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: 3 complete abstracts (541 words), 9 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
The entire nerve apparatus, composed of a central part, the brain and spinal cord, and a peripheral part, the cranial and spinal nerves, autonomic ganglia, and plexuses. (Stedman, 26th ed)
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: Nervous Systems; System, Nervous; Systems, Nervous.
Where it fits in the MeSH classification
- Broader topics
- Anatomy Category
- Narrower topics
- Central Nervous System; Ganglia; Nerve Net; Neural Pathways; Neuroglia; Neurons; Neurosecretory Systems; Peripheral Nervous System; Synapses
- See also
- Neurologic Manifestations
Research landscape
PubMed indexes 2,222,674 records tagged with the MeSH heading “Nervous System” (counts retrieved 2026-10-29). 348,490 of them (15.7%) were published from 2020 onward, and the busiest period so far is through 1999 with 895,888 records.
Reviews account for 239,568 records (10.8%) and meta-analyses for 6,420. Randomized controlled trials number 22,940 (1.0%) 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 | 895,888 |
| 2000-2009 | 436,353 |
| 2010-2019 | 541,943 |
| 2020 onward | 348,490 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 239,568 | 10.8% |
| Meta-analyses | 6,420 | 0.3% |
| Randomized controlled trials | 22,940 | 1.0% |
Method: PubMed query "Nervous System"[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 |
|---|---|---|---|---|
| Unraveling Tyrosine Hydroxylase in the Brain of a Crustacean: An Integrative Investigation Using Different Approaches | 2026 | Research article Design not recorded in structured metadata | 0 | cc by PMID 42900443 · DOI · PMC13683526 |
| Central Nervous System Reservoirs and HIV Cure: Therapeutic Opportunities and Challenges | 2026 | Review article Design not recorded in structured metadata | 0 | cc by PMID 42891909 · DOI · PMC13676512 |
| Glutamate tone in preBötzinger complex rhythmogenesis: ambient extracellular glutamate as a candidate excitability bias | 2026 | Review article Design not recorded in structured metadata | 0 | cc by PMID 42888295 · DOI · PMC13675367 |
Unraveling Tyrosine Hydroxylase in the Brain of a Crustacean: An Integrative Investigation Using Different Approaches [1]
Abstract reading summary — source excerpts
- Opening excerpt
- Tyrosine hydroxylase (TH), the rate-limiting enzyme in dopamine (DA) synthesis, is conserved across most animal phyla.
- Closing excerpt
- These findings may support further studies on catecholaminergic neurobiology.
- 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 (166 words)
Tyrosine hydroxylase (TH), the rate-limiting enzyme in dopamine (DA) synthesis, is conserved across most animal phyla. DA regulates motor activity, sensory processing motivation, neural homeostasis, and protection against oxidative stress. TH and DA have been described in vertebrates and in some invertebrates, including arthropods. This study investigated the anatomical location of TH and DA and characterized the biochemical and molecular structure of TH in the brain of the mangrove crab Ucides cordatus. This species is a useful environmental model for neurodegeneration studies, due to its occurrence in metal-contaminated mangrove ecosystems, and as prey of other species, including humans. Using immunohistochemistry, immunoblotting, and structural modeling, we mapped TH presence and distribution in the crustacean brain and analyzed its molecular and evolutionary characteristics. Our results revealed a TH fragment structurally similar to fragments found in 21 other species and in a complex dopaminergic network in U. cordatus, characterized by diverse neuronal morphologies, widespread projections, and sensitivity to dopaminergic neurotoxins. These findings may support further studies on catecholaminergic neurobiology.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42900443 · DOI · PMC13683526
Central Nervous System Reservoirs and HIV Cure: Therapeutic Opportunities and Challenges [2]
Abstract reading summary — source excerpts
- Opening excerpt
- Purpose of reviewDespite viral suppression with antiretroviral therapy, people with HIV (PWH) remain at increased risk of neurocognitive impairment, neuroinflammation, and potential viral rebound following therapy interruption.
- Closing excerpt
- Developing CNS-inclusive strategies that minimise adverse neurological effects may be an important step in achieving HIV cure.
- 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 (143 words)
Purpose of reviewDespite viral suppression with antiretroviral therapy, people with HIV (PWH) remain at increased risk of neurocognitive impairment, neuroinflammation, and potential viral rebound following therapy interruption. Although the central nervous system (CNS) is a recognised HIV reservoir, it is often not fully considered in cure approaches.Recent findingsHIV DNA and ongoing viral transcription persist in the CNS of ART-suppressed PWH, potentially contributing to neuroinflammation and neurocognitive dysfunction. HIV cure strategies, including latency-reversing/promoting agents, broadly neutralising antibodies and other approaches have varying degrees of CNS penetration, efficacy and potential neurotoxicity. Therefore, interventions aimed at silencing or eradicating HIV reservoirs require monitoring of both reservoir-targeting efficacy and neurological adverse effects. Greater consideration of CNS penetration, efficacy in targeting CNS reservoirs, and neurotoxicity is required in HIV cure studies. Developing CNS-inclusive strategies that minimise adverse neurological effects may be an important step in achieving HIV cure.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42891909 · DOI · PMC13676512
Glutamate tone in preBötzinger complex rhythmogenesis: ambient extracellular glutamate as a candidate excitability bias [3]
Abstract reading summary — source excerpts
- Opening excerpt
- The preBötzinger complex (preBötC) is essential for inspiratory rhythm generation, yet the biological processes that repeatedly establish the excitability state required for neuronal recruitment remain incompletely understood.
- Closing excerpt
- Finally, we outline experimental criteria for distinguishing a causal excitability bias from glutamate signals that merely reflect ongoing network activity.
- 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)
The preBötzinger complex (preBötC) is essential for inspiratory rhythm generation, yet the biological processes that repeatedly establish the excitability state required for neuronal recruitment remain incompletely understood. This unresolved issue is reflected in computational models of respiratory rhythmogenesis, which rely on a phenomenological baseline excitability parameter, [Formula: see text], without a defined biological substrate. Ambient extracellular glutamate signaling is well established in other brain regions, but its relevance to the respiratory network remains largely untested. Here, we evaluate the hypothesis that ambient extracellular glutamate outside synaptic clefts-termed glutamate tone-represents one biologically plausible candidate for a distributed extracellular network-state variable in the preBötC. We define glutamate tone as a continuously maintained but dynamically regulated extracellular glutamate signal arising from the balance of glutamate release, diffusion, transporter-mediated clearance, and astrocyte-dependent metabolism. We critically review evidence that extracellular glutamate handling can influence respiratory network activity, while emphasizing that direct evidence for a compartment-specific, rhythmogenesis-relevant glutamate tone remains lacking. We then evaluate candidate glutamate-sensing mechanisms, including peri-/extrasynaptic NMDA receptors and metabotropic glutamate receptors, and place them within the established framework of recurrent excitation, intrinsic membrane conductances, and inhibitory circuitry. We propose that glutamate tone, if present, would not generate the inspiratory burst directly, but could bias the excitability landscape from which neuronal recruitment and synchronization emerge. Finally, we outline experimental criteria for distinguishing a causal excitability bias from glutamate signals that merely reflect ongoing network activity.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42888295 · DOI · PMC13675367
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 Chronic stress and brain kynurenine pathway: addressing unresolved issues with a meta-analytic approach of preclinical studies, translational implication for psychiatric disorders [4]
- Research article Cue-Elicited Brain Activity and Treatment Outcomes in Substance Use Disorders: A Meta-Analysis [5]
- Research article Cortical 5-HT2A receptors in depression and suicide: a systematic review and meta-analysis of in vivo and post-mortem imaging studies [6]
- Research article Association Between Pulse Pressure and Structural Brain Changes in Aging: A Systematic Review and Meta-Analysis of Cross-Sectional and Longitudinal Studies [7]
- Research article The lifespan trajectories of brain activities related to conflict-driven cognitive control [8]
- Research article Brain-behavior relationships in task-based fMRI assessments of executive functions in children and adolescents with and without ADHD: a systematic review and ALE meta-analysis [9]
References
- de Andrade Gomes CAB, Cardim-Pires TR, Dos Santos RR, da Costa Simas MC, de Abreu Mello A, Vitorino LC, et al.. Unraveling Tyrosine Hydroxylase in the Brain of a Crustacean: An Integrative Investigation Using Different Approaches. . 2026. PMID 42900443 · DOI · PMC13683526
- Angelovich TA, Roche M, Gorry PR, Churchill MJ. Central Nervous System Reservoirs and HIV Cure: Therapeutic Opportunities and Challenges. . 2026. PMID 42891909 · DOI · PMC13676512
- Vázquez-Mendoza E, Olmos-Pastoresa CA, Chí-Castañeda D, López-Meraz ML, Beltran-Parrazal L, Morgado-Valle C. Glutamate tone in preBötzinger complex rhythmogenesis: ambient extracellular glutamate as a candidate excitability bias. . 2026. PMID 42888295 · DOI · PMC13675367
- de Bartolomeis A, Fornaro M, Scopetta E, Ricci C, Irano A, De Simone G, et al.. Chronic stress and brain kynurenine pathway: addressing unresolved issues with a meta-analytic approach of preclinical studies, translational implication for psychiatric disorders. Eur Neuropsychopharmacol. 2025. PMID 41202480 · DOI
- Evohr B, Wenzel S, Chen N, Wade C, Ekhtiari H, Ketron AC, et al.. Cue-Elicited Brain Activity and Treatment Outcomes in Substance Use Disorders: A Meta-Analysis. JAMA Netw Open. 2025. PMID 41379443 · DOI · PMC12699361
- Chapman GE, Turner G, Noar AP, Barba T, Zafar R, McCutcheon RA, et al.. Cortical 5-HT2A receptors in depression and suicide: a systematic review and meta-analysis of in vivo and post-mortem imaging studies. Mol Psychiatry. 2025. PMID 41053435 · DOI · PMC12602341
- Cecelja M, McNally R, Cleary J, Chowienczyk P. Association Between Pulse Pressure and Structural Brain Changes in Aging: A Systematic Review and Meta-Analysis of Cross-Sectional and Longitudinal Studies. J Am Heart Assoc. 2025. PMID 40913270 · DOI · PMC12554426
- Li Z, Petersen IT, Wang L, Radua J, Yang G, Liu X. The lifespan trajectories of brain activities related to conflict-driven cognitive control. Sci Bull (Beijing). 2025. PMID 40925803 · DOI · PMC12435917
- Zhang H, Liang X, Hsu CL, Chan RCF, Feng Y, Yeung YK, et al.. Brain-behavior relationships in task-based fMRI assessments of executive functions in children and adolescents with and without ADHD: a systematic review and ALE meta-analysis. BMC Psychiatry. 2025. PMID 41257668 · DOI · PMC12751750
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.