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 (758 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
A dense intricate feltwork of interwoven fine glial processes, fibrils, synaptic terminals, axons, and dendrites interspersed among the nerve cells in the gray matter of the central nervous system.
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: Neuropils; Neuropile; Neuropiles.
Where it fits in the MeSH classification
- Broader topics
- Neuroglia; Neurons
- Narrower topics
- Neuropil Threads
- See also
- Mushroom Bodies
Research landscape
PubMed indexes 1,222 records tagged with the MeSH heading “Neuropil” (counts retrieved 2026-10-29). 125 of them (10.2%) were published from 2020 onward, and the busiest period so far is 2000-2009 with 546 records.
Reviews account for 74 records (6.1%) and meta-analyses for 0. Randomized controlled trials number 0 (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 | 138 |
| 2000-2009 | 546 |
| 2010-2019 | 413 |
| 2020 onward | 125 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 74 | 6.1% |
| Meta-analyses | 0 | 0.0% |
| Randomized controlled trials | 0 | 0.0% |
Method: PubMed query "Neuropil"[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 |
|---|---|---|---|---|
| The functional organization of descending sensory-motor pathways in Drosophila | 2018 | Research article Design not recorded in structured metadata | 314 | cc by PMID 29943730 · DOI · PMC6019073 |
| Nanoconnectomic upper bound on the variability of synaptic plasticity | 2015 | Research article Design not recorded in structured metadata | 196 | cc by PMID 26618907 · DOI · PMC4737657 |
| Neuroarchitecture of the Drosophila central complex: A catalog of nodulus and asymmetrical body neurons and a revision of the protocerebral bridge catalog | 2018 | Research article Design not recorded in structured metadata | 152 | cc by PMID 30084503 · DOI · PMC6283239 |
| Sensory Enrichment and Deprivation During Development: Limited Effects on the Volumes of CNS Neuropils in Two Spiders With Different Ecology | 2025 | Research article Design not recorded in structured metadata | 1 | cc by PMID 41267511 · DOI · PMC12635599 |
The functional organization of descending sensory-motor pathways in Drosophila [1]
Abstract reading summary — source excerpts
- Opening excerpt
- In most animals, the brain controls the body via a set of descending neurons (DNs) that traverse the neck.
- Closing excerpt
- Our results reveal the basic functional map of descending pathways in flies and provide tools for systematic interrogation of neural circuits.
- 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 (147 words)
In most animals, the brain controls the body via a set of descending neurons (DNs) that traverse the neck. DN activity activates, maintains or modulates locomotion and other behaviors. Individual DNs have been well-studied in species from insects to primates, but little is known about overall connectivity patterns across the DN population. We systematically investigated DN anatomy in Drosophila melanogaster and created over 100 transgenic lines targeting individual cell types. We identified roughly half of all Drosophila DNs and comprehensively map connectivity between sensory and motor neuropils in the brain and nerve cord, respectively. We find the nerve cord is a layered system of neuropils reflecting the fly's capability for two largely independent means of locomotion -- walking and flight -- using distinct sets of appendages. Our results reveal the basic functional map of descending pathways in flies and provide tools for systematic interrogation of neural circuits.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 29943730 · DOI · PMC6019073
Nanoconnectomic upper bound on the variability of synaptic plasticity [2]
Abstract reading summary — source excerpts
- Opening excerpt
- Information in a computer is quantified by the number of bits that can be stored and recovered.
- Closing excerpt
- Because of stochastic variability of synaptic activation the observed precision requires averaging activity over several minutes.
- 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 (149 words)
Information in a computer is quantified by the number of bits that can be stored and recovered. An important question about the brain is how much information can be stored at a synapse through synaptic plasticity, which depends on the history of probabilistic synaptic activity. The strong correlation between size and efficacy of a synapse allowed us to estimate the variability of synaptic plasticity. In an EM reconstruction of hippocampal neuropil we found single axons making two or more synaptic contacts onto the same dendrites, having shared histories of presynaptic and postsynaptic activity. The spine heads and neck diameters, but not neck lengths, of these pairs were nearly identical in size. We found that there is a minimum of 26 distinguishable synaptic strengths, corresponding to storing 4.7 bits of information at each synapse. Because of stochastic variability of synaptic activation the observed precision requires averaging activity over several minutes.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 26618907 · DOI · PMC4737657
Neuroarchitecture of the Drosophila central complex: A catalog of nodulus and asymmetrical body neurons and a revision of the protocerebral bridge catalog [3]
Abstract reading summary — source excerpts
- Opening excerpt
- The central complex, a set of neuropils in the center of the insect brain, plays a crucial role in spatial aspects of sensory integration and motor control.
- Closing excerpt
- These lines, generated using the split-GAL4 method, will facilitate anatomical studies, behavioral assays, and physiological experiments.
- 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 (234 words)
The central complex, a set of neuropils in the center of the insect brain, plays a crucial role in spatial aspects of sensory integration and motor control. Stereotyped neurons interconnect these neuropils with one another and with accessory structures. We screened over 5,000 Drosophila melanogaster GAL4 lines for expression in two neuropils, the noduli (NO) of the central complex and the asymmetrical body (AB), and used multicolor stochastic labeling to analyze the morphology, polarity, and organization of individual cells in a subset of the GAL4 lines that showed expression in these neuropils. We identified nine NO and three AB cell types and describe them here. The morphology of the NO neurons suggests that they receive input primarily in the lateral accessory lobe and send output to each of the six paired noduli. We demonstrate that the AB is a bilateral structure which exhibits asymmetry in size between the left and right bodies. We show that the AB neurons directly connect the AB to the central complex and accessory neuropils, that they target both the left and right ABs, and that one cell type preferentially innervates the right AB. We propose that the AB be considered a central complex neuropil in Drosophila. Finally, we present highly restricted GAL4 lines for most identified protocerebral bridge, NO, and AB cell types. These lines, generated using the split-GAL4 method, will facilitate anatomical studies, behavioral assays, and physiological experiments.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 30084503 · DOI · PMC6283239
Sensory Enrichment and Deprivation During Development: Limited Effects on the Volumes of CNS Neuropils in Two Spiders With Different Ecology [4]
Abstract reading summary — source excerpts
- Opening excerpt
- Neuroplasticity is a core property of animal nervous systems, enabling structural changes in the brain in response to environmental stimuli or internal processes such as learning.
- Closing excerpt
- We discuss these findings in the context of potential mechanisms underlying environmental plasticity in the spider brain.
- 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 (228 words)
Neuroplasticity is a core property of animal nervous systems, enabling structural changes in the brain in response to environmental stimuli or internal processes such as learning. Among spiders-a diverse group of predators-neuroanatomy varies with hunting strategy: stationary species that build capture webs differ from cursorial species that hunt without webs, reflecting reliance on distinct sensory modalities. While neuroplasticity has been documented in cursorial jumping spiders, its direct drivers remain unclear. In this study, we tested how sensory input influences the central nervous system (CNS) and whether stationary and cursorial hunters differ in their plastic responses. Using sensory deprivation and enrichment, we reared spiders under four treatments: control (CON), vibratory enrichment (VIB), visual enrichment (VIS), and combined enrichment (VISVIB). We examined the stationary hunter Parasteatoda tepidariorum and the cursorial hunter Marpissa muscosa. We predicted that enrichment would enlarge neuropil volumes in modality-specific brain regions, with stronger vibratory effects in P. tepidariorum and stronger visual effects in M. muscosa. Contrary to our expectations, sensory enrichment did not increase the volume of the corresponding CNS neuropils in either species. Although certain neuropils showed significant differences in specific groups, no clear causal link to sensory input emerged. Instead, a substantial proportion of the variation in neuropil volume was explained by family effects (shared maternal origin). We discuss these findings in the context of potential mechanisms underlying environmental plasticity in the spider brain.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41267511 · DOI · PMC12635599
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 The reduced neuropil hypothesis: a circuit based model of schizophrenia [5]
- Research article Ultrastructure of synapses in the mammalian brain [6]
- Research article Energetics of functional activation in neural tissues [7]
- Research article Evolution of the central complex in the arthropod brain with respect to the visual system [8]
- Research article Structure of tau protein and assembly into paired helical filaments [9]
- Research article Olfactory system oscillations across phyla [10]
References
- Namiki S, Dickinson MH, Wong AM, Korff W, Card GM. The functional organization of descending sensory-motor pathways in Drosophila. . 2018. PMID 29943730 · DOI · PMC6019073
- Bartol TM, Bromer C, Kinney J, Chirillo MA, Bourne JN, Harris KM, et al.. Nanoconnectomic upper bound on the variability of synaptic plasticity. . 2015. PMID 26618907 · DOI · PMC4737657
- Wolff T, Rubin GM. Neuroarchitecture of the Drosophila central complex: A catalog of nodulus and asymmetrical body neurons and a revision of the protocerebral bridge catalog. . 2018. PMID 30084503 · DOI · PMC6283239
- Steinhoff POM, Mouginot P, Uhl GB. Sensory Enrichment and Deprivation During Development: Limited Effects on the Volumes of CNS Neuropils in Two Spiders With Different Ecology. . 2025. PMID 41267511 · DOI · PMC12635599
- Selemon LD, Goldman-Rakic PS. The reduced neuropil hypothesis: a circuit based model of schizophrenia. Biol Psychiatry. 1999. PMID 9894571 · DOI
- Harris KM, Weinberg RJ. Ultrastructure of synapses in the mammalian brain. Cold Spring Harb Perspect Biol. 2012. PMID 22357909 · DOI · PMC3331701
- Sokoloff L. Energetics of functional activation in neural tissues. Neurochem Res. 1999. PMID 9972882 · DOI
- Homberg U. Evolution of the central complex in the arthropod brain with respect to the visual system. Arthropod Struct Dev. 2008. PMID 18502176 · DOI
- Friedhoff P, von Bergen M, Mandelkow EM, Mandelkow E. Structure of tau protein and assembly into paired helical filaments. Biochim Biophys Acta. 2000. PMID 10899437 · DOI
- Kay LM. Olfactory system oscillations across phyla. Curr Opin Neurobiol. 2015. PMID 25460070 · DOI · PMC4374988
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.
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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.