REVIEW article
Front. Neuroanat.
This article is part of the Research TopicThe Major Discoveries of Cajal and His Disciples: Consolidated Milestones for the Neuroscience of the XXIst Century, Volume IIView all 6 articles
Cajal's organization of neuronal nucleus revisited
Provisionally accepted
- 1Universidad de Cantabria Facultad de Medicina, Santander, Spain
- 2Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain
- 3Nash Family Department of Neuroscience & Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, United States
- 4Institute of Biomedicine of Seville (IBiS)/“Virgen del Rocío” University Hospital/CSIC/University of Seville and Department of Medical Physiology and Biophysics, University of Seville, Sevillle, Spain
- 5Department of Basic Medical Sciences & Institute of Biomedical Technologies (ITB), University of La Laguna, San Cristóbal de La Laguna, Spain
- 6Universidad Europea del Atlántico, Santander, Spain
Select one of your emails
You have multiple emails registered with Frontiers:
Notify me on publication
Please enter your email address:
If you already have an account, please login
You don't have a Frontiers account ? You can register here
In 1906, Cajal was awarded the Nobel Prize in Physiology or Medicine for his pioneering studies on the structure and organization of nerve centers. Notably, in 1910, Cajal published a seminal work in which he described the essential components of the neuronal nucleus, primarily using his reduced silver nitrate procedure. Using modern microscopy techniques, we have identified the current equivalents of the structures originally described by Cajal. These include the "fibrillar center–dense fibrillar component units" of the nucleolus, "nuclear speckles," "transcription factories," and "the Cajal body." Importantly, these structures represent key nuclear compartments involved in the transcription of rDNA and protein-coding genes, pre-rRNA and pre-mRNA processing and spatial genome organization. Most of the nuclear components described by Cajal are now recognized as dynamic "nuclear condensates" assembled through liquid– liquid phase separation mechanisms that depend on various categories of RNA and RNA-binding proteins.
Keywords: Cajal and neuronal nucleus, Nuclear condensates, nucleolus, Nuclear speckles, Cajal body, transcription factories, nucleoskeleton
Received: 14 Oct 2025; Accepted: 17 Nov 2025.
Copyright: © 2025 Lafarga, Berciano, Narcis, Baltanás and Tapia. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Miguel Lafarga, lafargam@unican.es
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.