Increased doublecortin (DCX) expression and incidence of DCX-immunoreactive multipolar cells in the subventricular zone-olfactory bulb system of suicides

Anxiolytic- and antidepressant-like effects of Bacillus coagulans Unique IS-2 mediate via reshaping of microbiome gut-brain axis in rats

BACKGROUND

Due to the rising cases of treatment-refractory affective disorders, the discovery of newer therapeutic approaches is needed. In recent times, probiotics have garnered notable attention in managing stress-related disorders. Herein, we examined the effect of Bacillus coagulans Unique IS-2® probiotic on anxiety- and depression-like phenotypes employing maternal separation (MS) and chronic-unpredictable mild stress (CUMS) model in rats.

METHODS

Both male and female Sprague-Dawley rats were subjected to MS + CUMS. Probiotic treatment was provided for 6 weeks via drinking water. Anxiety- and depression-like phenotypes were assessed using sucrose-preference test (SPT), forced-swimming test (FST), elevated-plus maze test (EPM), and open-field test (OFT). Blood, brain, intestine, and fecal samples were obtained for biochemical and molecular studies.

RESULTS

Stress-exposed rats drank less sucrose solution, showed increased passivity, and explored less in open-arms in SPT, FST, and EPM, respectively. These stress-generated neurobehavioral aberrations were alleviated by 6-week of Bacillus coagulans Unique IS-2 treatment. The overall locomotor activity in OFT remained unchanged. The decreased levels of BDNF and serotonin and increased levels of C-reactive protein, TNF-α, IL-1β, and dopamine, in the hippocampus and/or frontal cortex of stress-exposed rats were reversed following probiotic treatment. Administration of probiotic also restored the systemic levels of L-tryptophan, L-kynurenine, kynurenic-acid, and 3-hydroxyanthranilic acid, villi/crypt ratio, goblet-cell count, Firmicutes to Bacteroides ratio, and levels of acetate, propionate, and butyrate in fecal samples. These results indicate remodeling of the microbiome gut-brain axis in Bacillus coagulans Unique IS-2 recipient rats. However, protein levels of doublecortin, GFAP, and zona occludens in the hippocampus and occludin-immunoreactivity in the intestine remained unchanged. No prominent sex-specific changes were noted.

CONCLUSION

Anxiolytic- and antidepressant-like effects of Bacillus coagulans Unique IS-2 in MS + CUMS rat model may be mediated via reshaping the microbiome gut-brain axis.

Consistency and Variation in Doublecortin and Ki67 Antigen Detection in the Brain Tissue of Different Mammals, including Humans

Recently, a population of "immature" neurons generated prenatally, retaining immaturity for long periods and finally integrating in adult circuits has been described in the cerebral cortex. Moreover, comparative studies revealed differences in occurrence/rate of different forms of neurogenic plasticity across mammals, the "immature" neurons prevailing in gyrencephalic species. To extend experimentation from laboratory mice to large-brained mammals, including humans, it is important to detect cell markers of neurogenic plasticity in brain tissues obtained from different procedures (e.g., post-mortem/intraoperative specimens vs. intracardiac perfusion). This variability overlaps with species-specific differences in antigen distribution or antibody species specificity, making it difficult for proper comparison. In this work, we detect the presence of doublecortin and Ki67 antigen, markers for neuronal immaturity and cell division, in six mammals characterized by widely different brain size. We tested seven commercial antibodies in four selected brain regions known to host immature neurons (paleocortex, neocortex) and newly born neurons (hippocampus, subventricular zone). In selected human brains, we confirmed the specificity of DCX antibody by performing co-staining with fluorescent probe for DCX mRNA. Our results indicate that, in spite of various types of fixations, most differences were due to the use of different antibodies and the existence of real interspecies variation.

Exercise more efficiently regulates the maturation of newborn neurons and synaptic plasticity than fluoxetine in a CUS-induced depression mouse model

Depression, a common and important cause of morbidity and mortality worldwide, is commonly treated with antidepressants, electric shock and psychotherapy. Recently, increasing evidence has shown that exercise can effectively alleviate depression. To determine the difference in efficacy between exercise and the classic antidepressant fluoxetine in treating depression, we established four groups: the Control, chronic unpredictable stress (CUS/STD), running (CUS/RUN) and fluoxetine (CUS/FLX) groups. The sucrose preference test (SPT), the forced swimming test (FST), the tail suspension test (TST), immunohistochemistry, immunofluorescence and stereological analyses were used to clarify the difference in therapeutic efficacy and mechanism between exercise and fluoxetine in the treatment of depression. In the seventh week, the sucrose preference of the CUS/RUN group was significantly higher than that of the CUS/STD group, while the sucrose preference of the CUS/FLX group did not differ from that of the CUS/STD group until the eighth week. Exercise reduced the immobility time in the FST and TST, while fluoxetine only reduced immobility time in the TST. Hippocampal structure analysis showed that the CUS/STD group exhibited an increase in immature neurons and a decrease in mature neurons. Exercise reduced the number of immature neurons and increased the number of mature neurons, but no increase in the number of mature neurons was observed after fluoxetine treatment. In addition, both running and fluoxetine reversed the decrease in the number of MAP2+ dendrites in depressed mice. Exercise increased the number of spinophilin-positive (Sp+) dendritic spines in the hippocampal CA1, CA3, and dentate gyrus (DG) regions, whereas fluoxetine only increased the number of SP+ spines in the DG. In summary, exercise promoted newborn neuron maturation in the DG and regulated neuronal plasticity in three hippocampal subregions, which might explain why running exerts earlier and more comprehensive antidepressant effects than fluoxetine.

BKM120 alters the migration of doublecortin-positive cells in the dentate gyrus of mice

BKM120 is an inhibitor of class I phosphoinositide 3-kinases and its anti-cancer effects have been demonstrated in various solid cancer models. BKM120 is highly brain permeable and has been reported to induce mood disturbances in clinical trials. Therefore, we examined whether BKM120 produces anxiety- and depression-like behaviors in mice, as with patients receiving BKM120 in clinical trials. In this study, repeated BKM120 treatment (2.0 or 5.0mg/kg, i.p., five times at 12-h interval) significantly induced anxiety- and depression-like behaviors in mice. Although abnormal changes in hippocampal neurogenesis have been suggested to, at least in part, associated with the pathogenesis of depression and anxiety, BKM120 did not affect the incorporation of 5-bromo-2'-deoxyuridine or the expression of doublecortin (DCX); however, it significantly enhanced the radial migration of DCX-positive cells in the dentate gyrus. BKM120-induced changes in migration were not accompanied by obvious neuronal damage in the hippocampus. Importantly, BKM120-induced anxiety- and depression-like behaviors were positively correlated with the extent of DCX-positive cell migration. Concomitantly, p-Akt expression was significantly decreased in the dentate gyrus. Moreover, the expression of p-c-Jun N-terminal kinase (JNK), p-DCX, and Ras homolog family member A (RhoA)-GTP decreased significantly, particularly in aberrantly migrated DCX-positive cells. Together, the results suggest that repeated BKM120 treatment enhances the radial migration of DCX-positive cells and induces anxiety- and depression-like behaviors by regulating the activity of Akt, JNK, DCX, and RhoA in the dentate gyrus. It also suggests that the altered migration of adult-born neurons in the dentate gyrus plays a role in mood disturbances.

The Subventricular Zone in Glioblastoma: Genesis, Maintenance, and Modeling

Glioblastoma (GBM) is a malignant tumor with a median survival rate of 15-16 months with standard care; however, cases of successful treatment offer hope that an enhanced understanding of the pathology will improve the prognosis. The cell of origin in GBM remains controversial. Recent evidence has implicated stem cells as cells of origin in many cancers. Neural stem/precursor cells (NSCs) are being evaluated as potential initiators of GBM tumorigenesis. The NSCs in the subventricular zone (SVZ) have demonstrated similar molecular profiles and share several distinctive characteristics to proliferative glioblastoma stem cells (GSCs) in GBM. Genomic and proteomic studies comparing the SVZ and GBM support the hypothesis that the tumor cells and SVZ cells are related. Animal models corroborate this connection, demonstrating migratory patterns from the SVZ to the tumor. Along with laboratory and animal research, clinical studies have demonstrated improved progression-free survival in patients with GBM after radiation to the ipsilateral SVZ. Additionally, key genetic mutations in GBM for the most part carry regulatory roles in the SVZ as well. An exciting avenue towards SVZ modeling and determining its role in gliomagenesis in the human context is human brain organoids. Here we comprehensively discuss and review the role of the SVZ in GBM genesis, maintenance, and modeling.

Genetic Ablation of the Inducible Form of Nitric Oxide in Male Mice Disrupts Immature Neuron Survival in the Adult Dentate Gyrus

Inducible nitric oxide synthase (iNOS) is an enzyme upregulated in the brain during neuroimmune stimuli which is associated with an oxidative and pro-inflammatory environment in several brain regions, including the hippocampal formation and the prefrontal cortex. The dentate gyrus of the hippocampal formation is the site of a process known as adult hippocampal neurogenesis (AHN). Although many endogenous and extrinsic factors can modulate AHN, the exact participation of specific proinflammatory mediators such as iNOS in these processes remains to be fully elucidated. Here, we investigated how the total genetic ablation of iNOS impacts the hippocampal neurogenic niche and microglial phenotype and if these changes are correlated to the behavioral alterations observed in iNOS knockout (K.O.) mice submitted or not to the chronic unpredictable stress model (CUS - 21 days protocol). Contrary to our initial hypothesis, at control conditions, iNOS K.O. mice displayed no abnormalities on microglial activation in the dentate gyrus. However, they did exhibit impaired newborn cells and immature neuron survival, which was not affected by CUS. The reduction of AHN in iNOS K.O. mice was accompanied by an increased positive coping response in the tail suspension test and facilitation of anxiety-like behaviors in the novelty suppressed feeding. Next, we investigated whether a pro-neurogenic stimulus would rescue the neurogenic capacity of iNOS K.O. mice by administering in control and CUS groups the antidepressant escitalopram (ESC). The chronic treatment with ESC could not rescue the neurogenic capacity or the behavioral changes observed in iNOS K.O. mice. Besides, in the ventromedial prefrontal (vmPFC) cortex there was no change in the expression or the chronic activation of PV neurons (evaluated by double labeling PV with FOSB) in the prelimbic (PrL) or infralimbic subregions. FOSB expression, however, increased in the PrL of iNOS K.O. mice. Our results suggest that iNOS seems essential for the survival of newborn cells and immature neurons in the hippocampus and seem to partially explain the anxiogenic-like behavior observed in iNOS K.O. mice. On the other hand, the iNOS ablation appears to result in increased activity of the PrL which could explain the antidepressant-like behaviors of iNOS K.O mice.

Immunohistochemical evidence for adult human neurogenesis in health and disease

Postnatal and adult neurogenesis in the subventricular zone and subgranular zone of animals such as rodents and non-human primates has been observed with many different technical approaches. Since most techniques used in animals cannot be used in humans, the majority of human neurogenesis studies rely on postmortem immunohistochemistry. This technique is difficult in human tissue, due to poor and variable preservation of antigens and samples. Nevertheless, a survey of the literature reveals that most published studies provide evidence for childhood and adult neurogenesis in the human brain stem cell niches. There are some conflicting results even when assessing the same markers and when using the same antibodies. Focusing on immunohistochemical studies on post-mortem human sections, we discuss the relative robustness of the literature on adult neurogenesis. We also discuss the response of the subventricular and subgranular zones to human disease, showing that the two niches can respond differently and that the stage of disease impacts neurogenesis levels. Thus, we highlight strong evidence for adult human neurogenesis, discuss other work that did not find it, describe obstacles in analysis, and offer other approaches to evaluate the neurogenic potential of the subventricular and subgranular zones of Homo sapiens. This article is categorized under: Neurological Diseases > Stem Cells and Development Reproductive System Diseases > Stem Cells and Development.

Reduced adult neurogenesis is associated with increased macrophages in the subependymal zone in schizophrenia

Neural stem cells in the human subependymal zone (SEZ) generate neuronal progenitor cells that can differentiate and integrate as inhibitory interneurons into cortical and subcortical brain regions; yet the extent of adult neurogenesis remains unexplored in schizophrenia and bipolar disorder. We verified the existence of neurogenesis across the lifespan by chartering transcriptional alterations (2 days-103 years, n = 70) and identifying cells indicative of different stages of neurogenesis in the human SEZ. Expression of most neural stem and neuronal progenitor cell markers decreased during the first postnatal years and remained stable from childhood into ageing. We next discovered reduced neural stem and neuronal progenitor cell marker expression in the adult SEZ in schizophrenia and bipolar disorder compared to controls (n = 29-32 per group). RNA sequencing identified increased expression of the macrophage marker CD163 as the most significant molecular change in schizophrenia. CD163⁺ macrophages, which were localised along blood vessels and in the parenchyma within 10 µm of neural stem and progenitor cells, had increased density in schizophrenia but not in bipolar disorder. Macrophage marker expression negatively correlated with neuronal progenitor marker expression in schizophrenia but not in controls or bipolar disorder. Reduced neurogenesis and increased macrophage marker expression were also associated with polygenic risk for schizophrenia. Our results support that the human SEZ retains the capacity to generate neuronal progenitor cells throughout life, although this capacity is limited in schizophrenia and bipolar disorder. The increase in macrophages in schizophrenia but not in bipolar disorder indicates that immune cells may impair neurogenesis in the adult SEZ in a disease-specific manner.

Anti-LINGO-1 antibody ameliorates cognitive impairment, promotes adult hippocampal neurogenesis, and increases the abundance of CB1R-rich CCK-GABAergic interneurons in AD mice

In view of the negative regulatory effect of leucine-rich repeat and immunoglobulin-like domain-containing nogo receptor-interacting protein 1 (LINGO-1) on neurons, an antibody against LINGO-1 (anti-LINGO-1 antibody) was herein administered to 10-month-old APP/PS1 transgenic Alzheimer's disease (AD) mice for 2 months as an experimental intervention. Behavioral, stereology, immunohistochemistry and immunofluorescence analyses revealed that the anti-LINGO-1 antibody significantly improved the cognitive abilities, promoted adult hippocampal neurogenesis (AHN), decreased the amyloid beta (Aβ) deposition, enlarged the hippocampal volume, and increased the numbers of total neurons and GABAergic interneurons, including GABAergic and CCK-GABAergic interneurons rich in cannabinoid type 1 receptor (CB1R), in the hippocampus of AD mice. In contrast, this intervention significantly reduced the number of GABAergic interneurons expressing LINGO-1 and CB1R in the hippocampus of AD mice. More importantly, we also found a negative correlation between LINGO-1 and CB1R on GABAergic interneurons in the hippocampus of AD mice, while the anti-LINGO-1 antibody reversed this relationship. These results indicated that LINGO-1 plays an important role in the process of hippocampal neuron loss in AD mice and that antagonizing LINGO-1 can effectively prevent hippocampal neuron loss and promote AHN. The improvement in cognitive abilities may be attributed to the improvement in AHN, and in the numbers of GABAergic interneurons and CCK-GABAergic interneurons rich in CB1Rs in the hippocampus of AD mice induced by the anti-LINGO-1 antibody. Collectively, the double target effect (LINGO-1 and CB1R) initiated by the anti-LINGO-1 antibody may provide an important basis for the study of drugs for the prevention and treatment of AD in the future.

Reduction in IGF1 mRNA in the Human Subependymal Zone During Aging

The cell proliferation marker, Ki67 and the immature neuron marker, doublecortin are both expressed in the major human neurogenic niche, the subependymal zone (SEZ), but expression progressively decreases across the adult lifespan (PMID: 27932973). In contrast, transcript levels of several mitogens (transforming growth factor α, epidermal growth factor and fibroblast growth factor 2) do not decline with age in the human SEZ, suggesting that other growth factors may contribute to the reduced neurogenic potential. While insulin like growth factor 1 (IGF1) regulates neurogenesis throughout aging in the mouse brain, the extent to which IGF1 and IGF family members change with age and relate to adult neurogenesis markers in the human SEZ has not yet been determined. We used quantitative polymerase chain reaction to examine gene expression of seven IGF family members [IGF1, IGF1 receptor, insulin receptor and high-affinity IGF binding proteins (IGFBPs) 2, 3, 4 and 5] in the human SEZ across the adult lifespan (n=50, 21-103 years). We found that only IGF1 expression significantly decreased with increasing age. IGFBP2 and IGFBP4 expression positively correlated with Ki67 mRNA. IGF1 expression positively correlated with doublecortin mRNA, whereas IGFBP2 expression negatively correlated with doublecortin mRNA. Our results suggest IGF family members are local regulators of neurogenesis and indicate that the age-related reduction in IGF1 mRNA may limit new neuron production by restricting neuronal differentiation in the human SEZ.

Postnatal low-concentration arsenic exposure induces autism-like behavior and affects frontal cortex neurogenesis in rats

This study aimed to explore the effects of postnatal low-concentration arsenic exposure on learning, social skills and frontal cortex neurogenesis in rats. Water-based arsenic exposure rat models were established on postnatal days 4-10 (P4-P10). The experimental animals were divided into four groups: the control group, a 15 μg/L As₂O₃ water group, a 30 μg/L As₂O₃ water group, and a 45 μg/L As₂O₃ water group. Cognitive function was examined with the Morris water maze, anxiety-like behavior with the open field test and light-dark box test, and social skills with a social interaction test. The frontal cortices of pups from each experimental group were sectioned at various time points after arsenic exposure. The morphologies and neurogenesis of the neurons in the frontal cortices were observed by hematoxylin-eosin staining, Nissl staining, and doublecortin (DCX) immunostaining. Significant positive correlations between arsenic concentration and deficits in learning and social skills were found, and the arsenic exposure groups showed significant increases in anxiety-like behavior compared with the control group (all Ps<0.05). Abnormal morphologic changes in the external granular layer and external pyramidal layer were positively correlated with the water arsenic concentration in the acute phase of arsenic exposure. However, at five weeks after arsenic exposure, the frontal cortex morphology was restored. Moreover, immunohistochemistry revealed that compared to the control group, the groups that were exposed to arsenic exhibited significantly higher levels of DCX expression in the external granular and external pyramidal layers (all Ps<0.001). Furthermore, the 30 μg/L and 45 μg/L arsenic exposure groups still showed some DCX expression at five weeks after exposure. In conclusion, postnatal low-concentration arsenic exposure impaired learning and social skills and increased anxiety-like behaviors, and abnormal frontal cortex neurogenesis may be the mechanism underlying these effects.

Mitral cells and the glucagon-like peptide 1 receptor: The sweet smell of success?

The olfactory bulb (OB) is often affected at very early stages of neurodegenerative disorders, in the so-called "prodromal" phase. In Parkinson's disease (PD), olfactory disturbances appear years before motor symptoms arise. Additionally, pathological alpha-synuclein aggregates are found in olfactory regions before spreading to other areas of the brain. Being positioned at the frontier between the brain and a potentially hostile environment, could explain the particular vulnerability of the OB. Mitral cells (MCs), the principal projecting neurons of the olfactory system, are involved in the pathogenesis and in the prion-like progression of PD. They are affected by Lewy pathology and are thought to contribute to the axonal transport of misfolded alpha-synuclein to other regions of the brain. Here, we first describe the main markers reported to distinguish MCs from other olfactory neurons. We focus on the glucagon-like peptide 1 receptor (GLP-1R), a membrane protein specifically expressed in MCs. After summarizing OB pathology, we explore the idea of targeting specifically MCs with GLP-1 or its analogues. Exenatide has shown great promise as a neuroprotective and neurorestorative agent and has been used in a clinical trial for clinical PD. Since GLP-1R activation has the ability to mitigate many facets of prodromal PD pathology, we postulate that once a robust biomarker is in place that is capable of identifying individuals in the prodromal phase of PD, homing in on GLP-1R could assist in deferring, or eradicating to a significant degree, the clinical manifestation of this debilitating human disorder.

Reactive Neuroblastosis in Huntington's Disease: A Putative Therapeutic Target for Striatal Regeneration in the Adult Brain

The cellular and molecular mechanisms underlying the reciprocal relationship between adult neurogenesis, cognitive and motor functions have been an important focus of investigation in the establishment of effective neural replacement therapies for neurodegenerative disorders. While neuronal loss, reactive gliosis and defects in the self-repair capacity have extensively been characterized in neurodegenerative disorders, the transient excess production of neuroblasts detected in the adult striatum of animal models of Huntington’s disease (HD) and in post-mortem brain of HD patients, has only marginally been addressed. This abnormal cellular response in the striatum appears to originate from the selective proliferation and ectopic migration of neuroblasts derived from the subventricular zone (SVZ). Based on and in line with the term “reactive astrogliosis”, we propose to name the observed cellular event “reactive neuroblastosis”. Although, the functional relevance of reactive neuroblastosis is unknown, we speculate that this process may provide support for the tissue regeneration in compensating the structural and physiological functions of the striatum in lieu of aging or of the neurodegenerative process. Thus, in this review article, we comprehend different possibilities for the regulation of striatal neurogenesis, neuroblastosis and their functional relevance in the context of HD.

Decline in Proliferation and Immature Neuron Markers in the Human Subependymal Zone during Aging: Relationship to EGF- and FGF-Related Transcripts

Neuroblasts exist within the human subependymal zone (SEZ); however, it is debated to what extent neurogenesis changes during normal aging. It is also unknown how precursor proliferation may correlate with the generation of neuronal and glial cells or how expression of growth factors and receptors may change throughout the adult lifespan. We found evidence of dividing cells in the human SEZ (n D 50) in conjunction with a dramatic age-related decline (21-103 years) of mRNAs indicative of proliferating cells (Ki67) and immature neurons (doublecortin). Microglia mRNA (ionized calcium-binding adapter molecule 1) increased during aging, whereas transcript levels of stem/precursor cells (glial fibrillary acidic protein delta and achaete-scute homolog 1), astrocytes (vimentin and pan-glial fibrillary acidic protein), and oligodendrocytes (oligodendrocyte lineage transcription factor 2) remained stable. Epidermal growth factor receptor (EGFR) and fibroblast growth factor 2 (FGF2) mRNAs increased throughout adulthood, while transforming growth factor alpha (TGFα), EGF, Erb-B2 receptor tyrosine kinase 4 (ErbB4) and FGF receptor 1 (FGFR1) mRNAs were unchanged across adulthood. Cell proliferation mRNA positively correlated with FGFR1 transcripts. Immature neuron and oligodendrocyte marker expression positively correlated with TGFα and ErbB4 mRNAs, whilst astrocyte transcripts positively correlated with EGF, FGF2, and FGFR1 mRNAs. Microglia mRNA positively correlated with EGF and FGF2 expression. Our findings indicate that neurogenesis in the human SEZ continues well into adulthood, although proliferation and neuronal differentiation may decline across adulthood. We suggest that mRNA expression of EGF- and FGF-related family members do not become limited during aging and may modulate neuronal and glial fate determination in the SEZ throughout human life.

Adult Neurogenesis and Gliogenesis: Possible Mechanisms for Neurorestoration

The subgranular zone (SGZ) and subventricular zone (SVZ) are developmental remnants of the germinal regions of the brain, hence they retain the ability to generate neuronal progenitor cells in adult life. Neurogenesis in adult brain has an adaptive function because newly produced neurons can integrate into and modify existing neuronal circuits. In contrast to the SGZ and SVZ, other brain regions have a lower capacity to produce new neurons, and this usually occurs via parenchymal and periventricular cell genesis. Compared to neurogenesis, gliogenesis occurs more prevalently in the adult mammalian brain. Under certain circumstances, interaction occurs between neurogenesis and gliogenesis, facilitating glial cells to transform into neuronal lineage. Therefore, modulating the balance between neurogenesis and gliogenesis may present a new perspective for neurorestoration, especially in diseases associated with altered neurogenesis and/or gliogenesis, cell loss, or disturbed homeostasis of cellular constitution. The present review discusses important neuroanatomical features of adult neurogenesis and gliogenesis, aiming to explore how these processes could be modulated toward functional repair of the adult brain.

Rauwolfia vomitoria inhibits olfaction and modifies olfactory bulb cells

The rising cost of orthodox medication has endeared so many to the use of herbs for the management of neurological conditions. Rauwolfia vomitoria (RV) one of such herbs is a rainforest shrub whose parts are used locally in the management of psychiatry and other medical issues. Its usefulness though not in doubt is wrapped with adverse reports as its active constituents depletes brain monoamine and dopamine stores. This motivated this research on the effects of the root bark extract on olfaction and the olfactory bulb of adult Wistar rats. Eighteen adult Wistar rats (220g average) were divided into three groups (n=6); control (placebo), 200mg/kg and 400mg/kg RV root bark extract, respectively. The oral administration lasted for seven days and on day 8, test of olfaction was carried out and the animals immediately anaesthetized with ketamine hydrochloride (i.p.) and perfuse-fixed with 10% neutral buffered formalin. All the brains were processed for histology and immunoreactivity. Results showed loss of body weights and olfaction in the 200mg/kg and 400mg/kg RV groups. There was hypertrophy and atrophy of mitral cells respectively, in the 200mg/kg and 400mg/kg RV groups, while there was hyperplasia of cells in the internal granular and plexiform layers of both groups. There was decreased neuron specific enolase (NSE) and neurofilament (NF) expression in the 200mg/kg RV group, while NF and glial fibrillary acidic protein (GFAP) expression was decreased in the 400mg/kg RV group. However, NSE expression was enhanced in the 400mg/kg group, while GFAP expression was enhanced in the 200mg/kg RV group. These results suggest that these doses of RV affect olfaction and appetite, and stimulate adverse cellular changes in the olfactory bulb.

Postpartum depression: Etiology, treatment and consequences for maternal care

This article is part of a Special Issue "Parental Care". Pregnancy and postpartum are associated with dramatic alterations in steroid and peptide hormones which alter the mothers' hypothalamic pituitary adrenal (HPA) and hypothalamic pituitary gonadal (HPG) axes. Dysregulations in these endocrine axes are related to mood disorders and as such it should not come as a major surprise that pregnancy and the postpartum period can have profound effects on maternal mood. Indeed, pregnancy and postpartum are associated with an increased risk for developing depressive symptoms in women. Postpartum depression affects approximately 10-15% of women and impairs mother-infant interactions that in turn are important for child development. Maternal attachment, sensitivity and parenting style are essential for a healthy maturation of an infant's social, cognitive and behavioral skills and depressed mothers often display less attachment, sensitivity and more harsh or disrupted parenting behaviors, which may contribute to reports of adverse child outcomes in children of depressed mothers. Here we review, in honor of the "father of motherhood", Jay Rosenblatt, the literature on postnatal depression in the mother and its effect on mother-infant interactions. We will cover clinical and pre-clinical findings highlighting putative neurobiological mechanisms underlying postpartum depression and how they relate to maternal behaviors and infant outcome. We also review animal models that investigate the neurobiology of maternal mood and disrupted maternal care. In particular, we discuss the implications of endogenous and exogenous manipulations of glucocorticoids on maternal care and mood. Lastly we discuss interventions during gestation and postpartum that may improve maternal symptoms and behavior and thus may alter developmental outcome of the offspring.