Sleep Substances: Their Roles And Evolution

As early as November 1906, the French psychophysiologists René Legendre and Henri Piéron initiated sleep deprivation in dogs in order to obtain an endogenously occurring sleep-inducing substance. In July 1907, a Japanese physicochemist, Kuniomi Ishimori, undertook almost the same experiments in dogs. The former published a series of short reports in French during 1907-1912 and a final full paper in 1913 (24), while the latter published a 29-page full paper in Japanese in 1909 (19). Both of the pioneer researchers independently reached the conclusion that a long-lasting state of wakefulness eventually causes the accumulation of a toxic substance in the brain which may trigger sleep.