Structural plasticity in the rat supraoptic nucleus during gestation, post-partum lactation and suckling-induced pseudogestation and lactation

1987 ◽  
Vol 115 (1) ◽  
pp. 97-NP ◽  
Author(s):  
C. M. Montagnese ◽  
D. A. Poulain ◽  
J.-D. Vincent ◽  
D. T. Theodosis
Keyword(s):  
Supraoptic Nucleus ◽  
Structural Changes ◽  
Post Partum ◽  
Structural Plasticity ◽  
Presynaptic Terminal ◽  
Gonadal Steroids ◽  
Late Gestation ◽  
Continuous Exposure ◽  
Anatomical Changes ◽  
Almost All

ABSTRACT In the supraoptic nucleus (SON) of parturient and lactating rats, large portions of the surface membranes of almost all oxytocinergic neurones are directly juxtaposed with no glial interposition. A significant number of the same neurones are also contacted by the same presynaptic terminal ('double' synapses). Our present observations have revealed that direct appositions between adjacent neurones in the SON increase quite rapidly during the day before parturition. 'Double' synapses also become visible during late gestation, but they appear more progressively. Earlier studies have shown that 1 month after weaning, as in virgin rats, there are again very few appositions and 'double' synapses in the nucleus. We show here that the SON can remain structurally modified, and to the same degree, beyond normal weaning time so long as lactation is prolonged by renewing suckling litters. However, if the mothers are deprived of their pups immediately after birth, neuronal appositions disappear within 2 days and 'double' synapses by 10 days. In non-pregnant primiparous rats, continuous exposure to suckling litters leads to pseudogestation and eventually lactation (in 16–22 days). Examination of the SON in such animals revealed that the oxytocinergic system is already modified by day 12 of dioestrus; during suckling-induced lactation, the anatomical changes are identical to those seen during a normal post-partum lactation. These observations indicate that neither gestation nor suckling alone are indispensable for the anatomical reorganization of the SON apparent at lactation. However, suckling is important in maintainingthe structural changes during prolonged lactation, and can lead to restructuring of the nucleus by inducing pseudogestation and lactation in non-pregnant animals. Taken together with earlier data, these results suggest that hormonal factors, especially oxytocin and gonadal steroids, may act singly or, more probably, in synergy to produce the structural plasticity of the adult oxytocinergic system. J. Endocr. (1987) 115, 97–105

scholarly journals Micro-CT data of early physiological cancellous bone formation in the lumbar spine of female C57BL/6 mice

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Michael Zenzes ◽  
Paul Zaslansky
Keyword(s):  
Cancellous Bone ◽  
Structural Changes ◽  
Bone Growth ◽  
Post Partum ◽  
Three Dimensional ◽  
Lumbar Vertebra ◽  
Tissue Growth ◽  
Micro Ct ◽  
Mineral Density ◽  
Ct Data

AbstractMicro-CT provides critical data for musculoskeletal research, yielding three-dimensional datasets containing distributions of mineral density. Using high-resolution scans, we quantified changes in the fine architecture of bone in the spine of young mice. This data is made available as a reference to physiological cancellous bone growth. The scans (n = 19) depict the extensive structural changes typical for female C57BL/6 mice pups, aged 1-, 3-, 7-, 10- and 14-days post-partum, as they attain the mature geometry. We reveal the micro-morphology down to individual trabeculae in the spine that follow phases of mineral-tissue rearrangement in the growing lumbar vertebra on a micrometer length scale. Phantom data is provided to facilitate mineral density calibration. Conventional histomorphometry matched with our micro-CT data on selected samples confirms the validity and accuracy of our 3D scans. The data may thus serve as a reference for modeling normal bone growth and can be used to benchmark other experiments assessing the effects of biomaterials, tissue growth, healing, and regeneration.

scholarly journals Non-ionotropic NMDA receptor signaling gates bidirectional structural plasticity of dendritic spines

2020 ◽  
Author(s):  
Ivar S. Stein ◽  
Deborah K. Park ◽  
Nicole Claiborne ◽  
Karen Zito
Keyword(s):  
Dendritic Spines ◽  
Structural Changes ◽  
Brain Plasticity ◽  
Structural Plasticity ◽  
Ion Flow ◽  
Neuronal Connections ◽  
Vital Component ◽  
Brain Circuit ◽  
Signaling Components

SUMMARYExperience-dependent refinement of neuronal connections is critically important for brain development and learning. Here we show that ion flow-independent NMDAR signaling is required for the long-term dendritic spine growth that is a vital component of brain circuit plasticity. We found that inhibition of p38 MAPK, shown to be downstream of non-ionotropic NMDAR signaling in LTD and spine shrinkage, blocked LTP-induced spine growth but not LTP. We hypothesized that non-ionotropic NMDAR signaling drives the cytoskeletal changes that support bidirectional spine structural plasticity. Indeed, we found that key signaling components downstream of non-ionotropic NMDAR function in LTD-induced spine shrinkage also are necessary for LTP-induced spine growth. Furthermore, NMDAR conformational signaling with coincident Ca2+ influx is sufficient to drive CaMKII-dependent long-term spine growth, even when Ca2+ is artificially driven through voltage-gated Ca2+ channels. Our results support a model in which non-ionotropic NMDAR signaling gates the bidirectional spine structural changes vital for brain plasticity.

Effect of different diet supplements in the pre- and post-partum period on reproductive performance in the dairy cow

2001 ◽  
Vol 26 (2) ◽  
pp. 313-321 ◽  
Author(s):  
N. H. Gardner ◽  
C. K. Reynolds ◽  
R.H. Phipps ◽  
A.K. Jones ◽  
D.E. Beever
Keyword(s):  
Sugar Beet ◽  
Dairy Cows ◽  
Reproductive Performance ◽  
Post Partum ◽  
Late Gestation ◽  
Diet Supplements ◽  
Group 2 ◽  
The Impact ◽  
Ration Group ◽  
Group 1

AbstractThe study compared the impact of feeding different energy supplements (barley, molassed sugar beet and fat) prior to calving and the effects of feeding supplemental fat post-partum, on subsequent production and reproductive efficiency of dairy cows. Forty-eight multiparous Holstein-Friesian dairy cows were assigned to one of two groups, six weeks prior to expected calving date and fed a grass based total mixed ration according to ME requirements for late gestation. Group 1 was supplemented with barley (B) or molassed sugar beet feed (SB) prior to calving and was then given a high starch lactation ration. Group 2 was supplemented with either fat (F) or no supplement (C) pre partum, and was then given a similar lactation ration as Group 1 but supplemented with fat. Lactation rations were fed through to week-20 post partum and the cows were monitored during this period. Milk yield (P<0.002) and milkfat (P<0.02) production were higher and milk protein concentration (P<0.001) was lower in Group 2. The number of days to first rise in progesterone following parturition was greater (P<0.01) in Group 2. Due to the design of the study, effects of prepartum supplementation were only evaluated within each lactation ration group. Conception rate to first service was higher (P<0.001) for B than SB supplemented cows in Group 1 and higher (P<0.02) for F than C supplemented cows in Group 2. Services per conception were lower (P=0.06) for B than SB supplemented cows in Group 1 and lower (P<0.05) for F than C supplemented cows in Group 2. Overall pregnancy rates and days open were not significantly different between the groups. The data shows that pre-partum nutrition had an important role in determining subsequent fertility. Despite having negative effects early post partum, supplementing with fat did not affect overall reproductive performance but it did improve milk production.

scholarly journals Hepatic thyroid signaling of heat-stressed late pregnant and early lactating cows

2017 ◽  
Vol 234 (2) ◽  
pp. 129-141 ◽  
Author(s):  
Joachim M Weitzel ◽  
Torsten Viergutz ◽  
Dirk Albrecht ◽  
Rupert Bruckmaier ◽  
Marion Schmicke ◽  
...  
Keyword(s):  
Heat Stress ◽  
Energy Intake ◽  
Plasma Cholesterol ◽  
Post Partum ◽  
High Energy ◽  
Late Gestation ◽  
Metabolic Adaptation ◽  
Marker Genes ◽  
Early Lactation ◽  
Proteomics Data

During the transition between late gestation and early lactation, dairy cows experience severe metabolic stress due to the high energy and nutrient requirements of the fetus and the mammary gland. Additional thermal stress that occurs with rising temperatures during the ongoing climate change has further adverse implications on energy intake, metabolism and welfare. The thyroid hormone (TH)-mediated cellular signaling has a pivotal role in regulation of body temperature, energy intake and metabolic adaptation to heat. To distinguish between energy intake and heat stress-related effects, Holstein cows were first kept at thermoneutrality at 15°C followed by exposure to heat stress (HS) at 28°C or pair-feeding (PF) at 15°C for 6 days, in late pregnancy and again in early lactation. Herein, we focused on hepatic metabolic changes associated with alterations in the hypothalamic–pituitary–thyroid axis in HS and PF animals. T3 and T4 levels dropped with HS or PF; however, in HS animals, this decline was more pronounced. Thyroid-stimulating hormone (TSH) levels remain unaffected, while plasma cholesterol concentrations were lower in HS than PF animals. Hepatic marker genes for TH action (THRA, DIO1 and PPARGC1) decreased after HS and were lower compared to PF cows but only post-partum. Proteomics data revealed reduced hepatic amino acid catabolism ante-partum and a shift toward activated beta-oxidation and gluconeogenesis but declined oxidative stress defense post-partum. Thus, liver metabolism of HS and PF cows adapts differently to diminished energy intake both ante-partum and post-partum, and a different TH sensitivity is involved in the regulation of catabolic processes.

scholarly journals P-glycoprotein expression and localization in the rat uterus throughout gestation and labor

Reproduction ◽  
2016 ◽  
pp. 195-204 ◽  
Author(s):  
Qi-Tao Huang ◽  
Oksana Shynlova ◽  
Mark Kibschull ◽  
Mei Zhong ◽  
Yan-Hong Yu ◽  
...  
Keyword(s):  
Cellular Localization ◽  
Post Partum ◽  
Late Gestation ◽  
Mrna Levels ◽  
Microvascular Endothelium ◽  
Rat Uterus ◽  
Pregnant Rats ◽  
Transporter Protein ◽  
P Glycoprotein

Uterine tissues contain the efflux transporter P-glycoprotein (P-gp, encoded by Abcb1a/1b gene), but little is known about how it changes through gestation. Our aim was to investigate the expression profile and cellular localization of P-gp in the pregnant, laboring and post-partum (PP) rat uterus. We propose that during pregnancy the mechanical and hormonal stimuli play a role in regulating myometrial Abcb1a/1b/P-gp. Samples from bilaterally and unilaterally pregnant rats were collected throughout gestation, during labor, and PP (n=4–6/gestational day). RNA and protein were isolated and subjected to quantitative PCR and immunoblotting; P-gp transcript and protein were localized by in situ hybridization and immunohistochemistry. Expression of Abcb1a/1b gene and membrane P-gp protein in uterine tissue (1) increased throughout gestation, peaked at term (GD19-21) and dropped during labor (GD23L); and (2) was upregulated only in gravid but not in empty horn of unilaterally pregnant rats. (3) The drop of Abcb1a/1b mRNA on GD23 was prevented by artificial maintenance of elevated progesterone (P4) levels in late gestation; (4) injection of the P4 receptor antagonist RU486 on GD19 caused a significant decrease in Abcb1 mRNA levels. (5) In situ hybridization and immunohistochemistry indicated that Abcb1/P-gp is absent from myometrium throughout gestation; (6) was expressed exclusively by uterine microvascular endothelium (at early gestation) and luminal epithelium (at mid and late gestation), but was undetectable during labor. In conclusion, ABC transporter protein P-gp in pregnant uterus is hormonally and mechanically regulated. However, its substrate(s) and precise function in these tissues during pregnancy remains to be determined.

scholarly journals Bilateral oophorectomy in a pregnant woman: hormonal profile from late gestation to post-partum: Case report

2005 ◽  
Vol 20 (2) ◽  
pp. 397-401 ◽  
Author(s):  
Paulina Villaseca ◽  
Carmen Campino ◽  
Eveline Oestreicher ◽  
David Mayerson ◽  
María Serón-Ferré ◽  
...  
Keyword(s):  
Case Report ◽  
Pregnant Woman ◽  
Post Partum ◽  
Late Gestation ◽  
Bilateral Oophorectomy ◽  
Hormonal Profile

Structural plasticity in the hypothalamic supraoptic nucleus at lactation affects oxytocin-, but not vasopressin-secreting neurones

Neuroscience ◽  
1986 ◽  
Vol 17 (3) ◽  
pp. 661-678 ◽  
Author(s):  
D.T. Theodosis ◽  
D.B. Chapman ◽  
C. Montagnese ◽  
D.A. Poulain ◽  
J.F. Morris
Keyword(s):  
Supraoptic Nucleus ◽  
Structural Plasticity ◽  
Hypothalamic Supraoptic Nucleus

scholarly journals Pleistocene megafaunal interaction networks became more vulnerable after human arrival

2015 ◽  
Vol 282 (1814) ◽  
pp. 20151367 ◽  
Author(s):  
Mathias M. Pires ◽  
Paul L. Koch ◽  
Richard A. Fariña ◽  
Marcus A. M. de Aguiar ◽  
Sérgio F. dos Reis ◽  
...  
Keyword(s):  
Structural Changes ◽  
Ecological Communities ◽  
Ecological Interactions ◽  
Ecological Data ◽  
The Past ◽  
As Species ◽  
Extinction Events ◽  
Almost All ◽  
The Impact ◽  
Unstable Dynamics

The end of the Pleistocene was marked by the extinction of almost all large land mammals worldwide except in Africa. Although the debate on Pleistocene extinctions has focused on the roles of climate change and humans, the impact of perturbations depends on properties of ecological communities, such as species composition and the organization of ecological interactions. Here, we combined palaeoecological and ecological data, food-web models and community stability analysis to investigate if differences between Pleistocene and modern mammalian assemblages help us understand why the megafauna died out in the Americas while persisting in Africa. We show Pleistocene and modern assemblages share similar network topology, but differences in richness and body size distributions made Pleistocene communities significantly more vulnerable to the effects of human arrival. The structural changes promoted by humans in Pleistocene networks would have increased the likelihood of unstable dynamics, which may favour extinction cascades in communities facing extrinsic perturbations. Our findings suggest that the basic aspects of the organization of ecological communities may have played an important role in major extinction events in the past. Knowledge of community-level properties and their consequences to dynamics may be critical to understand past and future extinctions.

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