WADA Hiromi

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WADA Hiromi Professor

Human Sciences / Psychology
Specialized Field
Developmental neurobehavioral toxicology
Research Subject
We evaluate developmental neurobehavioral toxicity of environmental pollutants using animal model systems. Pregnant rats are treated with environmental pollutants and resultant rats are examined if cognitive and social behaviors are impaired. Our goal is preventing children from neural damage caused by environmental pollutants.
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Lab. Letters: Messages from the Laboratory

Prevention is better than cure:
Research aiming at social contribution

Seafood such as fishes and shellfishes are contaminated with PCB, dioxin and the like. When we eat seafood, we take in these environmental pollutants. In our lab, environmental pollutants are administered to animals in order to evaluate their developmental impact on cognitive behaviors (learning, memory, attention, anxiety, depression) and social behaviors (communication with conspecifics, cognition of conspecifics). To prevent diseases, we strive to detect brain dysfunction in the early developmental stages. For instance, rat pups call their mother by producing ultrasonic vocalization at frequencies of 40-50 kHz. However, flame retardants, which can make flammable materials such as plastic, wood, fiber or paper nonflammable, render rat pups unable to produce the long vocalizations that normal pups produce. This makes it hard for the mother rat to notice the pups’ calls and respond to them. In the natural world, such communication impairments may jeopardize the survival of rat pups. Communication impairments may also lead to the collapse of the family or group. Rats that inhabit cities eat the kitchen waste that people discard. The alterations of ultrasonic vocalizations observed in rat pups may portend upcoming threats to humans.

  • An example of ultrasonic vocalizations in rat pups: Frequency modulated vocalizations, whose frequency changes, are considered to play a vital role in calling the mother rat.
  • Climbing is Professor Wada’s favorite pastime. Here he takes a break on his way to the summit of Mt. Kitahotakadake. He says “Climbing, research, life: These all involve the culmination of persistent efforts.”

Encouraging students to become independent researchers:
Persistent efforts are sure to pay off in the long run.

The basic approach to empirical studies involves answering research questions using your eyes, ears and body. I invariably advise my students to come to their own conclusions by analyzing data, reading scientific papers and thinking logically, instead of relying on others easily.

Additionally, those who conduct animal experiments should bear in mind that one needs to understand the ethics and welfare of animals and that daily rearing management, such as feeding rats and cleaning up their droppings, is part and parcel of experimentation. Several to 12 months of steady animal care will ultimately lead to our goal: preventing diseases. I believe that strenuous efforts such as patient animal care and study pay off in the end and that the experiences in our lab are sure to serve you well even after you venture out into the world.

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