Search

Growth/differentiation factor-5 (GDF5) is a member of the transforming growth factor-beta superfamily which has potent effects on dopaminergic neurones in vitro and in vivo. GDF5 is under investigation as a potential therapeutic agent for Parkinson's disease (PD), which is caused by the progressive degeneration of dopaminergic neurones projecting from the substantia nigra (SN) to the striatum. In the rat ventral mesencephalon (VM; the developing SN), GDF5 expression peaks at embryonic day 14, the time at which dopaminergic neurones undergo terminal differentiation. Addition of GDF5 protein to cultures of embryonic rat VM increases the survival and improves the morphology of dopaminergic neurones in these cultures. GDF5 treatment also increases the number of cells which adopt a dopaminergic phenotype in cultures of VM progenitor cells. Intracerebral administration of GDF5 has potent neuroprotective and restorative effects on the nigrostriatal pathway in animal models of PD. Furthermore, addition of GDF5 protein to embryonic rat dopaminergic neuronal transplants improves their survival and function in a rat model of PD. Thus, GDF5 has potential applications to PD therapy as a dopaminergic neuroprotective agent and as a factor that may induce a dopaminergic neuronal fate in unrestricted progenitor cells.

Growth/differentiation factor 5 (GDF5) is a member of the transforming growth factor-beta superfamily that is expressed in the developing CNS, including the ventral mesencephalon (VM). GDF5 has been shown to increase the survival of dopaminergic neurones in animal models of Parkinson's disease. This study was aimed at characterising the effects of GDF5 on dopaminergic neurones in vitro. Treatment with GDF5 induced a three-fold increase in the number of dopaminergic neurones in embryonic day 14 rat VM cultures after six days in vitro. A significant increase was also observed in the numbers of astrocytes in GDF5-treated cultures. GDF5 treatment also had significant effects on the morphology of dopaminergic neurones in these cultures; total neurite length, number of branch points and somal area were all significantly increased after six days in vitro. Analysis of neurite length and numbers of branch points at each level of the neuritic field revealed that the most pronounced effects of GDF5 were on the secondary and tertiary levels of the neuritic field. The specific type I receptor for GDF5, bone morphogenetic protein receptor (BMPR)-Ib, was found to be strongly expressed in freshly-dissected E14 VM tissue, but its expression was lost with increasing time in culture. Accordingly, treatment with GDF5 for 24 h from the time of plating induced increases in the numbers of dopaminergic neurones, while treatment with GDF5 for 24 h after six days in vitro did not. This study shows that GDF5 can promote both the survival and morphological differentiation of VM dopaminergic neurones in vitro, lending support to its potential as a candidate dopaminergic neurotrophin for use in the treatment of Parkinson's disease.

Introduction Attention-deficit/hyperactivity disorder (ADHD) is a frequent neurodevelopmental disorder. Inadequate placentation as a result of hypertensive disorders of pregnancy has been proposed to be a central mechanism of fetal neurodevelopmental comprise. Recently it has been shown that pre-eclampsia increases the risk of ADHD [Mann and McDermott, 2011] . Objectives We examined the association between hypertensive disorders of pregnancy and ADHD and behavioural difficulties among 7-year old children. We also examined whether circulating factors in serum from women with a HDP alter early patterns of fetal neural growth. Methods The study cohort consisted of 13,192 children (weighted = 13,500) who participated in the 7-year old wave of the Millennium Cohort Study (MCS); a representative cohort of British children born in 2000–2001. Hypertensive disorders of pregnancy (raised blood pressure, pre-eclampsia, eclampsia and toxaemia) were reported by mothers nine months post-delivery. ADHD was based on a doctor or health care professional diagnosis at age seven. Weighted logistic regression was performed, adjusting for several variables (e.g. depression, age, and poverty status). Sensitivity analyses were performed according to infant sex, parity and pre-pregnancy hypertension. To examine fetal neuronal growth, gestational day (GD) 14 rat cortical neurons were treated with 3% serum from either 5 severe cases of preeclampsia or 5 matched controls for 24h. The complexity of 75 individual neurons (15 neurons × 5 serum samples per group) was analysed using a modified line intercept approach to measure neurite number, total neurite length and branching. Results 1069 (7.9%) women reported hypertensive disorders of pregnancy and 166 (1.2%) children had an ADHD diagnosis. There was a significant association between HDP and ADHD (adjusted OR = 1.78; [95% CI: 1.03, 3.07]). This association was slightly reduced when women with pre-pregnancy hypertension were excluded (OR = 1.68; [95% CI: 0.96, 2.94]), but not when we excluded women with depression (OR = 2.15; [95% CI: 1.05, 4.43]). Stratifying the analyses by parity and infant sex did not influence these findings. In addition, exposure of GD 14 rat cortical neurons to serum from women with established pre-eclamspia lead to a significant increase in neuronal growth and branching ( P n = 75), when compared to those treated with serum from healthy controls. Conclusions These findings suggest that hypertensive disorders of pregnancy is associated with an increased risk of ADHD. It is important to confirm this in larger cohorts, and to understand the biological basis of this association and the contribution of in utero adversity to the aetiology of ADHD. We also show that exposure to serum from women with a hypertensive disorder of pregnancy, can alter early patterns of fetal neuronal growth, which in turn may affect early patterns of brain wiring, which has been implicated in ADHD.

Parkinson's disease (PD) is a chronic, age-related neurodegenerative disorder that affects 1–2% of the population over the age of 65. PD is characterised by the progressive degeneration of nigrostriatal dopaminergic (DA) neurons. This leads to disabling motor symptoms, due to the striatal DA denervation. Despite decades of research, there is still no therapy that can slow, stop or regenerate the dying midbrain DA neurons in PD. Current drug treatment regimes typically involve dopamine-replacement strategies. While these are effective in controlling the symptoms for several years, they do not attenuate the progressive neurodegeneration. There is now robust evidence that retrograde degeneration of nigrostriatal axons occurs early in PD pathogenesis, and precedes neuronal loss (Kordower et al., 2013). Therefore, a promising approach for restoring motor function in PD patients may be to develop strategies which regenerate nigrostriatal DA axons, so that they can re-establish their lost connections [Figure 1]. To address this, investigation of the potential for reactivation of the intrinsic axon growth capacity of midbrain DA neurons is needed. Information on the molecular mechanisms regulating nigrostriatal DA axonal growth and target innervation during their normal development will provide novel targets for axon regenerative therapy in PD

Objective To investigate the expression profile of microRNA (miRNA) in umbilical cord blood from infants with hypoxic ischemic encephalopathy (HIE). Study design Full-term infants with perinatal asphyxia were identified under strict enrollment criteria. Degree of encephalopathy was defined using both continuous multichannel electroencephalogram in the first 24 hours of life and modified Sarnat score. Seventy infants (18 controls, 33 with perinatal asphyxia without HIE, and 19 infants with HIE [further graded as 13 mild, 2 moderate, and 4 severe]) were included in the study. MiRNA expression profiles were determined using a microarray assay and confirmed using quantitative real-time polymerase chain reaction. Results Seventy miRNAs were differentially expressed between case and control groups. Of these hsa-miR-374a was the most significantly downregulated in infants with HIE vs controls. Validation of hsa-miR-374a expression using quantitative real-time polymerase chain reaction confirmed a significant reduction in expression among infants with HIE compared with those with perinatal asphyxia and healthy controls (mean relative quantification [SD] = 0.52 [0.37] vs 1.10 [1.52] vs 1.76 [1.69], P Conclusions We have shown a significant step-wise downregulation of hsa-miR-374a expression in cord blood of infants with perinatal asphyxia and subsequent HIE.

Neuroprotection and neuroregeneration are two of the most promising disease-modifying therapies for the incurable and widespread Parkinson's disease. In Parkinson's disease, progressive degeneration of nigrostriatal dopaminergic neurons causes debilitating motor symptoms. Neurotrophic factors play important regulatory roles in the development, survival and maintenance of specific neuronal populations. These factors have the potential to slow down, halt or reverse the loss of nigrostriatal dopaminergic neurons in Parkinson's disease. Several neurotrophic factors have been investigated in this regard. This review article discusses the neurodevelopmental roles and therapeutic potential of three dopaminergic neurotrophic factors: glial cell line-derived neurotrophic factor, neurturin and growth/differentiation factor 5.

Anatomy remains a cornerstone of medical education despite challenges that have seen a significant reduction in contact hours over recent decades; however, the rise of the "YouTube Generation" or "Generation Connected" (Gen C), offers new possibilities for anatomy education. Gen C, which consists of 80% Millennials, actively interact with social media and integrate it into their education experience. Most are willing to merge their online presence with their degree programs by engaging with course materials and sharing their knowledge freely using these platforms. This integration of social media into undergraduate learning, and the attitudes and mindset of Gen C, who routinely creates and publishes blogs, podcasts, and videos online, has changed traditional learning approaches and the student/teacher relationship. To gauge this, second year undergraduate medical and radiation therapy students (n = 73) were surveyed regarding their use of online social media in relation to anatomy learning. The vast majority of students had employed web-based platforms to source information with 78% using YouTube as their primary source of anatomy-related video clips. These findings suggest that the academic anatomy community may find value in the integration of social media into blended learning approaches in anatomy programs. This will ensure continued connection with the YouTube generation of students while also allowing for academic and ethical oversight regarding the use of online video clips whose provenance may not otherwise be known.

We have previously demonstrated that mitogen-activated protein kinase phosphatase 1, Mkp1, is expressed in the developing and rat adult substantia nigra and striatum, where it promotes the growth of nigral dopaminergic neurons. Mkp1 may therefore have therapeutic potential for Parkinson’s disease. In the present study, we have assessed the expression of Mkp1 and TH in the substantia nigra and striatum of parkinsonian rat models. Expression was measured at 4 and 10 days post-lesion in the 6-hydroxydopamine (6-OHDA) medial forebrain bundle lesion model and after 4, 10 and 28 days in the 6-OHDA striatal lesion model. Our results show that Mkp1 expression was transiently up-regulated in the substantia nigra at 4 days post-6-OHDA administration in the two models while TH expression was decreased at the later time-points examined. These data suggest that Mkp1 may play a role in counteracting the neurotoxic effects of 6-OHDA in nigral dopaminergic neurons.

Small molecule histone deacetylase inhibitors (HDIs) hold much promise as pharmacological modifiers of the epigenetic status of the central nervous system (CNS), given their ability to cross the blood-brain barrier. This is particularly relevant given the lack of disease-modifying therapies for many neurodegenerative diseases and that epigenetic perturbations are increasingly recognised as playing a key role in their pathophysiology. In particular, emerging evidence in recent years has shown that epigenetic dysregulation may contribute to dopaminergic neuronal death in Parkinson’s disease. As a result, a number of pan-HDIs have been explored as potential neuroprotective agents for dopaminergic neurons. However, it is not known if the neuroprotective effects of pan-histone deacetylase (HDAC) inhibition are a general phenomenon or if these effects require inhibition of specific classes of HDACs. Here, we examine the ability of class-specific HDIs to promote neurite growth in a variety of cellular contexts. We find that MC1568, a class IIa-specific HDI, promotes neurite growth and arbourisation and protects neurite arbours against neurotoxic insult. Furthermore, we show that class IIa-specific HDAC inhibition results in activation of the canonical Smad signalling pathway, which is known to promote the survival and growth of midbrain dopaminergic neurons. These results demonstrate the potential of class IIa-specific HDIs as regulators of neuronal structure and suggest they should be examined in animal models of Parkinson’s disease as the next stage in rationalising their use as a potential therapy for this disorder.

Identifying those infants most at risk for poor neurodevelopmental outcomes is crucial to allow for targeted surveillance or preventative interventions to be instigated from birth. One intriguing possibility is to use the molecular characteristics of the placenta at birth as a 'molecular barometer' of the in utero experience to predict future infant neurodevelopmental outcomes. Here we highlight the recent advances in the field and discuss the possibilities for an integrated approach across the '-omics' categories.

Gut microbiota is essential to human health, playing a major role in the bidirectional communication between the gastrointestinal tract and the central nervous system. The microbiota undergoes a vigorous process of development throughout the lifespan and establishes its symbiotic rapport with the host early in life. Early life perturbations of the developing gut microbiota can impact neurodevelopment and potentially lead to adverse mental health outcomes later in life. This review compares the parallel early development of the intestinal microbiota and the nervous system. The concept of parallel and interacting microbial–neural critical windows opens new avenues for developing novel microbiota-modulating based therapeutic interventions in early life to combat neurodevelopmental deficits and brain disorders.

The adult midbrain contains 75 % of all dopaminergic neurons in the CNS. Within the midbrain, these neurons are divided into three anatomically and functionally distinct clusters termed A8, A9 and A10. The A9 group plays a functionally non-redundant role in the control of voluntary movement, which is highlighted by the motor syndrome that results from their progressive degeneration in the neurodegenerative disorder, Parkinson’s disease. Despite 50 years of investigation, treatment for Parkinson’s disease remains symptomatic, but an intensive research effort has proposed delivering neurotrophic factors to the brain to protect the remaining dopaminergic neurons, or using these neurotrophic factors to differentiate dopaminergic neurons from stem cell sources for cell transplantation. Most neurotrophic factors studied in this context have been members of the transforming growth factor β (TGFβ) superfamily. In recent years, an intensive research effort has focused on understanding the function of these proteins in midbrain dopaminergic neuron development and their role in the molecular architecture that regulates the development of this brain region, with the goal of applying this knowledge to develop novel therapies for Parkinson’s disease. In this review, the current evidence showing that TGFβ superfamily members play critical roles in the regulation of midbrain dopaminergic neuron induction, differentiation, target innervation and survival during embryonic and postnatal development is analysed, and the implications of these findings are discussed.

Neural stem cells (NSCs) have been the focus of an intensive effort to direct their differentiation in vitro towards desired neuronal phenotypes for cell replacement therapies. It is thought that NSCs derived from older embryos have limited neurogenic capacity and are restricted towards an astroglial fate. This idea is largely based on studies that typically analysed NSC-derived progeny following one week of in vitro differentiation. In this report, the neurogenic capacity of older ventral midbrain (VM) NSCs was assessed. When the older NSCs were differentiated for three weeks, there were significant increases in the numbers of newly born neurons at 14 and 21 days, as assessed by 5-bromo-2'-deoxyuridine (BrdU) incorporation. Therefore this study demonstrates that older NSCs retain significantly more neurogenic potential than was previously thought. These data have implications for NSC preparatory protocols and the choice of donor age for cell transplantation studies, and contributes to the understanding of NSC behaviour in vitro.

Peroxisomes are intracellular organelles that perform vital metabolic functions. They have been extensively studied in the hepatic and renal systems, yet their pivotal roles in facilitating central nervous system patterning and in disease pathogenesis are only recently being firmly established by the neuroscience community. Peroxisomal functions including the break-down of long chain fatty acids, the removal of H2O2, and the biosynthesis of ether lipids. The build up of long chain fatty acids and H2O2 is detrimental to cellular function, and ether lipids play roles in maintaining cell membrane structure. These findings have major implications for treatments for the full spectrum of peroxisomal disorders. Here, we provide a timely review highlighting the most important data in recent times linking peroxisomal functions to brain formation, and we describe how peroxisomal deficiency and pathway dysfunction results in neurological deficits, the more severe of which result in life changing disabilities and death.

The nuclear factor kappa-B family of transcription factors have been extensively studied in the immune system where they function to orchestrate the molecular response to immune challenge. However in recent years, members of this family have also been shown to play physiological roles in the development and function of the nervous system. The two best studied members of the nuclear factor kappa-B family are the p65 and the p50 proteins. In this review, we outline recent developments regarding the functions of these proteins in regulating hippocampal neurogenesis, neuronal growth and learning and memory and discuss the implications of their dysregulation during the development of the nervous system

Parkinson’s disease (PD) is a neurodegenerative disease that is characterised by motor and non-motor symptoms which result from the progressive degeneration of nigrostriatal ventral midbrain (VM) dopaminergic (DA) neurons, as well as peripheral sympathetic neurons. PD is incurable, with current therapeutic strategies providing symptomatic relief. Neurotrophic factor (NTF) therapy has the potential to protect degenerating neurons in PD. However, there has been limited success in PD clinical trials due to neurotrophic strategies that are invasive, inefficient in delivering sustained neurotrophic support, do not protect all degenerating neurons and may have a compromised mechanism of action in the PD brain. Therefore, while neurotrophic therapy remains a promising disease-modifying approach for PD, it is important to identify novel neurotrophic strategies that can protect all neurons affected by PD. To address this need, we report an integrated approach for pre-clinical evaluation of potential neurotrophic strategies, e.g., pharmacological agents (e.g., drugs/small molecules), signalling proteins (e.g., morphogens) and/or genetic (gene/mRNA) modifications, in cellular models of the neuronal populations that are affected by PD. Herein, we describe, in detail, an in vitro protocol that allows a step-wise evaluation of the efficacy, and mechanism(s) of action, of novel neurotrophic strategies in VM DA neurons and sympathetic neurons, following an initial evaluation in a human cell line model of these cells, SH-SY5Y cells. The protocol uses the induction of neurite growth as the primary measure of neurotrophic action. Indeed, the neuro-protection/-restoration of PD-affected axons is widely thought to be an appropriate target for effective therapeutic intervention in PD.

Introduction Genetic and environmental influences each have equal weighting in the relative risk for a child of developing ASD. Recently, focal patches of abnormal laminar cytoarchitecture and cortical disorganization of neurons, have been demonstrated in the prefrontal and temporal cortex of children with ASD. This is suggestive of a probable dysregulation cortical lamination which occurs in the 2–3rd trimester of pregnancy, and implies that in utero adversity may disrupt the normal neurodevelopmental program and increase a child's risk of later developing ASD. Recent evidence indicates that pre-eclampsia may be one of these factors. Objectives Our objective was to assess the association between hypertension in pregnancy (HIP), including pre-eclampsia, and ASD among 7 year old children. Methods For this investigation, we utilized data from the Millennium Cohort Study, a cohort representative of children born in the UK in the year 2000–2001. Mothers were asked if they experienced any illnesses during pregnancy for which they needed medical attention. Those that responded yes were asked to choose which illnesses they suffered from, including "raised blood pressure, eclampsia/pre-eclampsia or toxaemia." ASD was parent-reported based on a diagnosis by a doctor or health care professional. We measured the association between HIP and ASD using weighted logistic regression, and adjusted for smoking during pregnancy, birth order, poverty, maternal ethnicity, age, education, depression, BMI, longstanding hypertension and diabetes. Results We included data from 13,098 people who responded to the question on health during pregnancy and ASD. There were 983 (7.5%) reported HIP cases and 199 reported ASD cases (1.5%). HIP was associated with ASD in both unadjusted (OR=2.27; [95%CI: 1.43–3.60]) and adjusted analysis (OR=2.10; [95%CI: 1.20–3.70]). When women who reported longstanding hypertension were excluded, HIP remained associated with ASD (adjusted OR=2.02; [95%CI: 1.12–3.63]). When women aged 40+ at the time of birth were excluded, the estimate increased slightly, but was not significantly changed (adjusted OR=2.63; [95%CI: 1.27–4.02]). Conclusion Hypertension in pregnancy was associated with ASD in this population even after controlling for known confounders. It is increasingly recognized that placental health and neurodevelopmental outcome are intrinsically linked. This raises the possibility of using clinical data regarding the clinical course of pregnancy and the molecular characteristics of the placenta at birth to predict a child risk of future ASD.

Radial glial cells serve diverse roles during the development of the central nervous system (CNS). In the embryonic brain, they are recognised as guidance conduits for migrating neuroblasts and as multipotent stem cells, generating both neurons and glia. While their stem cell capacities in the developing spinal cord are as yet not fully clarified, they are classically seen as a population of astrocytes precursors, before gradually disappearing as the spinal cord matures. Although the origins and lineages of CNS radial glial cells are being more clearly understood, the relationships between radial glial cells and growing white matter (WM) tracts are largely unknown. Here, we provide an in-depth description of the distribution and organisation of radial glial cell processes during the peak periods of axonogenesis in the rat spinal cord. We show that radial glial cell distribution is highly ordered in the WM from E14 to E18, when the initial patterning of axon tracts is taking place. We report that the density of radial glial cell processes is tightly conserved throughout development in the dorsal, lateral and ventral WM funiculi along the rostrocaudal axis of the spinal cord. We provide evidence that from E16 the dorsal funiculi grow within and are segregated by fascicles of processes emanating from the dorsomedial septum. The density of radial glial cells declines with the maturation of axon tracts and coincides with the onset of the radial glial cell–astrocyte transformation. As such, we propose that radial glial cells act as structural scaffolds by compartmentalising and supporting WM patterning in the spinal cord during embryonic development.

J. Neurochem. (2012) 120, 964–973. Abstract During pregnancy, activation of the maternal immune system results in inflammation in the foetal nervous system. The causative agents are pro-inflammatory cytokines like interleukin-1β (IL-1β), produced by the foetus. In this study, we examine the effect of IL-1β on the proliferation and differentiation of neural progenitor cells (NPCs) to better understand its potential effects on the developing brain. We find that the IL-1β receptor (IL-1R1) is expressed in the ventral mesencephalon of the developing brain. Furthermore, IL-1R1 is expressed on Nestin-positive, Sox-2-positive NPCs. IL-1β treatment reduced the numbers of proliferating NPCs, an effect prevented by the IL-1R1 receptor antagonist. LDH and MTT assays, and western blot analysis for cleaved caspase 3 and poly(ADP-ribose) polymerase, confirmed that this was not due to an increase in cell death but rather an induction of differentiation. To further study the effects of IL-1β on cell fate determination, we differentiated NPCs in the presence and absence of IL-1β. Il-1β promoted gliogenesis and inhibited neurogenesis, an effect that required p38-MAPK kinase signalling. In summary, these data show that exposure of NPCs to IL-1β affects their development. This necessitates an examination of the consequences that maternal immune system activation during pregnancy has on the cellular architecture of the developing brain.

During pregnancy, activation of the maternal immune system results in inflammation in the foetal nervous system. The causative agents are pro-inflammatory cytokines like interleukin-1β (IL-1β), produced by the foetus. In this study, we examine the effect of IL-1β on the proliferation and differentiation of neural progenitor cells (NPCs) to better understand its potential effects on the developing brain. We find that the IL-1β receptor (IL-1R1) is expressed in the ventral mesencephalon of the developing brain. Furthermore, IL-1R1 is expressed on Nestin-positive, Sox-2-positive NPCs. IL-1β treatment reduced the numbers of proliferating NPCs, an effect prevented by the IL-1R1 receptor antagonist. LDH and MTT assays, and western blot analysis for cleaved caspase 3 and poly(ADP-ribose) polymerase, confirmed that this was not due to an increase in cell death but rather an induction of differentiation. To further study the effects of IL-1β on cell fate determination, we differentiated NPCs in the presence and absence of IL-1β. Il-1β promoted gliogenesis and inhibited neurogenesis, an effect that required p38-MAPK kinase signalling. In summary, these data show that exposure of NPCs to IL-1β affects their development. This necessitates an examination of the consequences that maternal immune system activation during pregnancy has on the cellular architecture of the developing brain.

Neurogenesis occurs in the hippocampus of the developing and adult brain due to the presence of multipotent stem cells and restricted precursor cells at different stages of differentiation. It has been proposed that they may be of potential benefit for use in cell transplantation approaches for neurodegenerative disorders and trauma. Prolonged release of interleukin-1β (IL-1β) from activated microglia has a deleterious effect on hippocampal neurons and is implicated in the impaired neurogenesis and cognitive dysfunction associated with aging, Alzheimer's disease and depression. This study assessed the effect of IL-1β on the proliferation and differentiation of embryonic rat hippocampal NPCs in vitro. We show that IL-1R1 is expressed on proliferating NPCs and that IL-1β treatment decreases cell proliferation and neurosphere growth. When NPCs were differentiated in the presence of IL-1β, a significant reduction in the percentages of newly-born neurons and post-mitotic neurons and a significant increase in the percentage of astrocytes was observed in these cultures. These effects were attenuated by IL-1 receptor antagonist. These data reveal that IL-1β exerts an anti-proliferative, anti-neurogenic and pro-gliogenic effect on embryonic hippocampal NPCs, which is mediated by IL-1R1. The present results emphasise the consequences of an inflammatory environment during NPC development, and indicate that strategies to inhibit IL-1β signalling may be necessary to facilitate effective cell transplantation approaches or in conditions where endogenous hippocampal neurogenesis is impaired.

Several secreted proteins facilitate the growth and guidance of sympathetic axons to their target organs during development. Here we show that IL-1β, a key regulator of inflammation in the immune system, inhibits axonal growth and branching from cultured sympathetic neurons at a stage in development when their axons are ramifying within their targets in vivo. IL-1β is synthesised in sympathetic ganglia and its targets at this stage, and IL-1β protein is detectable in the axons and perikarya of the innervating neurons. It acts directly on developing axons to inhibit their growth via NF-κB signalling. These findings show that IL-1β is a novel locally, and target-derived factor that can regulate the extent of sympathetic axon growth during the late embryonic and early postnatal period in developing rat sympathetic neurons.

Nuclear factor κB (NF-κB) signaling is known to promote neurite growth from developing sensory neurons and to enhance the size and complexity of pyramidal neuron dendritic arbors in the developing cerebral cortex. In marked contrast, here we show that NF-κB signaling can also exert a potent inhibitory influence on neurite growth in certain neurons, and can either promote or inhibit neurite growth in the same neurons depending on the mechanism of NF-κB activation. In neonatal superior cervical ganglion sympathetic neurons, enhancing NF-κB transcriptional activity by overexpressing either the p65 NF-κB subunit or the IκB kinase-β (IKKβ) subunit of the IκB kinase complex, or by tumor necrosis factor α (TNFα) treatment, strongly inhibits neurite growth. Paradoxically in neonatal nodose ganglion sensory neurons, enhancing NF-κB transcriptional activity by p65/p50 overexpression increases neurite growth, whereas enhancing NF-κB transcriptional activity by IKKβ overexpression inhibits neurite growth. In addition to activating NF-κB, IKKβ overexpression leads to phosphorylation of p65 on serine 536. Blockade of serine 536 phosphorylation by a S536A-p65 mutant protein prevents the growth-inhibitory effects of IKKβ overexpression in both sensory and sympathetic neurons and the growth-inhibitory effects of TNFα on sympathetic neurons. Furthermore, expression of a p65 S536D phosphomimetic mutant inhibits neurite growth from sensory neurons. These results demonstrate that NF-κB can either stimulate or inhibit neurite growth in developing neurons depending on the phosphorylation status of p65.

The extracellular calcium-sensing receptor (CaSR) monitors the systemic extracellular free ionized calcium level ([Ca2+]o) in organs involved in systemic [Ca2+]o homeostasis. However, the CaSR is also expressed in the nervous system where its role is unknown. Here we find high levels of the CaSR in perinatal mouse sympathetic neurons when their axons are innervating and branching extensively in their targets. Manipulating CaSR function in these neurons by varying [Ca2+]o, using CaSR agonists and antagonists or expressing a dominant-negative CaSR markedly affects neurite growth in vitro Sympathetic neurons lacking the CaSR have smaller neurite arbors in vitro, and sympathetic innervation density is reduced in CaSR-deficient mice in vivo. Hippocampal pyramidal neurons, which also express the CaSR, have smaller dendrites when transfected with dominant-negative CaSR in postnatal organotypic cultures. Our findings reveal a crucial role for the CaSR in regulating the growth of neural processes in the peripheral and central nervous systems.

Nerve growth factor (NGF) has an important role in regulating sympathetic neuron survival and target field innervation during development. Here we show that glucocorticoid-induced tumor necrosis factor receptor-related protein (GITR), a member of the TNF superfamily, and its ligand (GITRL) are co-expressed in mouse sympathetic neurons when their axons are innervating their targets under the influence of target-derived NGF. In culture, GITRL enhanced NGF-promoted neurite growth from neonatal sympathetic neurons, and preventing GITR-GITRL interaction in these neurons or knocking down GITR inhibited NGF-promoted neurite growth without affecting neuronal survival. Tnfrsf18(-/-) (Gitr) neonates have reduced sympathetic innervation density in vivo compared with Gitr(+/+) littermates. GITR activation is required for the phosphorylation of extracellular signal-regulated kinases 1 and 2 by NGF that is necessary for neurite growth. Our results reveal a previously unknown signaling loop in developing sympathetic neurons that is crucial for NGF-dependent axon growth and target innervation.

Introduction Pre-eclampsia is a multi-systemic pregnancy disorder and characterised as a hypertensive condition which consists of symptoms such as high blood pressure and proteinuria in women in their second trimester (around 20weeks gestation). It globally affects 2–8% of all pregnancies and remains the leading pregnancy disorder. Magnesium sulphate (MgSO 4 ) is commonly administered for the prevention and treatment of life-threatening seizures in women with preeclampsia and fetal neuroprotection before anticipated preterm birth. Despite this the mechanisms of action of MgSO 4 are poorly understood, partly due to a lack of good cellular models. We have developed an in vitro placental model to investigate the effects of MgSO 4 on (1) cytotrophoblast differentiation (syncytialisation) and (2) on preventing placental inflammation. Objectives To investigate the effects of MgSO 4 on (1) cytotrophoblast differentiation (syncytialisation) and (2) on preventing placental inflammation. Methods Cytotrophoblast viability was examined at 24h and 48h post treatment with Lipopolysaccharide (LPS) (10–1000ng/ml) and MgSO 4 (100nM–1mM) by MTT assay. Pyknotic nuclei morphology was identified by immunofluorescence. Syncytial formation was assessed by β -HCG production via ELISA methodology and assessed by desmoplakin architectural staining of cells treated with MgSO 4 (1mM), LPS (200ng) and Forksolin (25 μ M) for 72h. Quantitative real-time PCR was used to evaluated ACVR2A mRNA and TNF- α mRNA expression. Results MgSO 4 has a dose dependent effect on cytotrophoblast viability. BeWo cells treated with 200ng/ml LPS had a statistically significant effect on cell viability (30% viable cells) after 48h. 1mM MgSO 4 pre-treatment of cells resulted in an increase in viability to 57% compared to controls. Similarly, 1mM MgSO 4 pre-treatment reduced development of pyknotic nuclei compared to controls. MgSO 4 reduced the mRNA expression of ACVR2A and TNF- α . Finally MgSO 4 may have the potential to alter cytotrophoblast differentiation. Conclusion MgSO 4 provides protection against LPS-induced inflammation by modulating syncytialisation and reducing pro-inflammatory cytokine expression in vitro .

Expression of the dopaminergic neurotrophin GDF-5 in developing rat ventral mesencephalon (VM) was found to begin at embryonic day (E) 12 and peak on E14, when dopaminergic neurones undergo terminal differentiation. In the adult rat, GDF-5 was found to be restricted to heart and brain, being expressed in many areas of the brain, including striatum and midbrain. This indicates a role for GDF-5 in the development and maintenance of dopaminergic neurones.

Anatomy educators are increasing their utilisation of radiology in anatomy education in line with growing requirements for undergraduate radiology competency and clinical need. We aimed to evaluate student perceptions of radiology and to outline the technical and academic considerations underlying the integration of radiology into musculoskeletal practical anatomy sessions. The formal integration of radiology into anatomy practical sessions took place over a 5-week period during the lower limb musculoskeletal component of the anatomy course taught to first-year medical students. During practical sessions, students were required to rotate between aligned audio-visual radiology presentations, osteology/anatomical models, and prosection/dissection learning stations. After completing the course, students were invited to complete a survey to establish their opinions on radiology as a mode of learning and their satisfaction with radiological integration in anatomical practical sessions. Most students were not familiar with radiology prior to attending our university. All our students agreed or strongly agreed that learning to read radiographs in anatomy is important and most agreed that radiology is a valid assessment tool. Sixty percent stated that radiology facilitated their understanding of anatomy. The majority believed that radiology was best suited to clinically relevant anatomy and X-rays were their preferred learning tool. The practical approach to integrating radiology into undergraduate musculoskeletal anatomy described here did not place strain on existing academic resources. Most students agreed that radiology should be increased in anatomy education and that learning to understand radiographs in anatomy was important for clinical practice.