Tryon, Valerie L Analysis of morphine-induced changes in the activity of periaqueductal gray neurons in the intact rat. [electronic resource] - Neuroscience Oct 2016 - 1-8 p. digital Publication Type: Journal Article ISSN: 1873-7544 Standard No.: 10.1016/j.neuroscience.2016.08.025 doi Subjects--Topical Terms: Analgesics, Opioid--pharmacologyAnimalsDrug Tolerance--physiologyMaleMedulla Oblongata--drug effectsMicroinjections--methodsMorphine--pharmacologyNeurons--drug effectsPain--drug therapyPain Measurement--drug effectsPeriaqueductal Gray--drug effectsRats, Sprague-Dawley