Periaqueductal gray μ and κ opioid receptors determine behavioral selection from maternal to predatory behavior in lactating rats - Klein, Marianne Orlandini; Cruz, Aline de Mello; Machado, Franciele Corrêa; Picolo, Gisele; Canteras, Newton Sabino; Felicio, Luciano Freitas (Behavioural Brain Research, 2014)