Haut PDF Sim1 function in the developing and adult brain

Sim1 function in the developing and adult brain

Sim1 function in the developing and adult brain

Sim], which codes for a bHLH-PAS transcription factor, is expressed in various areas of the brain, including the developing and postnatal paraventricular nucleus (PVN), a region of the h[r]

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CPG15 regulates synapse stability in the developing and adult brain

CPG15 regulates synapse stability in the developing and adult brain

In the retinogeniculate pathway as well as the hippo- campus, neuropil development in the cpg15 KO is ini- tially delayed but eventually reaches wild-type levels. We examined whether the deficit in dendritic spine synapse number also recovers with age by comparing spine and spine synapse densities between 2- and 9-mo-old cpg15 KO mice and wild-type littermates. Between 2 and 9 mo, both cpg15 KO mice and wild-type controls prune spines in a similar manner (Fig. 4E). Wild-type controls also prune spine synapses over this period, consistent with ongoing synapse remodeling and refinement (Markus and Petit 1987). However, cpg15 KO synapse density, which starts out lower than wild type at 2 mo, is not further reduced by 9 mo of age and remains relatively constant during this period (Fig. 4F). Thus, we see that neurons in the late developing DG of cpg15 KO mice initially form fewer spine synapses than wild-type neurons. Over time, these synapses are less likely to be pruned, so that by 9 mo, synapse numbers are similar in wild type and knockout. Increased loss of persistent spines in cpg15 KO mice In vivo imaging studies followed by EM have demon- strated that spine sprouting and retraction are associated with synapse formation and elimination (Trachtenberg et al. 2002; Knott et al. 2006) and that synaptogenesis is inversely correlated with spine motility (Konur and Yuste 2004). In light of the unusually large fraction of dendritic spines lacking synapses in the developing DG of cpg15 KO mice, we asked whether CPG15 depletion also affects dendritic spine dynamics. To this purpose, we performed in vivo imaging of neurons in the visual cortices of adult cpg15 KO mice. The cortex was chosen to assay spine dynamics because it is optically accessible via implanta- tion of cranial windows, allowing chronic monitoring of spine dynamics. In addition, previous studies have shown that even in the adult cortex, a significant fraction of dendritic spines remain dynamic, with the majority of events being either transient spine additions or reversible eliminations (Holtmaat et al. 2005, 2006). Persistent- dynamic events, including spines that emerge and persist (new-persistent spines) as well as spines that disappear and do not re-emerge (lost-persistent spines), likely best represent events that correspond to synapse formation and elimination (Holtmaat et al. 2005, 2006).
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The Cooperation of Nature and Nurture on Developing Meta-cognitive Abilities in Adolescents_ Gender-Based Function.

The Cooperation of Nature and Nurture on Developing Meta-cognitive Abilities in Adolescents_ Gender-Based Function.

2 Introduction Mystery about the human behaviour has always been an issue for the human kind to decode. After all conducted knowledge since ever knowledge explored science, human biology, physiology, chemistry and psychology centered the driving machine of the human kind in their head, their mind i.e. the brain. Scientifically, its structure and functions of its elements are called neuroscience, and since the outer language as verbal or non-verbal the human produces in ambiguous manners, signs, sounds, gestures, through their senses are the brain orders, by processes of perception, conception and production. To initiate discovering this phenomenon then, we should introduce the anatomical aspect of the brain in relation to linguistic interpretation since our focus is on the neurological matter in the neuro linguistic development of the human gender. Among all of those parameters as means of perception, conceptualizing, and producing in terms of logic, remembering, thinking, problem solving, and emotions orientations_ intelligence and memory majorly interpret the process of gender cognitive functions in common task performances measured by specific variables along three considerable phases; childhood, early adolescence, and late adolescence. The structure of gender brains is controversial in several scientific spheres; psychologists seek different perspectives on how much of gender cognitive skills are due to biological, neurochemical, and evolutionary factors as nature, or is the result of culture and socialization as nurture.
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Emotion modulation of the body-selective areas in the developing brain

Emotion modulation of the body-selective areas in the developing brain

These findings suggest that even though the body-selective areas are increasing in their levels of recruitment between childhood and adult- hood for processing dynamic body stimuli, the emotion modulation of these areas is already adult-like in children. This seems to be in ac- cordance with previous behavioural results into emotion recognition from body movements ( Lagerlof and Djerf, 2009; Ross et al., 2012 ). We previously described a sharp rise in emotion recognition accuracy from full-light human body movements between the ages of 4 and 8.5 years old ( Ross et al., 2012 ). After 8.5 years we found a much slower rate of improvement in recognition accuracy. In the current study our children subjects range from 6 to 11 years old, so as a group they might be indistinguishable from the adult group in terms of recognition accuracy. In which case finding no age difference in the amygdala response and emotion modulation of the body-selective areas should come as no surprise (indeed, there was no significant age difference in the brief post-scan behavioural emotion recognition task we performed here). It is also possible that the age di fferences in behavioural performance are linked to the differences in other brain functional circuits (e.g. execu- tive function). It could be the case, as shown using happy and angry faces in Hoehl et al. (2010) , that 5 –6 year old children would show heightened amygdala response to emotional bodies as compared to adults. Indeed, there is evidence that children younger than 6 years of
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Foxp2 regulates gene networks implicated in neurite outgrowth in the developing brain.

Foxp2 regulates gene networks implicated in neurite outgrowth in the developing brain.

well into 24 well plates and grown at 37uC in the presence of 5% CO 2 in complete medium. After 4 days in culture, cells were fixed using 4% Paraformal- dehyde solution for 15 minutes at room temperature and permeablised in wash solution (0.1% Triton X-100 in TBS). Antibodies were diluted in Blocking Solution (1% Fish Gelatine, 0.1% Triton X-100, 5% BSA in PBS). Cells were co-stained at 4uC overnight, using two primary antibodies; an anti-MAP2 rabbit polyclonal antibody (Chemicon) and an anti-Foxp2 mouse monoclonal antibody recognising an epitope near the C-terminal end of the protein (Gift from Prof. A. Banham). Detection was then facilitated via four rounds of antibody incubation, which allowed magnification of the Foxp2 signal. Cells were incubated with anti-rabbit TRITC (Alexa Fluor 568, Molecular Probes) plus anti-mouse biotinylated (BA9200, Vector Labs) secondary anti- bodies, followed by incubation with anti-rabbit TRITC plus anti- biotin FITC (Alexa Fluor 488, Molecular Probes) antibodies, each for 1 hour, shaking under limited light exposure. This secondary/ tertiary antibody incubation was then repeated under the same conditions. Nuclei were visualised using mounting media contain- ing a DAPI counterstain (VectaShield). Cells were viewed on a Nikon Eclipse TE2000U fluorescence inverted microscope. Images were captured using a Hamamatsu black and white C4742-95 Orca hi-sensitivity CCD camera with IPLab imaging software (Scanalytics Inc), and analysed using the neurite outgrowth function of Metamorph Version 7.6 (Molecular Devices). Statistical analyses were carried out using ANCOVA (analysis of covariance) for genotype and embryo, followed by post-hoc Sidak correction. Data are expressed as the mean 6 standard error of the mean (SEM).
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Integration and function of adult-born olfactory bulb neurons

Integration and function of adult-born olfactory bulb neurons

enthorinal cortex via the lateral olfactory tract (Davis, 2004; Neville and Haberly, 2004). Each MC also gives rise to long (up to 1 mm in mice) lateral dendrites that innervate the EPL and contact the dendrites of interneurons. The GCL is the location of granule cell (GC) somas. In general, a GC has short basal dendrites where it receives inputs from other brain regions. A primary dendrite extends toward the EPL, where it divides into secondary, and tertiary branches called the distal dendrites (Figure 1.3C). In the EPL, the GC makes dendrodendritic contact with the lateral dendrites of MCs, providing recurrent and lateral inhibition on these principal neurons (Arevian et al., 2008; Isaacson and Strowbridge, 1998; Jahr and Nicoll, 1982; Schoppa and Urban, 2003; Tan et al., 2010; Urban, 2002). The inhibition provided by the GCs synchronizes MC activity, allowing for fine spatio-temporal tuning of the responses of these principal cells to odors (Arevian et al., 2008; Urban, 2002; Yokoi et al., 1995). Compared to PGCs, fewer GC subpopulations exist. Based on their molecular content, GCs are more homogeneous with all cells expressing GAD protein, an enzyme responsible for the production of GABA. One third of these GAD+ cells selectively express mGluR2 and few cells express also calretinin or the glycoprotein 5T4 (Batista-Brito et al., 2008; Imamura et al., 2006; Murata et al., 2011; Yoshihara et al., 2012). Also sparingly represented in the GCL, the deep short-axon cells are also a population of GABAergic interneurons. Their morphology is similar to the short-axon cells of the GL with dendrites and axons innervating the GCL within one bulb. The function of the deep short-axon cells in the OB is not well understood. However, recordings from the Blanes cells, a subpopulation of deep short-axon cells, have demonstrated that they receive strong glutamatergic inputs from centrifugal fibers
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Transcriptomic analysis of the developing and adult mouse cochlear sensory epithelia

Transcriptomic analysis of the developing and adult mouse cochlear sensory epithelia

Functional Annotation of Selected Genes Differentially Expressed between P3 and Adult CSE IPA was used to access to functional properties of the selected genes up-regulated in P3 and adult CSE (Tables 1 and 2), confirmed by Q-PCR. Only significant functions (p,0.001) were reported. The selected P3 up-regulated genes were associated with multiple functions including auditory and vestibular system development, nervous system development, cellular growth/pro- liferation, and embryonic development (Fig. S1A) and signaling pathways such as, Notch signaling, embryonic stem cell pluripo- tency and Wnt/bcatenin signaling (Fig. S1B). Among these pathways, four are above threshold for significance (p,0.05). Inversely, the adult CSE up-regulated genes were related to biological functions including cell-to-cell interactions, DNA replication, cell cycle and cell death (Fig. S1C). For the pathways, the 26 selected up-regulated adult genes are mainly associated to NF-kB signaling, glucorticoid receptor signaling, FGF signaling and actin cytoskeleton signaling (Fig. S1D). DAVID (Database for Annotation, Visualization and Integrated Discovery) analysis gave mainly similar results as reported by IPA function and pathway analysis (data not shown). Gene lists from comparisons showing significant differences in gene expression were submitted to DAVID) (www.david.abcc.ncifcrf.gov). DAVID provides explor- atory visualization tools that promote discovery through functional Table 2. The 26 selected adult up-regulated genes.
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The BRAIN Initiative: developing technology to catalyse neuroscience discovery

The BRAIN Initiative: developing technology to catalyse neuroscience discovery

each other’s success and failures, and identify potentially synergistic research approaches when appropriate. Like the Apollo program, undertaking a grand challenge of this sort will require the development and integration of an array of new technologies, drawing on scientists and engineers from a multitude of disciplines. The neuroscience ‘moonshot’ differs, however, in that we cannot foresee exactly where these new technologies and experiments will take us. Charting a course to the moon was far simpler than unlocking the mysteries of our own minds! Future technological innovation will certainly propel neuroscience research in entirely new, unexpected direc- tions, as it has so often in the past. Consider, for instance, the evolution of the field of cerebral cartography, the focus of this special issue. The first era of systematic brain mapping, begun by Fritsch and Hitzig in the 1870s [67], culminated in Wilder Penfield’s systematic electrical stimulation studies in conscious human patients undergoing surgery for epilepsy [68]. These early experiments demonstrated beyond all doubt the localiz- ation of function within the cerebral cortex, including the primary sensory and motor areas, specialized language areas, hemispheric laterality and neural systems involved in memory. More penetrating studies awaited the invention of the intracortical microelectrode and anatomical tracer tech- niques based on anterograde and retrograde axoplasmic transport. With the advent of these tools, neuroscientists were able to explore the exquisitely selective response properties of single neurons [69,70], identify the cortical column as a primary unit of cerebral information processing [69,71] and discover a host of new cortical areas and the anatomical circuits that con- nect them [72–75]. The development of techniques for recording from awake, behaving animals [76] and for non-inva- sive imaging of the human brain [77–79] and animal brains [80] led to the rise of cognitive neuroscience in the last quarter of the twentieth century, bringing previously mysterious cognitive process such as attention, working memory, spatial navigation, decision-making and motor planning under direct empirical examination. The fusion of molecular and cell biological tech- niques with in vitro slice recordings enabled elucidation of many basic mechanisms of synaptic plasticity.
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Decreased microglial Wnt/β-catenin signalling drives microglial pro-inflammatory activation in the developing brain

Decreased microglial Wnt/β-catenin signalling drives microglial pro-inflammatory activation in the developing brain

using an imaging modality that is currently used to assess injury and predict outcome. Also, we wish to highlight that changes to the grey matter are also evident in preterm born infants, including changes in cortical microstructure(Ball et al., 2013), interneuron distribution(Stolp et al., 2019) and degeneration of axons(Back and Miller, 2014). However, the contribution of axonal injury to diffuse white matter is controversial, although it is evident in necrotic foci that are approximated to occur in only 5% of white matter injury cases(Riddle et al., 2011; Buser et al., 2012). Preterm born infants with apparent focal necrosis were excluded from our imaging- genomics analysis removing a significant contribution of a frank axonopathy from effecting the connectivity phenotype in this cohort. We cannot exclude however that effects on the grey matter in these infants are not important determiners of outcome and effected by changes in SNPs in genes of the WNT pathway. In addition, we found that the WNT pathway genes containing SNPs associated with white matter tractography phenotype belonged to a human brain-specific gene interaction network. This network further builds a case for a functional effect of WNT SNPs in human preterm infants, with consequences for the development of white matter structure(Greene et al., 2015). Specific prediction of the consequences of our identified SNPs found the majority were intron variants. Previous studies in experimental animals has shown that immune cell intron variants often effect cell function by altering enhancer binding(Farh et al., 2015). Altogether our clinical data build a case that these WNT pathway SNPs may be a useful way to stratify infants who are at highest risk for white matter damage, and to improve on our currently limited prognostic abilities related to long term outcome.
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The CD38-independent ADP-ribosyl cyclase from mouse brain synaptosomes: a comparative study of neonate and adult brain.

The CD38-independent ADP-ribosyl cyclase from mouse brain synaptosomes: a comparative study of neonate and adult brain.

characterized mammalian ADP-ribosyl cyclase) not only in adult but also in developing tissues. We show that Cd38 -/- synaptosomes preparations contain high ADP-ribosyl cyclase activities, which are more important in neonate than in adult, in line with the levels of endogenous cyclic nucleotide. By using an HPLC method and adapting the cycling assay initially developed to study endogenous cADPR, we accurately examined the properties of the synaptosomal ADP-ribosyl cyclase. This intracellular enzyme has estimated K m for NAD + of 21 µM, a broad optimal pH at 6.0-7.0, and concentration of free calcium has no major effect on its cADPR production. It binds NGD + , which inhibits its NAD + metabolizing activities (K i = 24 µM), despite its incapacity to cyclize this analogue. Interestingly, it is fully inhibited by low (micromolar) concentrations of zinc. We propose that this novel mammalian ADP-ribosyl cyclase regulates the production of cADPR and therefore calcium levels within brain synaptic terminals. In addition, this enzyme might be a potential target of neurotoxic Zn 2+ .
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Cytomegalovirus Infection of the Rat Developing Brain In Utero Prominently Targets Immune Cells and Promotes Early Microglial Activation

Cytomegalovirus Infection of the Rat Developing Brain In Utero Prominently Targets Immune Cells and Promotes Early Microglial Activation

shown that a subset of infiltrating regulatory B cells controls T lymphocytes and microglial responses [ 8 ]. Generally the early recruitment of peripheral immune cells, including monocytes and DCs, and the increased activation of microglial cells are likely to play important roles in the pathogenesis of congenital CMV infections of the brain. There is evidence to suggest that infiltrating monocytes have the capacity to give rise to microglial cells in some models of CNS infection [ 41 ]. In our model, the infiltration by monocytes and DC occurred in E17-infected brains but was less prevalent in P1 infected brains as compared to control brains. As the reduc- tion of the monocyte pool was concomitant with an increase of fraction IV cells at P1 stage, it could be inferred that infiltrating monocytes differentiated into activated microglia in the course of congenital CMV infection. Here, evidence for microglial activation, which is a com- plicated and heterogeneous process [ 42 ], was obtained by a combination of immunohis- tochemistry, morphological and flow cytometry analyzes. Whereas early microglial activation within the sites of productive infection is likely to regulate CMV infection, it might also have detrimental effects. Notably the role of microglia in shaping the brain during development, including synaptogenesis, synaptic pruning, or neocortical interneuron positioning, and in modulating synaptic plasticity and neuronal networks, is increasingly recognized [ 43 ]. The direct targeting of microglial cells by CMV and the modification in the activated state of micro- glia in utero might well have postnatal impact on brain functioning and pathology [ 44 ], strongly influencing, or at least interfering with, the outcome of congenital CMV infection and the severity of the related neurological manifestations. As an example, long-lasting effects of transient activation of microglia on adult neurogenesis in the olfactory bulb have been reported [ 45 ]. Generally
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Exploring the successive waves of cortical folding in the developing brain using MRI and spectral analysis of gyrification

Exploring the successive waves of cortical folding in the developing brain using MRI and spectral analysis of gyrification

2. MATERIAL AND METHODS 2.1. Methodological background SPANGY relies on the spectral decomposition of the mean cur- vature of the inner cortical surface (i.e. mesh of the grey/white mat- ter interface), based on the Laplace–Beltrami operator eigenfunc- tions (i.e. a generalization of Fourier analysis to any kind of do- main/surface). In this approach, the complexity of the power spec- trum is reduced by merging levels of successive orders, assuming a folding model of branching with doublings of spatial frequency [8] . In the adult brain, 7 bands of increasing frequencies (B0–B6) have been shown relevant and sufficient to characterize the curvature pat- terns in regards to the mesh spatial resolution and the expected size of folding patterns. This approach has further provided an anatomi- cally relevant segmentation of the cortical folds based on the local spectral composition : while the low frequency bands (B0-B3) have been related to the global brain shape, the last 3 bands (B4-B6) have been shown to account for the folds shaping. Furthermore, when the sulci were segmented according to their frequency compound, ele- ments associated with B4, B5 and B6 seemed to match essentially with primary, secondary and tertiary folds respectively. Neverthe- less, this anatomical analogy observed in the adult brain remains to be tested throughout the developmental process of folding. We thus applied SPANGY over a developmental range crucial for sulci appea- rance, covering not only the third trimester of pregnancy, but also the first post-natal months.
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Compartment and cell-type specific hypoxia responses in the developing Drosophila brain

Compartment and cell-type specific hypoxia responses in the developing Drosophila brain

Fig. 6. The biosensor reveals cell-type specific hypoxia states in central brain and optic lobe. (A –E) Dorsal views (in relation to the neuraxis) of immunostained brains for cell-type specific markers (gray): (A) anti-Deadpan (neuroblasts, NB), (B) anti-Prospero (ganglion mother cells, GMC), (C) anti-Elav (neurons), (D) anti-Repo (glial cells). The cell-specific nuclear staining shown in (A –D) was utilized as segmentation signal to create a mask to obtain the corresponding ratiometric analysis of each cell type (A ′–D′). The anti-Discs large staining (E) was used to outline neuroepithelial cells. The corresponding ratiometric analysis (E ′) was based on manual segmentation of the IPC and OPC using TrakEM2. (F) Mean ratio −1 (oxygenation) for each cell type in central brain and optic lobe, represented as a function of mean distance to tracheoles. The dotted line shows the average trend, obtained by averaging the fits of all normoxic brains. (G) Decaying exponential fits for all cell types. (H) Boxplot comparing ratiometric values of all cell types both in central brain and optic lobe (n=4). (I) Exposure to hyperoxia has a stronger effect in neuroblasts than in neuroepithelial cells (n=6). (J) Cell-type specific hypoxia response in the central brain and optic lobe based on biosensor data. Scale bar is applicable to all panels and is 40 µm. Error bars in (F) show s.e.m. *P<0.05, **P<0.01, ***P<0.001 Student ’s t-test or Mann–Whitney Wilcoxon test.
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Electrophysiological investigations of brain function in coma, vegetative and minimally conscious patients.

Electrophysiological investigations of brain function in coma, vegetative and minimally conscious patients.

benzodiazepine intake. When the subject is tired and drowsy, slower waves appear, and theta (4-7  Hz) becomes the predominant rhythm. In deep sleep states, the predominant rhythm is delta (0.5-4  Hz) (see Fig. 1.I-III for alpha, theta and delta waves). Following a brain injury, whether it is of traumatic or anoxic origin, the EEG can be altered and display abnormalities. A visible main effect is a slowing of the brain activity proportional to the severity of the injury. If cerebral suffering is diffuse, the predomi- nant rhythm is no longer posterior alpha but diffuse theta or delta. In some cases of severe brain lesions alpha or theta activity can be observed but it does not resemble a normal adult alpha activity as it is frontally distributed and not reactive to stimuli such as eye opening or closing. These rhythms are coined alpha-coma or theta-coma (Kaplan et  al., 1999) (see Figure 1.VII for an illustration of alpha coma). Along with the diffuse slowing commonly observed in DOC patients, several additional patterns have been reported. In case of supratentorial lesions, polymorphic focal delta rhythm can be visible over the damaged regions (Brenner, 2005). If there is asymmetric brain damage, the EEG will likely also be asymmetric; the electrogenesis of one hemisphere can appear almost normal whereas that of the other is severely impaired. Still a precise location of a lesion cannot be achieved with the EEG as its spatial resolution is low. When the lesions are infratento- rial, the EEG can display a close to normal activity as it is sometimes but not always the case in locked- in patients (LIS) (Markand, 1976; Patterson and Grabois, 1986; Jacome and Morilla-Pastor, 1990; Bassetti et al., 1994; Gutling et al., 1996; Gosseries et al., 2009).
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Dynamic spatiotemporal coordination of neural stem cell fate decisions through local feedback in the adult vertebrate brain

Dynamic spatiotemporal coordination of neural stem cell fate decisions through local feedback in the adult vertebrate brain

providing the first complete 4D dataset of NSC population behavior in situ. It is to note that, due to relatively weak mcm5:egfp staining, we could not efficiently resolve aNPs, which were therefore not considered in the dynamic analysis. To validate the reliability of this imaging, cell detection and tracking approach, we first tested whether it could recapitulate the results obtained on the static pattern of aNSC placement. We applied a point pattern analysis at every individual time point to address the relative position of activation events within the whole NSC population. As previously concluded, these events were found randomly positioned relative to each other ( Figures 4 A and B). This analysis further revealed that the NSC activation phase can span several consecutive time points prior to division. We could indeed fit the NSC activated phase with an exponential decreasing function with a decay rate of 0.217 ± 0.019 day -1 , corresponding to a mean aNSC half-life of 3.2 days ( Figure S6 B). Thus, in the following, we focused on the more temporally restricted event of cell division proper, reflecting the NSC recruitment event affecting cell fate. We refer to this event as the “mother cell” state (MC), defined as the imaged time point immediately preceding cell division) ( Figures 3 C,C’, 4 and S5 A, red cells). MC events also appeared randomly positioned relative to each other at any given time ( Figure 4 C).
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Environmental and Cognitive Enrichment in Childhood as Protective Factors in the Adult and Aging Brain

Environmental and Cognitive Enrichment in Childhood as Protective Factors in the Adult and Aging Brain

Hair et al., 2015 ). Moreover, children who experienced family persistent poverty perform almost 20 percentile ranks lower than other children at cognitive development test scores, even after controlling for parental investment and others background conditions ( Dickerson and Popli, 2016 ). Similarly, a recent neuroanatomical study tends to show some differences in brain structure of children and adolescents with low or high-income families, particularly in brain regions supporting language, reading, executive function and spatial skills ( Kolb and Gibb, 2015 ; Noble et al., 2015 ). Studies also linked socioeconomic factors with hippocampal and amygdala volumes ( Hanson et al., 2011 ; Luby et al., 2013 ). However, other studies report no association ( Hanson et al., 2011 ; Jednoróg et al., 2012 ). Parental socioeconomic status has therefore a strong impact on children’s cognitive abilities from an early age, and this condition has a direct link to future educational background ( Erola et al., 2016 ). In this regard, research has shown that home environment and adequate parenting (e.g., stimulations, interactions) enhance a better understanding of this link. Parents with higher level of education are better informed about protective or deleterious environmental factors to ensure children’s optimal development, starting from prenatal life ( Prickett and Augustine, 2016 ; Jeong et al., 2018 ). Studies have also highlighted that time investment from parents on children is linked to parental economic level ( Park, 2008 ) and has a major impact on cognitive outcomes in childhood ( Cunha and Heckman, 2009 ; Del Boca et al., 2017 ). This investment generally involves the amount of time children spend in physical or cultural activities with their father, mother, or both, but also their general exposure to discussion and social interaction. However, a further study shows that a child’s and adolescent’s own investment also matters, defeating an immutable social determinism ( Del Boca et al., 2017 ). Moreover, level of interest in books and arts is significantly higher before 12 years old and seems not related to parental income status ( Nanhou et al., 2016 ). Nevertheless, growing up in advantaged socioeconomic conditions and a stimulating environment in childhood seems to facilitate CR development ( Stern, 2009 ;
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Lexical-semantic system organization in the monolingual and bilingual developing brain

Lexical-semantic system organization in the monolingual and bilingual developing brain

Page | 67 The N400 effect in 24-month-olds was obtained focally over the right posterior-occipital recording sites and no significant effect was found over the other recording sites. In adult participants, the visual N400 effect is typically found over the right posterior recording sites, but in auditory tasks, asymmetrical effects are less consistent (for review, see van Petten & Luka, 2006). In children, an N400-like incongruity effect in a picture-word task was shown to be stronger and temporally more extended over the left hemisphere recording sites, but still, significant hemispheric differences were not found (Friedrich & Friedrici, 2004). Moreover, an N400-like priming effect for the spoken words was reported to be larger over the left than the right recording sites (Torkildsen et al., 2007). In that study, the effect was obtained over the fronto-central scalp positions whereas in our study, the effect was seen over the parietal-occipital positions. The front- central distribution in their study might be, however, associated with the recruitment of attention in the task since the words were presented together with visual cartoon characters to catch children’s attention. The negative waveforms for related and unrelated target words started to deviate from each other already during the first time window (0–200 ms) in our study, and the effect lasted until 600 ms, in contrast to the earlier studies in which the effect was obtained later (e.g., Friedrich & Friedrici, 2004; Torkildsen et al., 2007). However, in another study, where the N400 effect was compared in visual and auditory modalities (Holcomb & Neville, 1990), the effect in the auditory modality was obtained already in a 150–300 ms time interval in contrast to visual modality, where the effect was obtained in a 300–500 ms time interval, indicating that priming processes are not identical in two modalities. In addition to modality-specific differences in priming, there is also a possibility that the early part of the negativity is not part of the N400 effect, but it reflects the P100 component, shown to be modulated by word familiarity (Mills et al., 1997), word repetition (Friedrich and Friedrici, 2011), and also by priming when tested in a memory test after training of novel word-picture pairings (Friedrich & Friederici, 2011).
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Neural stem cell pools in the vertebrate adult brain: Homeostasis from cell‐autonomous decisions or community rules?

Neural stem cell pools in the vertebrate adult brain: Homeostasis from cell‐autonomous decisions or community rules?

A further important aspect will be to determine how these balanced adult SC systems are generated. Biologically, they are the product of developmental and post-developmental processes, thus of generally progressive changes, for example, in cell states (such as the acquisi- tion of quiescence), cell types (such as the differentiation of ependymal cells in the SEZ) or tissue architecture, that can take place over weeks to months. But it remains largely unknown which cellular dynamics underlie these transformations that generate a steady-state. Proper spatiotemporal models will be instrumental in this endeavor as well. While they currently start from a “mature” situation that mimics the arrangement and states of adult SC populations, they can also be tested for parameters that can generate this initial pattern from various quan- titative and spatial compositions of cells. An important question is, for example, whether they can be attained by simple self-organization pro- cesses, as a systems stable state. In the mouse SEZ, ependymal cells and NSCs originate from a common precursor. [96] Choices of fates are
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Adult neurogenesis : regulation, heterogeneity and functions of adult born interneurons in the olfactory bulb

Adult neurogenesis : regulation, heterogeneity and functions of adult born interneurons in the olfactory bulb

11 2.1 A brief historical overview of the study of neurogenesis: Early neuroanatomists like Ramon Cajal thought the adult nervous system was fixed and immutable. However, we now know that even if neurogenesis is most active during pre-natal development it continues throughout life in certain regions of the brain of most vertebrates and invertebrates. The dentate gyrus (DG) of the hippocampus and the OB of the adult brain are the two regions that keep adding neurons throughout life as described in many animal species. In 1962 Altman while studying the lesioned adult rat brain combined intracranial injections of thymidine- H(3) along with lesions and saw that along with brain regions associated with the lesion some neurons and neuroblasts were also labeled in the cerebral cortex, which suggested that the adult rat brain maybe capable of producing new neurons (Altman, 1962). In further studies using the same thymidine-H(3) technique Altman showed that new neurons were being generated in the DG of the adult rat, cat and guinea pig hippocampus (Altman, 1962, , 1963; Altman and Das, 1967). In contrast however, was the data obtained from the rhesus macaque visual cortex (Rakic, 1974). Using titrated thymidine injections and radiographic evidence Rakic concluded that there was no neurogenesis occurring postnatally based on the fact that no labeled cells were detected in the neocortex. Later in 1985, Rakic performed further experiments on the rhesus macaque; monkeys were injected with doses of thymidine-H (3) and sacrificed from 3 days to 6 years after injection. In this study the results revealed no labeled neurons in the neocortex, thus the study concluded that all neurogenesis ceases during early postnatal days (Rakic, 1985). At the same time, however, it has been demonstrated that the hippocampus retained dividing cells in adult mice much like in young mice and the same was also true for the adult OB (Kaplan and Hinds, 1977; Kaplan and Bell, 1984). Thus these conflicting sets of data set up a debate on the existence or absence of adult neurogenesis.
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Pattern formation and criticality in the developing retina

Pattern formation and criticality in the developing retina

4. What are the biophysical mechanisms of the spatiotemporal patterns formation in the early retina? Patterns vary upon parameters variation Having proposed a biophysical model for retinal waves [1], we use our equations to understand the underlying mechanisms of waves apparition and propagation:

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