Effects of retinoic acids on the dendritic morphology of cultured hippocampal neurons.
Vitamin A-derived retinoic acids (RAs) are known to exert a variety of biological actions, including modulatory effects on cell differentiation and apoptosis. A recent study has demonstrated that 13-cis-RA and all-trans-RA suppressed neurogenesis in the dentate gyrus of the hippocampus in adult mice. The present experiments were performed to see whether 13-cis-RA and all-trans-RA could alter the dendritic morphology of cultured hippocampal neurons via RA receptors: retinoic acid receptor (RAR) and retinoid X receptor (RXR). High doses of 13-cis-RA and all-trans-RA exerted a negative effect on the cultured hippocampal neurons, while a low dose of 13-cis-RA but not all-trans-RA caused a positive effect. The negative changes induced by 13-cis-RA and all-trans-RA were antagonized by RXR antagonists and RAR antagonists, respectively. The positive changes induced by a low dose of 13-cis-RA were blocked by both RXR antagonists and RAR antagonists. These results suggest that RAs at high concentrations cause a negative effect on the dendritic morphology of cultured hippocampal neurons through RA receptors, while RAs at low concentrations exert a positive influence on cultured hippocampal neurons.
Liu
Ying
Y
Department of Neuroscience, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan.
Kagechika
Hiroyuki
H
Ishikawa
Junko
J
Hirano
Hitoshi
H
Matsukuma
Satoshi
S
Tanaka
Kazuko
K
Nakamura
Shoji
S
D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D003712:Dendrites / Q000187:drug effects* / Q000473:pathology; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects* / Q000473:pathology; D015474:Isotretinoin / Q000494:pharmacology / Q000633:toxicity; D009474:Neurons / Q000187:drug effects / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018168:Receptors, Retinoic Acid / Q000819:agonists; D012176:Retinoids / Q000494:pharmacology / Q000633:toxicity; D014212:Tretinoin / Q000494:pharmacology* / Q000633:toxicity
D018168:Receptors, Retinoic Acid; D012176:Retinoids; D014212:Tretinoin; D015474:Isotretinoin