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:mRNAseq for baseline transcriptional profiling of D1 and D2 receptor-expressing medium spiny neurons from 5-6 month Q175 mice compared to WT littermates.
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.
Project description:NIH-3T3 cells transduced with either EBF1-, PPARg2- or empty vector were stimulated with hormones to initiate adipocyte differentiation. RNA extraction was done using TriZol at d0, d2, d4 and d10 after stimulation. Samples were handled according to standard affymetrix protocols. Keywords = Adipogenesis Keywords = adipocyte Keywords = early B-cell factor 1 (EBF1) Keywords = commitment Keywords = differentiation Keywords = NIH-3T3 Keywords = pparg Keywords: time-course
Project description:Use of addictive substances often creates powerful and enduring associations with external cues that act as relapse triggers in individuals recovering from a substance use disorder (SUD). In the reward-associated brain region, the nucleus accumbens (NAc), drug use or drug-associated cue exposure activates a subset of D1 dopamine receptor-expressing medium spiny neurons (D1-MSNs), which typically promotes drug seeking, and a smaller subset of D2 dopamine receptor-expressing MSNs (D2-MSNs), which typically opposes drug seeking. The activity-regulated transcription factor, Neuronal PAS Domain Protein 4 (NPAS4), is activated in a small subset of NAc neurons during cocaine conditioning, and NAc NPAS4 is required for drug-context memories. Using a new Npas4-TRAP mouse combined with chemogenetics, we found that the during cocaine conditioning, the NPAS4-positive ensemble is required for drug-context associations. Single-cell transcriptomic analyses and in situ hybridization of NAc tissues from drug-conditioned mice revealed that NPAS4 is expressed predominantly in MSNs, and using cell type-specific molecular genetic approaches, we found that NPAS4 in D2-MSNs, but not D1-MSNs, was required for both drug-context associations and cue-reinstated cocaine seeking. Similarly, NPAS4 in NAc D2-MSNs, but not D1-MSNs, blocked cocaine experience-dependent strengthening of glutamatergic prefrontal cortical (PFC) inputs onto D2-MSNs. Analysis of differential gene expression in D2-MSNs revealed that NPAS4 and cocaine conditioning influence a gene expression program associated with synapses, dendrites, neuronal projections, dopamine, and cocaine. Together, our data reveal that NPAS4 functions during active cocaine use to maintain the imbalance of D1-MSN:D2-MSN activation and cue-induced drug seeking by suppressing excitatory drive onto relapse-opposing NAc D2-MSN circuits.
Project description:D1- and D2-type medium spiny neurons (MSNs) are the principal projection neurons in the striatum, including in the dorsal striatum (caudate nucleus and putamen) and ventral striatum (nucleus accumbens and olfactory tubercle) that are generated by the lateral ganglionic eminence (LGE). Using conditional deletion, we show that mice lacking the Sp8 and Sp9 transcription factors (TFs) selectively have a severe reduction in D2 MSNs due to reduced neurogenesis in the LGE. Sp8/9 together drive expression of the Six3 TF in a spatial restricted domain of the LGE subventricular zone. Conditional deletion of Six3 also prevents the formation of most D2 MSNs, phenocopying the Sp8/9 loss of function. Finally, ChIP-Seq reveals that SP9 directly binds to the promoter and a putative enhancer of Six3. This study provides evidence for components of a transcription pathway, in a regionally restricted LGE domain, that selectively drives the generation of D2 MSNs.
Project description:NIH-3T3 cells transduced with either EBF1-, PPARg2- or empty vector were stimulated with hormones to initiate adipocyte differentiation. RNA extraction was done using TriZol at d0, d2, d4 and d10 after stimulation. Samples were handled according to standard affymetrix protocols. Keywords = Adipogenesis, early B-cell factor 1 (EBF1), commitment, differentiation, NIH-3T3, pparg
Project description:Variations in the human FTO gene have been linked to obesity and altered connectivity and function of the dopaminergic neurocircuitry. Here we report that FTO in D2 medium spiny neurons (MSNs) of mice regulates the excitability of these cells in vitro and in vivo as well as controls D2 MSN globus pallidus external projections. Lack of FTO in D2 MSNs translates into increased locomotor responses to novelty, associated with altered timing behavior without affecting reward responses to drugs of abuse and highly palatable food, or the ability to discount rewards. Pharmacological manipulation of D1R- and D2R-dependent pathways in these animals reveals an altered balance between D1 MSN- and D2 MSN-mediated control of motor output. These findings hold the potential to target a novel avenue for control of basal ganglia motor function, where modulation of FTO-dependent signaling in D2 MSNs may promote D1 MSN regulated locomotor behavior without altering reward signaling or inciting impulsivity.
Project description:The cellular heterogeneity of the brain confounds efforts to elucidate the biological properties of distinct neuronal populations. Using Bacterial Artificial Chromosome (BAC) transgenic mice which express EGFP-tagged ribosomal protein L10a in defined cell populations, we have developed a methodology to affinity purify polysomal mRNAs from genetically defined cell populations in the brain. The utility of this approach is illustrated by the comparative analysis of four types of neurons, revealing hundreds of genes that distinguish these four cell populations. We find that even two morphologically indistinguishable, intermixed subclasses of medium spiny neuron display vastly different translational profiles and present examples of the physiological significance of such differences. This genetically targeted Translating Ribosome Affinity Purification (TRAP) methodology is a generalizable method useful for the identification of molecular changes in any genetically defined cell type in response to genetic alterations, disease, or pharmacological perturbations. Keywords: Cell Type Comparison For each cell population, D1 and D2, three independent TRAP replicates were collected, and total RNA from the immunoprecipitates were amplified and hybridized. Data were normalized with the GC-RMA algorithm, and expression values on each chip were normalized to that chip’s 50th percentile. Data were then converted to log2 scale. We recommend that only genes where more than one sample has a normalized intensity larger than 16 (4 in log2 scale) should be kept in the analysis.
Project description:Background: Depression is the leading cause of disability which produces enormous health and economic burdens. In the reward circuitry, the nucleus accumbens (NAc) is a key brain region of depression pathophysiology, possibly based on differential activities of D1- or D2-type medium spiny neurons (MSNs). Methods: To separate D1- or D2-MSN specific transcriptomes in the NAc, RiboTag (RT) mice were crossed with D1- or D2-Cre lines and subjected to chronic social defeat stress. The cell-type specifically tagged ribosome-mRNA complex was pulled down by anti-HA antibody, and purified RNAs were subjected to RNA sequencing. Sequencing data were analyzed and defined differentially expressed genes (DEGs) were validated with RNAscope and viral overexpression in vivo. Results: Both MSN subtypes express distinct gene expression profiles according to stress groups. The DEGs are correlated with depression relevant gene ontology terms. Behavioral susceptibility and resilience are also correlated with subsets of DEGs, especially in D1-MSNs. Conclusions: Distinct subsets of genes are modulated in a cell-type specific manner in the NAc of depressed mice. Here we provided valuable transcriptome data sets for future studies on depression.