Details for: CL4023017

Cell ID: CL4023017

Cell Name: sst GABAergic cortical interneuron

Description: A transcriptomically distinct GABAergic neuron located in the cerebral cortex that expresses somatostatin (sst) and derived from the MGE.

Synonyms: SOM+ inhibitory interneuron, SST+ IN, somatostatin-expressing inhibitory interneuron

Selected Context(s): Overall

Gene Significance Landscape

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Cell Significance Index (CSI) is uniquely calculated to reveal cell-specific gene markers. More info here

Significant Genes List

Genes with the highest and lowest Percentile Rank Scores (PRS) for sst GABAergic cortical interneuron within the selected context(s).

Gene ID: A unique numerical identifier for this specific gene.
Symbol: Shortened abbreviation or name that represents this gene.
Ensembl Gene ID: A unique identifier assigned by Ensembl for genomic data mapping.
CSI Score: A combined effect size and statistical significance measure for sst GABAergic cortical interneuron. Higher scores indicate a stronger, more significant difference in expression.
(Previously described as "Fold Change", but now represents Cliff's Delta × –log10(p).)

Gene ID: A unique numerical identifier for this specific gene.
Symbol: Shortened abbreviation or name that represents this gene.
Ensembl Gene ID: A unique identifier assigned by Ensembl for genomic data mapping.
CSI Score: A combined effect size and statistical significance measure for sst GABAergic cortical interneuron. Higher scores indicate a stronger, more significant difference in expression.
Average CSI: csi sum / gene count
Cell network configuration

This network visualizes key genes for sst GABAergic cortical interneuron. It primarily includes:
1. Top genes highly significant for this cell (Num. Top Cell Genes - based on the 'Min. CSI' setting).
2. Any additional specific 'Context Genes' you add below.
The final network is a combined view. Choose an Interaction Source (pathways or protein interactions) and optionally compare CSI scores with a Baseline Cell Type.

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Target Cell for CSI:  sst GABAergic cortical interneuron (CL4023017)

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Edges (Interactions):
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## Summary The [sst GABAergic cortical interneuron](/details-cell/CL4023017), also known as a SOM+ inhibitory interneuron, is a distinct subclass of inhibitory neuron in the cerebral cortex characterized by the expression of somatostatin. Based on its highly specific gene expression profile, this cell type appears to function as a critical hub for synaptic integration and signaling modulation. Its identity is uniquely defined by a suite of genes involved in receiving and processing glutamatergic signals, such as the metabotropic glutamate receptors [GRM5](/details-gene/2915) and [GRM1](/details-gene/2911), alongside components for synaptic vesicle dynamics and cell adhesion. This suggests its primary role is to integrate excitatory inputs to precisely control inhibitory output, thereby shaping cortical network activity. ## Key Characteristics and Function The functional profile of the [sst GABAergic cortical interneuron](/details-cell/CL4023017) is dominated by genes essential for neurotransmission and synaptic organization. * **Synaptic Receptor and Signaling Hub:** The most specific markers for this cell type are components of neurotransmitter receptor systems. A high Z-score CSI for metabotropic glutamate receptors ([GRM5](/details-gene/2915), [GRM1](/details-gene/2911)) and NMDA receptor subunit [GRIN2A](/details-gene/2903) highlights its role as a key recipient of excitatory glutamatergic input. Concurrently, the specific expression of both GABA-B ([GABBR2](/details-gene/9568)) and GABA-A ([GABRB2](/details-gene/2561)) receptor subunits indicates that it is also intricately regulated by other inhibitory neurons. This diverse receptor profile is coupled with specific G-protein signaling components like [GNAS](/details-gene/2778) and calcium-binding proteins like [CALM1](/details-gene/801), suggesting the cell is equipped to integrate signals across multiple timescales to modulate its function. * **Specialized Synaptic Machinery:** The cell is defined by a unique set of proteins involved in synaptic structure and function. Genes such as [SYN2](/details-gene/6854), [SYNPR](/details-gene/132204) (synapsins), and [ERC2](/details-gene/26059) point to a specialized machinery for synaptic vesicle priming and release. Furthermore, high specificity for postsynaptic scaffolding and adhesion molecules like [DLGAP2](/details-gene/9228), [LRRC7](/details-gene/57554), [CSMD3](/details-gene/114788), and [CSMD2](/details-gene/121904) suggests that these neurons form highly stable and specific synaptic connections. * **Neuronal Development and Connectivity:** The specific expression of axon guidance and cell adhesion molecules, including [RTN4](/details-gene/57142) (Nogo), [CDH9](/details-gene/1007), and [OPCML](/details-gene/4978), may indicate their role in establishing and maintaining the precise circuit architecture characteristic of this interneuron subtype, which often targets the distal dendrites of pyramidal neurons. The neuregulin [NRG3](/details-gene/10718) further supports a role in neural development and cell-cell communication. * **Distinct Metabolic and Housekeeping Profile:** The anti-markers provide insight into what this cell is not. The strong negative CSI for numerous genes encoding mitochondrial electron transport chain components (e.g., [COX1](/details-gene/4512), [COX2](/details-gene/4513), [ND1](/details-gene/4535), [ATP6](/details-gene/4508)) and ubiquitously expressed genes like [GAPDH](/details-gene/2597), [FTH1](/details-gene/2495), and [B2M](/details-gene/567) suggests that this cell's identity is not defined by high-level metabolic or common housekeeping functions. Instead, its profile is dominated by highly specialized genes, underscoring its unique functional niche within the cortical circuit. ## Clinical Significance and Contextual Roles **Overall**, the distinct genetic signature of the [sst GABAergic cortical interneuron](/details-cell/CL4023017) implicates it in a range of neurological and psychiatric disorders. The balance between excitation and inhibition is fundamental to proper brain function, and the disruption of key modulators like sst+ interneurons can lead to circuit-level dysfunction. Several of its top specific markers are directly linked to human diseases. For example, [GRIN2A](/details-gene/2903) mutations are associated with epilepsy and neurodevelopmental disorders, highlighting the cell's role in controlling network excitability. The high specificity of [NRG3](/details-gene/10718) is notable, as this gene has been identified as a susceptibility locus for schizophrenia ([Link](https://doi.org/10.1073/pnas.94.18.9562)), suggesting that altered sst+ interneuron signaling or development could contribute to the pathophysiology of this disorder. Furthermore, [GRM5](/details-gene/2915) is a known therapeutic target and its dysregulation is implicated in conditions such as Fragile X syndrome and anxiety disorders. The specific expression of these and other genes like [CSMD3](/details-gene/114788), a candidate for benign adult familial myoclonic epilepsy ([Link](https://doi.org/10.1016/s0006-291x(03)01555-9)), firmly places this interneuron subtype at the center of investigations into diseases of cortical circuit hyperexcitability and dysregulation. ## Potential Mechanisms and Research Directions 1. **Hypothesis:** The co-expression of a rich and specific repertoire of metabotropic ([GRM5](/details-gene/2915)) and ionotropic ([GRIN2A](/details-gene/2903)) glutamate receptors suggests that sst+ interneurons function as advanced computational units. They may integrate excitatory inputs over different timescales—fast, precise signals via ionotropic receptors and slow, modulatory signals via metabotropic receptors—to dynamically adjust their inhibitory output and control cortical network states, such as oscillations. * **Surprising Findings:** It is remarkable that metabotropic glutamate receptors, which mediate slower signaling, are among the most highly specific defining markers for this cell. This finding elevates their importance from a secondary modulatory role to a core, identity-defining function, suggesting that slow integration is fundamental to how this interneuron operates. * **Testable Questions:** In acute cortical slices, does the application of a [GRM5](/details-gene/2915)-specific agonist versus an NMDA ([GRIN2A](/details-gene/2903)) agonist cause distinct changes in the firing threshold and pattern of sst+ interneurons in response to pyramidal neuron stimulation? 2. **Hypothesis:** The highly specific expression of large adhesion molecules like [CSMD3](/details-gene/114788) and [CDH9](/details-gene/1007) serves as a molecular code that dictates the precise and stable targeting of sst+ interneuron axons to the dendrites of principal neurons. This "adhesion code" may be critical for establishing the feedback inhibition motifs that are essential for preventing runaway excitation and synchronizing neuronal ensembles. * **Surprising Findings:** The high specificity of [RTN4](/details-gene/57142) (Nogo), a well-known inhibitor of neurite outgrowth ([Link](https://doi.org/10.1038/35000287)), is unexpected in a mature, integrated interneuron. Its specific expression may indicate a role not in development, but in actively maintaining synaptic stability by preventing aberrant axonal sprouting or synaptic reorganization in the adult cortex. * **Testable Questions:** If [CSMD3](/details-gene/114788) is selectively knocked out in sst+ interneurons during cortical development using a conditional genetic approach, does this result in mistargeting of their synapses onto the somas instead of the dendrites of pyramidal cells, leading to measurable deficits in dendritic integration and network oscillations?