Reassessing forebrain organization: recent evidence challenges the prosomere model.

Elsie Place, Elizabeth Manning, Seth Blackshaw, Marysia Placzek

Abstract readReview

In one paragraph

Review in Current opinion in genetics & development, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it

0cells of the map it votes in

0citing papers in PubMed

–field-weighted citation impact

1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

4 authors.

Elsie PlaceSchool of Biosciences, University of Sheffield, Sheffield, UK; Bateson Centre, University of Sheffield, Sheffield, UK. Electronic address: e.place@sheffield.ac.uk.

Elizabeth ManningSchool of Biosciences, University of Sheffield, Sheffield, UK; Bateson Centre, University of Sheffield, Sheffield, UK.

Seth BlackshawSolomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Neurology, Johns Hopkins University School of Medicine; Baltimore, MD, USA; Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA. Electronic address: sblack@jhmi.edu.

Marysia PlaczekSchool of Biosciences, University of Sheffield, Sheffield, UK; Bateson Centre, University of Sheffield, Sheffield, UK; Neuroscience Institute, University of Sheffield, Sheffield, UK. Electronic address: m.placzek@sheffield.ac.uk.

Funding

Development and function of hypothalamic Lhx6-positive neuronsR01MH126676 · NIMH · JOHNS HOPKINS UNIVERSITY · PI BLACKSHAW, SETH · 2021 to 2025

$2.0M

NIMH NIH HHS R01 MH126676Wellcome Trust

6 · The paper itself

Abstract

For over three decades, the prosomere model has influenced our understanding of vertebrate brain development by proposing that the forebrain consists of several transverse segments, termed prosomeres. However, advances in molecular genetics and imaging have challenged key assumptions of this model, including the existence of clear segmental boundaries and the positioning of forebrain axes. Here we critically review evidence from gene expression, fate-mapping, and morphogenesis studies, finding limited support for prosomeric segmentation and questioning the grouping of the hypothalamus with the telencephalon. We propose the tripartite hypothalamus model as an alternative framework that better aligns with recent data, restoring the hypothalamus's relationship to the diencephalon and recognizing the anterior forebrain as a uniquely complex, non-segmented unit with a posterior boundary within the diencephalon. These findings suggest a need to revise our understanding of forebrain structure, patterning, and evolution.

Indexed as

Body PatterningModels, BiologicalMorphogenesisProsencephalonAnimalsDiencephalonGene Expression Regulation, DevelopmentalHumansHypothalamusVertebrates

Identifiers

PMID42275768

DOI10.1016/j.gde.2026.102500

PMCPMC13308299

What Socratic holds

Textmetadata

LicenceTDM

Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.