Micro-finite element simulation of trabecular-bone post-yield behaviour – effects of material model,element size and type

Micro-finite element (micro-FE) analysis became a standard tool for the evaluation of trabecular bone mechanical properties. The accuracy of micro-FE models for linear analyses is well established. However, the accuracy of recently developed nonlinear micro-FE models for simulations of trabecular bone failure is not known. In this study, a trabecular bone specimen was compressed beyond the apparent yield point. The experiment was simulated using different micro-FE meshes with different element sizes and types, and material models based on cortical bone. The results from the simulations were compared with experimental results to study the effects of the different element and material models. It was found that a decrease in element size from 80 to 40 μm had little effect on predicted post-yield behaviour. Element type and material model had significant effects. Nevertheless, none of the established material models for cortical bone were able to predict the typical descent in the load-displacement curve seen during compression of trabecular bone.     

Opposing effects of two osmolytes – trehalose and glycerol – on thermal inactivation of rabbit muscle 6-phosphofructo-1-kinase

Trehalose and glycerol are known as good stabilizers of function and structure of several macromolecules against stress conditions. We previously reported that they have comparable effectiveness on protecting two yeast cytosolic enzymes against thermal inactivation. However, enzyme protection has always been associated to a decrease in catalytic activity at the stabilizing conditions i.e., the presence of the protective molecule. In the present study we tested trehalose and glycerol on thermal protection of the mammalian cytosolic enzyme phosphofructokinase. Here we found that trehalose was able to protect phosphofructokinase against thermal inactivation as well as to promote an activation of its catalytic activity. The enzyme incubated in the presence of 1 M trehalose did not present any significant inactivation within 2 h of incubation at 50 C, contrasting to control experiments where the enzyme was fully inactivated during the same period exhibiting a t_0.5 for thermal inactivation of 56± 5 min. On the other hand, enzyme incubated in the presence of 37.5% (v/v) glycerol was not protected against incubation at 50 C. Indeed, when phosphofructokinase was incubated for 45 min at 50 C in the presence of lower concentrations of glycerol (7.5–25%, v/v), the remaining activity was 2–4 times lower than control. These data show that the compatibility of effects previously shown for trehalose and glycerol with some yeast cytosolic enzymes can not be extended to all globular enzyme system. In the case of phosphofructokinase, we believe that its property of shifting between several different complex oligomers configurations can be influenced by the physicochemical properties of the stabilizing molecules. (Mol Cell Biochem 269: 203)     

The effects of background colouration and α-MSH treatment on melanophore frequency in winter flounder,Pleuronectes americanus

Winter flounder, Pleuronectes americanus, adapting to black or white backgrounds display significant increase and decline respectively in the number of visible epidermal melanophores over periods up to 8 weeks or longer. This contrasts with a stability in the number of visible dermal melanophores during the same periods of exposure to each background. Flounders treated with -melanophore stimulating hormone exhibited an enhanced rate of increase in number of visible epidermal melanophores when the background was changed from white to black, whereas white-adapted flounder treated with -melanophore stimulating hormone without background change did not manifest any such increase in number of epidermal melanophores. Flounder treated with -melanophore stimulating hormone after transfer from black to white displayed a similar initial decline in visible epidermal melanophore number as in control fish, but the final decline was significantly attenuated. Thus -melanophore stimulating hormone, which has no apparent influence on melanosome dispersion in this species, may have a limited morphological melanophore regulatory role which is discussed in relation to possible antagonistic and synergistic factors that could influence melanogenesis and visible melanophore numbers.Abbreviations DMI dermal melanophore index - EMI epidermal melanophore index - LSD least significant difference - MCH melanosome concentrating hormone - MIF melanogenesis inhibiting factor - MSF melanogenesis stimulating factor - MSH melanophore stimulating hormone     

Eutrophication of the salt valley reservoirs, 1968–73 I. The effects of eutrophication on standing crop and composition of phytoplankton

A study was carried out over a period of six years to determine the effects of eutrophication upon standing crop and composition of the phytoplankton in four recently constructed flood control reservoirs in Nebraska. Water samples collected weekly during June, July, and August from 1968–73 were analyzed for chlorophyll a, phytoplankton composition, and phytoplankton abundance. Total volume of phytoplankton was calculated from appropriate dimensions and formulae. Inorganic turbidity in one reservoir was an important factor regulating the size and composition of the phytoplankton standing crop. In that reservoir diatoms were the most important component of the phytoplankton community during those years in which inorganic turbidity was greatest. When inorganic turbidity declined, blue-green algae became dominant.In the clear-water reservoirs chlorophyll a, phytoplankton number, and phytoplankton volume were significantly correlated with reservoir age, with the oldest containing chlorophyll a concentrations up to 247 mg/m³ and mean phytoplankton volumes up to 329 mm³/l, values sufficient to place it in the hypereutrophic category. The reservoirs had 2–6 times more chlorophyll a present at the end of the study than at the beginning, with the increase being greatest in the newest reservoir. Phytoplankton volume was significantly correlated with chlorophyll a in all the reservoirs.Blue-green algae quickly became established as community dominants in the reservoirs, making up over 80 percent of the phytoplankton volume in the newest reservoir by the second year of its existence. In the other clear-water reservoirs, blue-greens usually constituted over 95 percent of the total phytoplankton volume in summer. three genera, Microcystis, Aphanizomenon, and Anabaena, were responsible for virtually the entire standing crop of blue-greens in all the reservoirs.     

pH buffering in acidic soils developed under Picea abies and Quercus robur – effects of soil organic matter, adsorbed cations and soil solution ionic strength

Soil solution chemistry, soil acidity andcomposition of adsorbed cations were determinedin two soil profiles developed under a mixedspruce (Picea abies and Piceasitchensis) stand and in one soil profiledeveloped under an oak (Quercus robur)stand. Soils under spruce were classified asSpodosols and soils under oak were classifiedas Inceptisols. All profiles were developed inthe same parent material; a Saahlian sandy tillcontaining less than 2% clay. In the mineralsoil, the contribution from mineral surfaces tothe total cation-exchange capacity (CEC_t)was estimated to be less than 3%. Soilsolution pH and the percent base saturation ofCEC_t [%BS = 100 (2Ca + 2Mg + Na + K)CEC_t ^–1] were substantially lower inthe upper 35–40 cm of the two Spodosols, ascompared to the Inceptisol. The total amount ofsoil adsorbed base cations (BC) did not differamong the three profiles on an area basis downto 1 m soil depth. Thus, soil acidification ofCEC_t due to net losses of BC could notexplain differences in soil pH and %BS amongthe soil profiles. A weak acid analogue, takingthe pH-effect of metal complexation intoconsideration, combined with soil solutionionic strength as a covariate, could describeboth the pH variation by depth within soilprofiles and pH differences between theInceptisol and the two Spodosol profiles. Ourresults confirm and extend earlier findingsfrom O and E horizons of Spodosols that theextent to which organic acid groups react withAl minerals to form Al-SOM complexes is a majorpH-buffering process in acidic forest soils. Wesuggest that an increasing Al-saturation of SOMis the major reason for the widely observed pHincrease by depth in acidic forest soils with apH less than approximately 4.5. Our resultsstrongly imply that changes in mass of SOM, theionic strength in soil solution and therelative composition of soil adsorbed Al and Hneed to be considered when the causality behindchanges in pH and base saturation isinvestigated.     

The effects of repeated administration of camphor-crataegus berry extract combination on blood pressure and on attentional performance – A randomized,placebo-controlled,double-blind study

The present study investigated the effects of repeated administration of Korodin^®, a combination of camphor and crataegus berry extract, on blood pressure and attentional functioning. This study was conducted based on a randomized, placebo-controlled, double-blind design. 54 persons participated (33 female, 21 male) with a mean age of 24.3 years. Blood pressure and body mass index were in the normal range. Participants received 20 drops of either Korodin^® or a placebo for four times with interjacent time intervals of about 10 min. Blood pressure was measured sphygmomanometrically before and after each administration. Attentional performance was quantified by using two paper-and-pencil tests, the d2 Test of Attention and Digit Symbol Test.Greater increases in blood pressure occurred after the four Korodin^® administrations in comparison to the four placebo administrations. The performance in two parameters of d2 Test of Attention was consistently superior after the intake of Korodin^®. The excellent tolerability and safety of Korodin^®, even after a total consumption of 80 drops, was confirmed.     

Study on the toxic effects of pharmaceutical drugs – Norfloxacin using Pangasius Sp. fish model and its mitigation using Artemisia pallens

In the present times, international environmental regulations are earnest on the risk caused by the release of toxins into the aquatic biome; predominantly the water bodies. The discharge of active pharmaceutical compounds in the environment is found to have fatal effects on the biota of the oceanic ecosystem. The key objective of the study is to scrutinize the toxicological reprecussion of norfloxacin, an antibiotic used to treat bacterial infections which being prescribed as human medicine was found to have the possibility to pollute the water resource and sediments via input from sewage treatment plants. To explicate this study, Pangasius sp. The fish model was tested with the drug and its effects were studied thereby. This study focuses on the oxidative stress parameters which can be probed by virtue of biological markers, hormonal changes after acclimatizing the fish at suitable LC₅₀ concentration of norfloxacin and the tissue damage assessed using histopathological analysis. The oxidative stress parameters were procured by analysis of biological markers such as Lipid peroxides, Conjugated diene, Protein sulfhydryl, Protein Carbonyl, Inorganic phosphorus, Superoxide dismutase and Catalase. The hormonal changes were studied concerning the changes in cortisol levels, which are influenced by oxidative stress. The mitigation effect and hepato-protective activity of Artemisia pallens were also studied with Norfloxacin treated fish, to imbibe the bioremediation as a strategic upfront for remediation.     

Interactions of intrinsically disordered Thellungiella salsuginea dehydrins TsDHN-1 and TsDHN-2 with membranes - synergistic effects of lipid composition and temperature on secondary structure

Dehydrins are intrinsically disordered (unstructured) proteins that are expressed in plants experiencing stressful conditions such as drought or low temperature. Dehydrins are typically found in the cytosol and nucleus, but also associate with chloroplasts, mitochondria, and the plasma membrane. Although their role is not completely understood, it has been suggested that they stabilize proteins or membrane structures during environmental stress, the latter association mediated by formation of amphipathic α-helices by conserved regions called the K-segments. Thellungiella salsuginea is a crucifer that thrives in the Canadian sub-Arctic (Yukon Territory) where it grows on saline-rich soils and experiences periods of both extreme cold and drought. We have cloned and expressed in Escherichia coli two dehydrins from this plant, denoted TsDHN-1 (acidic) and TsDHN-2 (basic). Here, we show using transmission-Fourier transform infrared (FTIR) spectroscopy that ordered secondary structure is induced and stabilized in these proteins by association with large unilamellar vesicles emulating the lipid compositions of plant plasma and organellar membranes. Moreover, this induced folding is enhanced at low temperatures, lending credence to the hypothesis that dehydrins stabilize plant outer and organellar membranes in conditions of cold.     

Effects of corticosteroid treatment on airway inflammation, mechanics, and hyperpolarized ³He magnetic resonance imaging in an allergic mouse model

The purpose of this study was to assess the effects of corticosteroid therapy on a murine model of allergic asthma using hyperpolarized (3)He magnetic resonance imaging (MRI) and respiratory mechanics measurements before, during, and after methacholine (MCh) challenge. Three groups of mice were prepared, consisting of ovalbumin sensitized/ovalbumin challenged (Ova/Ova, n = 5), Ova/Ova challenged but treated with the corticosteroid dexamethasone (Ova/Ova+Dex, n = 3), and ovalbumin-sensitized/saline-challenged (Ova/PBS, n = 4) control animals. All mice underwent baseline 3D (3)He MRI, then received a MCh challenge while 10 2D (3)He MR images were acquired for 2 min, followed by post-MCh 3D (3)He MRI. Identically treated groups underwent respiratory mechanics evaluation (n = 4/group) and inflammatory cell counts (n = 4/group). Ova/Ova animals exhibited predominantly large whole lobar defects at baseline, with significantly higher ventilation defect percentage (VDP = 19 ± 4%) than Ova/PBS (+2 ± 1%, P = 0.01) animals. Such baseline defects were suppressed by dexamethasone (0%, P = 0.009). In the Ova/Ova group, MCh challenge increased VDP on both 2D (+30 ± 8%) and 3D MRI scans (+14 ± 2%). MCh-induced VDP changes were diminished in Ova/Ova+Dex animals on both 2D (+21 ± 9%, P = 0.63) and 3D scans (+7 ± 2%, P = 0.11) and also in Ova/PBS animals on 2D (+6 ± 3%, P = 0.07) and 3D (+4 ± 1%, P = 0.01) scans. Because MCh challenge caused near complete cessation of ventilation in four of five Ova/Ova animals, even as large airways remained patent, this implies that small airway (<188 μm) obstruction predominates in this model. This corresponds with respiratory mechanics observations that MCh challenge significantly increases elastance and tissue damping but only modestly affects Newtonian airway resistance.     

Acute toxicity of ammonia and its effects on the haemolymph osmolality, ammonia-N, pH and ionic composition of early juvenile mud crabs, Scylla serrata (Forskål)

The current study was conducted to determine the LC(50) value of ammonia-N as well as the effects of acute exposure to elevated ammonia on the haemolymph osmolality, ionic composition, ammonia-N and pH levels of early juvenile mud crabs, Scylla serrata. The results show that early S. serrata juveniles have a high 96-h LC(50) value of 95.35 mg/L ammonia-N (6.81 mg/L NH(3)-N) or 6.80 mmol/L total ammonia-N (0.486 mmol/L NH(3)-N). Following a 96-h exposure, the haemolymph osmolality and K(+) levels of the surviving crabs remained unaltered (p>0.05) at all ammonia-N concentrations, while the haemolymph Na(+) and Ca(2+) were significantly lower (p<0.05) for the crabs exposed to 5.710 and 7.138 mmol/L ammonia-N. While the haemolymph ammonia-N levels of the crabs significantly increased (p<0.01) with increasing external ammonia-N concentrations, the haemolymph ammonia-N of the crabs remained below the external ammonia-N concentrations. The haemolymph pH of the crabs significantly increased between 0.714 and 4.283 mmol/L total ammonia-N. However, at 5.710 mmol/L total ammonia-N the haemolymph pH dropped and was not significantly different (p>0.05) from that of the control crabs which coincided with significantly lower (p<0.05) haemolymph Na(+) and Ca(2+) levels. These physiological responses may explain the high ammonia tolerance of early S. serrata juveniles.     

The effects of 10 weeks of resistance training combined with β-alanine supplementation on whole body strength, force production, muscular endurance and body composition

Carnosine (Carn) occurs in high concentrations in skeletal muscle is a potent physico-chemical buffer of H⁺ over the physiological range. Recent research has demonstrated that 6.4 g.day⁻¹ of β-alanine (β-ala) can significantly increase skeletal muscle Carn concentrations (M-[Carn]) whilst the resultant change in buffering capacity has been shown to be paralleled by significant improvements in anaerobic and aerobic measures of exercise performance. Muscle carnosine increase has also been linked to increased work done during resistance training. Prior research has suggested that strength training may also increase M-[Carn] although this is disputed by other studies. The aim of this investigation is to assess the effect of 10 weeks resistance training on M-[Carn], and, secondly, to investigate if increased M-[Carn] brought about through β-ala supplementation had a positive effect on training responses. Twenty-six Vietnamese sports science students completed the study. The subjects completed a 10-week resistance-training program whilst consuming 6.4 g.day⁻¹ of β-ala (β-ALG) or a matched dose of a placebo (PLG). Subjects were assessed prior to and after training for whole body strength, isokinetic force production, muscular endurance, body composition. β-Alanine supplemented subjects increased M-[Carn] by 12.81 ± 7.97 mmol.kg⁻¹ dry muscle whilst there was no change in PLG subjects. There was no significant effect of β-ala supplementation on any of the exercise parameters measured, mass or % body fat. In conclusion, 10 weeks of resistance training alone did not change M-[Carn].     

Comparative evaluation of the effects of treatment with tocilizumab and TNF-α inhibitors on serum hepcidin,anemia response and disease activity in rheumatoid arthritis patients

Introduction

Anemia of inflammation (AI) is a common complication of rheumatoid arthritis (RA) and has a negative impact on RA symptoms and quality of life. Upregulation of hepcidin by inflammatory cytokines has been implicated in AI. In this study, we evaluated and compared the effects of IL-6 and TNF-α blocking therapies on anemia, disease activity, and iron-related parameters including serum hepcidin in RA patients.

Methods

Patients (n = 93) were treated with an anti-IL-6 receptor antibody (tocilizumab) or TNF-α inhibitors for 16 weeks. Major disease activity indicators and iron-related parameters including serum hepcidin-25 were monitored before and 2, 4, 8, and 16 weeks after the initiation of treatment. Effects of tocilizumab and infliximab (anti-TNF-α antibody) on cytokine-induced hepcidin expression in hepatoma cells were analyzed by quantitative real-time PCR.

Results

Anemia at base line was present in 66% of patients. Baseline serum hepcidin-25 levels were correlated positively with serum ferritin, C-reactive protein (CRP), vascular endothelial growth factor (VEGF) levels and Disease Activity Score 28 (DAS28). Significant improvements in anemia and disease activity, and reductions in serum hepcidin-25 levels were observed within 2 weeks in both groups, and these effects were more pronounced in the tocilizumab group than in the TNF-α inhibitors group. Serum hepcidin-25 reduction by the TNF-α inhibitor therapy was accompanied by a decrease in serum IL-6, suggesting that the effect of TNF-α on the induction of hepcidin-25 was indirect. In in vitro experiments, stimulation with the cytokine combination of IL-6+TNF-α induced weaker hepcidin expression than did with IL-6 alone, and this induction was completely suppressed by tocilizumab but not by infliximab.

Conclusions

Hepcidin-mediated iron metabolism may contribute to the pathogenesis of RA-related anemia. In our cohort, tocilizumab was more effective than TNF-α inhibitors for improving anemia and normalizing iron metabolism in RA patients by inhibiting hepcidin production.     

Plane of nutrition during the rearing phase for replacement ewes of four genotypes: I – effects on growth and development,and on ovulation rate at first joining

Plane of nutrition (PN) offered to ewe replacements during the rearing phase (8 to 17 months) affects BW at joining and may affect reproductive performance when joined at ~19 months. The effects of PN offered to ewe replacements during their first winter (winter_1) and second summer (summer_2) were evaluated over 3 consecutive years, using 287 spring-born ewe lambs, representing four genotypes (Belclare (Bel), Charmoise×Scottish Blackface (C×SBF), Bel×SBF (Bel×SBF), Bel×SBF that were heterozygous either FecG^H or FecX^G mutations that increase ovulation rate (OR) (BelMG×SBF)). During extended (deferred) grazing in winter_1 (November to March) the lambs were offered herbage DM allowances (HA) of 0.75 (L) or 1.75 (H) kg/day. During summer_2 (March to August) the replacements were set stocked to maintain sward heights of 4 (L) or 6 (H) cm, thus yielding a 2×2 factorial design for the nutrition treatments (71 to 73 animals/treatment). Increasing HA during winter_1, and residual sward height during summer_2, increased (P<0.001) BW and body size at joining (19 months) but had no effect (P>0.05) on OR. Mean BW at joining was 53.3, 56.8, 56.6 and 61.7 (SEM 0.74) kg for ewes offered the LL, LH, HL and HH treatments, respectively. Mean OR of C×SBF and BelMG×SBF differed (P<0.001) from that of Bel×SBF by −0.58 and +0.47, respectively. Correlations between linear measurements (LMs) of body size and BW at 7, 12 and 17 months were all positive and significant (P<0.001). The precision of the set of LMs as a predictor of BW at joining improved with age (R² 0.46, 0.54 and 0.74 at 7, 12 and 17 months) but BW at a given age was a better predictor at all age time points. Chest girth was the best predictor, among the LMs, of BW at joining and its explanatory power increased with age. Equations developed using LMs at 7, 12 or 17 months, to predict BW at joining exhibited biases of −2.1, −1.5 and +0.9 kg, respectively. It is concluded that whilst altering PN during the rearing phase changed BW by 16% it had no effect on OR. There was no interaction (P>0.05) between the PN offered during winter_1 and summer_2, or PN and ewe genotype for BW at joining or OR. LMs, either at 7, 12 or 17 months of age, are useful predictors of BW at joining.     

Long-term effects of oxandrolone treatment in childhood on neurocognition,quality of life and social–emotional functioning in young adults with Turner syndrome

Turner syndrome (TS) is the result of (partial) absence of one X-chromosome. Besides short stature, gonadal dysgenesis and other physical aspects, TS women have typical psychological features. Since psychological effects of androgen exposure in childhood probably are long-lasting, we explored long-term psychological functioning after oxandrolone (Ox) therapy during childhood in adults with TS in terms of neurocognition, quality of life and social–emotional functioning. During the initial study, girls were treated with growth hormone (GH) combined with placebo (Pl), Ox 0.03 mg/kg/day, or Ox 0.06 mg/kg/day from the age of eight, and estrogen from the age of twelve. Sixty-eight women participated in the current double-blinded follow-up study (mean age 24.0 years, mean time since stopping GH/Ox 8.7 years). We found no effects on neurocognition. Concerning quality of life women treated with Ox had higher anxiety levels (STAI 37.4 ± 8.4 vs 31.8 ± 5.0, p = 0.002) and higher scores on the depression subscale of the SCL-90-R (25.7 ± 10.7 vs 20.5 ± 4.7, p = 0.01). Regarding social–emotional functioning, emotion perception for fearful faces was lower in the Ox-treated patients, without effect on interpersonal behavior. Our exploratory study is the first to suggest that androgen treatment in adolescence possibly has long-term effects on adult quality of life and social–emotional functioning. However, differences are small and clinical implications of our results seem limited. Therefore we would not recommend against the use of Ox in light of psychological consequences.     

Effects of taurine on metal cations,transthyretin and LRP-1 in a rat model of Alzheimer’s disease

BackgroundResearches on diagnosis and treatment of Alzheimer's disease, the most common type of dementia, are still ongoing. Taurine is frequently used in Alzheimer's disease models due to its protective effects. Metal cation dyshomeostasis is an important etiological factor for Alzheimer's disease. Transthyretin protein is thought to act as a transporter for the Aβ protein that accumulates in the brain and is eliminated in the liver and kidneys via the LRP-1 receptor. However, the effect of taurine on this mechanisms is not fully known.Methods30 male rats, aged 28 ± 4 months, were divided into 5 groups (n = 6) as follows: control group, sham group, Aβ 1–42 group, taurine group and taurine+Aβ 1–42 group. Oral taurine pre-supplementation was given as 1000 mg/kg-body weight/day for 6 weeks to taurine and taurine+Aβ 1–42 groups.ResultsPlasma copper, heart transthyretin and Aβ 1–42, brain and kidney LRP-1 levels were found to be decreased in the Aβ 1–42 group. Brain transthyretin was higher in taurine+Aβ 1–42 group and brain Aβ 1–42 was higher in Aβ 1–42 and taurine+Aβ 1–42 groups.ConclusionTaurine pre-supplementation maintained cardiac transthyretin levels, decreased cardiac Aβ 1–42 levels and increased brain and kidney LRP-1 levels. Taurine may have a potential to be used as a protective agent for aged people at high risk for Alzheimer's disease.     

A comparison of the effects of γ-ketotriazole,MCPA and carbaryl on the plasma membrane Mg2+-ATPase activity and lipid composition of rice shoots (Oryza sativa)

The effect of -ketotriazole, MCPA and carbaryl on the lipid composition and ATPase activity associated with plasma membrane fractions from rice (Oryza sativa cv Bahia) shoots was investigated. With -ketotriazole and MCPA treatments the relative amount of ⁵-avenasterol (%) was reduced in the plasma membrane, whereas with -ketotriazole a reduction was also found in the sitosterol content, expressed as a percentage of the total free sterol composition. The fatty acyl chain length of phosphatidylcholine fractions from MCPA-treated plants was also reduced. The plasma membrane Mg²⁺-ATPase activity was only stimulated in MCPA-treated plants. No changes were observed in lipid composition or ATPase activity with carbaryl treatment.     

The effects of gestational stress and Selective Serotonin reuptake inhibitor antidepressant treatment on structural plasticity in the postpartum brain — A translational model for postpartum depression

This article is part of a Special Issue “Parental Care”.Postpartum depression (PPD) is a common complication following childbirth experienced by one in every five new mothers. Although the neural basis of PPD remains unknown, previous research in rats has shown that gestational stress, a risk factor for PPD, induces depressive-like behavior during the postpartum period. Moreover, the effect of gestational stress on postpartum mood is accompanied by structural modifications within the nucleus accumbens (NAc) and the medial prefrontal cortex (mPFC)–limbic regions that have been linked to PPD. Mothers diagnosed with PPD are often prescribed selective serotonin reuptake inhibitor (SSRI) antidepressant medications and yet little is known about their effects in models of PPD. Thus, here we investigated whether postpartum administration of Citalopram, an SSRI commonly used to treat PPD, would ameliorate the behavioral and morphological consequences of gestational stress. In addition, we examined the effects of gestational stress and postpartum administration of Citalopram on structural plasticity within the basolateral amygdala (BLA) which together with the mPFC and NAc forms a circuit that is sensitive to stress and is involved in mood regulation. Our results show that postpartum rats treated with Citalopram do not exhibit gestational stress-induced depressive-like behavior in the forced swim test. In addition, Citalopram was effective in reversing gestational stress-induced structural alterations in the postpartum NAc shell and mPFC. We also found that gestational stress increased spine density within the postpartum BLA, an effect which was not reversed by Citalopram treatment. Overall, these data highlight the usefulness of gestational stress as a valid and informative translational model for PPD. Furthermore, they suggest that structural alterations in the mPFC–NAc pathway may underlie stress-induced depressive-like behavior during the postpartum period and provide much needed information on how SSRIs may act in the maternal brain to treat PPD.