Macular pigment in Henle fiber membranes: a model for Haidinger's brushes

The dichroic properties of lutein, presumed to be the macular pigment, are demonstrated and the structure of Henle fiber membranes is discussed. A consequence of the pigment molecules being incorporated into the bilipid components of these membranes is shown to be the production of Haidinger's brushes. Spectra of lutein in association with phospholipid model membranes at different temperatures are presented and these support the theory that such incorporation occurs. Additional experiments test an alternative model for Haidinger's brushes and show it to be inconsistent with the spectroscopic properties of lutein.