RESUMO
In view of the need for easily accessible biomarkers, we evaluated in ADHD children the epigenetic status of the 5'-untranslated region (UTR) in the SLC6A3 gene, coding for human dopamine transporter (DAT). We analysed buccal swabs and sera from 30 children who met DSM-IV-TR criteria for ADHD, assigned to treatment according to severity. Methylation levels at six-selected CpG sites (among which, a CGGCGGCGG and a CGCG motif), alone or in combination with serum titers in auto-antibodies against dopamine transporter (DAT aAbs), were analysed for correlation with CGAS scores (by clinicians) and Conners' scales (by parents), collected at recruitment and after 6 weeks. In addition, we characterized the DAT genotype, i.e., the variable number tandem repeat (VNTR) polymorphisms at the 3'-UTR of the gene. DAT methylation levels were greatly reduced in ADHD patients compared to control, healthy children. Within patients carrying at least one DAT 9 allele (DAT 9/x), methylation at positions CpG2 and/or CpG6 correlated with recovery, as evident from delta-CGAS scores as well as delta Conners' scales ('inattentive' and 'hyperactive' subscales). Moreover, hypermethylation at CpG1 position denoted severity, specifically for those patients carrying a DAT 10/10 genotype. Intriguingly, high serum DAT-aAbs titers appeared to corroborate indications from high CpG1 versus high CpG2/CpG6 levels, likewise denoting severity versus recovery in DAT 10/10 versus 9/x patients, respectively. These profiles suggest that DAT 5'UTR epigenetics plus serum aAbs can serve as suitable biomarkers, to confirm ADHD diagnosis and/or to predict the efficacy of treatment.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/genética , Polimorfismo Genético/genética , Adolescente , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Criança , Feminino , Genótipo , Humanos , MasculinoRESUMO
BACKGROUND: Autism spectrum disorder (ASD) is a neurodevelopmental disease which affects 1 in 88 children. Its etiology remains basically unknown, but it is apparent that neuroinflammation is involved in disease development. Great attention has been focused on pro-inflammatory cytokines, and several studies have reported their dysfunction unbalance in serum as well as in the brain. The present work aimed at evaluating putative dysregulation of interleukin-18 (IL-18), a pro-inflammatory cytokine of the IL-1 family in the sera of patients with ASD of different grades, compared to healthy controls, as well as in postmortem brain samples obtained from patients with tuberous sclerosis as well as acute inflammatory diseases. Moreover, quantitative analysis of IL-18 was performed in the sera and brain obtained from Reeler mice, an experimental model of autism. METHODS: Serum IL-18 levels were measured by ELISA. IL-18 was localized by immunohistochemical analysis in brain sections obtained from tuberous sclerosis and encephalitis patients, as well as from gender- and age-matched controls, and in the brain sections of both Reeler and wild-type mice. IL-18 was also quantified by Western blots in homogenates of Reeler and wild-type mice brains. IL-18 binding protein (IL-18BP) was evaluated in Reeler and wild-type mice plasma as well as in their brains (sections and homogenates). RESULTS: IL-18 content decreased in the sera of patients with autism compared to healthy subjects and in Reeler sera compared to wild-type controls. IL-18 was detected within glial cells and neurons in the brain of subjects affected by tuberous sclerosis and encephalitis whereas in healthy subjects, only a weak IL-18 positivity was detected at the level of glial cells. Western blot identified higher amounts of IL-18 in Reeler brain homogenates compared to wild-type littermates. IL-18BP was expressed in higher amounts in Reeler brain compared to the brain of wild-type mice, whereas no significant difference was detected comparing IL-18BP plasma levels. CONCLUSIONS: IL-18 is dysregulated in ASD patients. Further studies seemed necessary to clarify the molecular details behind IL-18 increase in the brain and IL-18 decrease in the sera of patients. An increase in the size of the patient cohort seems necessary to ascertain whether decreased IL-18 content in the sera can become a predictive biomarker of ASD and whether its measure, in combination with other markers (e.g., increased levels of brain-derived neurotrophic factor (BDNF)), may be included in a diagnostic panel.
Assuntos
Transtorno do Espectro Autista/patologia , Encéfalo/metabolismo , Interleucina-18/metabolismo , Adolescente , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Criança , Pré-Escolar , Citocinas/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Regulação da Expressão Gênica/genética , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Masculino , Camundongos , Camundongos Mutantes Neurológicos , Camundongos Transgênicos , Inquéritos e Questionários , Adulto JovemRESUMO
Brain serotonin 7 (5-HT7) receptors play an important functional role in learning and memory, in regulation of mood and motivation, and for circadian rhythms. Recently, we have studied the modulatory effects of a developmental exposure (under subchronic regimen) in rats with LP-211, a brain-penetrant and selective 5-HT7 receptor agonist. We aimed at further deciphering long-term sequelae into adulthood. LP-211 (0.250 mg/kg i.p., once/day) was administered for 5 days during the adolescent phase (postnatal days 43-45 to 47-49). When adult (postnatal days >70), forebrain areas were obtained for ex vivo immunohistochemistry, whose results prompted us to reconsider the brain connectivity maps presented in our previous study (Canese et al., Psycho-Pharmacol 2015;232:75-89.) Significant elevation in levels of 5-HT7 receptors were evidenced due to adolescent LP-211 exposure, in dorsal striatum (which also shows an increase of dopaminergic D2 auto-receptors) and-unexpectedly-in piriform cortex, with no changes in ventral striatum. We observed that functional connectivity from a seed on the right hippocampus was more extended than reported, also including the piriform cortex. As a whole, the cortical loop rearranged by adolescent LP-211 exposure consisted in a hippocampus receiving connections from piriform cortex and dorsal striatum, the latter both directly and through functional control over the 'extended amygdala'. Such results represent a starting point to explore neurophysiology of 5-HT7 receptors. Further investigation is warranted to develop therapies for sleep disorders, for impaired emotional and motivational regulation, for attentive and executive deficit. The 5-HT7 agonist LP-211 (0.250 mg/kg i.p., once/day) was administered for 5 days during adolescence (postnatal days 43-45 to 47-49) in rats. When adult (postnatal days >70), a significant elevation in levels of 5-HT7 receptors were evidenced in dorsal striatum and-unexpectedly-in piriform cortex.
Assuntos
Piperazinas/farmacologia , Prosencéfalo/efeitos dos fármacos , Prosencéfalo/crescimento & desenvolvimento , Receptores de Serotonina/metabolismo , Agonistas do Receptor de Serotonina/farmacologia , Animais , Imuno-Histoquímica , Masculino , Vias Neurais/efeitos dos fármacos , Vias Neurais/crescimento & desenvolvimento , Vias Neurais/metabolismo , Prosencéfalo/metabolismo , Ratos Wistar , Regulação para CimaRESUMO
Rett syndrome (RTT) is a rare neurodevelopmental disorder, characterized by severe behavioural and physiological symptoms. Mutations in the methyl CpG binding protein 2 gene (MECP2) cause more than 95% of classic cases. Motor abnormalities represent a significant part of the spectrum of RTT symptoms. In the present study we investigated motor coordination and fine motor skill domains in MeCP2-308 female mice, a validated RTT model. This was complemented by the in vivo magnetic resonance spectroscopy (MRS) analysis of metabolic profile in behaviourally relevant brain areas. MeCP2-308 heterozygous female mice (Het, 10-12 months of age) were impaired in tasks validated for the assessment of purposeful and coordinated forepaw use (Morag test and Capellini handling task). A fine-grain analysis of spontaneous behaviour in the home-cage also revealed an abnormal handling pattern when interacting with the nesting material, reduced motivation to explore the environment, and increased time devoted to feeding in Het mice. The brain MRS evaluation highlighted decreased levels of bioenergetic metabolites in the striatal area in Het mice compared to controls. Present results confirm behavioural and brain alterations previously reported in MeCP2-308 males and identify novel endpoints on which the efficacy of innovative therapeutic strategies for RTT may be tested.
Assuntos
Membro Anterior , Destreza Motora , Síndrome de Rett/psicologia , Animais , Comportamento Animal , Peso Corporal/genética , Química Encefálica/fisiologia , Modelos Animais de Doenças , Metabolismo Energético , Feminino , Genótipo , Espectroscopia de Ressonância Magnética , Proteína 2 de Ligação a Metil-CpG/genética , Camundongos , Motivação , Neostriado/metabolismo , Comportamento de Nidação , Desempenho Psicomotor , Síndrome de Rett/genéticaRESUMO
The serotonin 7 (5-HT7) receptor was the last serotonin receptor subtype to be discovered in 1993. This receptor system has been implicated in several central nervous system (CNS) functions, including circadian rhythm, rapid eye movement sleep, thermoregulation, nociception, memory and neuropsychiatric symptoms and pathologies, such as anxiety, depression and schizophrenia. In 1999, medicinal chemistry efforts led to the identification of SB-269970, which became the gold standard selective 5-HT7 receptor antagonist, and later of various selective agonists such as AS-19, LP-44, LP-12, LP-211 and E-55888. In this review, we summarize the preclinical pharmacological studies performed using these agonists, highlighting their strengths and weaknesses. The data indicate that 5-HT7 receptor agonists can have neuroprotective effects against N-methyl-d-aspartate-induced toxicity, modulate neuronal plasticity in rats, enhance morphine-induced antinociception and alleviate hyperalgesia consecutive to nerve lesion in neuropathic animals.
Assuntos
Avaliação Pré-Clínica de Medicamentos , Doenças do Sistema Nervoso/tratamento farmacológico , Receptores de Serotonina/metabolismo , Agonistas do Receptor de Serotonina/uso terapêutico , Animais , Regulação da Temperatura Corporal/efeitos dos fármacos , Ritmo Circadiano/efeitos dos fármacos , Humanos , Aprendizagem/efeitos dos fármacos , Doenças do Sistema Nervoso/prevenção & controle , Ratos , Agonistas do Receptor de Serotonina/química , Agonistas do Receptor de Serotonina/farmacologiaRESUMO
The serotonin receptor 7 (5-HT7-R) plays important functional roles in learning and memory, in regulation of mood and circadian rhythmicity. LP-211 is a new selective agonist, belonging to 1-arylpiperazine category. We report studies aimed to evaluate the modulatory effect of a subchronic regimen on behavioral/molecular parameters. At low dose [0.25 mg/kg intraperitoneally (i.p.)], LP-211 induced a 6-h anticipated wake up in adult mice (with no temporal landmark by constant light), acting as nonphotic stimulus for 'internal clock' resetting. In standard 12:12-h light/dark cycle, a subchronic effect (5-6 days at 0.25 mg/kg, once per day) was observed: delayed wake up, reduced peak of locomotor activity and no evidence for brain cellular proliferation after ex vivo analysis. Other studies in rats were aimed to investigate long-term effects of developmental LP-211 administration into adulthood. Subchronic LP-211 (0.125 mg/kg i.p. once per day during the prepuberal phase) reduced l-glutamate, N-methyl-d-aspartate receptor 1 and dopamine transporter within the ventral striatum. With LP-211 (0.25 mg/kg i.p. once per day during the postpuberal phase), clear reductions were observed in the immunoreactivity of serotonin transporter and dopaminergic D2 receptors in the ventral and dorsal striatum, respectively. Subchronic LP-211 in rats and mice appears to be a suitable tool for studying the role of 5-HT7-R in sleep disorders, emotional/motivational regulations, attentive processes and executive functions.
Assuntos
Comportamento Animal/fisiologia , Encéfalo/metabolismo , Ritmo Circadiano/fisiologia , Receptores de Serotonina/metabolismo , Animais , Comportamento Animal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Ritmo Circadiano/efeitos dos fármacos , Camundongos , Piperazinas/farmacologia , Ratos , Receptores de Dopamina D2/metabolismo , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Agonistas do Receptor de Serotonina/farmacologia , Fatores de TempoRESUMO
We report here the results of studies aimed to investigate the involvement of serotonin receptor 7 subtype (5-HT7-R) in the modulation of emotional response in Naples High-Excitability (NHE) rat, a validated model for hyperactivity and impaired attention. A range of dosages (0.0, 0.125, 0.250, or 0.500 mg/kg) of LP-211, a selective agonist of 5-HT7-Rs, has been evaluated in animals at different age (adolescence and adulthood). Male NHE and random bred (NRB) control rats were tested in an Elevated Zero-Maze (EZM) after LP-211 treatment in two different regimens: at the issue of adolescent, subchronic exposure (14 intraperitoneal [i.p.] injections, once/day, pnd 31-44, tested on pnd 45--Exp. 1) or as adult, acute effect (15 min after i.p. injection--Exp. 2). Adolescent, subchronic LP-211 at 0.500 mg/kg dosage increased the frequency of head-dips only in NHE rats. Drug effect on time spent and entries in open EZM quadrants were revealed with adult, acute administration of 0.125 mg/kg LP-211 (both strains), indicating a tendency toward anxiolytic effects. In conclusion, data demonstrate that subchronic stimulation of 5-HT7-Rs during prepuberal period increases novelty-seeking/risk-taking propensity in NHE adults. These sequels are revealing increased disinhibition and/or motivation to explore in the NHE rats, which are characterized by a hyperactive dopaminergic system. These data may open new perspectives in studying mechanism of risk-seeking behavior.
Assuntos
Emoções/efeitos dos fármacos , Piperazinas/farmacologia , Receptores de Serotonina/metabolismo , Assunção de Riscos , Agonistas do Receptor de Serotonina/farmacologia , Fatores Etários , Animais , Atenção/efeitos dos fármacos , Masculino , Ratos , Ratos Sprague-DawleyRESUMO
BACKGROUND: Possible interactions between nervous and immune systems in neuro-psychiatric disorders remain elusive. Levels of brain dopamine transporter (DAT) have been implicated in several impulse-control disorders, like attention deficit / hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD). Here, we assessed the interplay between DAT auto-immunity and behavioural / neurochemical phenotype. METHODS: Male CD-1 mice were immunized with DAT peptide fragments (DAT-i), or vehicle alone (VEH), to generate elevated circulating levels of DAT auto-antibodies (aAbs). Using an operant delay-of-reward task (20 min daily sessions; timeout 25 sec), mice had a choice between either an immediate small amount of food (SS), or a larger amount of food after a delay (LL), which increased progressively across sessions (from 0 to 150 sec). RESULTS: DAT-i mice exhibited spontaneous hyperactivity (2 h-longer wake-up peak; a wake-up attempt during rest). Two sub-populations differing in behavioural flexibility were identified in the VEH control group: they showed either a clear-cut decision to select LL or clear-cut shifting towards SS, as expected. Compared to VEH controls, choice-behaviour profile of DAT-i mice was markedly disturbed, together with long-lasting alterations of the striatal monoamines. Enhanced levels of DA metabolite HVA in DAT-i mice came along with slower acquisition of basal preferences and with impaired shifting; elevation also in DOPAC levels was associated with incapacity to change a rigid selection strategy. This scarce flexibility of performance is indicative of a poor adaptation to task contingencies. CONCLUSIONS: Hyperactivity and reduced cognitive flexibility are patterns of behaviour consistent with enduring functional impairment of striatal regions. It is yet unclear how anti-DAT antibodies could enter or otherwise affect these brain areas, and which alterations in DAT activity exactly occurred after immunization. Present neuro-behavioural alterations, coming along with an experimentally-induced rise of circulating DAT-directed aAbs, open the issue of a potential role for auto-immunity in vulnerability to impulse-control disorders.
Assuntos
Comportamento Animal/fisiologia , Cognição/fisiologia , Corpo Estriado/fisiopatologia , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Hipercinese/fisiopatologia , Fragmentos de Peptídeos/farmacologia , Animais , Cognição/efeitos dos fármacos , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/metabolismo , Comportamento Exploratório/fisiologia , Hipercinese/metabolismo , Imunização , Masculino , Camundongos , Fragmentos de Peptídeos/metabolismo , RecompensaRESUMO
Autism and schizophrenia are multifactorial disorders with increasing prevalence in the young population. Among candidate molecules, reelin (RELN) is a protein of the extracellular matrix playing a key role in brain development and synaptic plasticity. The heterozygous (HZ) reeler mouse provides a model for studying the role of reelin deficiency for the onset of these syndromes. We investigated whether early indices of neurobehavioral disorders can be identified in the infant reeler, and whether the consequences of ontogenetic adverse experiences may question or support the suitability of this model. A first study focused on the link between early exposure to Chlorpyryfos and its enduring neurobehavioral consequences. Our data are interesting in view of recently discovered cholinergic abnormalities in autism and schizophrenia, and may suggest new avenues for early pharmacological intervention. In a second study, we analyzed the consequences of repeated maternal separation early in ontogeny. The results provide evidence of how unusual stress early in development are converted into altered behavior in some, but not all, individuals depending on gender and genetic background. A third study aimed to verify the reliability of the model at critical age windows. Data suggest reduced anxiety, increased impulsivity and disinhibition, and altered pain threshold in response to morphine for HZ, supporting a differential organization of brain dopaminergic, serotonergic and opioid systems in this genotype. In conclusion, HZ exhibited a complex behavioral and psycho-pharmacological phenotype, and differential responsivity to ontogenetic adverse conditions. HZ may be used to disentangle interactions between genetic vulnerability and environmental factors. Such an approach could help to model the pathogenesis of neurodevelopmental psychiatric diseases.
Assuntos
Sintomas Comportamentais , Moléculas de Adesão Celular Neuronais/genética , Meio Ambiente , Proteínas da Matriz Extracelular/genética , Heterozigoto , Transtornos Mentais , Camundongos Mutantes Neurológicos , Proteínas do Tecido Nervoso/genética , Serina Endopeptidases/genética , Fatores Etários , Animais , Comportamento Animal/fisiologia , Sintomas Comportamentais/complicações , Sintomas Comportamentais/genética , Sintomas Comportamentais/metabolismo , Modelos Animais de Doenças , Humanos , Transtornos Mentais/complicações , Transtornos Mentais/genética , Transtornos Mentais/metabolismo , Camundongos , Camundongos Mutantes Neurológicos/genética , Camundongos Mutantes Neurológicos/crescimento & desenvolvimento , Camundongos Mutantes Neurológicos/psicologia , Proteína ReelinaRESUMO
Few animal studies focus on consequences of nicotine postnatal exposure, particularly through lactation. We have recently shown that forced nicotine drinking elevates maternal care, paradoxically provoking arousal and stress in pups. Present work aimed to evaluate the specific contribution of altered maternal cares, compared to the sequelae merely due to nicotine effects. Two groups were compared to water-drinking control dams: (i) free-choice dams (H2O+NIC group) drinking from two bottles, containing either nicotine or water; (ii) forced dams (NIC+NIC group) drinking from two bottles, both containing nicotine. We previously demonstrated that nicotine was indeed transferred to the lactating offspring. Regarding behavioural consequences at adolescence, both H2O+NIC and NIC+NIC rats were slower than controls in discovering a novel over a familiar compartment, whilst only NIC+NIC rats exhibited reduced risk-related avoidance and assessment behaviour. Brain analyses at adulthood suggest that, in prefrontal cortex, nicotine per se reduced serotonin, while the maternal overcare reduced CHRN-B2 gene-expression. As a whole, unescapable nicotine-enhanced maternal care could have an impact on the offspring arousal by acting on prefrontal CHRN-B2 gene-expression. When present results are translated to consequences of non-voluntary exposure in humans, we propose that children receiving altered attentions by a smoking caregiver might undergo a neuro-behavioural development biased towards emotional shyness.
Assuntos
Lactação , Exposição Materna/efeitos adversos , Nicotina/efeitos adversos , Agonistas Nicotínicos/efeitos adversos , Receptores Nicotínicos/metabolismo , Assunção de Riscos , Animais , Comportamento de Escolha , Comportamento Exploratório/efeitos dos fármacos , Comportamento Alimentar , Feminino , Expressão Gênica/efeitos dos fármacos , Masculino , Comportamento Materno/efeitos dos fármacos , Nicotina/administração & dosagem , Agonistas Nicotínicos/administração & dosagem , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/crescimento & desenvolvimento , Distribuição Aleatória , Ratos Wistar , Serotonina/metabolismoRESUMO
This study investigates the transfer of nicotine from lactating dams to their offspring through breast milk, in the frame of a research focused to ascertain toxicological and neuro-behavioural effects on pups as consequence of either unavoidable ("yoked & forced") or voluntary ("freely-chosen") maternal nicotine exposure. To this aim, plasmatic concentrations of nicotine and cotinine were determined by LC-MS/MS in Wistar rat pups whose mothers were orally administered with nicotine during lactation. Mothers were divided into a voluntary drinking group, an unavoidable consumption group, and controls. The limits of detection and quantification of the LC-MS/MS method were 0.20 and 0.65 ng/mL, respectively. Within-laboratory reproducibility (CV%) was <12%, with recovery of 86.2-118.8%. Results showed the presence of nicotine in 67% of samples from freely-chosen consumption group (1.30 ± 0.31 ng/mL) and in 60% of samples from yoked-consumption group (1.19 ± 0.62 ng/mL); cotinine was found in all the samples from freely-chosen (1.92 ± 0.77 ng/mL) and yoked-consumption groups (1.43 ± 0.30 ng/mL). Data provide an evidence-based support to maternal/offspring nicotine transfer as function of different ways of oral exposure.
Assuntos
Comportamento Animal/efeitos dos fármacos , Lactação , Nicotina/farmacologia , Agonistas Nicotínicos/farmacologia , Animais , Aleitamento Materno , Cotinina/sangue , Feminino , Masculino , Leite/química , Nicotina/farmacocinética , Agonistas Nicotínicos/farmacocinética , Ratos , Ratos WistarRESUMO
Adverse effects of nicotine during pregnancy have been greatly studied, while nowadays few works are focused on consequences of maternal tobacco smoking after birth. The present study investigated the behavioral and early neurochemical effects of nicotine treatment during first weeks of post-natal life in rats. We used "free choice" treatment (H2O+NIC dams could drink from two bottles, containing 10mg/L nicotine hydrogen tartrate salt, or water) versus "forced choice" (NIC+NIC mothers could drink from two bottles both containing nicotine hydrogen tartrate salt, range from 0.75mg/L to 4.09mg/L). We found that only "forced nicotine" had impact on maternal behavior, causing increased high-quality maternal care. This immediately impacted on neuro-chemical development, affecting NE levels (only males) in pup's striatum and prefrontal cortex (pFC) at PND 12. After weaning, animals were reared in normal conditions (two brother rats) or in Social Isolation. After two weeks, they were tested with Social Interaction Test (isolated rats met non-isolated opponents, siblings vs. non-siblings). As expected, isolated rats displayed an aggressive form of soliciting behavior: when facing an isolated unknown partner, the non-isolated rat tried to escape. Interestingly, if their dams were exposed to forced nicotine, both rats sooner behaved very affiliative (possibly empathic) between non-sibling partners. As expected, being exposed to post-natal nicotine could alter neuro-chemical development, but with important interactions between both maternal care and adolescent social behavior.
Assuntos
Comportamento Animal/efeitos dos fármacos , Comportamento de Escolha/efeitos dos fármacos , Exposição Materna/efeitos adversos , Nicotina/farmacologia , Isolamento Social , Animais , Animais Recém-Nascidos , Feminino , Lactação/efeitos dos fármacos , Masculino , Comportamento Materno/efeitos dos fármacos , Gravidez , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Ratos , DesmameRESUMO
Gambling Disorder (GD) is characterized by excessive gambling despite adverse consequences on individual functioning. In spite of some positive findings, it is difficult to draw any conclusion on the genetics of GD. Indeed, beyond DNA sequence variation, other regulatory mechanisms (like those that engage epigenetics) may explain gene alterations in this addictive disease. Wistar male rats underwent an operant task for the evaluation of individual propensity to gamble. Few rats, after having learnt to prefer nose-poking for a large over a small food reward, were sacrificed to obtain a baseline profile of gene expression at both central and peripheral levels. In the remaining rats, probability of occurrence of large-reward delivery decreased progressively to very low levels. Thus, rats were faced with temptation to "gamble", i.e. to nose-poke for a binge reward, whose delivery was omitted the majority of times. After 3weeks of testing, rats showing a clear-cut profile of either gambling proneness or aversion were selected and sacrificed after the last session. A selective down-regulation of i) serotonin transporter in prefrontal cortex, ii) tyrosine hydroxylase in ventral striatum, iii) dopamine transporter in lymphocytes was evidenced in "gambler" vs "non-gambler" rats. The exposure to such operant task (compared to home-cage alone) modulated ventrostriatal but not prefrontal genes. A consistent increase of DNA methylation, in one specific CpG site at serotonin transporter gene, was evident in prefrontal cortex of "gambler" rats. Elucidation of epigenetic changes occurring during GD progression may pave the way to the development of new therapeutic strategies through specific modulation of epigenetic factors.
Assuntos
Encéfalo/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Jogo de Azar/metabolismo , Linfócitos/metabolismo , Proteínas de Ligação a RNA/metabolismo , Tirosina 3-Mono-Oxigenase/metabolismo , Animais , Encéfalo/patologia , Condicionamento Operante , Metilação de DNA , Proteínas da Membrana Plasmática de Transporte de Dopamina/genética , Regulação para Baixo , Epigênese Genética , Jogo de Azar/genética , Jogo de Azar/patologia , Predisposição Genética para Doença , Linfócitos/patologia , Personalidade , Proteínas de Ligação a RNA/genética , Distribuição Aleatória , Ratos Wistar , Tirosina 3-Mono-Oxigenase/genéticaRESUMO
The prevalence, age of onset and symptomatology of many neurodevelopmental disorders strongly differ between genders. This review examines sex biases in human neurodevelopmental disorders and in validated animal models. A focus is made on disorders of well-established genetic origin, such as Rett syndrome, CDKL5-associated disorders, Fragile X and Down syndrome. Autism is also addressed, given its paradigmatic role as a sex-biased neurodevelopmental disorder. Reviewed literature confirms that a complex interaction between genetic factors and sex hormones may underlie the differential susceptibility of genders and may impact the severity of symptoms in most of the analyzed neurodevelopmental disorders. Even though further studies addressing the advantages and disadvantages conferred by biological sex in this class of disorders are needed to disentangle the underlying mechanisms, present findings suggest that modulation of sex steroid-related pathways may represent an innovative approach for these diseases. Much effort is now expected to unravel the potential therapeutic efficacy of drugs targeting sex hormones-related signaling pathways in neurodevelopmental disorders of well-established genetic origin.
Assuntos
Hormônios Esteroides Gonadais/metabolismo , Animais , Transtorno Autístico , Humanos , Proteína Reelina , Síndrome de RettRESUMO
UNLABELLED: Interest is rising for auto-immune contribution in neuro-psychiatry. We evaluated the auto-antibodies against dopamine transporter (DAT aAbs) in 61 children (46 ADHD who met DSM-IV-TR criteria, 15 healthy controls). METHODS: ADHD patients were assigned, according to severity, either to a non-pharmacological therapy (NPT, N=32) or to a pharmacological treatment (PT, N=14) with methylphenidate (MPH). In ADHD children, blood samples were withdrawn twice, at recruitment (T0 basal) and after 6 weeks (T1); following 16 excluded subjects, DAT genotype was characterized (9-repeat or 10-repeat alleles; N=15 each). After 18 months of NPT or PT, some patients (carrying at least one 9-repeat allele) were blood sampled again (T2), for comparison with healthy controls (final n=8) RESULTS: Compared to NPT, basal DAT aAbs titers were higher within most severe patients (then assigned to PT), specifically if carrying a DAT 10/10 genotype. DAT aAbs levels of NPT group resulted highly correlated with distinct subscales of Conners' Parent/Teacher Scales (Rs>0.34), especially within DAT 10/10 genotype (Rs>0.53). While T1 titers were elevated over T0 baseline for NPT children, such an increase was not observed in PT patients carrying at least one 9-repeat allele, who also showed behavioral response to subchronic MPH. After 12-24 months of MPH exposure, DAT aAbs titers in PT subjects were comparable to those of healthy controls, while titers remained significantly elevated in NPT patients. Data warrant further research on serum DAT aAbs, which could be used to confirm ADHD diagnosis and/or to monitor therapeutic efficacy of MPH.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Autoanticorpos/sangue , Estimulantes do Sistema Nervoso Central/uso terapêutico , Proteínas da Membrana Plasmática de Transporte de Dopamina/genética , Proteínas da Membrana Plasmática de Transporte de Dopamina/imunologia , Metilfenidato/uso terapêutico , Transtorno do Deficit de Atenção com Hiperatividade/sangue , Transtorno do Deficit de Atenção com Hiperatividade/tratamento farmacológico , Transtorno do Deficit de Atenção com Hiperatividade/genética , Criança , Análise Mutacional de DNA , Ensaio de Imunoadsorção Enzimática , Feminino , Seguimentos , Genótipo , Humanos , Masculino , Entrevista Psiquiátrica Padronizada , Repetições Minissatélites/genéticaRESUMO
Rho GTPases are key intracellular signaling molecules that coordinate dynamic changes in the actin cytoskeleton, thereby stimulating a variety of processes, including morphogenesis, migration, neuronal development, cell division and adhesion. Deviations from normal Rho GTPases activation state have been proposed to disrupt cognition and synaptic plasticity. This review focuses on the functional consequences of genetic ablation of upstream and downstream Rho GTPases molecules on cognitive function and neuronal morphology and connectivity. Available information on this issue is described and compared to that gained from mice carrying mutations in the most studied Rho GTPases and from pharmacological in vivo studies in which brain Rho GTPases signaling was modulated. Results from reviewed literature provide definitive evidence of a compelling link between Rho GTPases signaling and cognitive function, thus supporting the notion that Rho GTPases and their downstream effectors may represent important therapeutic targets for disorders associated with cognitive dysfunction.
Assuntos
Transtornos Cognitivos/metabolismo , Transdução de Sinais/genética , Proteínas rho de Ligação ao GTP/genética , Proteínas rho de Ligação ao GTP/metabolismo , Animais , Transtornos Cognitivos/genética , Regulação Enzimológica da Expressão Gênica/genética , Modelos Biológicos , Mutação , Plasticidade Neuronal/genéticaRESUMO
RATIONALE: We have recently reported nicotine-induced stimulation of reelin and glutamic acid decarboxylase 67 (GAD67) mRNA expression levels in the brain of heterozygous reeler mice (HRM), a putative animal model for the study of symptoms relevant to major behavioral disorders. OBJECTIVES: We aimed to evaluate long-term behavioral effects and brain molecular changes as a result of adaptations to nicotine exposure in the developing HRM males. METHODS: Adolescent mice (pnd 37-42) were exposed to oral nicotine (10 mg/l) in a 6-day free-choice drinking schedule. As expected, no differences in total nicotine intake between WT (wild-type) mice and HRM were found. RESULTS: Long-term behavioral effects and brain molecular changes, as a consequence of nicotine exposure during adolescence, were only evidenced in HRM. Indeed, HRM perseverative exploratory behavior and poor cognitive performance were modulated to WT levels by subchronic exposure to nicotine during development. Furthermore, the expected reduction in the expression of mRNA of reelin and GAD67 in behaviorally relevant brain areas of HRM appeared persistently restored by nicotine. For brain-derived neurotrophic factor (BDNF) mRNA expression, no genotype-dependent changes appeared. However, expression levels were increased by previous nicotine in brains from both genotypes. The mRNA encoding for nicotine receptor subunits (α7, ß2 and α4) did not differ between genotypes and as a result of previous nicotine exposure. CONCLUSION: These findings support the hypothesis of pre-existing vulnerability (based on haploinsufficiency of reelin) to brain and behavioral disorders and regulative short- and long-term effects associated with nicotine modulation.
Assuntos
Encéfalo/efeitos dos fármacos , Encéfalo/crescimento & desenvolvimento , Cognição/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Nicotina/farmacologia , Agonistas Nicotínicos/farmacologia , Administração Oral , Animais , Encéfalo/fisiologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Moléculas de Adesão Celular Neuronais/metabolismo , Cognição/fisiologia , Comportamento Exploratório/efeitos dos fármacos , Comportamento Exploratório/fisiologia , Proteínas da Matriz Extracelular/metabolismo , Glutamato Descarboxilase/metabolismo , Heterozigoto , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Camundongos Mutantes Neurológicos , Proteínas do Tecido Nervoso/metabolismo , RNA Mensageiro/metabolismo , Receptores Nicotínicos/metabolismo , Proteína Reelina , Serina Endopeptidases/metabolismoRESUMO
Autism Spectrum Disorders (ASD) are neurodevelopmental disorders with multifactorial origin characterized by social communication deficits and the presence of repetitive behaviors/interests. Several studies showed an association between the reelin gene mutation and increased risk of ASD and a reduced reelin expression in some brain regions of ASD subjects, suggesting a role for reelin deficiency in ASD etiology. Reelin is a large extracellular matrix glycoprotein playing important roles during development of the central nervous system. To deeply investigate the role of reelin dysfunction as vulnerability factor in ASD, we assessed the behavioral, neurochemical, and brain morphological features of reeler male mice. We recently reported a genotype-dependent deviation in the ultrasonic vocal repertoire and a general delay in motor development of reeler pups. We now report that adult male heterozygous (Het) reeler mice did not show social behavior and communication deficits during male-female social interactions. Wildtype and Het mice showed a typical light/dark locomotor activity profile, with a peak during the central interval of the dark phase. However, when faced with a mild stressful stimulus (a saline injection) only Het mice showed an over response to stress. In addition to the behavioral studies, we conducted high performance liquid chromatography and magnetic resonance imaging and spectroscopy to investigate whether reelin mutation influences brain monoamine and metabolites levels in regions involved in ASD. Low levels of dopamine in cortex and high levels of glutamate and taurine in hippocampus were detected in Het mice, in line with clinical data collected on ASD children. Altogether, our data detected subtle but relevant neurochemical abnormalities in reeler mice supporting this mutant line, particularly male subjects, as a valid experimental model to estimate the contribution played by reelin deficiency in the global ASD neurobehavioral phenotype.
RESUMO
Important reduction of reelin, a neural development- and plasticity-associated protein, and glutamic acid decarboxylase (GAD67) are reported in brains of schizophrenic patients. These individuals are consistently engaged in tobacco smoking and nicotine is thought to alleviate negative behavioral symptoms or cognitive alterations. In mouse brain, nicotine has been shown to reduce GAD67 promoter methylation and increase its transcription. We assessed the effects of administration of nicotine (1 mg/kg s.c.) for 6 days, in male mice heterozygous for reelin (HRM), a putative model for symptoms related to schizophrenia. Expression of reelin, GAD67 and brain-derived neurotrophic factor (BDNF) was measured in different brain areas. RNA expression analysis evidenced genotype-related changes, with a marked reduction in reelin and GAD67 gene expression in prefrontal cortex, hippocampus, cerebellum, and striatum from HRM. Nicotine treatment selectively reversed the HRM-related phenotype in most brain areas and increased BDNF gene expression in cortex and hippocampus of both genotypes. Locomotor performance in their home cage revealed that HRM subjects were characterized by general hyperactivity; with nicotine administration restoring WT-like levels of locomotion. These findings are interpreted within the hypothesis of pre-existing vulnerability (based on haploinsufficiency of reelin) to brain and behavioral disorders and regulative effects associated with nicotine exposure.
Assuntos
Encéfalo/efeitos dos fármacos , Encéfalo/enzimologia , Regulação Enzimológica da Expressão Gênica , Glutamato Descarboxilase/biossíntese , Nicotina/farmacologia , Animais , Feminino , Masculino , Camundongos , Camundongos Mutantes Neurológicos , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Proteína ReelinaRESUMO
Reelin is a large secreted extracellular matrix glycoprotein playing an important role in early neurodevelopment. Several genetic studies found an association between RELN gene and increased risk of autism suggesting that reelin deficiency may be a vulnerability factor in its etiology. Moreover, a reduced reelin expression has been observed in several brain regions of subjects with Autism Spectrum Disorders. Since a number of reports have documented presence of vocal and neuromotor abnormalities in patients with autism and suggested that these dysfunctions predate the onset of the syndrome, we performed a fine-grain characterization of the neonatal vocal and motor repertoire in reelin mutant mice to explore the developmental precursors of the disorder. Our findings evidence a general delay in motor and vocal development in heterozygous (50% reduced reelin) and reeler (lacking reelin gene) mutant mice. As a whole, an increased number of calls characterized heterozygous pup's emission. Furthermore, the typical ontogenetic peak in the number of calls characterizing wild-type pups on postnatal day 4 appeared slightly delayed in heterozygous pups (to day 6) and was quite absent in reeler littermates, which exhibited a flat profile during development. We also detected a preferential use of a specific call category (two-components) by heterozygous and reeler mice at postnatal days 6 and 8 as compared to their wild-type littermates. With regard to the analysis of spontaneous movements, a differential profile emerged early in development among the three genotypes. While only slight coordination difficulties are exhibited by heterozygous pups, all indices of motor development appear delayed in reeler mice. Overall, our results evidence a genotype-dependent deviation in ultrasonic vocal repertoire and a general delay in motor development in reelin mutant pups.