects on the theme of body temperature and body fluid from basic to applied are being advanced. The laboratory is still immature, but we are working hard to become a mecca in the world of this research field.
In any case, science tends to be a self-reliance on researchers. Many studies seem to lose sight of the needs of society. Our research is based on one goal: experiments with humans and experimental animals, and intellectual and useful sciences that will continue to be scientifically elucidated and applied and practiced in the near future. I am aiming.
Kei Nagashima
Overview of ongoing research and projects, and collaborative research
Thermal perception
How do well assess thermal information of body and environment?
According to textbooks, the temperature of the environment is transmitted from the skin to the somatosensory cortex and rises in consciousness (the spinal thalamus). However, the temperature sensation varies from person to person. Cold people may be the case (Reference 1). Also, the way in which temperature is sensed varies depending on the body part (Reference 2). In addition, the way of feeling varies greatly depending on the state of the body and the body temperature in the deep part. In other words, how does the sense of temperature and the sense of thermal comfort change with the state of the human body, rather than grasping the mechanism of temperature acceptance in terms of molecules and electrophysiology? I am trying to find out if it is different among humans. We conduct research using physiological methods, psychological methods, functional images (fNIRS, fMRI), etc. (References 3, 4, and 5)
Heat illness
Prevention of problems related to hyperthermia and development of the treatment including medicine
The onset of heat stroke differs greatly between the elderly and young. In all cases, high temperature, high humidity environment and dehydration are considered to be the major triggers (Reference 6). However, only drinking water and salt intake (or just dependence) will increase the number of heat stroke patients associated with global warming. We will strive to develop methods for preventing heat stroke, explore the unknown etiology and pathogenesis of heat stroke at the molecular level, and develop research that will be the basis for the development of therapeutics for the fatal severe heat stroke, including medication.
Behavioral thermoregulation
What is homeostasis of body temperature in humans？
The body temperature may be a constant temperature animal or a variable temperature animal. It may be misunderstood that constant-temperature animals maintain body temperature, and temperature-varying animals greatly change their body temperature while being affected by the temperature of the environment. However, for all living things, the temperature, its homeostasis, is very important for survival.
A mechanism that maintains body temperature despite changes in the environment is also provided for homeotherms and poikilotherms. The mechanism is to move, nest, and bathe in a very simple and suitable environment, which is called behavioral thermoregulation. In humans, putting on and taking off clothes and turning air conditioning on and off is also one of the behavioral body temperature controls. Much research has been done, but the physiological and neurological mechanisms have not been fully developed due to the intelligibility of their actions. We intend to clarify this mechanism and link it to various applications (References 7, 8). Currently, we are conducting joint research on comfortable and eco-friendly air conditioning in narrow spaces such as cars, and the creation of comfort by cooling and warmth stimuli using chemicals.
Water and salt intakes
How should we take water and salt during exercise or labor in a hot environment?
It is becoming common sense that drinking water and salt intake are important for the prevention of heat stroke. However, drinking water and taking salt is not a panacea for heat stroke. When and how much water and salt to take. We are also trying to clarify how the amount and composition of body fluids affect body temperature regulation (References 9 and 10).
文献
- Thermal regulation and comfort during a mild-cold exposure in young Japanese women complaining of unusual coldness. Nagashima K, Yoda T, Yagishita T, Taniguchi A, Hosono T, Kanosue K. J Appl Physiol. 2002 Mar;92(3):1029-35.
- Regional differences in temperature sensation and thermal comfort in humans. Nakamura M, Yoda T, Crawshaw LI, Yasuhara S, Saito Y, Kasuga M, Nagashima K, Kanosue K. J Appl Physiol. 2008 Dec;105(6):1897-906. doi: 10.1152/japplphysiol.90466.2008. Epub 2008 Oct 9.
- Brain activation during whole body cooling in humans studied with functional magnetic resonance imaging. Kanosue K, Sadato N, Okada T, Yoda T, Nakai S, Yoshida K, Hosono T, Nagashima K, Yagishita T, Inoue O, Kobayashi K, Yonekura Y. Neurosci Lett. 2002 Aug 30;329(2):157-60.
- Relative importance of different surface regions for thermal comfort in humans. Nakamura M, Yoda T, Crawshaw LI, Kasuga M, Uchida Y, Tokizawa K, Nagashima K, Kanosue K. Eur J Appl Physiol. 2013 Jan;113(1):63-76. doi: 10.1007/s00421-012-2406-9. Epub 2012 May 9.
- Mild hypohydration induced by exercise in the heat attenuates autonomic thermoregulatory responses to the heat, but not thermal pleasantness in humans. Tokizawa K, Yasuhara S, Nakamura M, Uchida Y, Crawshaw LI, Nagashima K. Physiol Behav. 2010 Jun 16;100(4):340-5. doi: 10.1016/j.physbeh.2010.03.008. Epub 2010 Mar 15.
- Central mechanisms for thermoregulation in a hot environment. Nagashima K. Ind Health. 2006 Jul;44(3):359-67. Review.
- Tail position affects the body temperature of rats during cold exposure in a low-energy state. Uchida Y, Tokizawa K, Nakamura M, Lin CH, Nagashima K. J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2012 Feb;198(2):89-95. doi: 10.1007/s00359-011-0690-1. Epub 2011 Oct 29.
- Hyperosmolality in the plasma modulates behavioral thermoregulation in mice: the quantitative and multilateral assessment using a new experimental system. Lin CH, Tokizawa K, Nakamura M, Uchida Y, Mori H, Nagashima K. Physiol Behav. 2012 Jan 18;105(2):536-43. doi: 10.1016/j.physbeh.2011.09.006. Epub 2011 Sep 14.
- Neuronal circuitries involved in thermoregulation. Nagashima K, Nakai S, Tanaka M, Kanosue K. Auton Neurosci. 2000 Dec 20;85(1-3):18-25. Review.
- The median preoptic nucleus is involved in the facilitation of heat-escape/cold-seeking behavior during systemic salt loading in rats. Konishi M, Kanosue K, Kano M, Kobayashi A, Nagashima K. Am J Physiol Regul Integr Comp Physiol. 2007 Jan;292(1):R150-9. Epub 2006 Jul 13.