Neurodevelopmental disorders (NDs) are a growing public health concern. These complex disorders cause failure of normal brain development, which leads to intellectual disability (ID) or autism in 3% of children. Accurate diagnosis of NDs is difficult due to complex overlapping phenotypes. Moreover, associations between phenotypically similar NDs and their overlapping molecular mechanisms remain unidentified. The chromosome 2q23.1 region is a newly discovered disease region. We have recently identified a novel ND, 2q23.1 deletion syndrome. The phenotype includes severe ID, significantly delayed speech, behavioral problems, seizures and short stature. This syndrome shares characteristics in common with other genetic syndromes, including Smith-Magenis (SMS, RAI1), Pitt-Hopkins (PTH, TCF4), Angelman (AS, UBE3A) and Rett (RTT, MECP2) syndromes, including ID, speech impairment, and seizures, in addition to other autism spectrum disorder (ASD)-associated phenotypes (associated with mutation of MBD1). The methyl-CpG binding domain protein 5 (MBD5) is thought to be the causative gene for the core phenotype seen in del2q23. We propose that MBD5 is a dosage dependent gene, wherein deletion or duplication results in two distinct syndromes. We hypothesize that deletions, mutations, and duplications in MBD5 and its associated overlapping gene networks are responsible for causing the phenotype seen in 2q23.1 disorders. Furthermore, we hypothesize that syndromic neurodevelopmental genes are involved in common biological networks that, when dysregulated, result in the overlapping phenotypes present in many of these neurodevelopmental disorders. We first show that the causative gene for 2q23.1 deletion syndrome is MBD5. We established a consortium of clinical diagnostic and research laboratories to accumulate a large cohort with genetic alterations of chromosome 2q23.1, acquiring 65 subjects with microdeletion or translocation. We sequenced translocation breakpoints, aligned microdeletions to determine the critical region, assessed effects on mRNA expression, and examined medical records, photos, and clinical evaluations. We identified MBD5 as the only locus that defined the critical region. Partial or complete deletion of MBD5 was associated with haploinsufficiency, intellectual disability, epilepsy, and autistic features. Sixteen alterations disrupted MBD5 alone, including partial deletions of noncoding regions not typically captured or considered pathogenic by current diagnostic screening. Expression profiles and clinical characteristics were largely indistinguishable between MBD5-specific alteration and deletion of the entire 2q23.1 interval. We surveyed MBD5 coding polymorphisms among 747 ASD subjects compared to 2,043 non-ASD subjects analyzed by whole-exome sequencing and detected an association with a highly conserved methyl-CpG binding domain missense variant, G79E (p=0.012). Thus, we establish that haploinsufficiency of MBD5 is the primary causal factor in 2q23.1 microdeletion syndrome and that mutations in MBD5 are associated with autism. Secondly, we show that MBD5 is a dosage dependent region, wherein deletion or duplication results in altered gene dosage. We previously established the 2q23.1 microdeletion syndrome and report herein 23 individuals with 2q23.1 duplications, thus establishing a complementary duplication syndrome. The observed phenotype includes intellectual disability, motor delay, language impairments, infantile hypotonia and gross motor delay, behavioral problems, autistic features, dysmorphic facial features (pinnae anomalies, arched eyebrows, prominent nose, small chin, thin upper lip), and minor digital anomalies (fifth finger clinodactyly and large broad first toe). The microduplication size varies among all cases and ranges from 680 kb to 53.7 Mb, encompassing a region that includes MBD5. Phenotypic analyses suggest that 2q23.1 duplication results in a slightly less severe phenotype than the reciprocal deletion. The features associated with a deletion, mutation, or duplication of MBD5 and the gene expression changes observed support MBD5 as a dosage sensitive gene critical for normal development. Dup(2)(q23.1) causes a phenotype similar to del(2)(q23.1) and other NDs, like SMS and autism, suggesting shared molecular pathways. Finally, chromatin-modifying genes play an important role in the genetic etiology of many NDs, including intellectual disability, epilepsy, and autism. Many monogenic NDs are caused by chromatin modifying genes, including 2q23.1 deletion and duplication, SMS, RTT, AS, fragile X syndrome (FXS), and PTH. Many of these disorders have overlapping features that include language, sleep, and behavioral anomalies. Investigation of relative gene expression by quantitative PCR and microarray of cell lines from individuals with disorders due to altered expression of MBD5, RAI1, MECP2, UBE3A, TCF4, and MBD1 revealed molecular signatures that allowed for the generation of a novel neurodevelopmental molecular network supporting the overlapping features across these syndromes. Further, knockdown of MBD5 and RAI1 in SH-SY5Y and HEK293T cell lines expanded the repertoire of genes involved in these pathways and showed that other chromatin modifying genes, as well as developmental genes are dysregulated. Pathway analyses showed that MBD5 and RAI1 function in chromatin remodeling, circadian rhythm, neuronal development, and cell growth/survival pathways. From these studies, precise gene dosage of chromatin modifying genes, such as RAI1 and MBD5 are clearly a requirement for normal neurodevelopment and function. Taken together, these studies have given us insight into the role of MBD5 as a dosage sensitive gene in two NDs. Furthermore, we gained insight of how dosage effects of MBD5 and RAI1 affect molecular pathways that are linked to neuronal and behavioral development. We have unveiled pathways and genes, which are important to normal human development, neurodevelopment and behavior. These findings support further investigations into the relationships among causative neurodevelopmental genes, which will lead to common points of regulation that may be targeted toward therapeutic intervention.

<p>Following the phase out of polybrominated diphenyl ethers (PBDEs), manufacturers turned to several alternative flame retardants (FRs) to meet flammability standards. Organophosphate FRs (OPFRs), and in particular tris (1,3-dichloropropyl) phosphate (TDCPP), have been increasingly detected in textiles and foam padding used in a variety of consumer products including camping equipment, upholstered furniture, and baby products. Like PBDEs, OPFRs are additive, meaning that they are not chemically bound to the treated material and can more readily leach out into the surrounding environment. Indeed, OPFRs have been detected in numerous environmental and biological matrices, often at concentrations similar to or exceeding that of PBDEs.</p><p>Although OPFRs have been in use for several decades, relatively little is known regarding their potential for adverse human and environmental health consequences. However, based on their structural similarity to OP pesticides, they may have analogous mechanisms of toxicity. OP pesticide toxicity is classically associated with cholinesterase inhibition, resulting in cholinergic intoxication syndrome. OPFRs have been shown to be ineffective cholinesterase inhibitors, however chlorpyrifos (CPF) and other OP pesticides have been shown to elicit adverse effects on developing organisms through other mechanisms.</p><p>The main objective of this research project was to evaluate the toxicity of four structurally similar OPFRs (TDCPP; tris (2,3-dibromopropyl) phosphate, (TDBPP); tris (1-chloropropyl) phosphate (TCPP) and tris (2-chloroethyl) phosphate (TCEP)) in comparison to chlorpyrifos (CPF), a well-studied OP pesticide. A combination of in vitro and in vivo models was used to elucidate potential mechanisms as well as functional consequences of exposure in developing organisms. </p><p>In the first research aim, a series of in vitro experiments with neurotypic PC12 cells was used to evaluate the effects of four structurally similar OPFRs (TDCPP, TDBPP, TCEP, or TCPP) and CPF on neurodevelopment. The effects of TDCPP were also compared to that of BDE-47, a major component of the commercial PentaBDE mixture. In general, TDCPP elicited similar or greater effects when compared to an equimolar concentration of CPF. All OPFRs tested produced similar decrements in cell number and altered phenotypic differentiation, while BDE-47 had no effect on cell number, cell growth, or neurite growth. </p><p>For the second research aim, zebrafish (Danio rerio) were used to evaluate the effects of the same suite of chemicals on early development. TDCPP, TDBPP, and CPF elicited overt toxicity (e.g., malformations or death) within the concentration range tested (0.033-100 µM). TDBPP was the most potent with 100% mortality by 6 days post fertilization (dpf) at &#8805;3.3 µM. CPF and TDCPP showed equivalent toxicity with malformations observed in at 10 µM and significant mortality (&#8805;75%) at &#8805;33 µM. There was no overt toxicity among TCEP- and TCPP-exposed fish. All test chemicals affected larval swimming behavior on 6 dpf at concentrations below the overt toxicity threshold. Parent chemical was detected in all in embryonic (1 dpf) and larval (5 dpf) tissues. TDCPP and TDBPP showed rapid and extensive metabolism.</p><p>Finally, for the third aim, juvenile (45-55 dpf) zebrafish were exposed to CPF (1 µg/g food) or TDCPP (Low TDCPP = 1 µg/g food; High TDCPP = 40 µg/g food) via diet for 28 days followed by a 7 day depuration period where all treatments received clean food. A dietary exposure was chosen to more closely recapitulate exposure in humans. Samples were collected at seven time points throughout the experiment: days 0, 7, 14, 21, 28, 30, 35. Whole tissues were collected for tissue accumulation and histopathology endpoints. Viscera and brain were dissected and flash frozen separately for DNA damage analyses. </p><p>Tissue measurements of CPF, TDCPP, and the metabolite bis (1,3-dichloropropyl) phosphate (BDCPP) were often below the method detection limit, however when present there was a trend towards increased accumulation with treatment and time. On Day 7 Low TDCPP caused a dramatic but transient increase in DNA damage in both viscera and brain that returned to control levels by Day 14. Similar results have been seen previously with other genotoxicants and may be due to CPF and High TDCPP inducing an adaptive response prior to the 7 day sampling point. All treatments shifted the neurohypophysis to adenohypophysis ratio (NH/AH; Day 7 only) and significantly increased thyroid follicle activation (Day 14). Finally High TDCPP affected gonad maturation, causing a significant increase in ovary follicle development (Day 14) and a transient but marked decrease in testes maturity (Day 7). Taken together these data suggest that dietary exposure to TDCPP and CPF elicits DNA damage in brain and viscera and alters endocrine function in juvenile zebrafish. Importantly, analyses were restricted to the first three time points (Days 0, 7, and 14) due to the emergence a disease among the experimental colony. Although these samples were collected prior to the disease becoming apparent, it remains a potential confounder of the current results.</p> / Dissertation

Le récepteur 5-HT6 de la sérotonine, un des derniers récepteurs de la sérotonine à avoir été découvert, est une des cibles les plus prometteuses pour traiter les déficits cognitifs de la schizophrénie et de la maladie d’Alzheimer. Les antagonistes 5-HT6 exercent des effets pro-cognitifs dans de nombreux paradigmes expérimentaux de cognition chez les rongeurs et plusieurs d’entre eux sont en développement clinique (phase III) dans la schizophrénie et la maladie d’Alzheimer. Exclusivement exprimé dans le système nerveux central, le récepteur 5-HT6 est présent dès les phases précoces du développement neural et est impliqué dans différents processus neuro-développementaux. Plusieurs études ont ainsi démontré que le récepteur jouait un rôle clé dans la migration des neurones (interneurones et neurones pyramidaux) du cortex cérébral (Riccio et al. Mol Psychiatry 14(3):280-90, 2009 ; Transl Psychiatry 11;1:e47, 2011 ; Jacobshagen et al. Development in revision). Grâce à un crible interactomique, notre équipe a récemment identifié un réseau de protéines recrutées par le domaine carboxy-terminal du récepteur, comprenant la cyclin-dependent kinase (Cdk)5 et certains de ses substrats et connues pour leur implication dans la migration neuronale, la pousse neuritique et la synaptogénèse. Nous avons également démontré que le récepteur stimulait la pousse neuritique de façon agoniste-indépendante par un mécanisme impliquant la phosphorylation du récepteur par Cdk5 et l’activation de la Rho GTPase Cdc42 (Duhr et al. Nature Chem. Biol., en révision). Cette étude a mis pour la première fois en évidence une activation constitutive d’un récepteur couplé aux protéines G dépendant de sa phosphorylation par une kinase associée. Des études préliminaires réalisées par l’équipe indiquent également que l’activation du récepteur 5-HT6 induit une diminution du nombre d’épines dendritiques et une modification de leur morphologie dans des cultures primaires de neurones d’hippocampe. Le projet de thèse aura pour objectif la caractérisation des mécanismes moléculaires impliqués dans cet effet. Une attention particulière sera portée sur le rôle de Cdk5 et de son substrat WAVE1, une protéine induisant la formation des épines dendritiques grâce à sa capacité à activer le complexe Arp2/3 (également identifié dans l’interactome du récepteur 5-HT6) et à promouvoir la polymérisation de l’actine. La phosphorylation de WAVE1 par Cdk5 inhibant son activité et la formation des épines, ce mécanisme pourrait être à l’origine de la diminution du nombre d’épines induite par le récepteur 5-HT6. Ces études seront réalisées in vitro, sur des cultures primaires de neurones d’hippocampe et in vivo, en utilisant un modèle (en cours de génération) de souris knock-in exprimant le récepteur 5-HT6 fusionné à une étiquette GFP. Grâce à ce modèle, un crible interactomique sera également réalisé afin d’identifier de nouveaux partenaires du récepteur potentiellement impliqués dans la différentiation neuronale dans un contexte tissulaire authentique. Ce projet sera réalisé à l’Institut de Génomique Fonctionnelle (IGF) au sein de l’équipe « Neuroprotéomique et signalisation des maladies neurologiques et psychiatriques » sous la co-direction de Philippe Marin et Séverine Chaumont-Dubel. Il permettra de caractériser de nouveaux substrats cellulaires potentiellement impliqués dans les déficits cognitifs de la schizophrénie de plus en plus considérée comme une pathologie du développement et d’identifier de nouvelles cibles pour le traitement précoce de ces déficits particulièrement invalidants et insuffisamment pris en en charge par l’arsenal antipsychotique existant. / The serotonin 5-HT6 receptor, one of the most recently cloned serotonin receptors, is a promising target for the treatment of cognitive deficits of both schizophrenia and Alzheimer’s disease. 5-HT6 receptor blockade by antagonists exerts pro-cognitive effects in a wide range of models of cognitive impairment in rodents and some of them are in phase III of clinical trials in schizophrenia and Alzheimer’s disease. The 5-HT6 receptor is exclusively expressed in the central nervous system, where it is detected at early phases of brain development. Studies have shown that 5-HT6 receptors have a key influence upon migration of both pyramidal neurons and interneurons of the cerebral cortex (Riccio et al. Mol Psychiatry 14(3):280-90, 2009 ; Transl Psychiatry 11;1:e47, 2011; Jacobshagen et al. Development, in revision). Using a proteomic strategy, our team recently identified a network of proteins interacting with the carboxy-terminal domain of the receptor. These include Cyclin-dependent kinase (Cdk)5 and some of its substrates, which are known to control neuro-developmental processes such as neuronal migration, neurite growth and dendritic spine morphogenesis. We have also demonstrated that the expression of the 5-HT6 receptor elicits neurite growth in an agonist-independent manner through a mechanism involving receptor phosphorylation at a serine residue by associated Cdk5 and engagement of the Rho GTPase Cdc42 (Duhr et al. Nature Chem. Biol., in revision). These studies show for the first time a constitutive activation of a G protein-coupled receptor mediated by its phosphorylation by an associated protein kinase. Preliminary experiments performed by the team also revealed that 5-HT6 receptors activation decreases the number of dendritic spines and modify spine morphology in hippocampal neurons in primary culture. This thesis project aims at characterizing the signalling mechanisms underlying the control of dendritic spine morphogenesis by the 5-HT6 receptors. Particular attention will be paid to Cdk5 and its substrate WAVE1, a protein known to induce neurite growth via the activation of the Arp2/3 complex (also identified in the 5-HT6 receptor interactome), which promotes actin polymerization. As phosphorylation of WAVE1 by Cdk5 inhibits its activity, we hypothesize that Cdk5-elicited phosphorylation of WAVE1 in the receptor-associated complex might underlies its control of spine morphogenesis. This project will combine in vitro studies performed on primary cultured hippocampal neurons and in vivo studies using transgenic mice expressing GFP tagged 5-HT6 receptors (this mouse line is currently being generated). We will also take advantage of this model to perform a novel interactomics screen to identify in an authentic tissue context novel receptor partners potentially involved in dendritic spine formation. This project should reveal novel cellular targets for the alleviation of the currently untreated and strongly debilitating cognitive deficits of schizophrenia, which are thought to result from abnormalities of brain development. It will be realized at the Institute of Functional Genomics in the “Neuroproteomics and signaling of neurodegenerative and psychiatric disorders” team under the supervision of Philippe Marin and Séverine Chaumont-Dubel.

Early brain development is characterized by rapid growth and perpetual reconfiguration, driven by a dynamic milieu of heterogeneous processes. Moreover, potent postnatal brain plasticity engenders increased vulnerability to environmental stimuli. However, little is known regarding the ontogeny and temporal manifestations of inter- and intra-regional functional connectivity that comprise functional brain networks. Recently, resting-state functional magnetic resonance imaging (fMRI) emerged as a promising non-invasive neuroinvestigative tool, measuring spontaneous fluctuations in blood oxygen level dependent (BOLD) signal at rest that reflect baseline neuronal activity. Its application has expanded to infant populations in the past decade, providing unprecedented insight into functional organization of the developing brain, as well as early biomarkers of abnormal/ disease states. However, rapid extension of the resting-state technique to infant populations leaves many methodological issues need to be resolved prior to standardization of the technique. The purpose of this thesis is to describe a protocol for intrinsic functional connectivity analysis, and extraction of resting-state networks in infants <12 months of age using the data-driven approach independent component analysis (ICA). To begin, we review the evolution of resting-state fMRI application in infant populations, including the biological premise for neural networks. Next, we present a protocol designed such that investigators without previous knowledge in the field can implement the analysis and reliably obtain viable results consistent with previous literature. Presented protocol provides detailed, albeit basic framework for RSN analysis, with interwoven discussion of basic theory behind each technique, as well as the rationale behind selecting parameters. The overarching goal is to catalyze efforts towards development of robust, infant-specific acquisition and preprocessing pipelines, as well as promote greater transparency by researchers regarding methods used. Finally, we review the literature, current methodological challenges and potential future directions for the field of infant resting-state fMRI.

Made available in DSpace on 2017-07-21T14:35:54Z (GMT). No. of bitstreams: 1 JOSE AUGUSTO POCHAPSKI.pdf: 2266023 bytes, checksum: e6666fece9c726545eef3a5015509386 (MD5) Previous issue date: 2016-02-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Parkinson's disease (PD) is the second most common neurodegenerative disease in the world population. However, its current treatment comes down to symptomatic relief. The omega-3 (-3) being an essential fatty acid for brain development, has been showing beneficial effects in PD. Therefore, the aim of this study was to evaluate whether treatment with -3 during early neurodevelopment periods provides a nootropic, antidepressant and/or neuroprotective effect in an animal model of PD. For this, female rats were treated with -3 during pregnancy (150, 300, 600 mg/Kg/day) and during pregnancy + lactation (300 mg/Kg /day). After completing two months of age the male offspring were submitted to the tests of sucrose preference, social recognition, object recognition and open field. Completing three months of age, the animals received in the prosencefalic unilateral 6-OHDA infusion and subsequent test of the rotational behavior or bilateral 6-OHDA infusion and subsequent tests of sucrose preference, social recognition and open field. A nootropic effect of -3 was observed from the results obtained on the tests of social recognition (-3 600) and object recognition (all groups -3). Regarding the animal model of PD, the -3 (all -3 groups) showed a reduction of the cognitive deficits induced by 6-OHDA, but without na antidepressive effect, although there was no demonstration of neuroprotection after unilateral lesion with 6-OHDA. Thus, this study the -3 demonstrated an nootropic and a possible neuroprotective effect of the -3 administration during the pregnancy period. / A doença de Parkinson (DP) é a segunda doença neurodegenerativa mais comum na população mundial, entretanto, seu atual tratamento resume-se a alívios sintomáticos. O ômega-3 (-3) sendo um ácido graxo essencial no neurodesenvolvimento, também vem apresentando efeitos benéficos na DP. Assim sendo, o objetivo deste trabalho foi avaliar se o tratamento com -3 durante os períodos iniciais do neurodesenvolvimento proporciona um efeito nootrópico, antidepressivo e/ou neuroprotetor em um modelo animal da DP. Para isso, ratas foram tratadas com -3 durante a gestação (150 ou 300 ou 600 mg/Kg/dia) e durante a gestação+lactação (300 mg/Kg/dia). Após terem completado dois meses de idade, os filhotes machos foram submetidos aos testes de preferência à sacarose, reconhecimento social, reconhecimento de objetos e campo aberto. Completando 3 meses de idade, estes animais receberam no feixe prosencefálico medial infusão unilateral de 6-OHDA e posterior teste do comportamento rotatório ou infusão bilateral de 6-OHDA e subsequentes testes de preferência à sacarose, reconhecimento social e campo aberto. Foi observado um efeito nootrópico do -3 a partir dos resultados obtidos aos dois meses nos testes de reconhecimento social (-3 600mg/Kg) e reconhecimento de objetos (todos grupos -3). Em relação ao modelo animal da DP, o tratamento com -3 (todos os grupos ω-3) reduziu os prejuízos cognitivos induzidos pela 6-OHDA, porém sem apresentar efeito antidepressivo nestes,além de não reduzir o número de rotações contralaterais após a lesão unilateral com a 6-OHDA. Com isso, demonstramos neste trabalho um efeito nootrópico e,possivelmente neuroprotetor, da administração do -3 durante o período da gestação. Palavras chave: Ômega-3. Neurodesenvolvimento. Doença de Parkinson.

O nascimento prematuro constitui-se em um fator de risco ao desenvolvimento. Por um lado a hospitalização em Unidade de Terapia Intensiva Neonatal (UTIN) pode proteger o bebê nascido pré-termo, por outro lado este sobrevive em um ambiente adverso, em que é exposto a estímulos estressores e dolorosos inerentes aos cuidados intensivos. Os objetivos do estudo foram: a) caracterizar e comparar o desenvolvimento neurocomportamental de bebês nascidos pré-termo, diferenciados pela idade gestacional; b) examinar associações entre os eventos estressores da UTIN e o desenvolvimento neurocomportamental. A amostra foi composta por 45 recém-nascidos pré-termo (RNPT) nascidos no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto-USP, distribuídos em três grupos: G1, 10 RNPT de 23 a 28 semanas de idade gestacional (IG); G2, 10 RNPT de 29 a 32 semanas de IG; G3, 25 RNPT de 34 a 37 semanas de IG (grupo controle). Apenas os neonatos G1 e G2 foram internados na UTIN. Os neonatos foram avaliados pela Neurobehavioral Assessment of the Preterm Infant (NAPI), antes de atingir 37 semanas de idade pós-concepcional (IPC). Os neonatos G1 e G2 foram avaliados em dois momentos (aos 32 e 35 semanas de IPC) e os G3 foram avaliados apenas nesta última idade. Na avaliação dos eventos estressores da UTIN foram realizadas a observação direta dos bebês e a análise diária do prontuário dos pacientes, durante a internação. Os resultados mostraram que, quanto ao desenvolvimento neurocomportamental na fase de 35 semanas de IPC, os neonatos G3 apresentaram os melhores resultados em relação aos neonatos G1 e G2. Os piores resultados na NAPI foram encontrados nos neonatos G2, com menores escores nos domínios motor e vigor e irritabilidade, em comparação aos neonatos G1 e G3. Além disso, destaca-se que a evolução do neurodesenvolvimento, de 32 para 35 semanas de IPC, foi melhor nos neonatos G1 quando comparados aos G2. Considerando-se a associação entre o neurodesenvolvimento e os eventos estressores da UTIN, observou-se que, aos 32 semanas de IPC, quanto maior o número de eventos de ventilação assistida, mais choro na avaliação neurocomportamental nos neonatos G1. Nos neonatos G2, por sua vez, quanto maior era o número de acessos periféricos, mais alerta e ativado os bebês se mantiveram, mais choro e melhor era o sinal de cachecol. Além disso, neste grupo, quanto mais exames médicos realizados mais alerta e chorando os bebês se mantiveram na avaliação NAPI. Na idade de 35 semanas IPC, nos G1 e G2, quanto maior era o número de acessos periféricos, mais tempo os bebês se mantiveram em estado de alerta na avaliação NAPI. A avaliação neurodesenvolvimental inicial na fase neonatal antes de atingir a idade do termo permitiu a identificação de riscos e recursos nos neonatos pré-termo. Apesar de extrema prematuridade, os neonatos G1 apresentaram mais recursos neurocomportamentais do que os neonatos pré-termo moderado, com 35 semanas de IPC. Os eventos estressores de manuseio dos neonatos e procedimentos dolorosos na UTIN mostraram associações com estados comportamentais ativados, o que interfere negativamente nos processos de regulação desenvolvimental dos bebês prematuros. / Preterm birth is a risk factor for development. On one hand hospitalization in the Neonatal Intensive Care Unit (NICU) can protect the preterm infants, on the other hand they survive in an adverse environment, where they are exposed to stressful and painful stimuli inherent in the intensive care. The objectives of the study were: a) to characterize and to compare the neurobehavioral development of preterm infants at different gestational ages; b) to examine associations between stressful events in NICU and the neurobehavioral development. The sample was composed of 45 preterm neonates (PT) born in the Hospital of Clinics, Faculty of Medicine at Ribeirão Preto - USP, divided into three groups: G1, 10 PT of 23-28 weeks of gestational age (GA), G2, 10 PT of 29-32 weeks GA, and G3, 25 PT of 34-37 weeks GA (control group). Only the G1 and G2 neonates were admitted to the NICU. The neonates were evaluated through Neurobehavioral Assessment of the Preterm Infant test (NAPI), prior reach 37 weeks of post-conceptional age (PCA). The G1 and G2 neonates were assessed at two time points (at 32 and 35 weeks of PCA) and G3 neonates were evaluated only in this last age. The assessment of the stressful events in the NICU was performed through direct observation of the infants and the daily analysis of the inpatients` charts during the hospitalization. The results showed that on the neurobehavioral development at 35 weeks of PCA, the G3 neonates showed better results in comparison to the G1 and G2 neonates. The worst results of NAPI were found in the G2 neonates, indicating lower scores in motor force and irritability, compared to the G1 and G3 neonates. Furthermore, the neurodevelopment evolution from 32 to 35 weeks of PCA was better in the G1 neonates than the G2 ones. Concerning the associations between the neurodevelopmental and the stressful events in the NICU, it was observed that, at 32 weeks of PCA, the greater the number of assisted ventilation events, the more crying happened in the neurobehavioral evaluation of the G1neonates. In the G2 neonates, in turn, the greater the number of peripheral access, the more alert and active the infants remained, the more crying and the best was the scarf sign. Moreover, in this group, the more medical examinations, the more alert and crying the infants remained during the NAPI assessment. In both groups of neonates at 35 weeks PCA, the greater the number of peripheral access, the longer the infants remained on alert state during the NAPI assessment. The initial neurodevelopmental assessment in the neonatal phase before reaching the age of term allowed the identification of risks and resources in preterm neonates. Although the G1 neonates presented extreme prematurity, they exhibit more neurobehavioral resources than the moderate preterm neonates at 35 weeks of PCA. The stressors stimuli of handling the neonates and painful procedures in the NICU setting were associated with more infants` activated behavioral states, which could impair the regulation developmental process of premature infants.

Les microglies, les cellules de l’immunité innée, résidentes du cerveau, sont impliquées dans la réponse inflammatoire cérébrale et le modelage des réseaux neuronaux au cours du développement. La perturbation de leurs activités par des stimuli environnementaux pouvant conduire à des altérations psychopathologiques, dans cette thèse, nous avons étudié le rôle des microglies dans les effets neurobiologiques et comportementaux d’un stimulus inflammatoire. Les travaux précédents ont révélé que l’administration de lipopolysaccharide (LPS), une endotoxine bactérienne, provoque des comportements de type dépressifs. Le rôle des microglies dans ces altérations a fait l’objet de la première étude de cette thèse (Chapitre 2). Afin de dépléter les microglies du cerveau, des souris adultes ont reçu par voie d’administration intra-hippocampique des liposomes contenant du clodronate, provoquant ainsi l’apoptose des microglies phagocytaires. L’administration de LPS active dans l’hippocampe la synthèse de cytokines pro-inflammatoires [interleukine (IL)-1b et facteur de nécrose tumorale (TNF)-a] et anti-inflammatoires (IL-10), et de l'indoleamine 2,3-dioxygénase, une enzyme impliquée dans le métabolisme du tryptophane aux activités pro-dépressives. La déplétion des microglies phagocytaires atténue les effets du LPS, à l’exception de l’IL-1b, dont l’expression est exacerbée. De plus, l’administration de clodronate prévient les effets du LPS sur les comportements de type dépressif. Dans leur ensemble, ces résultats ont révélé que les microglies phagocytaires sont impliquées dans les effets inflammatoires et comportementaux de type dépressif induits par le LPS. Nous avons ensuite étudié le rôle des microglies dans les effets comportementaux d’une inflammation maternelle précoce provoquée lors de la colonisation du cerveau fœtal par les microglies (Chapitres 3 & 4). Ainsi, nous avons administré au jour gestationnel (JG)9.5 du LPS à des souris gestantes et évalué la trajectoire développementale pré- et post-natale des microglies et du comportement de la progéniture (Chapitre 3). L’administration de LPS à JG9.5 provoque une réduction du pourcentage représenté par les microglies matures aux JG14.5 et 18.5 et des déficits comportementaux persistants à l’âge adulte avec un dimorphisme sexuel prononcé. Nous avons alors recherché à identifier les mécanismes moléculaires impliqués dans les effets du LPS administré à JG9.5, en étudiant la piste de l’action des cytokines inflammatoires (Chapitre 4). Pour cela, nous nous sommes focalisé sur l’IL-1b, la cytokine inflammatoire effectrice principale de l’activité microgliale. L’expression de l'IL-1b et des cytokines associées (IL-6, TNFa et IL-10) augmente dans le plasma maternel, le placenta et le cerveau fœtal, 2 et 4 heures après l’administration de LPS. Ces changements sont accompagnés d'un phénotype microglial immature à JG18.5 et d’une réduction de la population microgliale totale au jour postnatal (JPN)9. À l’âge adulte (JPN65), nous avons observé une modification morphologique de la microglie dans plusieurs structures cérébrales. Enfin, les souris adultes, prénatalement traitées au LPS, développent des altérations des comportements de type sociaux et des comportements répétitifs. Les altérations du nombre de microglies induites par le LPS sont corrélées aux troubles comportementaux, et ce, de façon spécifique en fonction du sexe des souris. Enfin, la co-administration de l'antagoniste du récepteur de l'IL-1 et de LPS chez les femelles gestantes au JG9.5 réduit, voire prévient les effets inflammatoires et comportementaux du LPS. [...] / Recent research on microglia has uncovered a multitude of activities that extends the role of these cells well beyond their traditional function as immune sentinels. The most prominent of these newly described activities is an intricate role in neuronal network remodeling notably upon environmental challenge or during brain development, the disruption of which can result in long lasting consequences relevant to several psychopathologies. We sought, in the current thesis, to identify some of the mechanisms involved. Our initial approach was to target the immune function of microglia, based on our previous findings linking systemic immunogenic challenge with lipopolysaccharide (LPS) in mice with the development of despair-like behavior/depression. Here, we sought to identify immune mediators activated in microglia following a single systemic challenge with LPS (Chapter 2). These studies were conducted in adult mice in which phagocytic microglia were depleted using a single injection of liposomal clodronate in the CA3 region of the hippocampus. LPS challenge significantly upregulated the expression of both pro-inflammatory [interleukin (IL)-1b and tumor necrosis factor (TNF)-a] and anti-inflammatory (IL-10) cytokines compared to saline treated animals. In addition, LPS highly increased the expression of indoleamine 2,3-dioxygenase (IDO), an important rate limiting enzyme for metabolizing tryptophan in the brain and an established indicator of the activation of this depression mediating pathway. Clodronate-mediated depletion attenuated all of these effects apart from IL-1b expression which was further exacerbated. Behavioral assessment of the mice demonstrated a significant LPS-induced increase of immobility in the forced swim test (FST), which was prevented by clodronate. This experimental approach provided a snapshot of the role of inflammation in the development of brain dysfunction mediated by microglia. In subsequent studies (chapter 3 & 4), and in order to perform a more comprehensive, longer-term investigation of microglia activity in neurodevelopment, we utilized a prenatal infection model using LPS to activate maternal immunity at a relatively early [Gestational Day (GD)9.5] time point when microglia colonize the fetal brain to assess the impact on microglial population during development and the subsequent behavior of the progeny (Chapter 3). The results demonstrated LPS reduced the percentage of mature microglial population at GD14.5 and GD18.5 representing mid to late gestation. In addition, prenatal LPS had a significant effect on the offspring’s neonatal as well as adult behavior, with a clear divergence along sex lines in adulthood. In the final study (Chapter 4), we sought to investigate the mechanisms underlying the changes we noted in microglial development and the sexually dimorphic behavioral deficits. For this, we focused on the role played by pro-inflammatory cytokines, particularly IL-1b which represents the main effector of microglial activation following infection or injury. Detailed analysis of the expression of IL-1b and other related cytokines (IL-6, TNF-a and IL-10) revealed an increased expression of these mediators in maternal plasma, placenta and fetal brain, 2 and 4 hours after the prenatal LPS treatment. These changes were accompanied with a decreased percentage of mature microglia in the brain of embryos at GD18.5 and of total microglia population at post-natal day (PND)9. In the adult offspring (PND65), we detected an increased density and altered microglial morphology in specific higher-order structures implicated in complex behaviors, as well as altered social preference and memory and increased repetitive actions. [...]

Orofacial clefts are among the most common congenital defects in the United States, affecting roughly 1 in 600 births annually. A majority of these cases are considered to be “isolated” clefts of the lip and/or palate (ICLP). However the term “isolated” is somewhat of a misnomer, as functional deficits frequently accompany ICLP. One of the most problematic yet understudied of these deficits involves the high prevalence of reading disabilities in this population. It has been estimated that as high as 46% of children with ICLP will be diagnosed with a reading disability, particularly dyslexia. Despite this high prevalence and the well-established neurological basis of dyslexia, relatively little attention has been paid to the role that brain development plays in the reading problems in ICLP. Previous studies from our lab have demonstrated significant changes in brain structure in children with ICLP (that have importantly correlated with functional measures). However we have yet to combine both a structural and functional neuroimaging study with an in-depth analysis of reading dysfunction in this population. The current study examined boys with ICLP, age 8-12 (boys have a higher prevalence of ICLP and show more significant reading problems that girls with ICLP) compared to healthy control boys. Measures of cognitive functioning were obtained with an emphasis on reading and language skills. In addition MRI scans were obtained which included volumetric measures, diffusion-weighted measures (DWI; white matter), and connectivity measures (resting-state fMRI). Even after controlling for the effect of socioeconomic status, boys with ICLP showed significant decreases in reading and language skills (particularly reading fluency). Boys with ICLP did not show significant differences on phonlogical measures (the primary cause of dyslexia). In addition, phonological measures were not predictive of reading fluency, while object naming tasks were predictive of reading fluency in boys with ICLP. For white matter integrity, measures of fractional anisotropy (FA) were found to be increased in the right occipital lobe for boys with ICLP indicating more organized white matter in this region. This increase in right occipital FA was also predictive of better reading outcomes, particularly reading fluency. For more specific white matter tracts, only the fornix and the tapetum (both associated with the temporal lobes) showed a significant difference with a decrease in FA for boys with ICLP. The decrease in FA in the tapetum was also predictive of better reading outcomes in ICLP. When looking at resting-state networks, boys with ICLP showed an increase in connectivity within posterior and subcortical regions when compared to healthy control boys, indicating stronger network connections within the posterior language regions of the brain. Taken together, these results point to differences in both structural and functional connectivity in the brains boys with ICLP. Furthermore, this pattern is different than that found in children with developmental dyslexia as there appears to be no disruption of the posterior reading systems. Cognitive measures also indicate normal phonological awareness in this group, further distinguishing them from dyslexic children. Boys with ICLP instead may be over-relying on these posterior, more visually oriented reading systems as a compensatory mechanism to overcome problems with the development of the typical “lexical route” of reading.

The aim of this review paper was to investigate variations in sex differentiation, andalso, examine what neurobiological underpinnings there are to gender identity andgender dysphoria. In addition, the most extreme form of gender dysphoria,transsexuality, will be described from a neurobiological perspective but also discussedin terms of the classification from DSM-5. One theory considered on how genderidentity originates is the fact that the sexual differentiation of the brain and thedifferentiation of sexual organs develop during different time periods. Alterationswere displayed in a demonstration of male-to-female (MTF) and female-to-male(FTM) transsexuals that showed reversed results in cell number in a part of thehypothalamus, acronymized INAH-3 and reversal volume results in another region,acronymized BSTc. Likewise, differences in grey matter in the right putamendepended upon their natal gender. It can be concluded that there is biologicalevidence for sex differentiation and indications that lead science into consideringbiological components for gender dysphoria. This conclusion suggests for futureresearch questions focused more on the possible genetic factors of gender identity,also, consider larger sample sizes and more replications. There is still incompleteknowledge of what exactly constitutes an individual’s gender identity.

Evidence from various sources suggests that schizophrenia may result from altered brain development. The adult olfactory epithelium provides an available 'window' on neuronal development because new neurons are formed there throughout life. This thesis set out to test the neurodevelopmental hypothesis of psychotic disease. Two cell-based models, skin fibroblast and olfactory mucosa culture, were employed to investigate this hypothesis. In order to first demonstrate the utility of olfactory mucosa culture as a model of neurodevelopment, and to allow the candidate to gain proficiency in the culture of this tissue, an investigation of the mitogenic and differentiating properties of insulin-like growth factor-I within this system was undertaken. Insulin-like growth factor-I has multiple effects within the developing nervous system but its role in neurogenesis in the adult nervous system is less clear. The adult olfactory mucosa is a site of continuing neurogenesis that expresses insulin-like growth factor-I, its receptor, and its binding proteins. The action of insulin-like growth factor-I was assayed in several serum-free culture systems combined with bromodeoxyuridine labelling of proliferating cells and immunochemistry for specific cell types. Once proficiency in olfactory mucosa culture was gained, this model was applied to biopsied olfactory mucosa from schizophrenia and bipolar disorder patients in order to test the developmental parameters of adhesion, cell proliferation, and cell death in a neural tissue. It was previously shown that olfactory cultures from individuals with schizophrenia had increased cell proliferation and attached less frequently than cultures from healthy controls suggesting disrupted neurogenesis. An aim of this study was to replicate those observations in individuals with schizophrenia and and extend them to individuals with bipolar disorder. After completion of the cell and tissue culture assays, microarray analysis of these cell-based models was used to reveal gene expression differences present between patients and healthy controls. Microarray analysis is a complicated technique and the limited amounts of RNA that can be extracted from a single nasal biopsy further compounds this issue. In order to obtain enough material for microarray hybridization RNA samples underwent antisense amplification. Therefore, with the aim of allowing the candidate to gain proficiency in both these techniques prior to microarray analysis of olfactory biopsies from patients with schizophrenia and bipolar disorder, a pilot microarray study of cultured skin fibroblasts from schizophrenia patients and healthy controls was performed. The present findings show that insulin-like growth factor-I and its receptor were expressed by globose basal cells (the neuronal precursor), by neurons and by olfactory ensheathing cells, the special glia of the olfactory nerve. Insulin-like growth factor-I reduced the numbers of proliferating neuronal precursors, induced their differentiation into neurons, and promoted morphological differentiation of neurons. In contrast, this growth factor was mitogenic for olfactory ensheathing cells. The evidence suggests that insulin-like growth factor-I is an autocrine/paracrine signal that induces neuronal precursors to differentiate into olfactory sensory neurons and induces olfactory ensheathing cells to proliferate and that olfactory mucosa culture is valuable in modelling neurodevelopmental processes. When the olfactory musoca culture model was applied to patients with psychosis, a two-fold increase in proliferation of neural cells was found in schizophrenia compared to controls and bipolars. In bipolar cultures there was a 3-fold increase in cell death compared to controls and schizophrenia. Microarray analysis of cultured skin fibroblasts revealed differential expression of over 1000 genes between patients and controls. Inspection of the significant data showed alterations to gene expression between groups in the cell cycle, oxidative phosphorylation, TCA cycle and oxidative stress pathways. Gene expression in each of these pathways was predominately decreased in schizophrenia. Quantitative PCR analysis of selected differentially expressed genes involved with cell cycle regulation validated the increased expression of vitamin D receptor, and decreased expression of proliferating cell nuclear antigen and DEAD (Asp-GIu-Ala-Asp) box polypeptide 5 in skin fibroblasts from patients with schizophrenia. Microarray analysis of biopsied olfactory mucosa showed 146 and 139 differentially expressed genes in schizophrenia and bipolar disorder respectively, compared to controls. Consistent with increased mitosis in schizophrenia biopsy cultures three genes that function to positively influence cell cycle had increased expression. In the bipolar disorder group a dysregulation of the phosphatidylinositolsignalling pathway was seen; five genes that either directly function within or interact with this pathway had decreased expression. There is speculation that the therapeutic effect of psychotropic drugs acting upon this pathway in bipolar disorder involves reduction of neuronal cell death. Increased mitosis of neural cells has now been observed in two separate groups of schizophrenic patients indicating a robust finding. The use of fibroblast and olfactory mucosal tissue can be used to study biological and genetic aspects of neurodevelopment in living humans both with and without psychotic disease. Biopsied olfactory mucosa provides benefits over the use of autopsied material for study of psychotic disease because post-mortem duration and agonal factors that lead to tissue, protein and nucleic acid degradation are not an issue. This study provides evidence for a neurodevelopmental aetiology of schizophrenia and bipolar disorder acting at the level of cell cycle control. Subtle changes in the timing of cell cycle regulation could account for the brain pathologies observed in these diseases. Olfactory mucosa culture is a valuable model of neurodevelopmental processes.