1. Endocrine regulation of cognition and neuroplasticity: our pursuit to unveil the complex interaction between hormones, the brain, and behaviour
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Galea, Liisa A.M., Uban, Kristina A., Epp, Jonathan R., Brummelte, Susanne, Barha, Cindy K., Wilson, Wendy L., Lieblich, Stephanie E., and Pawluski, Jodi L.
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Testosterone -- Physiological aspects ,Testosterone -- Research ,Estradiol -- Physiological aspects ,Estradiol -- Research ,Hippocampus (Brain) -- Research ,Neuroplasticity -- Physiological aspects ,Neuroplasticity -- Research ,Psychology and mental health - Abstract
Gonadal and stress hormones modulate neuroplasticity and behaviour. This review focuses on our findings over the past decade on the effects of estrogens and androgens on hippocampal neurogenesis, hippocampus-dependent learning and memory and the effects of reproductive experience in the rodent. Evidence suggests that acute estradiol initially enhances and subsequently suppresses cell proliferation in the dentate gyrus of adult female rodents. Repeated exposure to estradiol modulates hippocampal neurogenesis and cell death in adult female, but not male, rodents while, testosterone and dihydrotestosterone upregulate hippocampal neurogenesis in adult male rodents. Estradiol dose-dependently affects different brain regions involved in working memory (prefrontal cortex, hippocampus), reference memory (hippocampus) and conditioned place preference (amygdala). Pregnancy and motherhood differentially regulate adult hippocampal neurogenesis and spatial working memory in the dam after weaning. These studies and others demonstrate that the female brain responds to steroid hormones differently than the male brain. It is of the upmost importance to investigate the effects on neuroplasticity and behaviour in both the male and the female, particularly when modelling diseases that exhibit sex differences in incidence, etiology or treatment. Keywords: estradiol, neurogenesis, learning and memory, hippocampus, reproductive experience Les hormones de stress et gonadiques modulent la neuroplasticite et le comportement. Cette revue met l'accent sur Ies decouvertes des dernieres decennies quant aux effets des estroge, nes et des androgbnes sur la neurogenese de l'hippocampe, l'apprentissage dependant de l'hippocampe et les effets de l'experience de reproduction chez les rongeurs. Les donnees suggbrent qu'une quantite importante d'oestradiol augmente initialement puis diminue subsequemment la proliferation cellulaire dans le gyrus dente des rongeurs femelles adultes. Une exposition repetee a l'oestradiol module la neurogenese de l'hippocampe et la mort cellulaire chez les rongeurs femelles, mais pas chez les males, alors que la testosterone et la dihydrotestosterone regulent positivement la neurogenese de l'hippocampe chez les rongeurs adultes males. L'oestradiol peut affecter, independamment de la dose, differentes regions du cerveau impliquees dans la memoire de travail (cortex prefrontal et hippocampe), la memoire de reference (hippocampe) et la preference spatiale conditionnee (amygdale). La grossesse et la maternite regulent differemment la neurogenese de l'hippocampe et la memoire de travail chez les rongeurs femelles adultes apres la periode de sevrage. Ces etudes et d'autres demontrent que le cerveau de la femelle reagit differemment aux hormones steroidiennes que le cerveau des males. Il est de la plus grande importance d'en etudier Ies effets sur la neuroplasticite et le comportement autant chez les males que les femelles, particulierement lors de la modelisation de pathologies dont l'incidence, l'etiologie ou le traitement differe selon le sexe. Mots-cles: oestradiol, neurogenese, apprentissage et memoire, hippocampe, experience de reproduction
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- 2008