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 (464 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 the brain that connects the cerebral hemispheres with the spinal cord. It consists of the mesencephalon; PONS; and medulla oblongata.
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: Brain Stems; Brainstem; Brainstems; Truncus Cerebri; Cerebri, Truncus; Cerebrus, Truncus; Truncus Cerebrus.
Where it fits in the MeSH classification
- Broader topics
- Brain
- Narrower topics
- Mesencephalon; Reticular Formation; Rhombencephalon; Trigeminal Nuclei
Related concepts
- Cerebral Hemispheres
- Spinal Cord
- Mesencephalon
- Medulla Oblongata
Research landscape
PubMed indexes 193,078 records tagged with the MeSH heading “Brain Stem” (counts retrieved 2026-10-29). 17,668 of them (9.2%) were published from 2020 onward, and the busiest period so far is through 1999 with 101,409 records.
Reviews account for 12,726 records (6.6%) and meta-analyses for 219. Randomized controlled trials number 548 (0.3%) 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 | 101,409 |
| 2000-2009 | 38,920 |
| 2010-2019 | 35,081 |
| 2020 onward | 17,668 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 12,726 | 6.6% |
| Meta-analyses | 219 | 0.1% |
| Randomized controlled trials | 548 | 0.3% |
Method: PubMed query "Brain Stem"[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 |
|---|---|---|---|---|
| Motor cortex directly excites the substantia nigra pars reticulata, the basal ganglia output nucleus | 2026 | Research article Design not recorded in structured metadata | 8 | cc by PMID 42336891 · DOI · PMC13291323 |
| How does the cerebellum contribute to cognitive functions? | 2026 | Review article Design not recorded in structured metadata | 7 | cc by PMID 41871032 · DOI · PMC13008071 |
| Modulation of WNT and FGF18 enhances yield and subtype identity of hPSC-derived midbrain dopamine neurons | 2026 | Research article Design not recorded in structured metadata | 4 | cc by PMID 42138078 · DOI · PMC13178649 |
Motor cortex directly excites the substantia nigra pars reticulata, the basal ganglia output nucleus [1]
Abstract reading summary — source excerpts
- Opening excerpt
- Inhibitory neurons of the substantia nigra pars reticulata (SNr) serve as a primary output through which the basal ganglia regulate behavior.
- Closing excerpt
- These findings reveal functional pathways by which the motor cortex can directly modulate basal ganglia output to downstream targets.
- 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 (152 words)
Inhibitory neurons of the substantia nigra pars reticulata (SNr) serve as a primary output through which the basal ganglia regulate behavior. Using a virally targeted optogenetic approach, combined with whole cell patch-clamp recordings of SNr neurons, we show that, in mice, projection neurons of both primary and secondary motor cortices (M1 and M2) form monosynaptic excitatory connections onto different subpopulations of GABAergic SNr neurons. Furthermore, photostimulation of these cortical axon terminals markedly increases SNr neuron firing rate. To investigate the spatial organization of cortical input to the SNr, we employed a transsynaptic viral-labelling approach to identify SNr neurons receiving monosynaptic input from either M1 or M2. We found a topographical organization of the M1 and M2 projections in SNr. Chemogenetic inhibition of M1- and M2-targeted SNr neurons induced opposing changes in spontaneous behavior. These findings reveal functional pathways by which the motor cortex can directly modulate basal ganglia output to downstream targets.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42336891 · DOI · PMC13291323
How does the cerebellum contribute to cognitive functions? [2]
Abstract reading summary — source excerpts
- Opening excerpt
- Over the past 70 years, neuroscience has gained a deep understanding of how the cerebellum supports basic motor functions.
- Closing excerpt
- Addressing these key questions should help the field develop the testable, falsifiable hypotheses that are needed to solve this intriguing question.
- 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 (103 words)
Over the past 70 years, neuroscience has gained a deep understanding of how the cerebellum supports basic motor functions. Anatomical, clinical, and neuroimaging studies, however, have also firmly established that the cerebellum holds an important role in cognition. Even though this topic has received considerable attention, we still do not know the exact nature of this contribution. This Unsolved Mystery reviews known facts about how the cerebellum contributes to cognition and identifies roadblocks that have prevented the development of a unified theory. Addressing these key questions should help the field develop the testable, falsifiable hypotheses that are needed to solve this intriguing question.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41871032 · DOI · PMC13008071
Modulation of WNT and FGF18 enhances yield and subtype identity of hPSC-derived midbrain dopamine neurons [3]
Abstract reading summary — source excerpts
- Opening excerpt
- While clinical trials of human pluripotent stem cell-derived midbrain dopamine (mDA) neuron precursor grafts for Parkinson's disease (PD) are ongoing, current protocols remain suboptimal.
- Closing excerpt
- The Boost+ conditions present an optimized differentiation protocol with advantages for disease modeling and mDA neuron grafting paradigms.
- 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 (209 words)
While clinical trials of human pluripotent stem cell-derived midbrain dopamine (mDA) neuron precursor grafts for Parkinson's disease (PD) are ongoing, current protocols remain suboptimal. In particular, the yield of TH+ mDA neurons after in vivo grafting and the expression of certain mDA neuron and subtype-specific markers require improvement. Single-cell transcriptomic analyses of grafts have revealed low proportions of mDA neurons and substantial off-target contamination. Here, we present an optimized mDA neuron differentiation strategy that builds on our clinical-grade ("Boost") protocol by adding FGF18 and IWP2 treatment ("Boost+") at the neurogenesis stage. Boost+ mDA neurons show higher expression of EN1, PITX3, and ALDH1A1. Improvements in mDA neuron yield and transcriptional similarity to primary mDA neurons are observed in vitro and following transplantation. Single-nucleus RNA sequencing demonstrates enrichment of A9 mDA neurons within Boost+ grafts. Functional studies in vitro demonstrate increased dopamine production and release and improved electrophysiological properties. In vivo analyses show higher percentages of TH+ mDA neurons, resulting in efficient rescue of amphetamine-induced rotation behavior in the 6-OHDA rat model and rescue of deficits in some nondrug-induced assays, including the ladder rung assay, which are not improved by Boost mDA neurons. The Boost+ conditions present an optimized differentiation protocol with advantages for disease modeling and mDA neuron grafting paradigms.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42138078 · DOI · PMC13178649
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 Functional topography in the human cerebellum: a meta-analysis of neuroimaging studies [4]
- Research article Cerebellar atrophy in neurodegeneration-a meta-analysis [5]
- Research article The locus coeruleus as a global model failure system [6]
- Research article Explicit and Implicit Emotion Processing in the Cerebellum: A Meta-analysis and Systematic Review [7]
- Research article Cerebellar Volume in Autism: Literature Meta-analysis and Analysis of the Autism Brain Imaging Data Exchange Cohort [8]
- Research article Cerebellar structural and functional abnormalities in first-episode and drug-naive patients with schizophrenia: A meta-analysis [9]
References
- Thompson WS, Wekwejt P, Grillner S, Silberberg G. Motor cortex directly excites the substantia nigra pars reticulata, the basal ganglia output nucleus. . 2026. PMID 42336891 · DOI · PMC13291323
- Diedrichsen J, McDougle SD. How does the cerebellum contribute to cognitive functions?. . 2026. PMID 41871032 · DOI · PMC13008071
- Kim TW, Piao J, Bocchi VD, Koo SY, Choi SJ, Chaudhry F, et al.. Modulation of WNT and FGF18 enhances yield and subtype identity of hPSC-derived midbrain dopamine neurons. . 2026. PMID 42138078 · DOI · PMC13178649
- Stoodley CJ, Schmahmann JD. Functional topography in the human cerebellum: a meta-analysis of neuroimaging studies. Neuroimage. 2009. PMID 18835452 · DOI
- Gellersen HM, Guo CC, O'Callaghan C, O'Callaghan C, Tan RH, Sami S, et al.. Cerebellar atrophy in neurodegeneration-a meta-analysis. J Neurol Neurosurg Psychiatry. 2017. PMID 28501823 · DOI
- Jordan R. The locus coeruleus as a global model failure system. Trends Neurosci. 2024. PMID 38102059 · DOI
- Pierce JE, Thomasson M, Voruz P, Selosse G, Péron J. Explicit and Implicit Emotion Processing in the Cerebellum: A Meta-analysis and Systematic Review. Cerebellum. 2023. PMID 35999332 · DOI · PMC10485090
- Traut N, Beggiato A, Bourgeron T, Delorme R, Rondi-Reig L, Paradis AL, et al.. Cerebellar Volume in Autism: Literature Meta-analysis and Analysis of the Autism Brain Imaging Data Exchange Cohort. Biol Psychiatry. 2018. PMID 29146048 · DOI
- Ding Y, Ou Y, Pan P, Shan X, Chen J, Liu F, et al.. Cerebellar structural and functional abnormalities in first-episode and drug-naive patients with schizophrenia: A meta-analysis. Psychiatry Res Neuroimaging. 2019. PMID 30500474 · 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.