Project description:Using microarray, we compared the transcriptome of the wild-type and Gbx2-KO thalamus at E12.5. We show that Gbx2 promotes thalamic but inhibits habenular molecular characters.
Project description:The thalamus is organized into nuclei that have distinct input and output connectivities with the cortex. While first-order (FO) nuclei – also called core nuclei – relay input from sensory organs on the body surface and project to primary sensory areas, higher-order (HO) nuclei – matrix nuclei – instead receive their driver input from the cortex and project to secondary and associative areas within cortico-thalamo-cortical loops. Input-dependent processes have been shown to play a critical role in the emergence of FO thalamic neuron identity from a ground state HO neuron identity, yet how this identity emerges during development remains unknown. Here, using single-nucleus RNA sequencing of the developing embryonic thalamus we show that FO thalamic identity emerges after HO identity, and that peripheral input is critical for the maturation of excitatory, but not inhibitory FO-type neurons. Our findings reveal that subsets of HO neurons are developmentally co-opted into FO-type neurons, providing a mechanistic framework for the diversification of thalamic neuron types during development and evolution.
Project description:The thalamus of the brain acts as a relay station; taking inputs from several parts of the brain and then sending the information to the cortex and vice versa. It is also the structure know to affected in several brain developmental disorders such as schizophrenia, autism spectrum disorders, bipolar disorders etc. Upon in situ hybridisation one can visualise the expression of the transcription factor Tcf7l2 to be highest in prosomeric regions of the thalamus throughout development. With this information in mind we set out to find out, if the expression of Tcf7l2 is essential for the identity of the thalamic structure. Therefore, Tcf7l2 was knocked (KO) out using Cre+mice at embryonic stage E18.5 and postnatal adult stage P60. The E18.5 Tcf7l2 KO is a total knockout and the P60 Tcf7l2 KO is neuron-specific knockout. Total RNA was extracted and sent for sequencing using Illumina 2500. The data obtained was aligned by HISAT2 alignment tool, and the excon read counts were gathered using htseq counts, and expression normalization and differential gene expression was analysed using DESeq2.
Project description:Human brain organoid techniques have rapidly advanced to facilitate investigating human brain development and diseases. Recent reports in generation and fusion of regionally defined brain organoids provide further opportunities to investigate the specific brain domains and their interactions. Focus of brain organoids has been to generate telencephalon due to its direct relevance in a variety of forebrain disorders. Despite its importance as a relay hub between cortex and peripheral tissues, the investigation of three-dimensional (3D) organoid model for the human thalamus has not yet been explored. Here, we describe a method to differentiate human embryonic stem cells (hESCs) to the thalamic organoids (hThOs) that specifically recapitulate the development of thalamus. Single-cell RNA sequencing (scRNA-seq) revealed a formation of distinct thalamic lineage cells, a lineage divergence from telencephalic lineage. Importantly, we developed a 3D system to create the reciprocal projections between thalamus and cortex by fusing the two distinct region-specific organoids representing the developing thalamus or cortex. Our study provides a platform for understanding human thalamic development and modeling circuit organizations and related disorders in the brain.
Project description:The thalamus is the principal information hub of the vertebrate brain, with essential roles in sensory and motor information processing, attention, and memory. The complex array of thalamic nuclei develops from a restricted pool of neural progenitors. We apply longitudinal single-cell RNA-sequencing and regional abrogation of Sonic hedgehog (Shh) to map the developmental trajectories of thalamic progenitors, intermediate progenitors, and post-mitotic neurons as they coalesce into distinct thalamic nuclei. These data reveal that the complex architecture of the thalamus is established early during embryonic brain development through the coordinated action of four cell differentiation lineages derived from Shh-dependent and independent progenitors. We systematically characterize the gene expression programs that define these thalamic lineages across time and demonstrate how their disruption upon Shh depletion causes pronounced locomotor impairment resembling infantile Parkinson’s disease. These results reveal key principles of thalamic development and provide mechanistic insights into neurodevelopmental disorders resulting from thalamic dysfunction.
Project description:Gliomas arising in the brainstem and thalamus are devastating tumors that are difficult to surgically resect due to their proximity to eloquent brain structures. Here, we performed a comprehesive genomic and epigenomic study, using gene expression and methylation microarrays, to research on th different genomic and epigenetic signatures between brainstem, thalamic, and supratentorial gliomas. Comparison of brainstem, thalamic and supratentorial gliomas
Project description:Effect of thalamic deletion of mouse Sox2, or Nr2f1, on gene expression in the visual thalamus (dorsolateral geniculate nucleus, dLGN), as described in "SOX2 and NR2F1 coordinate the gene expression program of the early postnatal visual thalamus" (bioRxiv doi number to be updated) To address the effect of Sox2, or Nr2f1, Cre-mediated thalamic deletion in mouse, on gene expression in the visual thalamus (dLGN), we dissected the dLGN from mutant (Sox2, or Nr2f1) and control mice at postnatal day 0 (P0), for both Sox2 and Nr2f1 mutants. We then performed gene expression analysis by RNAseq.
Project description:The striatum is the main input structure of the basal ganglia, receiving information from the cortex and the thalamus and consisting of D1- and D2- medium spiny neurons (MSNs). D1-MSNs and D2-MSNs are essential for motor control and cognitive behaviors and have implications in Parkinson’s Disease. In the present study, we demonstrated that Sp9 positive progenitors produced both D1-MSNs and D2-MSNs and that Sp9 expression was rapidly downregulated in postmitotic D1-MSNs. Furthermore, we found that sustained Sp9 expression in lateral ganglionic eminence (LGE) progenitor cells and their descendants led to promoting D2-MSNs identity and repressing D1-MSNs identity during striatal development. As a result, sustained Sp9 expression resulted in an imbalance between D1-MSNs and D2-MSNs in the mouse striatum. In addition, the fate-changed D2 like-MSNs survived normally in adulthood. Taken together, our finding supported that Sp9 was sufficient to promote D2-MSNs identity and repress D1-MSNs identity, and Sp9 was a negative regulator of D1-MSNs fate. The striatum is the main input structure of the basal ganglia, receiving information from the cortex and the thalamus and consisting of D1- and D2- medium spiny neurons (MSNs). D1-MSNs and D2-MSNs are essential for motor control and cognitive behaviors and have implications in Parkinson’s Disease. In the present study, we demonstrated that Sp9 positive progenitors produced both D1-MSNs and D2-MSNs and that Sp9 expression was rapidly downregulated in postmitotic D1-MSNs. Furthermore, we found that sustained Sp9 expression in lateral ganglionic eminence (LGE) progenitor cells and their descendants led to promoting D2-MSNs identity and repressing D1-MSNs identity during striatal development. As a result, sustained Sp9 expression resulted in an imbalance between D1-MSNs and D2-MSNs in the mouse striatum. In addition, the fate-changed D2 like-MSNs survived normally in adulthood. Taken together, our finding supported that Sp9 was sufficient to promote D2-MSNs identity and repress D1-MSNs identity, and Sp9 was a negative regulator of D1-MSNs fate.
Project description:Acupuncture stimulations at GB34 and LR3 inhibit the reduction of tyrosine hydroxylase in the nigrostriatal dopaminergic neurons in the parkinsonism animal models. Especially, behavioral tests showed that acupuncture stimulations improved the motor dysfunction in a previous study. The thalamus is a crucial area for the motor circuit and has been identified as one of the most markedly damaged areas in Parkinson’s disease (PD), so acupuncture stimulations might also have an effect on the thalamic damage. We investigated gene expression profile changes in the thalamic region of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism models after acupuncture at the acupoints GB34 and LR3 C57BL/6 mice were divided into four experimental groups; ① C: Control, ② M: MPTP-treatment only, ③ MA: MPTP- and acupuncture-treatment at acupoints GB34 and LR3, ④ MNA: MPTP- and acupuncture-treatment at non-acupoints. Total RNA was isolated from two brains' thalamic regions of each experimental group (4 experimental group × 2 samples of each experimental group = total 8 samples).
Project description:Neuronal cell diversity is essential to endow distinct brain regions with specific functions. During development, progenitors within these regions are characterised by specific gene expression programs, contributing to the generation of diversity in postmitotic neurons and glia. While the region-specific molecular diversity of neurons and astrocytes is increasingly understood, whether these cells share region-specific programs remains unknown. Here, we show that in the neocortex and thalamus, neurons and astrocytes express shared region-specific transcriptional and epigenetic signatures. These signatures not only distinguish cells across brain regions but are also detected across substructures within regions, such as distinct thalamic nuclei, where clonal analysis reveals the existence of common nucleus-specific progenitors for neurons and glia. Consistent with their shared molecular signature, regional specificity is maintained following astrocyte-to-neuron reprogramming. A detailed understanding of these regional-specific signatures may thus inform strategies for future cell-based brain repair.