Scientists create animal model of how HIV affects brain. (Johns Hopkins University)

A genetically altered mouse gives science the first laboratory animal that can be used to study how HIV infects cells in the brain, researchers report.

In a study published in the journal Science December 11, 1992, scientists report that by engineering genes, they have created a mouse that carries a select part of the genetic pattern of HIV. The researchers also inserted into the mouse strain a genetic marker that causes cells to turn blue when the HIV gene fragment is expressed.

The result, said Janice Clements of Johns Hopkins University School of Medicine, Baltimore, Maryland, is that cells within the mouse that are targeted by some strains of HIV turn …