The primary motor cortex electrical and chemical stimulation attenuates the chronic neuropathic pain by activation of the periaqueductal grey matter: the role of NMDA receptors - Negrini-Ferrari, Sylmara Esther; Medeiros, Priscila; Malvestio, Rafael Braghetto; Silva, Mariana de Oliveira; Medeiros, Ana Carolina; Coimbra, Norberto Cysne; Machado, Hélio Rubens; Freitas, Renato Leonardo de (Behavioural Brain Research, 2021)