Contents

20 February 1987
Vol 235, Issue 4791

About The Cover

A color graphic display of an optical density scan of prefrontal cortex from a cynomolgus monkey, hybridized with an RNA probe transcribed from complementary DNA clone Am4 coding for Alzheimer amyloid polypeptide. Each color represents an optical density range of grain clusters, with red as highest, green as intermediate, and blue as lowest density. See page 873. [Graphic provided by John H. Morrison, Gerald A. Higgins, David A. Lewis, and Michael C. Wilson, Scripps Clinic and Research Foundation, La Jolla, CA 92037; and Sina Bahmanyar, Dmitry Goldgaber, S. K. Shankar, and D. Carleton Gajdusek, National Institutes of Health, Bethesda, MD 20205; computer software (E.M.M.A.) by Warren Young and Mark Shin, Scripps Clinic and Research Foundation]