Details for: CL0000850

Cell ID: CL0000850

Cell Name: serotonergic neuron

Description: A neuron that releases serotonin as a neurotransmitter.

Synonyms: 5-HT neuron, 5-hydroxytryptamine neuron, serotinergic neuron

Selected Context(s): Overall

Gene Significance Landscape

Display Options
Score:
Display
Genes

Contexts:

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 serotonergic neuron 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 serotonergic neuron. 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 serotonergic neuron. 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 serotonergic neuron. 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.

Maximum number of selected genes.
Select a context for the baseline cell.
Select a context for the target cell.
Target Cell for CSI:  serotonergic neuron (CL0000850)

 Legend
Nodes (Genes):
 Query Gene
Node size also reflects Target Cell CSI magnitude.
Node Color (Target Cell CSI in specific network):
 Very High
 High
 Medium
 Low
 Very Low
 N/A or Not Sig.
Edges (Interactions):
 STRING (Protein-Protein)
 ONTOLOGY (Shared Pathway)
 Colors vary by pathway category; default arrow applies.

Loading network (please wait)...

## Summary A [serotonergic neuron](/details-cell/CL0000850) is a neuron that releases serotonin as its primary neurotransmitter, playing a critical role in modulating a wide range of physiological processes including mood, cognition, and sleep. Based on its gene significance profile, this cell type is characterized by the highly specific expression of a vast array of genes involved in synaptic communication and architecture. **Overall**, its molecular signature is dominated by a diverse suite of neurotransmitter receptors, ion channels, and cell adhesion molecules, underscoring its function as a key node for integrating diverse neural inputs and maintaining stable, complex synaptic connections within the central nervous system. ## Key Characteristics and Function The functional identity of the [serotonergic neuron](/details-cell/CL0000850) is defined by a constellation of genes essential for neuronal signaling, excitability, and structural integrity. The analysis of its top markers, based on expression specificity (csi_z), reveals several key functional clusters. * **Synaptic Receptors and Signal Integration:** A striking feature is the high specificity of numerous genes encoding receptors for other neurotransmitters. This includes receptors for the primary excitatory neurotransmitter, glutamate ([GRM5](/details-gene/2915), [GRIA2](/details-gene/2891), [GRIA4](/details-gene/2893), [GRIN2A](/details-gene/2903)), and the primary inhibitory neurotransmitter, GABA ([GABRB1](/details-gene/2560), [GABBR2](/details-gene/9568)). This suggests that [serotonergic neurons](/details-cell/CL0000850) are not simply output cells but serve as sophisticated integration centers, where the release of serotonin is tightly modulated by a constant balance of excitatory and inhibitory inputs from other neural circuits. * **Ion Channel Activity and Neuronal Excitability:** The cell's electrical properties are shaped by a specific set of ion channels. Key markers include the voltage-gated calcium channel subunit [CACNA1B](/details-gene/774), which is critical for neurotransmitter release, and the potassium channel-interacting protein [KCNIP4](/details-gene/80333), which modulates A-type potassium channels ([Link](https://doi.org/10.1073/pnas.022509299)). Furthermore, the high specificity of [HCN1](/details-gene/348980), a hyperpolarization-activated "pacemaker" channel, may endow these neurons with intrinsic rhythmic firing capabilities that are fundamental to their modulatory role. * **Synaptic Adhesion and Neuronal Architecture:** A significant number of top markers are cell adhesion and synaptic organizing molecules. These include [CSMD3](/details-gene/114788), [MDGA2](/details-gene/161357), [OPCML](/details-gene/4978), [CSMD1](/details-gene/64478), [KIRREL3](/details-gene/84623), [CNTNAP5](/details-gene/129684), and [DSCAM](/details-gene/1826). This strong genetic signature highlights the importance of precise and stable synaptic connections for the function of these neurons, suggesting they form highly defined and enduring circuits. The expression of [ERC2](/details-gene/26059) further supports a role in the structural organization of the active zone for neurotransmitter release. * **Signal Transduction and Neuromodulation:** The cell's identity is also shaped by modulators of intracellular signaling pathways. [RGS7](/details-gene/6000), a regulator of G-protein signaling, likely plays a role in terminating signals from G-protein coupled receptors, such as [GRM5](/details-gene/2915). The top marker [PRSS55](/details-gene/203074), a serine-type endopeptidase, represents a unique and highly specific component whose function in the context of serotonergic signaling remains to be elucidated. **Overall**, the anti-markers for this cell type are predominantly genes involved in ubiquitous cellular processes such as metabolism ([GAPDH](/details-gene/2597)), protein degradation ([UBB](/details-gene/7314)), general transcription ([BBX](/details-gene/56987)), and RNA processing ([DDX5](/details-gene/1655), [SRRM2](/details-gene/23524)). This profile reinforces the notion that the identity of the [serotonergic neuron](/details-cell/CL0000850) is established by a highly specialized suite of neuronal-specific genes rather than the suppression of markers from other lineages. ## Clinical Significance and Contextual Roles The gene signature of [serotonergic neurons](/details-cell/CL0000850) implicates them in a variety of neurological and psychiatric conditions. The central role of serotonin in mood regulation is well-established, and dysfunction in these neurons is a key factor in depression and anxiety disorders. The specific marker genes identified in this analysis point to additional, more direct clinical connections. For instance, the CUB and Sushi multiple domains 3 gene, [CSMD3](/details-gene/114788), has been identified as a candidate gene for benign adult familial myoclonic epilepsy ([Link](https://doi.org/10.1016/s0006-291x(03)01555-9)). The Down syndrome cell adhesion molecule, [DSCAM](/details-gene/1826), is located in a critical region for Down syndrome and is involved in nervous system development ([Link](https://doi.org/10.1093/hmg/7.2.227)). Furthermore, many of the top markers, such as the glutamate receptor subunits ([GRIN2A](/details-gene/2903), [GRIA2](/details-gene/2891)) and ion channels ([CACNA1B](/details-gene/774)), are established players in synaptic plasticity, and their dysregulation is associated with a wide spectrum of disorders, from epilepsy to schizophrenia and neurodegenerative diseases. The neuregulin [NRG3](/details-gene/10718) has also been implicated as a susceptibility gene in psychiatric illnesses. This molecular profile suggests that the vulnerability of [serotonergic neurons](/details-cell/CL0000850) in disease may stem not only from serotonin dysregulation but also from perturbations in their fundamental capacity to receive inputs and maintain synaptic structure. ## Potential Mechanisms and Research Directions 1. **Hypothesis:** The molecular identity of [serotonergic neurons](/details-cell/CL0000850) is more defined by their capacity to integrate excitatory and inhibitory signals than by their serotonin output alone. The highly specific co-expression of a diverse array of glutamate ([GRM5](/details-gene/2915), [GRIA2](/details-gene/2891)) and GABA ([GABRB1](/details-gene/2560)) receptor subunits suggests these neurons function as sophisticated computational hubs, translating complex local field information into global serotonergic tone. * **Surprising Findings:** It is notable that the most specific genetic markers for a neuron defined by its release of serotonin are not serotonin synthesis or transport genes, but rather the machinery for sensing glutamate and GABA. This highlights the critical role of afferent input in shaping the function of this neuromodulatory system. * **Testable Questions:** How does the specific subunit composition of glutamate and GABA receptors on [serotonergic neurons](/details-cell/CL0000850) vary across different brain regions, and how does this diversity translate into distinct firing patterns and serotonin release dynamics in response to upstream circuit activation? 2. **Hypothesis:** The functional stability and precision of serotonergic circuits are critically dependent on a unique set of cell adhesion molecules and extracellular proteases that actively maintain synaptic architecture. The top marker, the serine protease [PRSS55](/details-gene/203074), may act locally to cleave specific substrates, thereby regulating the function of co-expressed adhesion molecules like [CSMD3](/details-gene/114788) and [MDGA2](/details-gene/161357) to permit synaptic plasticity or ensure long-term structural integrity. * **Surprising Findings:** The identification of a serine protease, [PRSS55](/details-gene/203074), as the single most specific marker for this neuron type is unexpected. Proteolytic activity is not commonly considered a core identity feature of a neuronal subtype, suggesting a novel mechanism of synaptic regulation may be at play. * **Testable Questions:** What are the endogenous substrates of [PRSS55](/details-gene/203074) at the serotonergic synapse, and does its enzymatic activity modulate synaptic strength or structure in response to neuronal activity or pharmacological intervention?