Treatment Of Neurodevelopmental Disorders Research Articles

Modified adeno-associated virus targets the bacterial enzyme chondroitinase ABC to select mouse neuronal populations in vivo using the Cre-LoxP system.

Current methods of experimentally degrading the specialized extracellular matrix (ECM), perineuronal nets (PNNs) have several limitations. Genetic knockout of ECM components typically has only partial effects on PNNs, and knockout of the major ECM component aggrecan is lethal in mice. Direct injection of the chondroitinase ABC (ChABC) enzyme into the mammalian brain is effective at degrading PNNs in vivo but this method typically lacks consistent, localized spatial targeting of PNN degradation. PNNs also regenerate within weeks after a ChABC injection, thus limiting the ability to perform long‐term studies. Previous work has demonstrated that viral delivery of ChABC in mammalian neurons can successfully degrade PNNs for much longer periods, but the effects are similarly diffuse beyond the injection site. In an effort to gain cell‐specific targeting of ChABC, we designed an adeno‐associated virus encoding ChABC under the control of the Cre‐LoxP system. We show that this virus is effective at targeting the synthesis of ChABC to Cre‐expressing mouse neurons in vivo. Although ChABC expression is localized to the Cre‐expressing neurons, we also note that ChABC is apparently trafficked and secreted at projection sites, as was previously reported for the non‐Cre dependent construct. Overall, this method allows for cell‐specific targeting of ChABC and long‐term degradation of PNNs, which will ultimately serve as an effective tool to study the function of cell‐autonomous regulation of PNNs in vivo. This novel approach may also aid in determining whether specific, long‐term PNN loss is an appropriate strategy for treatment of neurodevelopmental disorders associated with PNN pathology.

Understanding and addressing pseudoscientific practices in the treatment of neurodevelopmental disorders: Considerations for applied behavior analysis practitioners

AbstractPseudoscientific practices are commonly used and promoted in the field of developmental disabilities. Behavior analysts should anticipate encountering such treatments in practice and understand their ethical obligations with regard to these practices. Thoughts on why pseudoscientific practices are frequently sought are presented for context in understanding this complex issue. This discussion will serve to prepare behavior analysts for how to address situations in which clients may ask behavior analysts to use pseudoscientific practices. Additionally, this discussion covers arguments for the dangers of using pseudoscientific practices, a guide to resources for information on evidence‐based practice and ethics, and ideas on how to handle a situation in which a parent or caregiver asks the behavior analyst to integrate a pseudoscientific approach into the treatment of a child with a neurodevelopmental disorder.

Network Biology Approaches to Identify the Drug Lead Molecule for Neurodevelopmental Disorders in Human

Aims: To identify most novel drug target and lead molecule for neurodevelopmental disorder Autism, Intellectual Disability (ID) and Attention Deficit Hyperactivity Disorder (ADHD) diseases through system biology approaches Background: Neurodevelopmental disorders (NNDs) are disabilities associated chiefly with the functioning of the neurological system and brain. Children with neurodevelopmental disorders have difficulties with speech, behaviour, learning and other neurological functions. Systems biology is a holistic approach to enciphering the complexity of biological systems and their interactions. It opens the way to a more successful discovery of novel therapeutics. Objective: To identify most novel drug target and lead molecule for neurodevelopmental disorder Autism, Intellectual Disability (ID) and Attention Deficit Hyperactivity Disorder (ADHD) diseases through system biology approaches. Methods: A list of genes was collected from NCBI database for Autism, Intellectual Disability (ID) and Attention Deficit Hyperactivity Disorder (ADHD) diseases. STRING database and Cytoscape software was used for construction and interpreting molecular interaction in the network. 3D structure of target protein, was build and validated.The phytochemicals were identified through various research articles and filtered out by virtual screening through Molinspiration. Molecular docking analyses of known phytochemical with target proteins were performed usingAutoDock tool. Result: AKT1 for Autism, SNAP25 for Intellectual Disability (ID) and DRD4 for Attention Deficit Hyperactivity Disorder (ADHD) were identified as most potential drug target through network study. further the modelled structure of obtained target were undergo molecular docking study with kown phytochemicals. Based on lowest binding energy, Huperzine A for Autism and ID, Valerenic acid for ADHD found to be the most potential therapeutic molecules. Conclusion: Huperzine A against Autism and ID, Valerenic acid against ADHD found to be the most potential therapeutic molecules and expected to be effective in the treatment of NNDs. Phytochemicals do not have side effects so extract of these can be taken in preventive form too as these disorders occur during developmental stages of the child. Further the obtained molecule if experimentally validated would play promising role for the treatment of NDDs in human.

Considerations for Clinical Therapeutic Development of Statins for Neurodevelopmental Disorders.

The 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMG-CoA reductase) inhibitors lovastatin and simvastatin have both been investigated in clinical trials designed to treat the cognitive deficits associated with neurodevelopmental disorders such as neurofibromatosis type 1, fragile X and autism. In a recent study, the therapeutic efficacy of lovastatin and simvastatin were compared in a fragile X ( Fmr1 ) mouse model. The authors concluded that lovastatin was superior to simvastatin in rescuing the Fmr1 phenotypes, and cautioned against considering simvastatin as treatment for neurodevelopmental disorders. We discuss these findings in the context of published literature and argue that more support is needed for this potentially far-reaching conclusion. We further provide recommendations to improve the translation of pre-clinical studies of cognitive disorders into the clinical domain. The potential use of statins for antagonizing RAS (rat sarcoma viral oncogene homolog) signaling was first recognized nearly three decades ago (Mendola and Backer, 1990; Sebti et al., 1991). Functional RAS requires post-translational farnesylation to become membrane bound and active. Since farnesyl (like cholesterol) is a product of the mevalonate synthesis pathway, its synthesis can be reduced by interfering with the rate-limiting enzyme, 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMG-CoA reductase). Statins, designed as high-affinity HMG-CoA reductase inhibitors, are commonly prescribed for hypercholesterolemia. Over the past several decades, various types of statins have been extensively investigated as potential cancer therapeutics using cellular models, mouse studies, and human clinical trials (Gazzerro et al., 2012; Pisanti et al., 2014; Sopkova et al., 2017). On the basis of these findings, Alcino Silva and colleagues explored whether statins might have efficacy in the treatment of RASopathies, a group of neurodevelopmental disorders resulting from mutations that lead to …

A truncating Aspm allele leads to a complex cognitive phenotype and region-specific reductions in parvalbuminergic neurons

Neurodevelopmental disorders are heterogeneous and identifying shared genetic aetiologies and converging signalling pathways affected could improve disease diagnosis and treatment. Truncating mutations of the abnormal spindle-like microcephaly associated (ASPM) gene cause autosomal recessive primary microcephaly (MCPH) in humans. ASPM is a positive regulator of Wnt/β-Catenin signalling and controls symmetric to asymmetric cell division. This process balances neural progenitor proliferation with differentiation during embryogenesis, the malfunction of which could interfere with normal brain development. ASPM mutations may play a role also in other neurodevelopmental disorders, nevertheless, we lack the details of how or to what extent. We therefore assessed neurodevelopmental disease and circuit endophenotypes in mice with a truncating Aspm1–7 mutation. Aspm1–7 mice exhibited impaired short- and long-term object recognition memory and markedly enhanced place learning in the IntelliCage®. This behaviour pattern is reminiscent of a cognitive phenotype seen in mouse models and patients with a rare form of autism spectrum disorder (ASD) as well as in mouse models of altered Wnt signalling. These alterations were accompanied by ventriculomegaly, corpus callosum dysgenesis and decreased parvalbumin (PV)+ interneuron numbers in the hippocampal Cornu Ammonis (CA) region and thalamic reticular nucleus (TRN). PV+ cell number correlated to object recognition (CA and TRN) and place learning (TRN). This opens the possibility that, as well as causing MCPH, mutant ASPM potentially contributes to other neurodevelopmental disorders such as ASD through altered parvalbuminergic interneuron development affecting cognitive behaviour. These findings provide important information for understanding the genetic overlap and improved treatment of neurodevelopmental disorders associated with ASPM.

S.18.03 IGF1 and derivatives in the treatment of neurodevelopmental disorders

Amitriptyline is prescribed for treating the symptoms of neuroinflammatory disorders including neuropathic pain and fibromyalgia. As amitriptyline has evidence of modulating the neuroimmune interface; the effects of amitriptyline treatment on T-cell phenotype and function were examined in vitro. Peripheral blood mononuclear cells(PBMCs) were isolated and treated with amitriptyline, nortriptyline and a combination of both drugs. Toxicity for T-cells was assessed by Annexin V/Propidium Iodide staining. Activation status and cytokine expression by T-cells post treatment was assessed by flow cytometry. The levels of secreted cytokines, chemokines and neurotrophins were measured by ELISA in the supernatants. There was no significant increase in T-cell death following 24 or 48 h compared to controls. There were significantly lower frequencies of CD8+ T-cells after treatment with amitriptyline, nortriptyline and a combination of both compared to a Vehicle Control(VC)(p<0.001). The frequencies of naive CD8+CD45RA+ cells were significantly lower after amitriptyline, nortriptyline and a combination of both (p<0001). The frequencies of CD27+CD4+(p<0.05) and CD27+CD8+(p<0.01) T-cells were also significantly lower following combination drug treatment. Significantly lower frequencies of IFN-γ-producing CD8+ T-cells were observed with all treatment combinations(p<0.05) and frequencies of IL-17-producing CD4+ and CD8+ T-cells were significantly lower following amitriptyline treatment (p<0.05). Frequencies of Natural Killer T-cells were significantly higher following treatment with nortriptyline (p<0.05). Significantly higher levels of IL-16 (p<0.001) and lower levels of TNF-β (p<0.05) were observed in supernatants. This data indicates that both amitriptyline and nortriptyline modulate the phenotype and function of T-cells and this may have clinical relevance in the pathologies of its off-label applications.

Genetic Counseling in Neurodevelopmental Disorders.

Neurodevelopmental disorders (NDDs), including global developmental delay (GDD), intellectual disability (ID), and autism spectrum disorder (ASD), represent a continuum of developmental brain dysfunction. Although the etiology of NDD is heterogeneous, genetic variation represents the largest contribution, strongly supporting the recommendation for genetic evaluation in individuals with GDD/ID and ASD. Technological advances now allow for a specific genetic diagnosis to be identified in a substantial portion of affected individuals. This information has important ramifications for treatment, prognosis, and recurrence risk, as well as psychological and social benefits for the family. Genetic counseling is a vital service to enable patients and their families to understand and adapt to the genetic contribution to NDDs. As the demand for genetic evaluation for NDDs increases, genetic counselors will have a predominant role in the ongoing evaluation of NDDs, especially as identification of genetic etiologies has the potential to lead to targeted treatments for NDDs in the future.

Neurobiology and Therapeutic Potential of α5-GABA Type A Receptors

α5 subunit containing GABA type A receptors (GABAARs) have long been an enigmatic receptor subtype of interest due to their specific brain distribution, unusual surface localization and key role in synaptic plasticity, cognition and memory. These receptors are uniquely positioned to sculpt both the developing and mature hippocampal circuitry due to high overall expression and a distinct peak within the critical synapse formation period during the second postnatal week. Unlike the majority of other GABAARs, they exhibit both receptor clustering at extrasynaptic sites via interactions with the radixin scaffold as well as synaptic sites via gephyrin, thus contributing respectively to tonic currents and synaptic GABAergic neurotransmission. α5 GABAAR signaling can be altered in neurodevelopmental disorders including autism and mental retardation and by inflammation in CNS injury and disease. Due to the unique physiology and pharmacology of α5 GABAARs, drugs targeting these receptors are being developed and tested as treatments for neurodevelopmental disorders, depression, schizophrenia, and mild cognitive impairment. This review article focuses on advances in understanding how the α5 subunit contributes to GABAAR neurobiology. In particular, I discuss both recent insights and remaining knowledge gaps for the functional role of these receptors, pathologies associated with α5 GABAAR dysfunction, and the effects and potential therapeutic uses of α5 receptor subtype targeted drugs.

Identifying Windows of Susceptibility by Temporal Gene Analysis

Increased understanding of developmental disorders of the brain has shown that genetic mutations, environmental toxins and biological insults typically act during developmental windows of susceptibility. Identifying these vulnerable periods is a necessary and vital step for safeguarding women and their fetuses against disease causing agents during pregnancy and for developing timely interventions and treatments for neurodevelopmental disorders. We analyzed developmental time-course gene expression data derived from human pluripotent stem cells, with disease association, pathway, and protein interaction databases to identify windows of disease susceptibility during development and the time periods for productive interventions. The results are displayed as interactive Susceptibility Windows Ontological Transcriptome (SWOT) Clocks illustrating disease susceptibility over developmental time. Using this method, we determine the likely windows of susceptibility for multiple neurological disorders using known disease associated genes and genes derived from RNA-sequencing studies including autism spectrum disorder, schizophrenia, and Zika virus induced microcephaly. SWOT clocks provide a valuable tool for integrating data from multiple databases in a developmental context with data generated from next-generation sequencing to help identify windows of susceptibility.

Tunisie : pratique infirmière de la remédiation cognitive en pédopsychiatrie

Cognitive remediation is today afforded a significant place in the treatment of neurodevelopmental disorders. A hospital team, comprising in particular a nurse offering consultations in a child psychiatry unit in a public hospital in Tunis, shares its experience with regard to this technique which aims to restore impaired cognitive functions in order to improve the efficiency and quality of life of young patients.

Dopamine Triggers the Maturation of Striatal Spiny Projection Neuron Excitability during a Critical Period

Neural circuits are formed and refined during childhood, including via critical changes in neuronal excitability. Here, we investigated the ontogeny of striatal intrinsic excitability. We found that dopamine neurotransmission increases from the first to the third postnatal week in mice and precedes the reduction in spiny projection neuron (SPN) intrinsic excitability during the fourth postnatal week. In mice developmentally deficient for striatal dopamine, direct pathway D1-SPNs failed to undergo maturation of excitability past P18 and maintained hyperexcitability into adulthood. We found that the absence of D1-SPN maturation was due to altered phosphatidylinositol 4,5-biphosphate dynamics and a consequent lack of normal ontogenetic increases in Kir2 currents. Dopamine replacement corrected these deficits in SPN excitability when provided from birth or during a specific period of juvenile development (P18-P28), but not during adulthood. These results identify a sensitive period of dopamine-dependent striatal maturation, with implications for the pathophysiology and treatment of neurodevelopmental disorders.

Response to adrenocorticotropic in attention deficit hyperactivity disorder-like symptoms in electrical status epilepticus in sleep syndrome is related to electroencephalographic improvement: A retrospective study.

Encephalopathy with electrical status epilepticus in sleep (ESES) syndrome is a rare epilepsy syndrome of childhood that is characterized by sleep-induced epileptiform discharges and problems with cognition or behavior. The neuropsychiatric symptoms in ESES syndrome, among which the ADHD-like symptoms are prominent, bear a close resemblance to symptoms in various developmental disorders. Positive response to adrenocorticotropic hormone (ACTH) is associated with the normalization of the EEG and improvement of neuropsychiatric function. This study aimed to determine the improvement in ADHD-like symptoms in response to ACTH and establish a relationship between improvement in clinical symptoms and EEG parameters. Seventy-five patients with ESES syndrome, who had clinically displayed ADHD-like symptoms, had been treated with ACTH for ESES, and their medical records were retrospectively reviewed. Sleep EEGs were recorded at referral and follow-up visits, and short courses of ACTH were administered when spike-wave index (SWI) was ≥15%. The assessment of treatment effectiveness was based on reduction in SWI and the clinician-reported improvement in ADHD-like symptoms. Statistical analyses were conducted in order to investigate the relationship between the clinical and EEG parameters. Following treatment with ACTH, a reduction in SWI in all the patients was accompanied by a mean improvement of 67% in ADHD-like symptoms. Disappearance/reduction of foci and cessation/reduction of seizures were achieved in patients with formerly antiepileptic-resistant seizures. Multiple linear regressions established that pretreatment SWI and treatment delay predicted posttreatment SWI, while reduction in SWI, treatment delay, and the presence of foci predicted improvement in ADHD-like symptoms. Improvement in ADHD-like symptoms showed high correlation and was timely with the resolution of ESES. It is suggested that ESES and ADHD may be the two different expressions of a common neurobiological abnormality. With enhanced interpretation of sleep EEG, a more thorough assessment and treatment of neurodevelopmental disorders is possible.

The Relationship between Skewed X-chromosome Inactivation and Neurological Disorders Development

X-chromosome inactivation (XCI) is a process by which one of the copies of the X chromosome in mammalian female cells is inactivated. The XCI causes a balanced X-linked gene quantity between male and females; moreover, it results mosaic females which have paternal active X in some cells and maternal active X in others. Cellular mosaicism is a noteworthy phenomenon and lowers the risk of X-linked diseases in women because the presentation of a mutation on both X chromosomes is unlikely. Therefore, in heterozygous females, the XCI will be present only on the half of the X genome. In contrast, a similar mutation will present in all of the cells of men.Female carriers of some neurological disorders such as autism, Rett syndrome , adreno-leukodystrophyand X-linked mental retardation are reported to present XCI. These observations underscore the important role of X chromosome in the brain which may be related to the existence of a chromosomal signature of gene expression associated with the X-chromosome for neurological conditions not normally associated with that chromosome.In this review, we focused on latestinvestigations on the role of XCI in neurodevelopmental disorders and how these investigations can be effective in the treatment of neurodevelopmental disorders.

The Effect of Oxytocin on Social and Non-Social Behaviour and Striatal Protein Expression in C57BL/6N Mice.

Oxytocin has been suggested as a promising new treatment for neurodevelopmental disorders. However, important gaps remain in our understanding of its mode of action, in particular, to what extent oxytocin modulates social and non-social behaviours and whether its effects are generalizable across both sexes. Here we investigated the effects of a range of oxytocin doses on social and non-social behaviours in C57BL/6N mice of both sexes. As the striatum modulates social and non-social behaviours, and is implicated in neurodevelopmental disorders, we also conducted a pilot exploration of changes in striatal protein expression elicited by oxytocin. Oxytocin increased prepulse inhibition of startle but attenuated the recognition memory in male C57BL/6N mice. It increased social interaction time and suppressed the amphetamine locomotor response in both sexes. The striatum proteome following oxytocin exposure could be clearly discriminated from saline controls. With the caveat that these results are preliminary, oxytocin appeared to alter individual protein expression in directions similar to conventional anti-psychotics. The proteins affected by oxytocin could be broadly categorized as those that modulate glutamatergic, GABAergic or dopaminergic signalling and those that mediate cytoskeleton dynamics. Our results here encourage further research into the clinical application of this peptide hormone, which may potentially extend treatment options across a spectrum of neurodevelopmental conditions.

MG-124 The investicate project: Identification of new variation, establishment of stem cells, and tissue collection advancing treatment efforts

Objective Neurodevelopmental disorders (NDDs) are a large and complex group of disorders with varied etiologies. Recent advances in sequencing, induced stem cells, and small molecule screening technologies provide an opportunity to develop personalised treatment for NDDs. Methods The INVESTICATE project recruits patients with NDDs from Children’s Hospitals in Canada and internationally. Patients are enrolled if they have a similarly affected sibling and negative genetic tests, or a de novo balanced chromosomal rearrangement (BCR). We use Next-Generation Sequencing tools to find variation and structural variant breakpoints. Fibroblasts from patients undergo rapid induced pluripotent stem cell (iPSC) re-programming, neural progenitor cell (NPC) differentiation, CRSIPR/Cas9 mutation correction, and finally cell phenotyping. Where feasible, we collect brains from cases with reduced life expectancy. Patient-derived NPCs undergo high-throughput small molecule screening to reverse cell phenotypes associated with disease. Results INVESTICATE has recruited six families, and we identified mutations in genes not previously associated with NDDs. We identified a stop codon altering single base deletion in one family, a 51-basepair promoter deletion in another family, and a gene truncating chromosomal translocation implicating chromatin remodelling, netrins, and maintenance of brain pH in NDDs. Functional assays using iPSC-NPCs of these rare variants support their role in disease. Conclusions INVESTICATE is a rapid bedside-to-bench and back again pipeline capable of finding variants missed using standard methodology, and complements variant detection with a full battery of cell phenotyping assays, brain collection, and high-throughput screening. INVESTICATE is well positioned to attempt to provide cost-effective, personalised care to children with NDDss.

Microbes & neurodevelopment--Absence of microbiota during early life increases activity-related transcriptional pathways in the amygdala.

The mammalian amygdala is a key emotional brain region for eliciting social behaviour, critically involved in anxiety and fear-related behaviours, and hence a focus of research on neurodevelopmental and stress-related disorders such as autism and anxiety. Recently, increasing evidence implicates host-microbe interactions in the aetiology of these conditions. Germ-free (GF) mice, devoid of any microbiota throughout organismal maturation, are a well-established tool to study the effects of absence of the microbiota on host physiology. A growing body of independently replicated findings confirm that GF animals demonstrate altered anxiety-related behaviour and impaired social behaviour. However, the underlying mechanisms of this interaction and the nature of the pathways involved are only insufficiently understood. To further elucidate the molecular underpinnings of microbe-brain interaction, we therefore exploited unbiased genome-wide transcriptional profiling to determine gene expression in the amygdala of GF and GF mice that have been colonised after weaning. Using RNA-sequencing and a comprehensive downstream analysis pipeline we studied the amygdala transcriptome and found significant differences at the levels of differential gene expression, exon usage and RNA-editing. Most surprisingly, we noticed upregulation of several immediate early response genes such as Fos, Fosb, Egr2 or Nr4a1 in association with increased CREB signalling in GF mice. In addition, we found differential expression and recoding of several genes implicated in brain physiology processes such as neurotransmission, neuronal plasticity, metabolism and morphology. In conclusion, our data suggest altered baseline neuronal activity in the amygdala of germ-free animals, which is established during early life and may have implications for understanding development and treatment of neurodevelopmental disorders.

Treatment of Neurodevelopmental Disorders

Treatment of Neurodevelopmental Disorders

Molecular Convergence of Neurodevelopmental Disorders

Neurodevelopmental disorders (NDDs) are caused by mutations in diverse genes involved in different cellular functions, although therecan be crosstalk, or convergence, between molecular pathways affected by different NDDs. To assess molecular convergence, we generated human neural progenitor cell models of 9q34 deletion syndrome, caused by haploinsufficiency of EHMT1, and 18q21 deletion syndrome, caused by haploinsufficiency of TCF4. Using next-generation RNA sequencing, methylation sequencing, chromatin immunoprecipitation sequencing, and whole-genome miRNA analysis, we identified several levels of convergence. We found mRNA and miRNA expression patterns that were more characteristic of differentiating cells than of proliferating cells, and we identified CpG clusters that had similar methylation states in both models of reduced gene dosage. There was significant overlap of gene targets of TCF4 and EHMT1, whereby 8.3% of TCF4 gene targets and 4.2% of EHMT1 gene targets were identical. These data suggest that 18q21 and 9q34 deletion syndromes show significant molecular convergence but distinct expression and methylation profiles. Common intersection points might highlight the most salient features of disease and provide avenues for similar treatments for NDDs caused by different genetic mutations.

Protective and therapeutic potency of N-acetyl-cysteine on propionic acid-induced biochemical autistic features in rats

BackgroundThe investigation of the environmental contribution for developmental neurotoxicity is very critical. Many environmental chemical exposures are now thought to contribute to the development of neurological disorders, especially in children. Results from animal studies may guide investigations of human populations towards identifying either environmental toxicants that cause or drugs that protect from neurotoxicity and may help in treatment of neurodevelopmental disorders.ObjectiveTo study both the protective and therapeutic effects of N-acetyl cysteine on brain intoxication induced by propionic acid (PPA) in rats.MethodsTwenty-eight young male Western Albino rats were enrolled in the present study. They were grouped into four equal groups, each of 7 animals. Group 1: control group, orally received only phosphate buffered saline; Group 2: PPA-treated group, received a neurotoxic dose of of PPA of 250 mg/kg body weight/day for 3 days; Group 3: protective group, received a dose of 50 mg/kg body weight/day N-acetyl-cysteine for one week followed by a similar dose of PPA for 3 days; and Group 4: therapeutic group, treated with the same dose of N-acetyl cysteine after being treated with the toxic dose of PPA. Serotonin, interferon gamma (IFN-γ), and glutathione-s-transferase activity, together with Comet DNA were assayed in the brain tissue of rats in all different groups.ResultsThe obtained data showed that PPA caused multiple signs of brain toxicity as measured by depletion of serotonin (5HT), increase in IFN-γ and inhibition of glutathione-s-transferase activity as three biomarkers of brain dysfunction. Additionally Comet DNA assay showed remarkably higher tail length, tail DNA % damage and tail moment. N-acetyl-cysteine was effective in counteracting the neurotoxic effects of PPA.ConclusionsThe low dose and the short duration of N-acetyl-cysteine treatment tested in the present study showed much more protective rather than therapeutic effects on PPA-induced neurotoxicity in rats, as there was a remarkable amelioration in the impaired biochemical parameters representing neurochemical, inflammatory, detoxification and DNA damage processes.

Developmental Trajectories of the Fronto-Temporal Lobes from Infancy to Early Adulthood in Healthy Individuals

Brain development during early life in healthy individuals is rapid and dynamic, indicating that this period plays a very important role in neural and functional development. The frontal and temporal lobes are known to play a particularly important role in cognition. The study of healthy frontal and temporal lobe development in children is therefore of considerable importance. A better understanding of how these brain regions develop could also aid in the diagnosis and treatment of neurodevelopmental disorders. Some devel-opmental studies have used magnetic resonance imaging (MRI) to examine infant brains, but it remains the case that relatively little is known about cortical brain development in the first few years of life. In the present study we examined whole brain, temporal lobe and frontal lobe developmental trajectories from infancy to early adulthood in healthy individuals, considering gender and brain hemisphere differences. We performed a cross-sectional, longitudinal morphometric MRI study of 114 healthy individuals (54 females and 60 males) aged 1 month to 25 years old (mean age ± SD 8.8 ± 6.9). We measured whole brain, temporal and frontal lobe gray matter (GM)/white matter (WM) volumes, following previously used protocols. There were significant non-linear age-related volume changes in all regions. Peak ages of whole brain, temporal lobe and frontal lobe development occurred around pre-adolescence (9-12 years old). GM volumes for all regions increased significantly as a function of age. Peak age was nevertheless lobe specific, with a pattern of earlier peak ages for females in both temporal and frontal lobes. Growth change in whole brain GM volume was larger in males than in females. However, GM volume growth changes for the temporal and frontal lobes showed a somewhat different pattern. GM volume for both temporal and frontal lobes showed a greater increase in females until around 5-6 years old, at which point this tendency reversed (GM volume changes in males became greater), with male GM volume increasing for a longer time than that of females. WM volume growth changes were similar across regions, all increasing rapidly until early childhood but slowing down thereafter. All regions displayed significant rightward volumetric asymmetry regardless of sex. Furthermore, the right temporal and frontal lobes showed a greater volumetric increase than the left for the first several years, with this tendency reversing at around 6 years of age. In addition, the left frontal and temporal lobes increased in volume for a longer period of time. Taken together, these findings indicated that brain developmental trajectories differ depending on brain region, sex and brain hemisphere. Gender-related factors such as sex hormones and functional laterality may affect brain development.