High incidence of estrous cycle irregularities in heterogeneous stock (HS) rats is associated with footshock-resistant cocaine intake. - Sneddon EA; Chonwattanagul S; Bai K; Kurup PH; Plasil SL; Doyle MR; Zahedi S; Simpson S; Sichel BC; Othman DN; Brennan M; Palmer AA; et al. (Psychopharmacology, 2026)