Neuronal diversity of neuropeptide signaling, including galanin, in the mouse locus coeruleus
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA990681 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR25114146.fastq.gz | Fastqsanger.gz | |||
| SRR25114147.fastq.gz | Fastqsanger.gz | |||
| SRR25114148.fastq.gz | Fastqsanger.gz | |||
| SRR25114149.fastq.gz | Fastqsanger.gz |
Items per page: 5 1 - 4 of 4 |
Similar Datasets
Project description:Purpose: The locus coeruleus (LC) is a small nucleus in the pons, with norepinephrine (NE) as its major transmitter. It plays key roles in wakefulness and is associated with disorders like depression. The study aims to analyze single-cell RNA-seq data to subdivide neurons in the LC and chart their neuropeptide, co-transmitter, and receptor profiles. It also seeks to build a precise map of galanin and its receptors in the mouse LC, and understand the role of neuropeptide expression and signaling. Results: The study identified 24 clusters in total, with 3 NE, 17 glutamate, and 5 GABA subtypes. NE neurons expressed at least 19 neuropeptide transcripts, mainly galanin (Gal) but not Npy, and >30 neuropeptide receptors. Among galanin receptors, Galr1 was expressed in ~19% of NE neurons, and highly expressed in GABA neurons surrounding the NE ensemble. Patch-clamp electrophysiology and cell-type-specific Ca2+-imaging using GCaMP6s revealed that a GalR1 agonist inhibits no more than ~35% of NE neurons, with the effect being direct and not relying on feed-forward GABA inhibition. Conclusions: The results define a role for the galanin system in NE functions and provide a conceptual framework for the action of many other peptides and their receptors. The study found that most NE neurons express mRNA transcripts for galanin, at least 19 neuropeptides (but not Npy), and >30 neuropeptide receptors, including Galr1 at low levels. Selective activation of GalR1 inhibited the spontaneous activity of a subset of NE neurons possibly through the activation of Kv currents. These findings offer new insights into the role of neuropeptide expression and signaling in mouse LC.
2023-07-03 | GSE236349 | GEO
Project description:The locus coeruleus (LC) is a small nucleus in the pons from which ascending and descending projections innervate major parts of the central nervous system. Its major transmitter is norepinephrine (NE). This system is evolutionarily conserved, including in humans, and its functions are associated with wakefulness and related to disorders, such as depression. Here, we performed single-cell ribonucleic acid-sequencing (RNA-seq) to subdivide neurons in the LC (24 clusters in total) into 3 NE, 17 glutamate, and 5 γ-aminobutyric acid (GABA) subtypes, and to chart their neuropeptide, cotransmitter, and receptor profiles. We found that NE neurons expressed at least 19 neuropeptide transcripts, notably galanin (Gal) but not Npy, and >30 neuropeptide receptors. Among the galanin receptors, Galr1 was expressed in ~19% of NE neurons, as was also confirmed by in situ hybridization. Unexpectedly, Galr1 was highly expressed in GABA neurons surrounding the NE ensemble. Patch-clamp electrophysiology and cell-type-specific Ca2+-imaging using GCaMP6s revealed that a GalR1 agonist inhibits up to ~35% of NE neurons. This effect is direct and does not rely on feed-forward GABA inhibition. Our results define a role for the galanin system in NE functions, and a conceptual framework for the action of many other peptides and their receptors.
| S-EPMC10401028 | biostudies-literature
Project description:Identifying factors underlying selective neuronal vulnerability is crucial for understanding Alzheimer's disease (AD) pathophysiology. The Neuromodulatory Subcortical System (NSS) includes nuclei that exhibit early, but varied vulnerability to tau accumulation and neuronal loss. This varied vulnerability represents a valuable opportunity to explore the underlying mechanisms of AD. In this study, we investigated factors contributing to selective neuronal vulnerability by comparing transcriptomic profiles of two similar NSS nuclei with differing vulnerabilities to AD, the locus coeruleus and substantia nigra. Using paired samples from well-characterized postmortem human tissue from individuals in early Braak stages and free of comorbid neuropathologic diagnoses, we identified pathways related to cholesterol homeostasis and antioxidant pathways response as key potential drivers of vulnerability.
2025-03-26 | GSE273787 | GEO
Project description:Decades of research confirm that noradrenergic locus coeruleus (LC) neurons are essential for arousal, attention, motivation, and stress responses. While most studies on LC transmission focused unsurprisingly on norepinephrine (NE), adrenergic signaling cannot account for all the consequences of LC activation. Galanin coexists with NE in the vast majority of LC neurons, yet the precise function of this neuropeptide has proved to be surprisingly elusive given our solid understanding of the LC system. To elucidate the contribution of galanin to LC physiology, here we briefly summarize the nature of stimuli that drive LC activity from a neuroanatomical perspective. We go on to describe the LC pathways in which galanin most likely exerts its effects on behavior, with a focus on addiction, depression, epilepsy, stress, and Alzheimer?s disease. We propose a model in which LC-derived galanin has two distinct functions: as a neuromodulator, primarily acting via the galanin 1 receptor (GAL1), and as a trophic factor, primarily acting via galanin receptor 2 (GAL2). Finally, we discuss how the recent advances in neuropeptide detection, optogenetics and chemical genetics, and galanin receptor pharmacology can be harnessed to identify the roles of LC-derived galanin definitively. This article is part of a Special Issue entitled SI: Noradrenergic System.
| S-EPMC4874918 | biostudies-other
Project description:Post-mortem investigations indicate that the locus coeruleus (LC) is the initial site of hyperphosphorylated pretangle tau, a precursor to neurofibrillary tangles (NFTs) found in Alzheimer's disease (AD). The presence of pretangle tau and NFTs in the LC correlates with AD progression. LC neuron integrity and quantity are linked to cognitive states, with degeneration associated with AD. However, the mechanisms of pretangle tau-induced LC degeneration are unclear. This study examined the transcriptomic and mitochondrial profiles of LC noradrenergic neurons after transduction with pseudophosphorylated human tau. Tau hyperphosphorylation increased the somatic expression of the L-type calcium channel (LTCC), impaired mitochondria health, and led to deficits in spatial and olfactory learning. Sex-dependent alterations in gene expression were observed in rats transduced with pretangle tau. Chronic LTCC blockade prevented behavioral deficits and altered mitochondrial mRNA expression, suggesting a potential link between LTCC hyperactivity and mitochondrial dysfunction. Our research provides insights into the consequences of tau pathology in the originating structure of AD.
2024-11-16 | GSE272794 | GEO
Project description:We analyzed the transcriptomic profile of post-mortem explants from dorsal nucleus of vagus nerve, locus coeruleus and substantia nigra obtained from controls and Braak 4 (BK4) and 5 (BK5) stages of Parkinson’s disease (PD) patients in order to investigate how gene-gene interaction patterns vary along different anatomical regions in patients and controls. The comparative transcriptional networks analyses indicate that the main hubs in PD networks are related to ubquitin/proteasome, oxidative stress, neuroprotection, neurogenesis and PD associated proteins. Transcriptomic profiles of controls and Parkinson’s disease patients were compared using SAM test for LC or Wilcoxon Mann-Whitney test for SN and VA (p<0.005 and p<0.01, respectively) in order to identify differentially expressed transcripts.
2015-01-11 | E-GEOD-43490 | biostudies-arrayexpress
Project description:Alzheimer's disease (AD) often begins with non-cognitive symptoms such as olfactory deficits, which can predict later cognitive decline, though the mechanisms remain unclear. Pathologically, the brainstem locus coeruleus (LC), the main source of the neurotransmitter noradrenalin (NA) modulating olfactory information processing is affected ealy. Here we show early and distinct loss of noradrenergic input to the olfactory bulb (OB) coinciding with impaired olfaction in an AD mouse model, before appearance of amyloid plaques. Mechanistically, OB microglia recognize and phagocytose LC axons. Reducing phagocytosis genetically preserves LC axons and olfaction. Importantly, patients with prodromal AD display elevated TSPO-PET signals in the OB, similarly to AppNL-G-F mice. We further confirm early LC axon degeneration in post-mortem OBs in patients with early AD. Our findings reveal a mechanism linking early LC damage to hyposmia in AD, suggesting olfactory testing and neurocircuit imaging for early diagnosis and enable timely therapeutic intervention for Alzheimer's disease.
2025-07-21 | GSE302245 | GEO
Project description:Sleep disturbances are common in patients with neurodegeneration, including Alzheimer's disease (AD), which can occur at early stages of AD and are proposed as potent risk factors for disease onset and progression. The underlying causes of this early-onset sleep disturbances remain unclear. Here we found that 5xFAD transgenic mice display significantly reduced sleep and prolonged wakefulness as early as 2 months of age. This early-onset sleep disruption correlates with increased tonic neuronal activity in the Locus Coeruleus (LC), which is mediated by heightened neuronal excitability due to impaired Kv4 and Kv7 channel conductance. Notably, we discovered that these young transgenic mice develop brain region-specific tau hyperphosphorylation (p-tau) in the LC. To investigate the pathological role of LC p-tau, we induce p-tau by inoculating synthetic human tau fibril into the LC of wild-type mice. This fibril inoculation replicated the reduction in Kv conductance and increased LC neuronal excitability in a tau-dependent manner. Modulating Kv4 and Kv7 channels restored normal excitability in both fibril-inoculated wild-type mice and young 5xFAD mice. Furthermore, fibril inoculation was sufficient to induce 5xFAD-like sleep disruptions in wild-type mice. Finally, pharmacological reduction of p-tau, both ex vivo and in vivo, effectively restored normal electrophysiological properties of LC neurons and normalized sleep/wake patterns in fibril-inoculated wild-type mice and young 5xFAD mice. Therefore, our findings identify a neural mechanism underlying early-onset sleep disturbances in a mouse model of AD amyloidosis and highlight the pathological consequences of LC tau hyperphosphorylation.
2025-09-01 | GSE283155 | GEO