Opioid neurotransmission modulates defensive behavior and fear-induced antinociception in dangerous environments - Coimbra, Norberto Cysne; Calvo, Fabrício; Almada, Rafael Carvalho; Freitas, Renato Leonardo; Paschoalin-Maurin, Tatiana; Anjos-Garcia, Tayllon dos; Elias Filho, Daoud Hibrahim; Ubiali, Walter Adriano; Lobão-Soares, Bruno; Tracey, Irene (Neuroscience, 2017)