Project description:The lateral septum contains a number of molecularly defined cell populations. We used the viral-TRAP protocol (Nectow et al.,2017) to profile lateral septum neurotensin neurons.
Project description:We used the phospho-TRAP protocol (Knight et al., 2011) to profile lateral septum populations that are activated following 1 hour of restraint stress.
Project description:By comparing single cell transcriptomes of neurons participating in medial vs. lateral hippocampal networks in the mouse, we identify Latrophilin-2 as a molecular marker of the lateral network.
Project description:Glutamatergic projection neurons of the lateral habenula (LHb) effect behavioral statemodulation by regulating the activity of midbrain monoaminergic neurons. Identifying circuit mechanisms that control LHb output is of interest for understanding motivated behaviors. A small population of neurons within the medial subnucleus of the mouse LHb express the GABAergic synthesizing enzyme GAD2 and are capable of inhibiting nearby LHb projection neurons. However, these neurons lack most markers of classic inhibitory interneurons, and they co-express the vesicular glutamate transporter VGLUT2. To determine the molecular phenotype of these neurons, we genetically tagged the nuclei of GAD2-positive cells and used fluorescence-activated nuclear sorting followed by single nuclear RNA sequencing (FANS-snRNAseq) to determine the full transcriptional profile of GAD2+ neurons isolated from LHb. Our data demonstrate that LHb GAD2+ neurons co-express markers of both glutamatergic and GABAergic transmission and that they are transcriptionally distinct from GABAergic interneurons or habenular glutamatergic neurons. We show sex-specific differences in gene expression in this neuronal population and find that these gene sets are enriched for genes involved in depression. Finally, we identify the Ntng2 gene encoding the cell adhesion protein Netrin-G2 as a selective marker of LHb GAD2+ neurons that may contribute to their target projections. These data show the value of using genetic enrichment of rare cell types for transcriptome studies, and they advance understanding of the molecular composition of a functionally important class of neurons in the LHb.
Project description:The lateral superior olive (LSO), a conspicuous integration center in the auditory brainstem, contains a remarkably heterogeneous neuron population. Ascending neurons, predominantly principal neurons (pLSOs), process interaural level differences for sound localization. Descending neurons (lateral olivocochlear neurons, LOCs) provide feedback into the cochlea and likely protect from acoustic overexposure. The molecular determinants of the neuronal diversity in the LSO are largely unknown. Here, we employed patch-seq analysis in juvenile mice to classify LSO neurons by their functional and molecular profiles, including developmental aspects. Across the sample (n=86), genes involved in ATPsynthesis were particularly highly expressed, confirming the energy expenditure of auditory neurons. Two clusters were identified, pLSOs and LOCs. They were distinguishable by 353 differentially expressed genes (DEGs), most being novel for the LSO. Electrophysiological analysis corroborated the transcriptomic clustering. We focused on genes impacting neuronal input-output properties and validated some by immunohistochemistry, electrophysiology, and pharmacology. These genes encode proteins like osteopontin, Kv11.3, and Kvb3 (pLSO-specific), calcitonin-gene-related peptide (LOC-specific), or Kv7.2 and Kv7.3 (no DEGs). We identified 12 ‘Super DEGs’ and 12 genes demonstrating ‘Cluster similarity’. Collectively, we provide fundamental and comprehensive insights into the molecular composition of individual ascending and descending neurons in the juvenile auditory brainstem and how this may relate to their specific functions, including developmental aspects.
Project description:In order to characterize the response to noise of various cell types in the inner ear, the cochleae from wild-type mice, naive or subjected to a 2h, 105 dB SPL noise insult, were dissected out. To further examine spiral ganglion neurons in more detail, non-neuronal populations were removed in one set of samples. In another set of samples, the lateral wall tissue was isolated to better understand how cells from the stria respond to noise insults. The resulting tissue was then dissociated to obtain a single cell suspension, and profiled by single cell RNA-seq.