Osmotic properties ofLimulusseawaters and organ cultures: An unrecognized issue

Abstract

Excised eyes of the horseshoe crab (Limulus polyphemus) have long provided robust preparations for fundamental studies of the visual neuroscience of photoreceptors. Such preparations are particularly useful for immersion in perfusion chambers whose perfusate can be varied as needed. Little attention has been paid in the past to the osmotic properties of such perfusates because they have generally been virtually isotonic with natural seawater. We here report that (1) some recentLimulusstudies have used organ culture perfusates that are severely hypotonic and (2) that that fact has not been adequately disclosed.