RETROGRADE TRACING OF ZINC-CONTAINING NEURONS BY SELENIDE IONS - A SURVEY OF 7 SELENIUM-COMPOUNDS

The autometallographic retrograde tracing of zinc-containing neurons b y intracerebral injection of sodium selenite (Na2SeO3), introduced by Danscher in 1982, has recently been described in more detail. Intracer ebral injections of both sodium selenide (Na2Se) and sodium selenite ( Na2SeO3) have been successfully used; however, sodium selenite had a r ather toxic effect on the injected tissue. In the present study, we te sted seven different selenium compounds to find the most suitable comp ound for retrograde tracing of zinc-positive pathways. Among the teste d compounds, sodium selenide (Na2Se) caused insignificant necrosis wit hin the injection site and was easily transported retrogradely when ha ndled anaerobically. Sodium selenide is therefore recommended as the c ompound of choice.