Whistleblower: Columbia University stroke experiments in baboons (2003)
In October 2003, a Columbia University veterinarian exposed experiments being conducted by assistant professor of neurology and neurosurgery E. Sander Connolly.  The veterinarian “turned to PETA after her concerns for the animals’ well-being were ignored by school officials and, later, by the federal agencies tasked with overseeing the school.” 
Connolly was causing strokes in baboons by removing their eyeballs, then reaching a clamp through the eye socket to the brain. He would clamp the internal carotid artery to induce a stroke, so that he could test a drug to treat stokes. 
The experiments were carried out multiple times between July 2001 and September 2002, while the whistleblower was employed as a veterinarian at Columbia. She contacted PETA after the university consistently failed to follow the protocol, which called for post-operative monitoring, pain medications, or timely euthanasia for animals in severe distress. Some animals languished in severe distress for up to seven days until they died or were killed.
Dr. Nicholas Dodman, a board-certified anesthesiologist and former professor of veterinary anesthesiology, reviewed the Columbia protocol and concluded that the analgesic was inadequate to prevent the perception of pain during removal of the eye and some other aspects of the surgery, a view shared by the veterinarian/whistleblower.
In a letter to PETA, neurologist Robert S. Hoffman said the baboons are "kept alive for either three or ten days after experiencing a major stroke and in a condition of profound disability. This is obviously as terrifying for animals as it is for humans unless one believes that animals are incapable of terror or other emotional distress." 
In an interview with the Associated Press the whistleblower stated: "What I saw at Columbia was apathy on the part of the employees, and almost purposeful neglect on the part of veterinarians. … People at Columbia wouldn't talk to me. If you express concern, you get blacklisted." 
The US Department of Agriculture and Office of Laboratory Animal Welfare subsequently investigated the matter and concluded that 11 of the baboons had received “inadequate or questionable care.”
 People for the Ethical Treatment of Animals, “Columbia University Cruelty,” http://www.peta.org/features/columbia-university-cruelty-deadly-animal-experimentation/#ixzz36FPci5FC
 Huang J, Mocco J, Choudhri TF, et al. (December 2000). "A modified transorbital baboon model of reperfused stroke". Stroke 31 (12): 3054–63