RESUMO
Oprm1, the gene encoding the µ-opioid receptor, has multiple reported transcripts, with a variable 3' region and many alternative sequences encoding the C-terminus of the protein. The functional implications of this variability remain mostly unexplored, though a recurring notion is that it could be exploited by developing selective ligands with improved clinical profiles. Here, we comprehensively examined Oprm1 transcriptional variants in the murine central nervous system, using long-read RNAseq as well as spatial and single-cell transcriptomics. The results were validated with RNAscope in situ hybridization. We found a mismatch between transcripts annotated in the mouse genome (GRCm38/mm10) and the RNA-seq results. Sequencing data indicated that the primary Oprm1 transcript has a 3' terminus located on chr10:6,860,027, which is â¼ 9.5 kilobases downstream of the longest annotated exon 4 end. Long-read sequencing confirmed that the final Oprm1 exon included a 10.2 kilobase long 3' untranslated region, and the presence of the long variant was unambiguously confirmed using RNAscope in situ hybridization in the thalamus, striatum, cortex and spinal cord. Conversely, expression of the Oprm1 reference transcript or alternative transcripts of the Oprm1 gene was absent or close to the detection limit. Thus, the primary transcript of the Oprm1 mouse gene is a variant with a long 3' untranslated region, which is homologous to the human OPRM1 primary transcript and encodes the same conserved C-terminal amino acid sequence.
Assuntos
Prosencéfalo , Receptores Opioides mu , Medula Espinal , Receptores Opioides mu/genética , Receptores Opioides mu/metabolismo , Animais , Camundongos , Medula Espinal/metabolismo , Prosencéfalo/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Éxons , Regiões 3' não TraduzidasRESUMO
Messenger RNA splicing and degradation are critical for gene expression regulation, the abnormality of which leads to diseases. Previous methods for estimating kinetic rates have limitations, assuming uniform rates across cells. DeepKINET is a deep generative model that estimates splicing and degradation rates at single-cell resolution from scRNA-seq data. DeepKINET outperforms existing methods on simulated and metabolic labeling datasets. Applied to forebrain and breast cancer data, it identifies RNA-binding proteins responsible for kinetic rate diversity. DeepKINET also analyzes the effects of splicing factor mutations on target genes in erythroid lineage cells. DeepKINET effectively reveals cellular heterogeneity in post-transcriptional regulation.
Assuntos
Splicing de RNA , Análise de Célula Única , Humanos , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Estabilidade de RNA , Prosencéfalo/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/genética , Animais , FemininoRESUMO
Subcortical heterotopia is a cortical malformation associated with epilepsy, intellectual disability, and an excessive number of cortical neurons in the white matter. Echinoderm microtubule-associated protein like 1 (EML1) mutations lead to subcortical heterotopia, associated with abnormal radial glia positioning in the cortical wall, prior to malformation onset. This perturbed distribution of proliferative cells is likely to be a critical event for heterotopia formation; however, the underlying mechanisms remain unexplained. This study aimed to decipher the early cellular alterations leading to abnormal radial glia. In a forebrain conditional Eml1 mutant model and human patient cells, primary cilia and centrosomes are altered. Microtubule dynamics and cell cycle kinetics are also abnormal in mouse mutant radial glia. By rescuing microtubule formation in Eml1 mutant embryonic brains, abnormal radial glia delamination and heterotopia volume were significantly reduced. Thus, our new model of subcortical heterotopia reveals the causal link between Eml1's function in microtubule regulation and cell position, both critical for correct cortical development.
Assuntos
Centrossomo , Proteínas Associadas aos Microtúbulos , Microtúbulos , Prosencéfalo , Animais , Centrossomo/metabolismo , Humanos , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Prosencéfalo/metabolismo , Prosencéfalo/patologia , Prosencéfalo/embriologia , Microtúbulos/metabolismo , Camundongos , Cílios/metabolismo , Cílios/patologia , Mutação/genética , Células Ependimogliais/metabolismo , Células Ependimogliais/patologia , Ciclo Celular/genéticaRESUMO
Multiple embryonic origins give rise to forebrain oligodendrocytes (OLs), yet controversies and uncertainty exist regarding their differential contributions. We established intersectional and subtractional strategies to genetically fate map OLs produced by medial ganglionic eminence/preoptic area (MGE/POA), lateral/caudal ganglionic eminences (LGE/CGE), and dorsal pallium in the mouse brain. We found that, contrary to the canonical view, LGE/CGE-derived OLs make minimum contributions to the neocortex and corpus callosum, but dominate piriform cortex and anterior commissure. Additionally, MGE/POA-derived OLs, instead of being entirely eliminated, make small but sustained contribution to cortex with a distribution pattern distinctive from those derived from the dorsal origin. Our study provides a revised and more comprehensive view of cortical and white matter OL origins, and established valuable new tools and strategies for future OL studies.
Assuntos
Oligodendroglia , Prosencéfalo , Animais , Oligodendroglia/metabolismo , Oligodendroglia/citologia , Prosencéfalo/embriologia , Prosencéfalo/citologia , Camundongos , Linhagem da Célula/genéticaRESUMO
Rett syndrome (RTT) is a neurodevelopmental disorder caused by de novo mutations in the MECP2 gene. Although miRNAs in extracellular vesicles (EVs) have been suggested to play an essential role in several neurological conditions, no prior study has utilized brain organoids to profile EV-derived miRNAs during normal and RTT-affected neuronal development. Here we report the spatiotemporal expression pattern of EV-derived miRNAs in region-specific forebrain organoids generated from female hiPSCs with a MeCP2:R255X mutation and the corresponding isogenic control. EV miRNA and protein expression profiles were characterized at day 0, day 13, day 40, and day 75. Several members of the hsa-miR-302/367 cluster were identified as having a time-dependent expression profile with RTT-specific alterations at the latest developmental stage. Moreover, the miRNA species of the chromosome 14 miRNA cluster (C14MC) exhibited strong upregulation in RTT forebrain organoids irrespective of their spatiotemporal location. Together, our results suggest essential roles of the C14MC and hsa-miR-302/367 clusters in EVs during normal and RTT-associated neurodevelopment, displaying promising prospects as biomarkers for monitoring RTT progression.
Assuntos
Encéfalo , Vesículas Extracelulares , Proteína 2 de Ligação a Metil-CpG , MicroRNAs , Organoides , Síndrome de Rett , Síndrome de Rett/genética , Síndrome de Rett/metabolismo , Síndrome de Rett/patologia , MicroRNAs/genética , MicroRNAs/metabolismo , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/genética , Humanos , Organoides/metabolismo , Organoides/patologia , Feminino , Proteína 2 de Ligação a Metil-CpG/genética , Proteína 2 de Ligação a Metil-CpG/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/citologia , Mutação , Prosencéfalo/metabolismoRESUMO
Leptin is a hormone produced by the small intestines and adipose tissue that promotes feelings of satiety. Leptin receptors (LepRs) are highly expressed in the hypothalamus, enabling central neural control of hunger. Interestingly, LepRs are also expressed in several other regions of the body and brain, notably in the cerebral cortex and hippocampus. These brain regions mediate higher-order sensory, motor, cognitive, and memory functions, which can be profoundly altered during periods of hunger and satiety. However, LepR expression in these regions has not been fully characterized on a cell-type-specific basis, which is necessary to begin assessing their potential functional impact. Consequently, we examined LepR expression on neurons and glia in the forebrain using a LepR-Cre transgenic mouse model. LepR-positive cells were identified using a 'floxed' viral cell-filling approach and co-labeling immunohistochemically for cell-type-specific markers, i.e., NeuN, VGlut2, GAD67, parvalbumin, somatostatin, 5-HT3R, WFA, S100ß, and GFAP. In the cortex, LepR-positive cells were localized to lower layers (primarily layer 6) and exhibited non-pyramidal cellular morphologies. The majority of cortical LepR-positive cells were neurons, while the remainder were identified primarily as astrocytes or other glial cells. The majority of cortical LepR-positive neurons co-expressed parvalbumin, while none expressed somatostatin or 5-HT3R. In contrast, all hippocampal LepR-positive cells were neuronal, with none co-expressing GFAP. These data suggest that leptin can potentially influence neural processing in forebrain regions associated with sensation and limbic-related functions.
Assuntos
Camundongos Transgênicos , Neurônios , Prosencéfalo , Receptores para Leptina , Animais , Receptores para Leptina/metabolismo , Receptores para Leptina/genética , Camundongos , Neurônios/metabolismo , Prosencéfalo/metabolismo , Neuroglia/metabolismo , Masculino , Astrócitos/metabolismoRESUMO
In adult songbirds, new neurons are born in large numbers in the proliferative ventricular zone in the telencephalon and migrate to the adjacent song control region HVC (acronym used as proper name) [A. Reiner et al., J. Comp. Neurol. 473, 377-414 (2004)]. Many of these new neurons send long axonal projections to the robust nucleus of the arcopallium (RA). The HVC-RA circuit is essential for producing stereotyped learned song. The function of adult neurogenesis in this circuit has not been clear. A previous study suggested that it is important for the production of well-structured songs [R. E. Cohen, M. Macedo-Lima, K. E. Miller, E. A. Brenowitz, J. Neurosci. 36, 8947-8956 (2016)]. We tested this hypothesis by infusing the neuroblast migration inhibitor cyclopamine into HVC of male Gambel's white-crowned sparrows (Zonotrichia leucophrys gambelii) to block seasonal regeneration of the HVC-RA circuit. Decreasing the number of new neurons in HVC prevented both the increase in spontaneous electrical activity of RA neurons and the improved structure of songs that would normally occur as sparrows enter breeding condition. These results show that the incorporation of new neurons into the adult HVC is necessary for the recovery of both electrical activity and song behavior in breeding birds and demonstrate the value of the bird song system as a model for investigating adult neurogenesis at the level of long projection neural circuits.
Assuntos
Neurogênese , Prosencéfalo , Vocalização Animal , Animais , Neurogênese/fisiologia , Prosencéfalo/fisiologia , Prosencéfalo/citologia , Vocalização Animal/fisiologia , Masculino , Pardais/fisiologia , Neurônios/fisiologia , Regeneração Nervosa/fisiologiaRESUMO
The integrated stress response (ISR), a pivotal protein homeostasis network, plays a critical role in the formation of long-term memory (LTM). The precise mechanism by which the ISR controls LTM is not well understood. Here, we report insights into how the ISR modulates the mnemonic process by using targeted deletion of the activating transcription factor 4 (ATF4), a key downstream effector of the ISR, in various neuronal and non-neuronal cell types. We found that the removal of ATF4 from forebrain excitatory neurons (but not from inhibitory neurons, cholinergic neurons, or astrocytes) enhances LTM formation. Furthermore, the deletion of ATF4 in excitatory neurons lowers the threshold for the induction of long-term potentiation, a cellular model for LTM. Transcriptomic and proteomic analyses revealed that ATF4 deletion in excitatory neurons leads to upregulation of components of oxidative phosphorylation pathways, which are critical for ATP production. Thus, we conclude that ATF4 functions as a memory repressor selectively within excitatory neurons.
Assuntos
Fator 4 Ativador da Transcrição , Memória de Longo Prazo , Neurônios , Animais , Camundongos , Fator 4 Ativador da Transcrição/metabolismo , Fator 4 Ativador da Transcrição/genética , Astrócitos/metabolismo , Potenciação de Longa Duração , Memória de Longo Prazo/fisiologia , Camundongos Knockout , Neurônios/metabolismo , Prosencéfalo/metabolismo , MasculinoRESUMO
Alloparenting refers to the practice of caring for the young by individuals other than their biological parents. The relationship between the dynamic changes in psychological functions underlying alloparenting and the development of specific neuroreceptors remains unclear. Using a classic 10-day pup sensitization procedure, together with a pup preference and pup retrieval test on the EPM (elevated plus maze), we showed that both male and female adolescent rats (24 days old) had significantly shorter latency than adult rats (65 days old) to be alloparental, and their motivation levels for pups and objects were also significantly higher. In contrast, adult rats retrieved more pups than adolescent rats even though they appeared to be more anxious on the EPM. Analysis of mRNA expression using real-time-PCR revealed a higher dopamine D2 receptor (DRD2) receptor expression in adult hippocampus, amygdala, and ventral striatum, along with higher dopamine D1 receptor (DRD1) receptor expression in ventral striatum compared to adolescent rats. Adult rats also showed significantly higher levels of 5-hydroxytryptamine receptor 2A (HTR2A) receptor expression in the medial prefrontal cortex, amygdala, ventral striatum, and hypothalamus. These results suggest that the faster onset of alloparenting in adolescent rats compared to adult rats, along with the psychological functions involved, may be mediated by varying levels of dopamine DRD1, DRD2, and HTR2A in different forebrain regions.
Assuntos
Prosencéfalo , RNA Mensageiro , Receptor 5-HT2A de Serotonina , Receptores de Dopamina D1 , Receptores de Dopamina D2 , Animais , Receptores de Dopamina D2/metabolismo , Receptores de Dopamina D2/genética , Masculino , Ratos , Feminino , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D1/genética , RNA Mensageiro/metabolismo , RNA Mensageiro/genética , Receptor 5-HT2A de Serotonina/metabolismo , Receptor 5-HT2A de Serotonina/genética , Prosencéfalo/metabolismo , Empatia/fisiologia , Fatores Etários , Caracteres Sexuais , Ratos Sprague-Dawley , Comportamento Animal/fisiologia , Tonsila do Cerebelo/metabolismoRESUMO
BACKGROUND: Sexual differentiation of the brain occurs in all major vertebrate lineages but is not well understood at a molecular and cellular level. Unlike most vertebrates, sex-changing fishes have the remarkable ability to change reproductive sex during adulthood in response to social stimuli, offering a unique opportunity to understand mechanisms by which the nervous system can initiate and coordinate sexual differentiation. METHODS: This study explores sexual differentiation of the forebrain using single nucleus RNA-sequencing in the anemonefish Amphiprion ocellaris, producing the first cellular atlas of a sex-changing brain. RESULTS: We uncover extensive sex differences in cell type-specific gene expression, relative proportions of cells, baseline neuronal excitation, and predicted inter-neuronal communication. Additionally, we identify the cholecystokinin, galanin, and estrogen systems as central molecular axes of sexual differentiation. Supported by these findings, we propose a model of sexual differentiation in the conserved vertebrate social decision-making network spanning multiple subtypes of neurons and glia, including neuronal subpopulations within the preoptic area that are positioned to regulate gonadal differentiation. CONCLUSIONS: This work deepens our understanding of sexual differentiation in the vertebrate brain and defines a rich suite of molecular and cellular pathways that differentiate during adult sex change in anemonefish.
This study provides key insights into brain sex differences in sex-changing anemonefish (Amphiprion ocellaris), a species that changes sex in adulthood in response to the social environment. Using single nucleus RNA-sequencing, the study provides the first brain cellular atlas showing sex differences in two crucial reproductive areas: the preoptic area and telencephalon. The research identifies notable sex-differences in cell-type proportions and gene expression, particularly in radial glia and glutamatergic neurons that co-express the neuropeptide cholecystokinin. It also highlights differences in preoptic area neurons likely involved in gonadal regulation. This work deepens our understanding of sexual differentiation of the brain in vertebrates, especially those capable of adult sex change, and illuminates key molecular and cellular beginning and endpoints of the process.
Assuntos
Prosencéfalo , Caracteres Sexuais , Diferenciação Sexual , Animais , Prosencéfalo/fisiologia , Prosencéfalo/metabolismo , Masculino , Feminino , Diferenciação Sexual/fisiologia , Neurônios/fisiologia , Neurônios/metabolismo , Peixes/fisiologia , Perciformes/fisiologia , Galanina/metabolismo , Galanina/genética , Colecistocinina/metabolismoRESUMO
De novo variants in the Cytoplasmic FMR1-interacting protein 2 (CYFIP2) have been repeatedly associated with neurodevelopmental disorders and epilepsy, underscoring its critical role in brain development and function. While CYFIP2's role in regulating actin polymerization as part of the WAVE regulatory complex (WRC) is well-established, its additional molecular functions remain relatively unexplored. In this study, we performed unbiased quantitative proteomic analysis, revealing 278 differentially expressed proteins (DEPs) in the forebrain of Cyfip2 knock-out embryonic mice compared to wild-type mice. Unexpectedly, these DEPs, in conjunction with previously identified CYFIP2 brain interactors, included not only other WRC components but also numerous proteins associated with membraneless organelles (MLOs) involved in mRNA processing and translation within cells, including the nucleolus, stress granules, and processing bodies. Additionally, single-cell transcriptomic analysis of the Cyfip2 knock-out forebrain revealed gene expression changes linked to cellular stress responses and MLOs. We also observed morphological changes in MLOs in Cyfip2 knock-out brains and CYFIP2 knock-down cells under basal and stress conditions. Lastly, we demonstrated that CYFIP2 knock-down in cells, potentially through WRC-dependent actin regulation, suppressed the phosphorylation levels of the alpha subunit of eukaryotic translation initiation factor 2 (eIF2α), thereby enhancing protein synthesis. These results suggest a physical and functional connection between CYFIP2 and various MLO proteins and also extend CYFIP2's role within the WRC from actin regulation to influencing eIF2α phosphorylation and protein synthesis. With these dual functions, CYFIP2 may fine-tune the balance between MLO formation/dynamics and protein synthesis, a crucial aspect of proper mRNA processing and translation.
Assuntos
Citoesqueleto de Actina , Proteínas Adaptadoras de Transdução de Sinal , Fator de Iniciação 2 em Eucariotos , Camundongos Knockout , Transtornos do Neurodesenvolvimento , Animais , Camundongos , Fosforilação , Fator de Iniciação 2 em Eucariotos/metabolismo , Fator de Iniciação 2 em Eucariotos/genética , Transtornos do Neurodesenvolvimento/metabolismo , Transtornos do Neurodesenvolvimento/genética , Transtornos do Neurodesenvolvimento/patologia , Citoesqueleto de Actina/metabolismo , Citoesqueleto de Actina/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Humanos , Proteômica/métodos , Prosencéfalo/metabolismo , Encéfalo/metabolismoRESUMO
Formation of the corpus callosum (CC), anterior commissure (AC), and postoptic commissure (POC), connecting the left and right cerebral hemispheres, is crucial for cerebral functioning. Collapsin response mediator protein 2 (CRMP2) has been suggested to be associated with the mechanisms governing this formation, based on knockout studies in mice and knockdown/knockout studies in zebrafish. Previously, we reported two cases of non-synonymous CRMP2 variants with S14R and R565C substitutions. Among the, the R565C substitution (p.R565C) was caused by the novel CRMP2 mutation c.1693C > T, and the patient presented with intellectual disability accompanied by CC hypoplasia. In this study, we demonstrate that crmp2 mRNA could rescue AC and POC formation in crmp2-knockdown zebrafish, whereas the mRNA with the R566C mutation could not. Zebrafish CRMP2 R566C corresponds to human CRMP2 R565C. Further experiments with transfected cultured cells indicated that CRMP2 with the R566C mutation could not bind to kinesin light chain 1 (KLC1). Knockdown of klc1a in zebrafish resulted in defective AC and POC formation, revealing a genetic interaction with crmp2. These findings suggest that the CRMP2 R566C mutant fails to bind to KLC1, preventing axonal elongation and leading to defective AC and POC formation in zebrafish and CC formation defects in humans. Our study highlights the importance of the interaction between CRMP2 and KLC1 in the formation of the forebrain commissures, revealing a novel mechanism associated with CRMP2 mutations underlying human neurodevelopmental abnormalities.
Assuntos
Peptídeos e Proteínas de Sinalização Intercelular , Proteínas do Tecido Nervoso , Proteínas de Peixe-Zebra , Peixe-Zebra , Animais , Humanos , Animais Geneticamente Modificados , Corpo Caloso/metabolismo , Embrião não Mamífero , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/genética , Cinesinas/metabolismo , Cinesinas/genética , Proteínas do Tecido Nervoso/metabolismo , Proteínas do Tecido Nervoso/genética , Prosencéfalo/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genéticaRESUMO
Sleep disruption and impaired synaptic processes are common features in neurodegenerative diseases, including Alzheimer's disease (AD). Hyperphosphorylated Tau is known to accumulate at neuronal synapses in AD, contributing to synapse dysfunction. However, it remains unclear how sleep disruption and synapse pathology interact to contribute to cognitive decline. Here, we examined sex-specific onset and consequences of sleep loss in AD/tauopathy model PS19 mice. Using a piezoelectric home-cage monitoring system, we showed PS19 mice exhibited early-onset and progressive hyperarousal, a selective dark-phase sleep disruption, apparent at 3 months in females and 6 months in males. Using the Morris water maze test, we report that chronic sleep disruption (CSD) accelerated the onset of decline of hippocampal spatial memory in PS19 males only. Hyperarousal occurs well in advance of robust forebrain synaptic Tau burden that becomes apparent at 6-9 months. To determine whether a causal link exists between sleep disruption and synaptic Tau hyperphosphorylation, we examined the correlation between sleep behavior and synaptic Tau, or exposed mice to acute or chronic sleep disruption at 6 months. While we confirm that sleep disruption is a driver of Tau hyperphosphorylation in neurons of the locus ceruleus, we were unable to show any causal link between sleep loss and Tau burden in forebrain synapses. Despite the finding that hyperarousal appears earlier in females, female cognition was resilient to the effects of sleep disruption. We conclude sleep disruption interacts with the synaptic Tau burden to accelerate the onset of cognitive decline with greater vulnerability in males.
Assuntos
Disfunção Cognitiva , Modelos Animais de Doenças , Camundongos Transgênicos , Prosencéfalo , Sinapses , Proteínas tau , Animais , Proteínas tau/metabolismo , Masculino , Feminino , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/etiologia , Sinapses/metabolismo , Sinapses/patologia , Camundongos , Prosencéfalo/metabolismo , Caracteres Sexuais , Tauopatias/metabolismo , Tauopatias/patologia , Transtornos do Sono-Vigília/metabolismo , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Camundongos Endogâmicos C57BLRESUMO
Zebrafish is a useful model organism in neuroscience; however, its gene expression atlas in the adult brain is not well developed. In the present study, we examined the expression of 38 neuropeptides, comparing with GABAergic and glutamatergic neuron marker genes in the adult zebrafish brain by comprehensive in situ hybridization. The results are summarized as an expression atlas in 19 coronal planes of the forebrain. Furthermore, the scanned data of all brain sections were made publicly available in the Adult Zebrafish Brain Gene Expression Database (https://ssbd.riken.jp/azebex/). Based on these data, we performed detailed comparative neuroanatomical analyses of the hypothalamus and found that several regions previously described as one nucleus in the reference zebrafish brain atlas contain two or more subregions with significantly different neuropeptide/neurotransmitter expression profiles. Subsequently, we compared the expression data in zebrafish telencephalon and hypothalamus obtained in this study with those in mice, by performing a cluster analysis. As a result, several nuclei in zebrafish and mice were clustered in close vicinity. The present expression atlas, database, and anatomical findings will contribute to future neuroscience research using zebrafish.
Assuntos
Neuropeptídeos , Prosencéfalo , Peixe-Zebra , Animais , Peixe-Zebra/anatomia & histologia , Prosencéfalo/metabolismo , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Atlas como Assunto , Expressão Gênica , Bases de Dados Genéticas , CamundongosRESUMO
Circular RNAs (circRNAs) are upregulated during neurogenesis. Where and how circRNAs are localized and what roles they play during this process have remained elusive. Comparing the nuclear and cytoplasmic circRNAs between H9 cells and H9-derived forebrain (FB) neurons, we identify that a subset of adenosine (A)-rich circRNAs are restricted in H9 nuclei but exported to cytosols upon differentiation. Such a subcellular relocation of circRNAs is modulated by the poly(A)-binding protein PABPC1. In the H9 nucleus, newly produced (A)-rich circRNAs are bound by PABPC1 and trapped by the nuclear basket protein TPR to prevent their export. Modulating (A)-rich motifs in circRNAs alters their subcellular localization, and introducing (A)-rich circRNAs in H9 cytosols results in mRNA translation suppression. Moreover, decreased nuclear PABPC1 upon neuronal differentiation enables the export of (A)-rich circRNAs, including circRTN4(2,3), which is required for neurite outgrowth. These findings uncover subcellular localization features of circRNAs, linking their processing and function during neurogenesis.
Assuntos
Transporte Ativo do Núcleo Celular , Adenosina , Núcleo Celular , Neurogênese , Neurônios , Proteína I de Ligação a Poli(A) , RNA Circular , RNA , RNA Circular/metabolismo , RNA Circular/genética , Neurônios/metabolismo , Adenosina/metabolismo , Núcleo Celular/metabolismo , Humanos , Proteína I de Ligação a Poli(A)/metabolismo , Proteína I de Ligação a Poli(A)/genética , Animais , RNA/metabolismo , RNA/genética , Linhagem Celular , Diferenciação Celular , Citoplasma/metabolismo , Prosencéfalo/metabolismoRESUMO
Intranasal administration of total bovine brain gangliosides (6 mg/kg) to rats protected the CA1 hippocampal neurons from the death caused by two-vessel occlusion model (with hypotension) of forebrain ischemia/reperfusion injury. The immunohistochemical reaction of specific antibodies to marker proteins of activated microglia (Iba1) and astrocytes (GFAP) in hippocampal slices revealed the neuroprotective effect of exogenous gangliosides which can be mostly explained by their ability to suppress neuroinflammation and gliosis. The expression of neurotrophic factor BDNF in the CA1 region of hippocampus did not differ in sham-operated rats and animals exposed to ischemia/reperfusion. However, the administration of gangliosides increased the BDNF expression in both control and ischemic groups. The intranasal route of administration allows using lower concentrations of gangliosides preventing the death of hippocampal neurons.
Assuntos
Administração Intranasal , Fator Neurotrófico Derivado do Encéfalo , Região CA1 Hipocampal , Gangliosídeos , Neurônios , Fármacos Neuroprotetores , Traumatismo por Reperfusão , Animais , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/metabolismo , Gangliosídeos/farmacologia , Ratos , Masculino , Região CA1 Hipocampal/efeitos dos fármacos , Região CA1 Hipocampal/patologia , Região CA1 Hipocampal/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/administração & dosagem , Ratos Wistar , Proteína Glial Fibrilar Ácida/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas dos Microfilamentos/metabolismo , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/patologia , Isquemia Encefálica/metabolismo , Prosencéfalo/efeitos dos fármacos , Prosencéfalo/patologia , Prosencéfalo/metabolismo , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Astrócitos/patologia , Microglia/efeitos dos fármacos , Microglia/metabolismo , Microglia/patologia , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de DoençasRESUMO
Cultural and genetic inheritance combine to enable rapid changes in trait expression, but their relative importance in determining trait expression across generations is not clear. Birdsong is a socially learned cognitive trait that is subject to both cultural and genetic inheritance, as well as being affected by early developmental conditions. We sought to test whether early-life conditions in one generation can affect song acquisition in the next generation. We exposed one generation (F1) of nestlings to elevated corticosterone (CORT) levels, allowed them to breed freely as adults, and quantified their son's (F2) ability to copy the song of their social father. We also quantified the neurogenetic response to song playback through immediate early gene (IEG) expression in the auditory forebrain. F2 males with only one corticosterone-treated parent copied their social father's song less accurately than males with two control parents. Expression of ARC in caudomedial nidopallium (NCM) correlated with father-son song similarity, and patterns of expression levels of several IEGs in caudomedial mesopallium (CMM) in response to father song playback differed between control F2 sons and those with a CORT-treated father only. This is the first study to demonstrate that developmental conditions can affect social learning and neurogenetic responses in a subsequent generation.
Assuntos
Corticosterona , Aprendizagem , Vocalização Animal , Animais , Vocalização Animal/fisiologia , Masculino , Aprendizagem/fisiologia , Corticosterona/metabolismo , Feminino , Tentilhões/fisiologia , Prosencéfalo/metabolismo , Prosencéfalo/fisiologia , Genes PrecocesRESUMO
Human brain organoid models have emerged as a promising tool for studying human brain development and function. These models preserve human genetics and recapitulate some aspects of human brain development, while facilitating manipulation in an in vitro setting. Despite their potential to transform biology and medicine, concerns persist about their fidelity. To fully harness their potential, it is imperative to establish reliable analytic methods, ensuring rigor and reproducibility. Here, we review current analytical platforms used to characterize human forebrain cortical organoids, highlight challenges, and propose recommendations for future studies to achieve greater precision and uniformity across laboratories.
Assuntos
Encéfalo , Organoides , Humanos , Organoides/citologia , Organoides/metabolismo , Encéfalo/citologia , Reprodutibilidade dos Testes , Prosencéfalo/citologiaRESUMO
The telencephalon has undergone remarkable diversification and expansion throughout vertebrate evolution, exhibiting striking variations in structural and functional complexity. Nevertheless, fundamental features are shared across vertebrate taxa, such as the presence of distinct regions including the pallium, subpallium, and olfactory structures. Teleost fishes have a uniquely "everted" telencephalon, which has confounded comparisons of their brain regions to other vertebrates. Here we combine spatial transcriptomics and single nucleus RNA-sequencing to generate a spatially-resolved transcriptional atlas of the Mchenga conophorus cichlid fish telencephalon. We then compare cell-types and anatomical regions in the cichlid telencephalon with those in amphibians, reptiles, birds, and mammals. We uncover striking transcriptional similarities between cell-types in the fish telencephalon and subpallial, hippocampal, and cortical cell-types in tetrapods, and find support for partial eversion of the teleost telencephalon. Ultimately, our work lends new insights into the organization and evolution of conserved cell-types and regions in the vertebrate forebrain.
Assuntos
Ciclídeos , Prosencéfalo , Telencéfalo , Animais , Telencéfalo/citologia , Prosencéfalo/citologia , Ciclídeos/genética , Transcriptoma , Vertebrados/genética , Evolução BiológicaRESUMO
Somatosensation is essential for animals to perceive the external world through touch, allowing them to detect physical contact, temperature, pain, and body position. Studies on rodent vibrissae have highlighted the organization and processing in mammalian somatosensory pathways.1,2 Comparative research across vertebrates is vital for understanding evolutionary influences and ecological specialization on somatosensory systems. Birds, with their diverse morphologies, sensory abilities, and behaviors, serve as ideal models for investigating the evolution of somatosensation. Prior studies have uncovered tactile-responsive areas within the avian telencephalon, particularly in pigeons,3,4,5,6 parrots,7 and finches,8 but variations in somatosensory maps and responses across avian species are not fully understood. This study aims to explore somatotopic organization and neural coding in the telencephalon of Anna's hummingbirds (Calypte anna) and zebra finches (Taeniopygia guttata) by using in vivo extracellular electrophysiology to record activity in response to controlled tactile stimuli on various body regions. These findings reveal unique representations of body regions across distinct forebrain somatosensory nuclei, indicating significant differences in the extent of areas dedicated to certain body surfaces, which may correlate with their behavioral importance.