First time I heard about antycyclotomic $\Gamma$-extensions in 1972 from Pavel Kurchanov, in connection with his paper
http://www.mathnet.ru/php/archive.phtml?wshow=paper&jrnid=sm&paperid=3020&option_lang=eng
Actually, his goal was to construct elliptic curves of infinite rank over $\Gamma$-extension.\Gamma$-extensions. (According to Mazur's conjecture, one cannot do it over the cyclotomic extensions.)

