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 (651 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 part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem.
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: Encephalon.
Where it fits in the MeSH classification
- Broader topics
- Central Nervous System
- Narrower topics
- Blood-Brain Barrier; Brain Stem; Cerebral Ventricles; Glymphatic System; Gray Matter; Limbic System; Prosencephalon; White Matter
- See also
- Cerebral Decortication; Psychosurgery
Related concepts
- Central Nervous System
- Skull
- Neural Tube
- Prosencephalon
- Mesencephalon
- Rhombencephalon
- Cerebrum
- Cerebellum
- Brain Stem
Research landscape
PubMed indexes 1,446,428 records tagged with the MeSH heading “Brain” (counts retrieved 2026-10-29). 237,569 of them (16.4%) were published from 2020 onward, and the busiest period so far is through 1999 with 553,080 records.
Reviews account for 149,152 records (10.3%) and meta-analyses for 4,807. Randomized controlled trials number 13,258 (0.9%) 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 | 553,080 |
| 2000-2009 | 286,341 |
| 2010-2019 | 369,438 |
| 2020 onward | 237,569 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 149,152 | 10.3% |
| Meta-analyses | 4,807 | 0.3% |
| Randomized controlled trials | 13,258 | 0.9% |
Method: PubMed query "Brain"[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 |
| 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 |
| Bridging language phenotypes, neural dynamics and gene regulation in autism | 2026 | Review article Design not recorded in structured metadata | 0 | cc by PMID 42903569 · DOI · PMC13681050 |
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
Glutamate tone in preBötzinger complex rhythmogenesis: ambient extracellular glutamate as a candidate excitability bias [2]
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
Bridging language phenotypes, neural dynamics and gene regulation in autism [3]
Abstract reading summary — source excerpts
- Opening excerpt
- Autism Spectrum Disorders (ASDs) affect approximately 1% of the global population, with prevalence rising over recent decades.
- Closing excerpt
- This approach shows how integrating genetic variation, non-invasive neuroimaging, and behavioral phenotypes can advance our understanding of ASD and inform targeted, mechanism-based interventions.
- 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 (253 words)
Autism Spectrum Disorders (ASDs) affect approximately 1% of the global population, with prevalence rising over recent decades. Although ASDs are heritable (~70%), translating genetic findings into effective therapeutics remains challenging due to the vast number of implicated risk genes (>700) and the limited influence of individual genes on disease expression. Their collective impact and convergent expression patterns of small-effect genes provide insights into ASD-related neurobiological mechanisms. Current interventions remain symptom-focused and do not address underlying neurodevelopmental mechanisms. Emerging approaches in functional genomics offer new insights into ASD pathogenesis by exploring gene expression diversity, yet clinical applications remain distant. Language deficits are among the most frequent and disabling features of ASD, profoundly affecting individuals' and families' quality of life. Recent evidence from neuroimaging and electrophysiology studies suggests disrupted neural oscillatory dynamics are linked to language deficits in ASD. Several ASD-associated genes have been implicated in biological pathways involved in the regulation of brain oscillatory dynamics, suggesting a potential mechanistic link between genetic variation, altered brain rhythms, and language impairment. We propose a neurophysiological imaging genetics framework that leverages neural oscillatory profiles as endophenotypes for targeted investigation and as functional readouts of gene expression. Within this framework, neuromodulation is proposed as an experimental approach to investigate and potentially modulate altered oscillatory dynamics associated with speech communication deficits in ASD, while integrating oscillation-related ASD candidate genes into a symptom-oriented model of functional genomics. This approach shows how integrating genetic variation, non-invasive neuroimaging, and behavioral phenotypes can advance our understanding of ASD and inform targeted, mechanism-based interventions.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42903569 · DOI · PMC13681050
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 Is criticality a unified setpoint of brain function? [4]
- Research article The 'reading' brain: Meta-analytic insight into functional activation during reading in adults [5]
- Research article Hippocampal volume asymmetry in Alzheimer disease: A systematic review and meta-analysis [6]
- Research article Peri-ictal imaging abnormalities in non-convulsive status epilepticus: A systematic review and meta-analysis comparing magnetic resonance imaging and computed tomography perfusion [7]
- Research article Linguistic and emotional prosody: A systematic review and ALE meta-analysis [8]
- Research article Deep brain stimulation for epilepsy: A systematic review and meta-analysis of randomized and non-randomized studies of thalamic targeting [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
- 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
- Vinurel M, Wang X, Kordon D, Jochaut D, Speranza M, Boeckx C, et al.. Bridging language phenotypes, neural dynamics and gene regulation in autism. . 2026. PMID 42903569 · DOI · PMC13681050
- Hengen KB, Shew WL. Is criticality a unified setpoint of brain function?. Neuron. 2025. PMID 40555236 · DOI · PMC12374783
- Turker S, Fumagalli B, Kuhnke P, Hartwigsen G. The 'reading' brain: Meta-analytic insight into functional activation during reading in adults. Neurosci Biobehav Rev. 2025. PMID 40254114 · DOI
- Pusparani Y, Pusparani Y, Lin CY, Jan YK, Lin FY, Liau BY, et al.. Hippocampal volume asymmetry in Alzheimer disease: A systematic review and meta-analysis. Medicine (Baltimore). 2025. PMID 40068028 · DOI · PMC11903023
- Bosque-Varela P, Kuchukhidze G, Hahn W, Jünemann C, Machegger L, Möller L, et al.. Peri-ictal imaging abnormalities in non-convulsive status epilepticus: A systematic review and meta-analysis comparing magnetic resonance imaging and computed tomography perfusion. Epilepsia. 2025. PMID 40827398 · DOI · PMC12779322
- Themistocleous C. Linguistic and emotional prosody: A systematic review and ALE meta-analysis. Neurosci Biobehav Rev. 2025. PMID 40379231 · DOI
- Dhaliwal JK, Ruiz-Perez M, Chari A, Piper RJ, Tisdall MM, Hart M. Deep brain stimulation for epilepsy: A systematic review and meta-analysis of randomized and non-randomized studies of thalamic targeting. Epilepsy Res. 2025. PMID 40516441 · DOI
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.