title: Plasma hormonal profiles and dendritic spine density and morphology in the hippocampal CA1 stratum radiatum, evidenced by light microscopy, of virgin and postpartum female rats.
abstract: Successful reproduction requires that changes in plasma follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), oxytocin (OT), estrogen (E(2)) and progesterone (P(4)) occur together with the display of maternal behaviors. Ovarian steroids and environmental stimuli can affect the dendritic spines in the rat hippocampus. Here, studying Wistar rats, it is described: (a) the sequential and concomitant changes in the hormonal profile of females at postpartum days (PP) 4, 8, 12, 16, 20 and 24, comparing to estrous cycle referential values; (b) the dendritic spine density in the stratum radiatum of CA1 (CA1-SR) Golgi-impregnated neurons in virgin females across the estrous cycle and in multiparous age-matched ones; and (c) the proportion of different types of spines in the CA1-SR of virgin and postpartum females, both in diestrus. Plasma levels of gonadotrophins and ovarian hormones remained low along PP while LH increased and PRL decreased near the end of the lactating period. The lowest dendritic spine density was found in virgin females in estrus when compared to diestrus and proestrus phases or to postpartum females in diestrus (p<0.03). Other comparisons among groups were not statistically significant (p>0.4). There were no differences in the proportions of the different spine types in nulliparous and postpartum females (p>0.2). Results suggest that medium layer CA1-SR spines undergo rapid modifications in Wistar females across the estrous cycle (not quite comparable to Sprague-Dawley data or to hormonal substitutive therapy following ovariectomy), but persistent effects of motherhood on dendritic spine density and morphology were not found in this area.
authors.affiliation: Departament of Physiological Sciences, Universidade Federal de Ciências da Saúde de Porto Alegre, Sarmento Leite 245, Porto Alegre, 90050-170 RS, Brazil.
authors.forename: Janaína
authors.initials: J
authors.lastname: Brusco
authors.forename: Raul
authors.initials: R
authors.lastname: Wittmann
authors.forename: Márcia S
authors.initials: MS
authors.lastname: de Azevedo
authors.forename: Aldo B
authors.initials: AB
authors.lastname: Lucion
authors.forename: Celso R
authors.initials: CR
authors.lastname: Franci
authors.forename: Márcia
authors.initials: M
authors.lastname: Giovenardi
authors.forename: Alberto A
authors.initials: AA
authors.lastname: Rasia-Filho
mesh_terms: D000818:Animals; D003712:Dendrites / Q000145:classification / Q000502:physiology* / Q000648:ultrastructure; D030762:Estrous Cycle / Q000097:blood; D005260:Female; D006624:Hippocampus / Q000166:cytology* / Q000502:physiology; D006728:Hormones / Q000097:blood*; D007091:Image Processing, Computer-Assisted; D009474:Neurons / Q000166:cytology*; D049590:Postpartum Period / Q000097:blood* / Q000502:physiology*; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D016622:Silver Staining / Q000379:methods; D013997:Time Factors
chemical_list: D006728:Hormones