Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
With the growing use of selective serotonin reuptake inhibitor medications (SSRIs) for the treatment of depression during the perinatal period, questions have been raised about the longterm impact of these medications on development. We aimed to investigate how developmental SSRI exposure may alter affect-related behaviors and associated molecular processes in offspring using a rodent model of maternal stress and depression. For this purpose, prenatally stressed or non-stressed male offspring were exposed to fluoxetine (5 mg/kg/day) or vehicle, via lactation, until weaning. Primary results show that postnatal fluoxetine exposure differentially altered anxiety-like behavior by increasing anxiety in non-stressed offspring and decreasing anxiety in prenatally stressed offspring. In the hippocampus, developmental fluoxetine exposure decreased BDNF IV and TrkB mRNA expression. Prenatal stress alone also decreased escape behaviors and decreased hippocampal BDNF IV mRNA expression. These data provide important evidence for the long-term programming effects of early-life exposure to SSRIs on brain and behavior.
ISSN: 0012-1630

hal-01305478
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01305478
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01305478/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01305478/file/Developmental%20SSRIs%2C%20anxiety%20and%20BDNF_accepted.pdf
DOI : 10.1002/dev.21385

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
Neurogenesis initiates during early development and it continues through later developmental stages and in adult animals to enable expansion, remodeling, and homeostasis of the nervous system. The generation of nerve cells has been analyzed in detail in few bilaterian model organisms, leaving open many questions about the evolution of this process. As the sister group to bilaterians, cnidarians occupy an informative phylogenetic position to address the early evolution of cellular and molecular aspects of neurogenesis and to understand common principles of neural development. Here we review studies in several cnidarian model systems that have revealed significant similarities and interesting differences compared to neurogenesis in bilaterian species, and between different cnidarian taxa. Cnidarian neurogenesis is currently best understood in the sea anemone Nematostella vectensis, where it includes epithelial neural progenitor cells that express transcription factors of the soxB and atonal families. Notch signaling regulates the number of these neural progenitor cells, achaete-scute and dmrt genes are required for their further development and Wnt and BMP signaling appear to be involved in the patterning of the nervous system. In contrast to many vertebrates and Drosophila, cnidarians have a high capacity to generate neurons throughout their lifetime and during regeneration. Utilizing this feature of cnidarian biology will likely allow gaining new insights into the similarities and differences of embryonic and regenerative neurogenesis. The use of different cnidarian model systems and their expanding experimental toolkits will thus continue to provide a better understanding of evolutionary and developmental aspects of nervous system formation.
ISSN: 1759-7692

Droits : http://creativecommons.org/licenses/by-nc/
hal-01405097
http://hal.upmc.fr/hal-01405097
http://hal.upmc.fr/hal-01405097/document
http://hal.upmc.fr/hal-01405097/file/Rentzsch_et_al-2016-Wiley_Interdisciplinary_Reviews__Developmental_Biology.pdf
DOI : 10.1002/wdev.257

Éditeur(s) : HAL CCSD
Résumé : International audience
Several forthcoming wireless telecommunication systems will use electromagnetic frequencies at millimeter waves (MMWs), and technologies developed around the 60-GHz band will soon know a widespread distribution. Free nerve endings within the skin have been suggested to be the targets of MMW therapy which has been used in the former Soviet Union. So far, no studies have assessed the impact of MMW exposure on neuronal metabolism. Here, we investigated the effects of a 24-h MMW exposure at 60.4 GHz, with an incident power density (IPD) of 5 mW/cm2, on the dopaminergic turnover of NGF-treated PC12 cells. After MMW exposure, both intracellular and extracellular contents of dopamine (DA) and 3,4-dihydroxyphenylacetic acid (DOPAC) were studied using high performance liquid chromatography. Impact of exposure on the dopamine transporter (DAT) expression was also assessed by immunocytochemistry. We analyzed the dopamine turnover by assessing the ratio of DOPAC to DA, and measuring DOPAC accumulation in the medium. Neither dopamine turnover nor DAT protein expression level were impacted by MMW exposure. However, extracellular accumulation of DOPAC was found to be slightly increased, but not significantly. This result was related to the thermal effect, and overall, no evidence of non-thermal effects of MMW exposure were observed on dopamine metabolism. © 2017 The Author. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.
Journal of Radiation Research

hal-01580502
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01580502
DOI : 10.1093/jrr/rrx004
PUBMED : 28339776

Éditeur(s) : HAL CCSD Elsevier - International Brain Research Organization
Résumé : International audience
Women are more likely to develop depression during childbearing years with up to 20% of women suffering from depression during pregnancy and in the postpartum period. Increased prevalence of depression during the perinatal period has resulted in frequent selective serotonin reuptake inhibitor (SSRI) antidepressant treatment; however the effects of such medications on the maternal brain remain limited. Therefore, the aim of the present study is to investigate the effects of the SSRI medication, fluoxetine, on neurobiological differences in the maternal brain. To model aspects of maternal depression, gestational stress was used. Sprague-Dawley rat dams were exposed to either gestational stress and/or fluoxetine (5mg/kg/day) to form the following four groups: 1. Control+Vehicle, 2. Stress+Vehicle, 3. Control+Fluoxetine 4. Stress+Fluoxetine. At weaning maternal brains were collected. Main findings show that gestational stress alone increased synaptophysin and serotonin metabolism in the CG2 region of the cortex while fluoxetine treatment after stress normalized these effects. In the hippocampus, fluoxetine treatment, regardless of gestational stress exposure, decreased both global measures of methylation in the dentate gyrus, as measured by Dnmt3a immunoreactivity, as well as serotonin metabolism. No further changes in synaptophysin, PSD-95, or Dnmt3a immunoreactivity were seen in the cortical or hippocampal areas investigated. These findings show that gestational stress and SSRI medication affect the neurobiology of the maternal brain in a region-specific manner. This work adds to a much needed area of research aimed at understanding neurobiological changes associated with maternal depression and the role of SSRI treatment in altering these changes in the female brain
ISSN: 0306-4522

hal-01301509
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01301509
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01301509/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01301509/file/Gestational%20stress%20and%20fluoxetine%20treatment%20%281%29.pdf
PUBMED : 27060483