RESUMO
Environmental tobacco smoke (ETS) exposure during brain development has been associated with several disorders, such as depression, anxiety, sudden infant death syndrome, and the predisposition to addiction. The endocannabinoid system plays an essential role in neuronal development. We investigated the effects of early postnatal ETS exposure on the endocannabinoid system in different brain regions. C57BL/6 J mice were exposed to ETS that was generated from 3R4F cigarettes from postnatal day 3 (P3) to P14. Receptors and enzymes of the endocannabinoid system were assessed in infancy, adolescence, and adulthood by Western blot. In the brainstem, ETS exposure decreased cannabinoid 1 (CB1) receptor, CB2 receptor, N-arachidonoyl phosphatidyl ethanol-specific phospholipase D (NAPE-PLD), and fatty acid amino hydrolase (FAAH) levels and increased in diacylglycerol lipase (DAGL) and monoacylglycerol lipase (MAGL) levels during infancy and decreased CB2 and FAAH levels during adulthood. In the striatum, ETS decreased in the NAPE-PLD and MAGL levels and increased FAAH levels during infancy, increased FAAH levels during adolescence, and decreased NAPE-PLD levels during adulthood. The present findings indicate that exposure to ETS during a critical period of brain development can disturb the endocannabinoid system in the brainstem and striatum, regions that are involved in the pathogenesis of sudden infant death syndrome and the susceptibility to addiction.
Assuntos
Tronco Encefálico/efeitos dos fármacos , Fumar Cigarros/efeitos adversos , Corpo Estriado/efeitos dos fármacos , Endocanabinoides/metabolismo , Poluição por Fumaça de Tabaco/efeitos adversos , Amidoidrolases/metabolismo , Animais , Animais Recém-Nascidos , Tronco Encefálico/crescimento & desenvolvimento , Tronco Encefálico/metabolismo , Corpo Estriado/crescimento & desenvolvimento , Corpo Estriado/metabolismo , Corpo Estriado/patologia , Lipase Lipoproteica/metabolismo , Camundongos Endogâmicos C57BL , Monoacilglicerol Lipases/metabolismo , Fosfolipase D/metabolismo , Receptor CB1 de Canabinoide/efeitos dos fármacos , Receptor CB1 de Canabinoide/metabolismo , Receptor CB2 de Canabinoide/efeitos dos fármacos , Receptor CB2 de Canabinoide/metabolismoRESUMO
Dopamine is widely involved in behaviors related to motor activity, cognition, motivation, and reward. Dopamine signal is transduced through the dopamine receptor gene family. The dopamine D1 receptor (D1R) is highly expressed in the striatum, and is responsible for regulating the motor function. Recently, we have reported that the knockdown (KD) mice in which D1R was conditionally eliminated at adult stage, displayed a hypoactivity in the home cage than wild type mice; however, conventional D1R knockout (KO) mice show hyperactive phenotypes. In order to assess whether the difference in the time of eliminating D1R expression affects the behavioral phenotypes, we generated D1R KD mice at the postnatal and adult stages, and compared their motor function with D1R KO mice. Consequently, D1R KD at postnatal and adult stages resulted in severe locomotive defects compared with D1R KO mice. These results suggested that D1R has versatile functions, and the knockdown timing greatly influences the normal motor activity in the adolescent to adult stages.
Assuntos
Envelhecimento , Regulação da Expressão Gênica no Desenvolvimento/genética , Hipercinese/genética , Receptores de Dopamina D1/deficiência , Fatores Etários , Animais , Animais Recém-Nascidos , Antibacterianos/farmacologia , Corpo Estriado/embriologia , Corpo Estriado/crescimento & desenvolvimento , Corpo Estriado/metabolismo , Fosfoproteína 32 Regulada por cAMP e Dopamina/metabolismo , Doxiciclina/farmacologia , Embrião de Mamíferos , Comportamento Exploratório/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Hipercinese/fisiopatologia , Locomoção/efeitos dos fármacos , Locomoção/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Destreza Motora/fisiologia , Receptores de Dopamina D1/genéticaRESUMO
Paraquat (PQ) and maneb (MB) are widely used herbicides. Wingless (Wnt) proteins serve a role in the development and differentiation of dopaminergic neurons. Previous studies demonstrated that combined exposure to PQ and MB damages dopaminergic neurons in the midbrain. Effects of PQ and MB exposure on midbrain Wnt proteins have also been previously reported. In the present study, from the 5th day of gestation to weaning of the offspring, pregnant SpragueDawley rats were administrated saline, or PQ and MB at two different doses: high, 15 mg/kg body weight PQ + 45 mg/kg body weight MB; or low, 10 mg/kg body weight PQ + 30 mg/kg body weight MB. Dopamine content in the striatum was examined by high performance liquid chromatography with a fluorescence detector and mRNA and protein expression of Wnt1, Wnt5a, nuclear receptor related factor 1 (Nurr1) and tyrosine hydroxylase (TH) in the midbrain was examined by reverse transcriptionquantitative polymerase chain reaction and western blotting. Combined exposure to PQ and MB during development decreased mRNA and protein expression of Wnt1, TH and Nurr1 and increased expression of Wnt5a in the offspring.
Assuntos
Neurônios Dopaminérgicos/efeitos dos fármacos , Membro 2 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Proteína Wnt-5a/genética , Proteína Wnt1/genética , Animais , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/crescimento & desenvolvimento , Corpo Estriado/patologia , Dopamina/genética , Dopamina/metabolismo , Neurônios Dopaminérgicos/metabolismo , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Lactação/efeitos dos fármacos , Lactação/genética , Maneb/toxicidade , Paraquat/toxicidade , Gravidez , Ratos , Substância Negra/efeitos dos fármacos , Substância Negra/crescimento & desenvolvimento , Substância Negra/patologia , Tirosina 3-Mono-Oxigenase/genéticaRESUMO
Degeneration of the striatum can occur in multiple disorders with devastating consequences for the patients. Infantile infections with streptococcus, measles, or herpes can cause striatal necrosis associated with dystonia or dyskinesia; and in patients with Huntington's disease the striatum undergoes massive degeneration, leading to behavioral, psychological and movement issues, ultimately resulting in death. Currently, only supportive therapies are available for striatal degeneration. Clinical trials have shown some efficacy using transplantation of fetal-derived primary striatal progenitors. Large banks of fetal progenitors that give rise to medium spiny neurons (MSNs), the primary neuron of the striatum, are needed to make transplantation therapy a reality. However, fetal tissue is of limited supply, has ethical concerns, and is at risk of graft immunorejection. An alternative potential source of MSNs is induced pluripotent stem cells (iPSCs), adult somatic tissues reprogrammed back to a stem cell fate. Multiple publications have demonstrated the ability to differentiate striatal MSNs from iPSCs. Previous publications have demonstrated that the efficacy of fetal progenitor transplants is critically dependent upon the age of the donor embryo/fetus as well as the age of the transplant recipient. With the advent of iPSC technology, a question that remains unanswered concerns the graft's "age," which is crucial since transplanting pluripotent cells has an inherent risk of over proliferation and teratoma formation. Therefore, in order to also determine the effect of transplant recipient age on the graft, iPSCs were differentiated to three stages along a striatal differentiation paradigm and transplanted into the striatum of both neonatal and adult immunodeficient mice. This study demonstrated that increased murine transplant-recipient age (adult vs neonate) resulted in decreased graft survival and volume/rostro-caudal spread after six weeks in vivo, regardless of "age" of the cells transplanted. Importantly, this study implicates that the in vivo setting may provide a better neurogenic niche for iPSC-based modeling as compared to the in vitro setting. Together, these results recapitulate findings from fetal striatal progenitor transplantation studies and further demonstrate the influence of the host environment on cellular survival and maturation.
Assuntos
Transplante de Tecido Encefálico/métodos , Corpo Estriado/crescimento & desenvolvimento , Corpo Estriado/imunologia , Sobrevivência de Enxerto/fisiologia , Células-Tronco Pluripotentes Induzidas/imunologia , Células-Tronco Pluripotentes Induzidas/transplante , Fatores Etários , Animais , Animais Recém-Nascidos , Sobrevivência Celular/fisiologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCIDRESUMO
Neural cultures derived from Huntington's disease (HD) patient-derived induced pluripotent stem cells were used for 'omics' analyses to identify mechanisms underlying neurodegeneration. RNA-seq analysis identified genes in glutamate and GABA signaling, axonal guidance and calcium influx whose expression was decreased in HD cultures. One-third of gene changes were in pathways regulating neuronal development and maturation. When mapped to stages of mouse striatal development, the profiles aligned with earlier embryonic stages of neuronal differentiation. We observed a strong correlation between HD-related histone marks, gene expression and unique peak profiles associated with dysregulated genes, suggesting a coordinated epigenetic program. Treatment with isoxazole-9, which targets key dysregulated pathways, led to amelioration of expanded polyglutamine repeat-associated phenotypes in neural cells and of cognitive impairment and synaptic pathology in HD model R6/2 mice. These data suggest that mutant huntingtin impairs neurodevelopmental pathways that could disrupt synaptic homeostasis and increase vulnerability to the pathologic consequence of expanded polyglutamine repeats over time.
Assuntos
Doença de Huntington/metabolismo , Neurogênese/fisiologia , Neurônios/metabolismo , Neurônios/fisiologia , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/biossíntese , Células Cultivadas , Disfunção Cognitiva/tratamento farmacológico , Corpo Estriado/crescimento & desenvolvimento , Corpo Estriado/metabolismo , Epigenômica , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/fisiologia , Perfilação da Expressão Gênica , Técnicas de Silenciamento de Genes , Histonas/metabolismo , Humanos , Proteína Huntingtina/genética , Células-Tronco Pluripotentes Induzidas/fisiologia , Isoxazóis/farmacologia , Isoxazóis/uso terapêutico , Camundongos , Camundongos Transgênicos , Proteínas do Tecido Nervoso/biossíntese , Peptídeos/metabolismo , Transdução de Sinais/efeitos dos fármacos , Tiofenos/farmacologia , Tiofenos/uso terapêuticoRESUMO
Adolescence is a period during which the medial prefrontal cortex (mPFC) undergoes significant remodeling. The netrin-1 receptor, deleted in colorectal cancer (DCC), controls the extent and organization of mPFC dopamine connectivity during adolescence and in turn directs mPFC functional and structural maturation. Dcc haploinsufficiency leads to increased mPFC dopamine input, which causes improved cognitive processing and resilience to behavioral effects of stimulant drugs of abuse. Here we examine the effects of Dcc haploinsufficiency on the dynamic expression of dopamine receptors in forebrain targets of C57BL6 mice. We conducted quantitative receptor autoradiography experiments with [3H]SCH-23390 or [3H]raclopride to characterize D1 and D2 receptor expression in mPFC and striatal regions in male Dcc haploinsufficient and wild-type mice. We generated autoradiograms at early adolescence (PND21±1), mid-adolescence (PND35±2), and adulthood (PND75±15). C57BL6 mice exhibit overexpression and pruning of D1, but not D2, receptors in striatal regions, and a lack of dopamine receptor pruning in the mPFC. We observed age- and region-specific differences in D1 and D2 receptor density between Dcc haploinsufficient and wild-type mice. Notably, neither group shows the typical pattern of mPFC dopamine receptor pruning in adolescence, but adult haploinsufficient mice show increased D2 receptor density in the mPFC. These results show that DCC receptors contribute to the dynamic refinement of D1 and D2 receptor expression in striatal regions across adolescence. The age-dependent expression of dopamine receptor in C57BL6 mice shows marked differences from previous characterizations in rats.
Assuntos
Envelhecimento , Corpo Estriado/metabolismo , Córtex Pré-Frontal/metabolismo , Receptores de Superfície Celular/metabolismo , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D2/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Animais , Corpo Estriado/crescimento & desenvolvimento , Receptor DCC , Haploinsuficiência , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Núcleo Accumbens/crescimento & desenvolvimento , Núcleo Accumbens/metabolismo , Córtex Pré-Frontal/crescimento & desenvolvimento , Receptores de Superfície Celular/genética , Proteínas Supressoras de Tumor/genéticaRESUMO
Human Dopamine- and cAMP-regulated phosphoprotein of molecular weight 32kDa (DARPP-32, also known as PPP1R1B) gene codes for different transcripts that are mainly translated into two DARPP-32 protein isoforms, full length (fl)-DARPP-32 and truncated (t)-DARPP. The t-DARPP lacks the first 36 residues at the N-terminal, which alters its function. In the central nervous system, fl-DARPP-32 is highly expressed in GABAergic striatal medium spiny neurons (MSNs), where it integrates dopaminergic and glutamatergic input signaling. However, no information about human DARPP-32 isoform expression during MSNs maturation is available. In this study, our aim is to determine the expression of the two DARPP-32 isoforms in human fetal and adult striatal samples. We show that DARPP-32 isoform expression is differentially regulated during human striatal development, with the t-DARPP isoform being virtually absent from whole ganglionic eminence (WGE) and highly induced in the adult striatum (in both caudate and putamen). We next compared the four most common anti-DARPP-32 antibodies used in human specimens, to study their recognition of the two isoforms in fetal and adult human striatal samples by western blot and immunohistochemistry. The four antibodies specifically identify the fl-DARPP-32 in both fetal and adult samples, while t-DARPP form was only detected in adult striatal samples. In addition, the lack of t-DARPP recognition in human adult striatum by the antibody generated against the full-length domain produces in turn different efficacy by immunohistochemical analysis. In conclusion, our results show that expression of human DARPP-32 protein isoforms depends on the striatal neurodevelopmental stage with t-DARPP being specific for the human adult striatum.
Assuntos
Corpo Estriado/crescimento & desenvolvimento , Corpo Estriado/metabolismo , Fosfoproteína 32 Regulada por cAMP e Dopamina/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Western Blotting , Corpo Estriado/citologia , Corpo Estriado/embriologia , Feminino , Neurônios GABAérgicos/citologia , Neurônios GABAérgicos/metabolismo , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Isoformas de Proteínas , RNA Mensageiro/metabolismo , Homologia de Sequência de AminoácidosRESUMO
Identifying the steps involved in striatal development is important both for understanding the striatum in health and disease, and for generating protocols to differentiate striatal neurons for regenerative medicine. The most prominent neuronal subtype in the adult striatum is the medium spiny projection neuron (MSN), which constitutes more than 85% of all striatal neurons and classically expresses DARPP-32. Through a microarray study of genes expressed in the whole ganglionic eminence (WGE: the developing striatum) in the mouse, we identified the gene encoding the transcription factor Forkhead box protein P1 (FoxP1) as the most highly up-regulated gene, thus providing unbiased evidence for the association of FoxP1 with MSN development. We also describe the expression of FoxP1 in the human fetal brain over equivalent gestational stages. FoxP1 expression persisted through into adulthood in the mouse brain, where it co-localised with all striatal DARPP-32 positive projection neurons and a small population of DARPP-32 negative cells. There was no co-localisation of FoxP1 with any interneuron markers. FoxP1 was detectable in primary fetal striatal cells following dissection, culture, and transplantation into the adult lesioned striatum, demonstrating its utility as an MSN marker for transplantation studies. Furthermore, DARPP-32 expression was absent from FoxP1 knock-out mouse WGE differentiated in vitro, suggesting that FoxP1 is important for the development of DARPP-32-positive MSNs. In summary, we show that FoxP1 labels MSN precursors prior to the expression of DARPP-32 during normal development, and in addition suggest that FoxP1 labels a sub-population of MSNs that are not co-labelled by DARPP-32. We demonstrate the utility of FoxP1 to label MSNs in vitro and following neural transplantation, and show that FoxP1 is required for DARPP-32 positive MSN differentiation in vitro.
Assuntos
Diferenciação Celular/fisiologia , Corpo Estriado , Fatores de Transcrição Forkhead/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Células-Tronco Neurais/fisiologia , Neurônios/citologia , Neurônios/metabolismo , Proteínas Repressoras/metabolismo , Animais , Animais Recém-Nascidos , Proteínas de Transporte/metabolismo , Células Cultivadas , Corpo Estriado/citologia , Corpo Estriado/embriologia , Corpo Estriado/crescimento & desenvolvimento , Fosfoproteína 32 Regulada por cAMP e Dopamina/metabolismo , Embrião de Mamíferos , Endodesoxirribonucleases , Feto/citologia , Fatores de Transcrição Forkhead/genética , Técnicas In Vitro , Camundongos , Camundongos Knockout , Proteínas do Tecido Nervoso/metabolismo , Células-Tronco Neurais/transplante , Proteínas Nucleares/metabolismo , Proteínas Repressoras/genética , Estatísticas não ParamétricasRESUMO
Recently, we found that early life exposure to arsenic at low doses resulted to cause brain cholinergic deficits and exhibited a trend of recovery on withdrawal of arsenic exposure. In continuation to this, the present study has been carried out to assess the impact of low level arsenic exposure on brain dopaminergic system and associated behavior in developing rats and investigate if neurobehavioral changes are recovered or persistent. Early life exposure (PD22-PD59) to arsenic (2 or 4 mg/kg body weight, p.o.) in rats resulted to increase the motor activity on PD60, compared to controls. The hyperactivity in arsenic exposed rats was found to be linked with increase in the binding of DA-D2 receptors (38%, 56%), mRNA expression of DAR-D2 receptor gene (68%, 97%) and expression of tyrosine hydroxylase protein (1.93, 2.73-fold) in the corpus striatum as compared to controls on PD60. Exposure to arsenic enhanced generation of ROS (47%, 84%) and was associated with decrease in the mitochondrial membrane potential (13.3%, 15.33%), activity of mitochondrial complexes and increased oxidative stress. Disruption in the expression of pro-apoptotic, anti-apoptotic and stress marker proteins was also distinct in the corpus striatum of arsenic exposed rats. The severity of changes in the behavioral and neurochemical endpoints were found to persist in rats exposed to arsenic at high dose and exhibited a trend of recovery at low dose on withdrawal of arsenic exposure on PD90. Early life arsenic exposure appears to be critical and vulnerable as development of dopamine receptors continues during this period.
Assuntos
Arsênio/toxicidade , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/crescimento & desenvolvimento , Dopamina/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Fatores Etários , Animais , Animais Recém-Nascidos , Caspase 3/metabolismo , Corpo Estriado/metabolismo , Corpo Estriado/ultraestrutura , Relação Dose-Resposta a Droga , Comportamento Exploratório/efeitos dos fármacos , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Receptores Dopaminérgicos/metabolismo , Tirosina 3-Mono-Oxigenase/metabolismo , Proteína X Associada a bcl-2/metabolismoRESUMO
Glial cell line-derived neurotrophic factor (GDNF) exerts neuroprotective and neurorestorative effects on neurons and GDNF plays a significant role in maintenance of the dopamine neurons utilizing grafting to create a nigrostriatal microcircuit of Gdnf knockout (Gdnf(-/-)) tissue. To further evaluate the role of GDNF on organization of the nigrostriatal system, single or double grafts of ventral mesencephalon (VM) and lateral ganglionic eminence (LGE) with mismatches in Gdnf genotypes were performed. The survival of single grafts was monitored utilizing magnetic resonance imaging (MRI) and cell survival and graft organization were evaluated with immunohistochemistry. The results revealed that the size of VM single grafts did not change over time independent of genotype, while the size of the LGE transplants was significantly reduced already at 2 weeks postgrafting when lacking GDNF. Lack of GDNF did not significantly affect the survival of tyrosine hydroxylase (TH)-positive neurons in single VM grafts. However, the survival of TH-positive neurons was significantly reduced in VM derived from Gdnf(+/+) when co-grafted with LGE from the Gdnf(-/-) tissue. In contrast, lack of GDNF in the VM portion of co-grafts had no effect on the survival of TH-positive neurons when co-grafted with LGE from Gdnf(+/+) mice. The TH-positive innervation of co-grafts was sparse when the striatal co-grafts were derived from the Gdnf(-/-) tissue while dense and patchy when innervating LGE producing GDNF. The TH-positive innervation overlapped with the organization of dopamine and cyclic AMP-regulated phosphoprotein-relative molecular mass 32,000 (DARPP-32)-positive neurons, that was disorganized in LGE lacking GDNF production. In conclusion, GDNF is important for a proper striatal organization and for survival of TH-positive neurons in the presence of the striatal tissue.
Assuntos
Corpo Estriado/crescimento & desenvolvimento , Corpo Estriado/fisiologia , Neurônios Dopaminérgicos/fisiologia , Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Animais , Transplante de Tecido Encefálico , Sobrevivência Celular/fisiologia , Corpo Estriado/cirurgia , Fosfoproteína 32 Regulada por cAMP e Dopamina/metabolismo , Feminino , Técnicas de Genotipagem , Fator Neurotrófico Derivado de Linhagem de Célula Glial/genética , Imuno-Histoquímica , Imageamento por Ressonância Magnética , Mesencéfalo/embriologia , Mesencéfalo/fisiologia , Mesencéfalo/transplante , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Neurônios/fisiologia , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
Corticostriatal projection neurons (CStrPN) project from the neocortex to ipsilateral and contralateral striata to control and coordinate motor programs and movement. They are clinically important as the predominant cortical population that degenerates in Huntington's disease and corticobasal ganglionic degeneration, and their injury contributes to multiple forms of cerebral palsy. Together with their well-studied functions in motor control, these clinical connections make them a functionally, behaviorally, and clinically important population of neocortical neurons. Little is known about their development. "Intratelencephalic" CStrPN (CStrPNi), projecting to the contralateral striatum, with their axons fully within the telencephalon (intratelencephalic), are a major population of CStrPN. CStrPNi are of particular interest developmentally because they share hodological and axon guidance characteristics of both callosal projection neurons (CPN) and corticofugal projection neurons (CFuPN); CStrPNi send axons contralaterally before descending into the contralateral striatum. The relationship of CStrPNi development to that of broader CPN and CFuPN populations remains unclear; evidence suggests that CStrPNi might be evolutionary "hybrids" between CFuPN and deep layer CPN-in a sense "chimeric" with both callosal and corticofugal features. Here, we investigated the development of CStrPNi in mice-their birth, maturation, projections, and expression of molecular developmental controls over projection neuron subtype identity.
Assuntos
Córtex Cerebral/anatomia & histologia , Córtex Cerebral/crescimento & desenvolvimento , Corpo Estriado/anatomia & histologia , Corpo Estriado/crescimento & desenvolvimento , Neurônios/citologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Axônios/metabolismo , Córtex Cerebral/metabolismo , Corpo Estriado/metabolismo , Proteínas de Ligação a DNA/metabolismo , Imuno-Histoquímica , Indóis , Proteínas com Domínio LIM/metabolismo , Proteínas de Ligação à Região de Interação com a Matriz/metabolismo , Camundongos , Proteínas do Tecido Nervoso/metabolismo , Vias Neurais/anatomia & histologia , Vias Neurais/crescimento & desenvolvimento , Vias Neurais/metabolismo , Marcadores do Trato Nervoso , Neurônios/metabolismo , Proteínas Repressoras/metabolismo , Fatores de Transcrição SOXD/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/metabolismoRESUMO
Research in programming has focused in the study of stimuli that affect sensitive periods of development such as prenatal and neonatal stage. We previously showed that exposure to estradiol valerate to female rats during the first 12 h of life increased catecholamine content in ventromedial-arcuatus hypothalamus of the adult rat. However, changes in others dopaminergic circuits have not been studied. The purpose of this work was to determine the neurotransmitters changes induced by neonatal estradiol valerate (0.1 mg/50 µl s. c. per rat) administration on nigrostriatal pathway of adult female rats. Sesame oil (50 µl s. c. per rat) was administered in a control parallel group. EV-1 adult rats presented effective markers of long-term estrogenization as decreased serum levels of progesterone and a reduction in the size of estrogen-sensitive organs. In the brain, neonatal estradiol valerate administration led to a significant increase in dopamine content in striatum, substantia nigra and ventral tegmental area. With respect to the contents of dopamine metabolites, only 3-methoxytyramine content increased in substantia nigra and ventral tegmental area. In addition, the content of noradrenaline increased only in striatum. Interestingly, estrogenized rats lacked locomotor activity induced by acute dose of amphetamine (1 mg/kg i. p.). Altogether, these results show that neonatal exposure to estradiol valerate permanently modified the content of monoamine neurotransmitters in nigrostriatal pathway and amphetamine-induced locomotor activity of adult female rats. This might imply that estrogenized rats could have changes in the expression of key proteins in dopaminergic regulation, as tyrosine hydroxylase and dopamine transporter.
Assuntos
Dopamina/metabolismo , Estradiol/análogos & derivados , Substância Negra/metabolismo , Anfetamina/metabolismo , Animais , Animais Recém-Nascidos , Corpo Estriado/crescimento & desenvolvimento , Corpo Estriado/metabolismo , Estradiol/metabolismo , Feminino , Atividade Motora , Neurotransmissores/metabolismo , Ratos , Ratos Sprague-Dawley , Substância Negra/crescimento & desenvolvimentoRESUMO
Illicit use of prescription opioid analgesics (e.g., oxycodone) in adolescence is a pressing public health issue. Our goal was to determine whether oxycodone self administration differentially affects striatal neurotransmitter receptor gene expression in the dorsal striatum of adolescent compared to adult C57BL/6J mice. Groups of adolescent mice (4 weeks old, n=12) and of adult mice (11 weeks old, n=11) underwent surgery during which a catheter was implanted into their jugular veins. After recovering from surgery, mice self administered oxycodone (0.25 mg/kg/infusion) 2 h/day for 14 consecutive days or served as yoked saline controls. Mice were sacrificed within 1h after the last self-administration session and the dorsal striatum was isolated for mRNA analysis. Gene expression was analyzed with real time PCR using a commercially available neurotransmitter receptor PCR array containing 84 genes. We found that adolescent mice self administered less oxycodone than adult mice over the 14 days. Monoamine oxidase A (Maoa) and neuropeptide Y receptor 5 mRNA levels were lower in adolescent mice than in adult mice without oxycodone exposure. Oxycodone self administration increased Maoa mRNA levels compared to controls in both age groups. There was a positive correlation of the amount of oxycodone self administered in the last session or across 14 sessions with Maoa mRNA levels. Gastrin-releasing peptide receptor mRNA showed a significant Drug × Age interaction, with point-wise significance. More genes in the dorsal striatum of adolescents (19) changed in response to oxycodone self administration compared to controls than in adult (4) mice. Overall, this study demonstrates that repeated oxycodone self administration alters neurotransmitter receptors gene expression in the dorsal striatum of adolescent and adult mice.
Assuntos
Corpo Estriado/efeitos dos fármacos , Corpo Estriado/metabolismo , Entorpecentes/farmacologia , Oxicodona/farmacologia , Receptores de Neurotransmissores/metabolismo , Fatores Etários , Animais , Corpo Estriado/crescimento & desenvolvimento , Comportamento de Procura de Droga/fisiologia , Expressão Gênica/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Monoaminoxidase/metabolismo , Entorpecentes/administração & dosagem , Transtornos Relacionados ao Uso de Opioides/metabolismo , Oxicodona/administração & dosagem , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptores de Neuropeptídeo Y/metabolismo , AutoadministraçãoRESUMO
It is known that retinal input is necessary for the normal development of striate cortex and its corticocortical connections, but there is little information on the role that retinal input plays in the development of retinotopically organized connections between V1 and surrounding visual areas. In nearly all lateral extrastriate areas, the anatomical and physiological representation of the nasotemporal axis of the visual field mirrors the representation of this axis in V1. To determine whether the mediolateral topography of striate-extrastriate projections is preserved in neonatally enucleated rats, we analyzed the patterns of projections resulting from tracer injections placed at different sites along the mediolateral axis of V1. We found that the correlation between the distance from injection sites to the lateral border of V1 and the distance of the labeling patterns in area 18a was strong in controls and much weaker in enucleates. Data from pairs of injections in the same animal revealed that the separation of area 18a projection fields for a given separation of injection sites was more variable in enucleated than in control rats. Our analysis of single and double tracer injections suggests that neonatal bilateral enucleation weakens, but not completely abolishes, the mediolateral topography in area 18a.
Assuntos
Corpo Estriado , Enucleação Ocular , Campos Visuais , Animais , Corpo Estriado/crescimento & desenvolvimento , Corpo Estriado/patologia , Corpo Estriado/fisiopatologia , RatosRESUMO
Neocortical and striatal TRPV1 (vanilloid or capsaicin) receptors (TRPV1Rs) are excitatory ligand-gated ion channels, and are implicated in psychiatric disorders. However, the purported presynaptic neuromodulator role of TRPV1Rs in glutamatergic, serotonergic or dopaminergic terminals of the rodent forebrain remains little understood. With the help of patch-clamp electrophysiology and neurochemical approaches, we mapped the age-dependence of presynaptic TRPV1R function, and furthermore, we aimed at exploring whether the presence of CB1 cannabinoid receptors (CB1Rs) influences the function of the TRPV1Rs, as both receptor types share endogenous ligands. We found that the major factor which affects presynaptic TRPV1R function is age: by post-natal day 13, the amplitude of capsaicin-induced release of dopamine and glutamate is halved in the rat striatum, and two weeks later, capsaicin already loses its effect. However, TRPV1R receptor function is not enhanced by chemical or genetic ablation of the CB1Rs in dopaminergic, glutamatergic and serotonergic terminals of the mouse brain. Altogether, our data indicate a possible neurodevelopmental role for presynaptic TRPV1Rs in the rodent brain, but we found no cross-talk between TRPV1Rs and CB1Rs in the same nerve terminal.
Assuntos
Corpo Estriado/fisiologia , Receptor CB1 de Canabinoide/fisiologia , Canais de Cátion TRPV/fisiologia , Animais , Capsaicina/farmacologia , Corpo Estriado/diagnóstico por imagem , Corpo Estriado/crescimento & desenvolvimento , Dopamina/metabolismo , Potenciais Pós-Sinápticos Excitadores , Feminino , Ácido Glutâmico/metabolismo , Técnicas In Vitro , Masculino , Camundongos , Camundongos Knockout , Terminações Pré-Sinápticas/metabolismo , Terminações Pré-Sinápticas/fisiologia , Cintilografia , Ratos , Ratos Wistar , Receptor CB1 de Canabinoide/genética , Serotonina/metabolismo , Canais de Cátion TRPV/efeitos dos fármacosRESUMO
After reproductive senescence or gonadectomy, changes occur in neural gene expression, ultimately altering brain function. The endocrine mechanisms underlying these changes in gene expression beyond immediate hormone loss are poorly understood. To investigate this, we measured changes in gene expression the dorsal striatum, where 17ß-estradiol modulates catecholamine signaling. In human caudate, quantitative PCR determined a significant elevation in ß1-adrenergic receptor (ß1AR) expression in menopausal females when compared with similarly aged males. No differences were detected in ß2-adrenergic and D1- and D2-dopamine receptor expression. Consistent with humans, adult ovariectomized female rats exhibited a similar increase in ß1AR expression when compared with gonadectomized males. No sex difference in ß1AR expression was detected between intact adults, prepubertal juveniles, or adults gonadectomized before puberty, indicating the necessity of pubertal development and adult ovariectomy. Additionally, increased ß1AR expression in adult ovariectomized females was not observed if animals were masculinized/defeminized with testosterone injections as neonates. To generate a model system for assessing functional impact, increased ß1AR expression was induced in female-derived cultured striatal neurons via exposure to and then removal of hormone-containing serum. Increased ß1AR action on cAMP formation, cAMP response element-binding protein phosphorylation and gene expression was observed. This up-regulation of ß1AR action was eliminated with 17ß-estradiol addition to the media, directly implicating this hormone as a regulator of ß1AR expression. Beyond having implications for the known sex differences in striatal function and pathologies, these data collectively demonstrate that critical periods early in life and at puberty program adult gene responsiveness to hormone loss after gonadectomy and potentially reproductive senescence.
Assuntos
Corpo Estriado/metabolismo , Hormônios/deficiência , Puberdade/fisiologia , Receptores Adrenérgicos beta 1/genética , Diferenciação Sexual/genética , Adolescente , Adulto , Envelhecimento/genética , Envelhecimento/metabolismo , Envelhecimento/fisiologia , Animais , Corpo Estriado/crescimento & desenvolvimento , Estradiol/deficiência , Estradiol/farmacologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Hormônios/farmacologia , Humanos , Masculino , Ovariectomia , Puberdade/genética , Puberdade/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores Adrenérgicos beta 1/metabolismo , Diferenciação Sexual/efeitos dos fármacos , Diferenciação Sexual/fisiologia , Fatores de Tempo , Regulação para Cima/genética , Regulação para Cima/fisiologiaRESUMO
The effects of thyroid hormones (THs) on brain development and function are largely mediated by the control of gene expression. This is achieved by the binding of the genomically active T3 to transcriptionally active nuclear TH receptors (TRs). T3 and the TRs can either induce or repress transcription. In hypothyroidism, the reduction of T3 lowers the expression of a set of genes, the positively regulated genes, and increases the expression of negatively regulated genes. Two mechanisms may account for the effect of hypothyroidism on genes regulated directly by T3: first, the loss of T3 signaling and TR transactivation, and second, an intrinsic activity of the unliganded TRs directly responsible for repression of positive genes and enhancement of negative genes. To analyze the contribution of the TR subtypes α and ß, we have measured by RT-PCR the expression of a set of positive and negative genes in the cerebral cortex and the striatum of TR-knockout male and female mice. The results indicate that TRα1 exerts a predominant but not exclusive role in the regulation of positive and negative genes. However, a fraction of the genes analyzed are not or only mildly affected by the total absence of TRs. Furthermore, hypothyroidism has a mild effect on these genes in the absence of TRα1, in agreement with a role of unliganded TRα1 in the effects of hypothyroidism.
Assuntos
Córtex Cerebral/metabolismo , Corpo Estriado/metabolismo , Expressão Gênica , Receptores alfa dos Hormônios Tireóideos/fisiologia , Receptores beta dos Hormônios Tireóideos/fisiologia , Animais , Animais Recém-Nascidos , Córtex Cerebral/crescimento & desenvolvimento , Corpo Estriado/crescimento & desenvolvimento , Feminino , Expressão Gênica/genética , Perfilação da Expressão Gênica , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Análise em Microsséries , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/fisiologia , Receptores alfa dos Hormônios Tireóideos/genética , Receptores alfa dos Hormônios Tireóideos/metabolismo , Receptores beta dos Hormônios Tireóideos/genética , Receptores beta dos Hormônios Tireóideos/metabolismoRESUMO
This study was undertaken to investigate the effect of cypermethrin on the expression patterns of mRNAs in the striatum of adulthood alone and postnatal pre-exposed followed by adulthood re-exposed rats using discover chips rat microarrays. The expression patterns of V-akt murine thymoma viral oncogene homolog 1, B-cell lymphoma 2 (BCL-2), BCL-2-associated X protein, caspase 1, caspase 9, death-associated protein 3 and interleukin-1ß were validated by the qRT-PCR. The expressions of inducible nitric oxide synthase (iNOS) and major histocompatibility complex (MHC) II were assessed immunohistochemically; however, tumour protein p53 and cytochrome c (mitochondrial and cytosolic) expressions were checked at protein level by western blotting. Cypermethrin differentially regulated 65 transcripts at one or the other stage of exposure and 21 transcripts exhibited more pronounced alterations in the postnatal pre-exposed and adulthood re-challenged rats. The results of qRT-PCR were in accordance with the microarray observations and the expressions of iNOS, p53 and cytosolic cytochrome c and MHC II positivity were increased while the level of mitochondrial cytochrome c was reduced in adulthood treated animals. The effects were more pronounced in the postnatal pre-exposed followed by adulthood re-exposed rats. The results obtained thus suggest that multiple pathways are involved in the neurodegeneration as well as in enhancing the vulnerability of neurons in cypermethrin pre-exposed postnatal animals upon re-exposure during adulthood.
Assuntos
Corpo Estriado , Regulação da Expressão Gênica/efeitos dos fármacos , Inseticidas/toxicidade , Piretrinas/toxicidade , RNA Mensageiro/metabolismo , Fatores Etários , Animais , Animais Recém-Nascidos , Apoptose/efeitos dos fármacos , Apoptose/genética , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/crescimento & desenvolvimento , Corpo Estriado/metabolismo , Citocromos c/genética , Citocromos c/metabolismo , Citocinas/genética , Citocinas/metabolismo , Perfilação da Expressão Gênica , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Ratos , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
Early life experiences have profound influences on behavior and neurochemical parameters in adult life. The aim of this study is to verify neonatal handling-induced sex specific differences on learning and reversal learning as well as oxidative stress parameters in the prefrontal cortex and striatum of adult rats. Litters of rats were non-handled or handled (10 min/day, days 1-10 after birth). In adulthood, learning and reversal learning were evaluated using a Y maze associated with palatable food in male and female rats. Morris water maze reversal learning was verified in males. Oxidative stress parameters were evaluated in both genders. Male neonatal handled animals had a worse performance in the Y maze reversal learning compared to non-handled ones and no difference was observed in the water maze reversal learning task. Regarding females, neonatal handled rats had a better performance during the Y maze learning phase compared to non-handled ones. In addition, neonatal handled female animals showed a decreased SOD/CAT ratio in the PFC compared to non-handled females. We conclude that neonatal handling effects on learning and memory in adult rats are sex and task specific. The sex specific differences are also observed in the evaluation of antioxidant enzymes activities with neonatal handling affecting only females.
Assuntos
Antioxidantes/metabolismo , Regulação Enzimológica da Expressão Gênica/fisiologia , Manobra Psicológica , Reversão de Aprendizagem/fisiologia , Caracteres Sexuais , Animais , Animais Recém-Nascidos , Catalase/metabolismo , Comportamento de Escolha , Corpo Estriado/enzimologia , Corpo Estriado/crescimento & desenvolvimento , Feminino , Masculino , Aprendizagem em Labirinto/fisiologia , Córtex Pré-Frontal/enzimologia , Córtex Pré-Frontal/crescimento & desenvolvimento , Gravidez , Ratos , Ratos Wistar , Tempo de Reação , Espécies Reativas de Oxigênio/metabolismo , Compostos de Sulfidrila/metabolismo , Superóxido Dismutase/metabolismo , Fatores de TempoRESUMO
Forkhead-box protein P2 is a transcription factor that has been associated with intriguing aspects of cognitive function in humans, non-human mammals, and song-learning birds. Heterozygous mutations of the human FOXP2 gene cause a monogenic speech and language disorder. Reduced functional dosage of the mouse version (Foxp2) causes deficient cortico-striatal synaptic plasticity and impairs motor-skill learning. Moreover, the songbird orthologue appears critically important for vocal learning. Across diverse vertebrate species, this well-conserved transcription factor is highly expressed in the developing and adult central nervous system. Very little is known about the mechanisms regulated by Foxp2 during brain development. We used an integrated functional genomics strategy to robustly define Foxp2-dependent pathways, both direct and indirect targets, in the embryonic brain. Specifically, we performed genome-wide in vivo ChIP-chip screens for Foxp2-binding and thereby identified a set of 264 high-confidence neural targets under strict, empirically derived significance thresholds. The findings, coupled to expression profiling and in situ hybridization of brain tissue from wild-type and mutant mouse embryos, strongly highlighted gene networks linked to neurite development. We followed up our genomics data with functional experiments, showing that Foxp2 impacts on neurite outgrowth in primary neurons and in neuronal cell models. Our data indicate that Foxp2 modulates neuronal network formation, by directly and indirectly regulating mRNAs involved in the development and plasticity of neuronal connections.