Summary: Why do some brain cells perish while others remain untouched in neurodegenerative diseases? Researchers have moved closer to an answer, identifying five specific subgroups of neurons in the motor cortex that are uniquely susceptible to ALS and Frontotemporal Dementia (FTD).
By analyzing the “molecular fingerprints” (transcriptomes) of neurons from 80 individuals, the team discovered that pathological clumps of the protein TDP-43 predominantly target excitatory cells—those responsible for transmitting and amplifying nerve signals. This discovery of “selective vulnerability” suggests that future treatments must be precision-tailored to these specific high-risk cell types rather than the brain as a whole.
Key Facts
- The “TDP-43” Clump: A hallmark of both ALS and FTD is the accumulation of TDP-43 protein aggregates, which disrupt cellular function and lead to neuron death.
- Excitatory Focus: The study found that excitatory neurons in the motor cortex—the area controlling movement—are significantly more susceptible to these protein clumps than inhibitory neurons.
- Five Target Subgroups: Using advanced transcriptomics, researchers identified five distinct subgroups of neurons, each impacted by the disease in a unique way.
- Selective Vulnerability: This molecular mapping explains why symptoms like muscle wasting and paralysis occur: the disease selectively destroys the specific “amplifying” cells needed for movement.
Source: DZNE
Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) belong to a spectrum of neurodegenerative diseases with overlapping symptoms, characterized by muscle wasting, paralysis, dementia, and other serious impairments.
There are currently no effective treatments. Many patients have a common hallmark: A protein called TDP-43 clumps together in the neurons of the brain to form tiny lumps.
Researchers at DZNE and Ulm University Hospital, together with international experts, have now discovered that these pathological changes primarily affect certain cells.
Their findings, published in the scientific journal Nature Communications, could contribute to the development of new therapies.
For their study, the research team led by Prof. Karin Danzer examined brain tissue from deceased patients with ALS, with a mixed form of ALS and FTD, as well as from individuals who had not shown neurological symptoms during their lifetime. All samples came from the “motor cortex”, a brain area responsible for movement control. In total, neurons from around 80 individuals in Germany, the Netherlands, Scotland, and the United States were analyzed using advanced techniques.
“In ALS, as well as in the mixed form of ALS and FTD, TDP-43 deposits occur in different regions of the brain. However, the motor cortex is particularly relevant for movement disorders, which is why we focused on this area,” explains Karin Danzer, a research group leader at DZNE’s Ulm site and at Ulm University Hospital. The researchers found that not all neurons in this area are equally affected.
“The protein aggregates occur predominantly within excitatory cells, that is, within neurons that serve to transmit and amplify nerve signals. These cells seem to be particularly susceptible to the disease.
“This phenomenon is referred to as selective vulnerability and known for a long time in the field. In addition, within the affected neurons, we found five subgroups. Each of these is impacted by the disease in a specific way,” explains Danzer.
Disease mechanisms
The findings are based on the “transcriptome” of affected neurons. This molecular fingerprint provides information about which genes are active in affected cells and therefore enable to distinguish pathological processes in different cells. Based on this signature, the researchers were also able to identify cell type-specific changes.
“Our data offer insights into disease mechanisms and thus point to possible targets for therapy development. For example, one can see how the activity of certain genes is altered depending on the cell type.
“The observation that not all neurons are equally affected suggests that future therapies will need to be tailored to specific cell types in order to combat the disease effectively,” says Danzer.
Key Questions Answered:
A: It’s all about location and cell type. This study shows that the disease is a “precision striker.” It specifically targets the excitatory neurons in the motor cortex—the brain’s command center for muscles. When these “amplifiers” are destroyed by TDP-43 clumps, the signal to move simply never reaches the muscles.
A: Scientists look at the transcriptome, which is a map of which genes are “turned on” in a cell. By comparing the fingerprints of healthy cells vs. diseased cells, the researchers could see exactly which genetic pathways were failing in those five vulnerable subgroups. It’s like a crime scene investigation for the brain.
A: It provides the “coordinates” for a cure. Instead of a “shotgun approach” where a drug tries to help the whole brain, scientists can now develop therapies that specifically protect those five high-risk cell types. By stabilizing the specific genes that fail in these neurons, we might be able to stop the paralysis before it starts.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- Journal paper reviewed in full.
- Additional context added by our staff.
About this neurology and ALS research news
Author: Marcus Neitzert
Source: DZNE
Contact: Marcus Neitzert – DZNE
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Multi-modal dissection of cell-type specific TDP-43 pathology in the motor cortex” by Wolfgang P. Ruf, Julia K. Kühlwein, Laura Meier, Sarah J. Brockmann, Jaehyun LeeBae, Ghazaleh Sadri-Vakili, Deniz Yilmazer-Hanke, Susanne Petri, Dietmar R. Thal, Veselin Grozdanov & Karin M. Danzer. Nature Communications
DOI:10.1038/s41467-026-69944-6
Abstract
Multi-modal dissection of cell-type specific TDP-43 pathology in the motor cortex
Cytoplasmic TDP-43 pathology is a pathological sign of ALS/ALS-FTD and a converging disease event across different genotypes, phenotypes and CNS areas. To understand this process and target it therapeutically, we need to define which cell types are affected and which cell-type specific effects make them particularly vulnerable.
We coupled flow-cytometry nuclear sorting and sequencing with single-nucleus multi-omic ATAC-seq and RNA-seq and spatial transcriptomics to define the transcriptional cell type of affected neurons in the post-mortem ALS/ALS-FTD motor cortex (30 ALS, 20 ALS-FTD & 32 control samples).
Here, we show that mainly excitatory cortical neurons are affected by TDP-43 pathology and define the cell types that are affected the most: intratelencephalic L2-L3-LINC00507-FREM3, L3-L5-RORB-LNX2, L3-L5-RORB-ADGRL4 & L6-THEMIS-LINC00343 neurons and extratelencephalic L5-FEZF2-NTNG1 neurons.
Transcriptional aberrations by TDP-43 pathology, like cryptic exon inclusion, are cell-type specific and affect distinct gene sets in each cell type, highlighting the need to address TDP-43 pathology in a cell-type specific manner.
