Newly found dendrite bottlenecks may reshape how neurons handle information

by University Hospital of Bonn

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Neurons receive thousands of signals via tree-like extensions called dendrites. Until now, these dendrites were thought to be relatively smooth cables that conduct electrical signals to the cell body. An international research team led by University Hospital of Bonn (UKB), the University of Bonn and the DZNE has determined that this picture is incomplete.

Using various advanced microscopy techniques, it identified tiny, previously overlooked constrictions along the dendrites. These newly discovered structures, which the researchers call dendritic shaft constrictions, are only a few hundred nanometers wide—about 500 to 1,000 times thinner than a human hair—and occur in various types of neurons in both mouse and human brains.

The study results have been published in the journal Science Advances.

Dendrites do more than relay

Small tree-like projections, known as dendrites, function as neurons' receiving antennas. They pick up electrical signals from other nerve cells and relay this information to the cell body, with dendritic spines serving as contact points for other neurons. In this way, dendrites enable communication within the nervous system.

Since they can alter their shape and the number of their branches to store new information, they also play a central role in what is known as neural plasticity and, consequently, in learning processes and memory.

The structure of dendrites is closely linked to their function. Dendritic spines, with their bulbous heads connected to the dendrite by a thin neck, are typical examples of this. With diameters ranging from a few tens to a few hundred nanometers, the necks of the spines form compartments that are essential for function and plasticity. In contrast, dendrite shafts are traditionally interpreted as smooth, continuous cables.

Hidden features below light microscopy

"While dendritic spines have long been known due to their prevalence, the constrictions in shaft diameter that we discovered have not been documented before. Another factor was that the diameter of these constrictions ranges from a few tens to a few hundred nanometers, which is below the resolution limit of conventional light microscopy," said first author Dr. Tony Kelly, a postdoctoral researcher in Professor Heinz Beck's research group at the Institute for Experimental Epileptology and Cognitive Research of UKB and the University of Bonn.

"Even in high-resolution electron microscopy data sets, such local diameter variations may have been regarded until now as random irregularities rather than biologically significant structures."

In collaboration with numerous experts in high-resolution microscopy, including Professor Ulrich Kubitscheck at the Clausius Institute for Physical and Theoretical Chemistry at the University of Bonn and Professor Valentin Nägerl at the Institute of Anatomy and Cell Biology at the University of Göttingen, the research team was able to use multiple methods to identify localized constrictions in the diameter of the dendritic shaft, which they refer to as dendritic shaft constrictions (DSC).

Constrictions may isolate signals

Using a combination of high-resolution imaging techniques, including expansion microscopy, STED (Stimulated Emission Depletion) microscopy, scanning probe microscopy and serial electron microscopy, the researchers demonstrated that dendrites in both mouse and human neurons exhibit localized diameter constrictions in the nanoscale range along their shafts.

Computer simulations and experiments suggest that these constrictions can divide the dendrites into small electrical compartments. Signals arriving beyond a constriction can become stronger locally while being transmitted less effectively to the cell body. This also promotes the activation of NMDA receptors, which are important for changes in synaptic strength and learning processes.

"Our findings therefore reveal a previously unrecognized structural feature that may allow individual dendrites to process information locally rather than merely relaying it," said last author Beck, who is a member of the ImmunoSensation Cluster of Excellence and the Transdisciplinary Research Area (TRA) "Life & Health" at the University of Bonn.

"Dendritic shaft constrictions could represent a new fundamental element in how neurons perform complex computations, although their precise biological role and how they are formed remain to be determined."

Publication details

Tony Kelly et al, Dendritic shaft constrictions shape synaptic integration in neurons, Science Advances (2026). DOI: 10.1126/sciadv.aec4911. www.science.org/doi/10.1126/sciadv.aec4911

Journal information: Science Advances

Key medical concepts

Receptors, N-Methyl-D-AspartateNeuronal Plasticity

Clinical categories

Neurology Provided by University Hospital of Bonn Who's behind this story?

Sadie Harley

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Citation: Newly found dendrite bottlenecks may reshape how neurons handle information (2026, September 14) retrieved 14 September 2026 from https://medicalxpress.com/news/2026-09-newly-dendrite-bottlenecks-reshape-neurons.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.