9-cis-13,14-Dihydroretinoic Acid Is an Endogenous Retinoid Acting as RXR Ligand in Mice.

The retinoid X receptors (RXRs) are ligand-activated transcription factors which heterodimerize with a number of nuclear hormone receptors, thereby controlling a variety of (patho)-physiological processes. Although synthetic RXR ligands are developed for the treatment of various diseases, endogenous ligand(s) for these receptors have not been conclusively identified. We show here that mice lacking cellular retinol binding protein (Rbp1-/-) display memory deficits reflecting compromised RXR signaling.

Retinoid x receptor gamma is implicated in docosahexaenoic acid modulation of despair behaviors and working memory in mice.

Background: Omega-3 polyunsaturated fatty acids, including docosahexaenoic acid (DHA), have antidepressant and promnemonic functions. The mechanisms of such activities are still elusive and may involve retinoid X receptors (RXRs), transcription factors known to bind DHA in vitro.

Methods: Promnemonic and antidespair activities of acute DHA treatment were tested in BALBcByJ mice using spontaneous alternation and forced swim test, respectively.