title: Epigenetic modulation of the developing serotonergic neurotransmission in the semi-precocial rodent Octodon degus.
abstract: Environmental influences during early life periods, particularly those provided by the mother or parents, are generally considered to have a strong impact on the development of brain and behaviour of the offspring. In the semi-precocial South American species Octodon degus, a rodent becoming increasingly popular in different laboratory research fields, the present study aimed to examine the consequences of the disturbance of the parent-offspring interaction induced by parental separation on the serotonergic neurotransmission. Based on a quantitative neurochemical approach using brain homogenates obtained from cortical regions and the hippocampus our results revealed that (i) the tissue levels of serotonin and 5-hydroxyindoleacetic acid showed in both sexes a moderate, around two-fold increase until adulthood, indicating relatively matured cortical and hippocampal serotonergic systems at birth. In addition, we found an age-, region- and sex-specific pattern of changes in the serotonergic system induced by (ii) an acute stress challenge early in life (1-h parental separation at the postnatal day 3, 8, 14 or 21) with the most pronounced effects at earlier ages (between postnatal days 3 and 14) in the female cortex and (iii) repeated stress exposure (1h daily) during the first 3 weeks of life affecting cortical regions of both sexes. Taken together, these data indicate that early life stress (i.e. parental separation) influences the developing serotonergic system in the semi-precocial O. degus, even if the brain is relatively well matured at the early stages of postnatal development.
authors.affiliation: Otto von Guericke University Magdeburg, Institute of Biology, Department of Zoology/Developmental Neurobiology, Germany.
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Jezierski
authors.forename: Katharina
authors.initials: K
authors.lastname: Braun
authors.forename: Michael
authors.initials: M
authors.lastname: Gruss
mesh_terms: D000367:Age Factors; D000375:Aging / Q000502:physiology; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D001921:Brain / Q000254:growth & development* / Q000378:metabolism; D002540:Cerebral Cortex / Q000254:growth & development / Q000378:metabolism; D004777:Environment; D044127:Epigenesis, Genetic / Q000235:genetics*; D005260:Female; D008297:Male; D008426:Maternal Deprivation; D009434:Neural Pathways / Q000254:growth & development / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D009769:Object Attachment; D046329:Octodon / Q000235:genetics* / Q000254:growth & development*; D012701:Serotonin / Q000378:metabolism*; D012727:Sex Characteristics; D012919:Social Behavior; D013315:Stress, Psychological / Q000235:genetics; D009435:Synaptic Transmission / Q000235:genetics*
chemical_list: D012701:Serotonin