Ryosuke Cohen is a Japanese mail artist who is involved in Mail Art movement since the 1980s. He runs his Brain Cell project since 1985. The project is an interaction between mail artists who send their stamps, stickers, drawings or other images to Ryosuke, who then incorporate them into his cells. The cells are printed in 150 copies and some of the copies Ryosuke contributes to mail art projects and exhibitions. Brain Cell has enlisted over 6,000 contributors from 80 nations since 1985.