ApoE4 Weakens the Blood-Brain Barrier in Mice (image) NIH/National Institute of Neurological Disorders and Stroke Share Print E-Mail Caption Destructive enzymes (shown in green) become more active and weaken the blood-brain barrier in mice that are genetically engineered to produce only human ApoE4 (right), rather than mouse ApoE (left). Credit Robert Bell, Ph.D., University of Rochester Medical Center, New York. Usage Restrictions Please credit Robert Bell, Ph.D., University of Rochester Medical Center, New York. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.