title: Decrease in neuronal spine density in the postpartum period in the amygdala and bed nucleus of the stria terminalis in rat.
abstract: In pregnancy and the postpartum period, many women have emotional instability and some suffer from depression. The ovarian steroid hormone milieu is markedly changed during these periods, and this hormonal change may be an important cause of peripartum emotional instability. The amygdala is a central region of emotion, and the bed nucleus of the stria terminalis (BNST), which is considered to be the extended amygdala, is also involved in the emotional response. The amygdala and BNST are well characterized as target brain regions for ovarian steroid hormones, and this suggests that the functional response of neurons in these regions to hormonal fluctuation is affected in the peripartum period. In this study, we investigated the neuronal morphology in the central (CeA) and basolateral (BLA) nucleus of the amygdala and BNST on gestational days 15 (G15) (mid-gestation) and 20 (G20) (late gestation) and 4days after delivery (P4) (early postpartum) in rat. Golgi staining showed that the dendritic spine density, and particularly the number of mature mushroom-type spines, in the CeA, BLA and BNST was significantly decreased at P4, compared with G15 and G20 and with virgin females in the estrous phase in the normal estrous cycle (Est). Interestingly, the presence of pups after delivery influenced the spine density in the BNST. The density was significantly decreased with pup presence compared with pup absence at P4, and compared with G15, G20 and Est. These results provide fundamental insights into the neuronal basis underlying emotional instability during pregnancy and postpartum.
authors.affiliation: Department of Obstetrics and Gynecology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Seiki
authors.initials: S
authors.lastname: Matsuo
authors.affiliation: Department of Anatomy and Neurobiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan. Electronic address: matsuken@koto.kpu-m.ac.jp.
authors.forename: Ken Ichi
authors.initials: KI
authors.lastname: Matsuda
authors.affiliation: Ushimado Marine Institute, Graduate School of Natural Science and Technology, Okayama University, Ushimado, Setouchi, Okayama, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Takanami
authors.affiliation: Department of Obstetrics and Gynecology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Taisuke
authors.initials: T
authors.lastname: Mori
authors.affiliation: Department of Anatomy and Neurobiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Tanaka
authors.affiliation: School of Health Sciences, Bukkyo University, Kyoto, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Kawata
authors.affiliation: Department of Obstetrics and Gynecology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Jo
authors.initials: J
authors.lastname: Kitawaki
mesh_terms: D000679:Amygdala / Q000648:ultrastructure*; D000818:Animals; D005260:Female; D009474:Neurons / Q000648:ultrastructure*; D049590:Postpartum Period; D017208:Rats, Wistar; D012686:Septal Nuclei / Q000648:ultrastructure*; D013131:Spine / Q000648:ultrastructure*
keywords: Amygdala; Bed nucleus of the stria terminalis; Postparturition; Pregnancy; Spine density