Contents

27 March 1992
Vol 255, Issue 5052

About The Cover

Fluorescence micrograph of neural cells that were generated in vitro from stem cells of the central nervous system of an adult mouse. Epidermal growth factor induced the proliferation of a multipotent progenitor. When given an appropriate substrate, these cells differentiated into neurons (orange) and astrocytes (green). See page 1707. [Micrograph by Samuel Weiss]