Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 4 complete abstracts (690 words), 10 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
Most generally any neurons which are not motor or sensory. Interneurons may also refer to neurons whose axons remain within a particular brain region in contrast to projection neurons, which have axons projecting to other brain regions.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Interneuron; Intercalated Neurons; Intercalated Neuron; Neuron, Intercalated; Neurons, Intercalated.
Where it fits in the MeSH classification
- Broader topics
- Neurons
- Narrower topics
- Amacrine Cells; Cerebellar Golgi Cells; Commissural Interneurons; Renshaw Cells; Retinal Bipolar Cells
Related concepts
Research landscape
PubMed indexes 18,055 records tagged with the MeSH heading “Interneurons” (counts retrieved 2026-10-29). 3,355 of them (18.6%) were published from 2020 onward, and the busiest period so far is 2010-2019 with 5,364 records.
Reviews account for 1,379 records (7.6%) and meta-analyses for 6. Randomized controlled trials number 8 (0.0%) as a share of all records on the topic. Randomized trials make up only a small share of this literature, so much of what is known comes from laboratory, observational or descriptive work.
Show the data
| Period | Records |
|---|---|
| through 1999 | 4,951 |
| 2000-2009 | 4,385 |
| 2010-2019 | 5,364 |
| 2020 onward | 3,355 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 1,379 | 7.6% |
| Meta-analyses | 6 | 0.0% |
| Randomized controlled trials | 8 | 0.0% |
Method: PubMed query "Interneurons"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-29.
Reading the evidence in neuroscience
Neuroscience draws on tools with different strengths: cellular and animal work can manipulate circuits directly, while human imaging and electrophysiology observe the living brain at lower resolution. Small imaging studies are prone to false positives, and findings in animals do not always carry over to people. Clinical neurology and psychiatry rely on trials and cohort studies whose outcomes are often symptom scales. Check the species, the sample size, how the outcome was measured and whether results were replicated.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
| Study / authors | Year | Source label / design | Europe PMC citations | Licence / source |
|---|---|---|---|---|
| Parvalbumin Interneuron Dysfunction in Neurological Disorders: Focus on Epilepsy and Alzheimer's Disease | 2024 | Review article Design not recorded in structured metadata | 51 | cc by PMID 38791587 · DOI · PMC11122153 |
| Dynamic responses of striatal cholinergic interneurons control behavioral flexibility | 2024 | Research article Design not recorded in structured metadata | 46 | cc by PMID 39693433 · DOI · PMC11654678 |
| Comment on 'Accumbens cholinergic interneurons dynamically promote dopamine release and enable motivation' | 2024 | Research article Design not recorded in structured metadata | 25 | cc by PMID 38748470 · DOI · PMC11095934 |
| Oxytocin facilitates social behavior of female rats via selective modulation of interneurons in the medial prefrontal cortex | 2026 | Research article Design not recorded in structured metadata | 5 | cc by PMID 41720765 · DOI · PMC12923783 |
Parvalbumin Interneuron Dysfunction in Neurological Disorders: Focus on Epilepsy and Alzheimer's Disease [1]
Abstract reading summary — source excerpts
- Opening excerpt
- Parvalbumin expressing (PV+) GABAergic interneurons are fast spiking neurons that provide powerful but relatively short-lived inhibition to principal excitatory cells in the brain.
- Closing excerpt
- This suggests that PV+ interneurons could be important targets in developing future treatments for patients with epilepsy and comorbid disorders, such as AD, where seizures and cognitive decline are directly linked to specific PV+ interneuron deficits.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (232 words)
Parvalbumin expressing (PV+) GABAergic interneurons are fast spiking neurons that provide powerful but relatively short-lived inhibition to principal excitatory cells in the brain. They play a vital role in feedforward and feedback synaptic inhibition, preventing run away excitation in neural networks. Hence, their dysfunction can lead to hyperexcitability and increased susceptibility to seizures. PV+ interneurons are also key players in generating gamma oscillations, which are synchronized neural oscillations associated with various cognitive functions. PV+ interneuron are particularly vulnerable to aging and their degeneration has been associated with cognitive decline and memory impairment in dementia and Alzheimer's disease (AD). Overall, dysfunction of PV+ interneurons disrupts the normal excitatory/inhibitory balance within specific neurocircuits in the brain and thus has been linked to a wide range of neurodevelopmental and neuropsychiatric disorders. This review focuses on the role of dysfunctional PV+ inhibitory interneurons in the generation of epileptic seizures and cognitive impairment and their potential as targets in the design of future therapeutic strategies to treat these disorders. Recent research using cutting-edge optogenetic and chemogenetic technologies has demonstrated that they can be selectively manipulated to control seizures and restore the balance of neural activity in the brains of animal models. This suggests that PV+ interneurons could be important targets in developing future treatments for patients with epilepsy and comorbid disorders, such as AD, where seizures and cognitive decline are directly linked to specific PV+ interneuron deficits.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 38791587 · DOI · PMC11122153
Dynamic responses of striatal cholinergic interneurons control behavioral flexibility [2]
Abstract reading summary — source excerpts
- Opening excerpt
- Striatal cholinergic interneurons (CINs) are key to regulating behavioral flexibility, involving both extinguishing learned actions and adopting new ones.
- Closing excerpt
- These findings shed light on how CIN dynamics regulate behavioral flexibility.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (156 words)
Striatal cholinergic interneurons (CINs) are key to regulating behavioral flexibility, involving both extinguishing learned actions and adopting new ones. However, the mechanisms driving these processes remain elusive. In this study, we initially demonstrate that chronic alcohol consumption disrupts the burst-pause dynamics of CINs and impairs behavioral flexibility. We next aimed to elucidate the mechanisms by which CIN dynamics control behavioral flexibility. We found that extinction learning enhances acetylcholine (ACh) release and that mimicking this enhancement through optogenetic induction of CIN burst firing accelerates the extinction process. In addition, we demonstrate that disrupting CIN pauses via continuous optogenetic stimulation reversibly impairs the updating of goal-directed behaviors. Overall, we demonstrate that CIN burst firing, which increases ACh release, promotes extinction learning, aiding the extinguishment of learned behaviors. Conversely, CIN firing pauses, which lead to ACh dips, are crucial for reversal learning, facilitating the adaptation of new actions. These findings shed light on how CIN dynamics regulate behavioral flexibility.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 39693433 · DOI · PMC11654678
Comment on 'Accumbens cholinergic interneurons dynamically promote dopamine release and enable motivation' [3]
Abstract reading summary — source excerpts
- Opening excerpt
- Acetylcholine is widely believed to modulate the release of dopamine in the striatum of mammals.
- Closing excerpt
- In light of this and other publications that did not observe large acetylcholine-evoked dopamine transients in vivo, the conditions under which such release occurs in behaving animals remain unknown.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (176 words)
Acetylcholine is widely believed to modulate the release of dopamine in the striatum of mammals. Experiments in brain slices clearly show that synchronous activation of striatal cholinergic interneurons is sufficient to drive dopamine release via axo-axonal stimulation of nicotinic acetylcholine receptors. However, evidence for this mechanism in vivo has been less forthcoming. Mohebi, Collins and Berke recently reported that, in awake behaving rats, optogenetic activation of striatal cholinergic interneurons with blue light readily evokes dopamine release measured with the red fluorescent sensor RdLight1 (Mohebi et al., 2023). Here, we show that blue light alone alters the fluorescent properties of RdLight1 in a manner that may be misconstrued as phasic dopamine release, and that this artefactual photoactivation can account for the effects attributed to cholinergic interneurons. Our findings indicate that measurements of dopamine using the red-shifted fluorescent sensor RdLight1 should be interpreted with caution when combined with optogenetics. In light of this and other publications that did not observe large acetylcholine-evoked dopamine transients in vivo, the conditions under which such release occurs in behaving animals remain unknown.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 38748470 · DOI · PMC11095934
Oxytocin facilitates social behavior of female rats via selective modulation of interneurons in the medial prefrontal cortex [4]
Abstract reading summary — source excerpts
- Opening excerpt
- The hypothalamic neuropeptide oxytocin is best known for its prosocial behavioral effects.
- Closing excerpt
- We further demonstrate that activation of these OTR+ interneurons inhibits principal cells specifically projecting to the basolateral amygdala, thus providing a putative mechanism of selective oxytocin action in this sociability-promoting cortical network.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (126 words)
The hypothalamic neuropeptide oxytocin is best known for its prosocial behavioral effects. However, the precise anatomical and cellular targets for oxytocin in the cortex during social behavior remain elusive. Here we show that oxytocin neurons project directly to the medial prefrontal cortex where evoked axonal oxytocin release facilitates social behaviors in adult female rats. In conjunction, we report that local oxytocin receptor-expressing (OTR+) cells are predominantly interneurons, whose activation promotes social interaction. Notably, this prosocial effect persists even under physiological challenge (hunger), pointing to a dedicated prosocial circuit capable of overriding primary survival drives. We further demonstrate that activation of these OTR+ interneurons inhibits principal cells specifically projecting to the basolateral amygdala, thus providing a putative mechanism of selective oxytocin action in this sociability-promoting cortical network.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41720765 · DOI · PMC12923783
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article GABAergic Interneurons in the Neocortex: From Cellular Properties to Circuits [5]
- Research article Neuronal diversity and temporal dynamics: the unity of hippocampal circuit operations [6]
- Research article Interneurons. Fast-spiking, parvalbumin⁺ GABAergic interneurons: from cellular design to microcircuit function [7]
- Research article The neocortical circuit: themes and variations [8]
- Research article Interneuron cell types are fit to function [9]
- Research article Network abnormalities and interneuron dysfunction in Alzheimer disease [10]
References
- Leitch B. Parvalbumin Interneuron Dysfunction in Neurological Disorders: Focus on Epilepsy and Alzheimer's Disease. . 2024. PMID 38791587 · DOI · PMC11122153
- Huang Z, Chen R, Ho M, Xie X, Gangal H, Wang X, et al.. Dynamic responses of striatal cholinergic interneurons control behavioral flexibility. . 2024. PMID 39693433 · DOI · PMC11654678
- Taniguchi J, Melani R, Chantranupong L, Wen MJ, Mohebi A, Berke JD, et al.. Comment on 'Accumbens cholinergic interneurons dynamically promote dopamine release and enable motivation'. . 2024. PMID 38748470 · DOI · PMC11095934
- Schimmer S, Kania A, Lefevre A, Afordakos K, Wang KY, Lebedeva J, et al.. Oxytocin facilitates social behavior of female rats via selective modulation of interneurons in the medial prefrontal cortex. . 2026. PMID 41720765 · DOI · PMC12923783
- Tremblay R, Lee S, Rudy B. GABAergic Interneurons in the Neocortex: From Cellular Properties to Circuits. Neuron. 2016. PMID 27477017 · DOI · PMC4980915
- Klausberger T, Somogyi P. Neuronal diversity and temporal dynamics: the unity of hippocampal circuit operations. Science. 2008. PMID 18599766 · DOI · PMC4487503
- Hu H, Gan J, Jonas P. Interneurons. Fast-spiking, parvalbumin⁺ GABAergic interneurons: from cellular design to microcircuit function. Science. 2014. PMID 25082707 · DOI
- Harris KD, Shepherd GM. The neocortical circuit: themes and variations. Nat Neurosci. 2015. PMID 25622573 · DOI · PMC4889215
- Kepecs A, Fishell G. Interneuron cell types are fit to function. Nature. 2014. PMID 24429630 · DOI · PMC4349583
- Palop JJ, Mucke L. Network abnormalities and interneuron dysfunction in Alzheimer disease. Nat Rev Neurosci. 2016. PMID 27829687 · DOI · PMC8162106
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-10-31; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-10-29.
See how EvidenceLib is built. Spotted an error? Email support@evidencehelix.com.
Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.