Dietary retinoic acid affects song maturation and gene expression in the song system of the zebra finch.
Vitamin A, an essential nutrient, is required in its acidic form (retinoic acid) for normal embryogenesis and neuronal development, typically within well-defined concentration ranges. In zebra finches, a songbird species, localized retinoic acid synthesis in the brain is important for the development of song, a learned behavior sharing significant commonalities with speech acquisition in humans. We tested how dietary retinoic acid affects the development of song behavior and the brain's system for song control. Supplemental doses of retinoic acid given to juveniles during the critical period for song learning resulted in more variable or plastic-like songs when the birds reached adulthood, compared to the normal songs of vehicle-fed controls. We also observed that several genes (brinp1, nrgn, rxr-alpha, and sdr2/scdr9) had altered levels of expression in specific nuclei of the song system when comparing the experimental and control diet groups. Interestingly, we found significant correlations between gene expression levels in nuclei of the anterior forebrain pathway (lMAN and area X) and the degree of variability in the recorded songs. We observed, however, no major morphological effects such as changes in the volumes of song nuclei. Overall, our results lend further support to a fundamental role of retinoic acid in song maturation and point to possible molecular pathways associated with this action. The data also demonstrate that dietary content of Vitamin A can affect the maturation of a naturally learned complex behavior.
Neurological Sciences Institute, Oregon Health and Science University, Beaverton, Oregon 97006, USA.
William E
WE
Wood
Christopher R
CR
Olson
Peter V
PV
Lovell
Claudio V
CV
Mello
D000375:Aging / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology*; D003423:Critical Period, Psychological; D046369:Finches / Q000378:metabolism / Q000502:physiology*; D005526:Food, Formulated; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000502:physiology*; D053400:High Vocal Center / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D007858:Learning / Q000187:drug effects / Q000502:physiology; D008297:Male; D009419:Nerve Tissue Proteins / Q000235:genetics; D009434:Neural Pathways / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D020890:Neuregulin-1 / Q000235:genetics; D016548:Prosencephalon / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics; D047490:Retinoid X Receptor alpha / Q000235:genetics; D013018:Sound Spectrography; D014212:Tretinoin / Q000378:metabolism* / Q000494:pharmacology; D014801:Vitamin A / Q000378:metabolism; D014828:Vocalization, Animal / Q000187:drug effects / Q000502:physiology*
D009419:Nerve Tissue Proteins; D020890:Neuregulin-1; D011956:Receptors, Cell Surface; D047490:Retinoid X Receptor alpha; C478768:stromal cell-derived receptor 2, mouse; D014801:Vitamin A; D014212:Tretinoin