Gene Therapy Approach Shows Promise for Hydrocephalus

Researchers develop AAV-based method to target cerebrospinal fluid production, revealing new insights into postnatal neurogenesis

October 20, 2026
3 min

The Medicine Maker

Overview

In mice, an AAV-based approach that enabled targeted ablation of choroid plexus epithelial cells reduced parenchymal edema and corpus callosum MRI signal abnormalities after hydrocephalus induction. It did not substantially reduce ventricular enlargement. In neonatal mice, choroid plexus ablation was associated with fewer neuroblasts and reduced hippocampal and overall brain volumes.

Background

Hydrocephalus involves abnormal cerebrospinal fluid (CSF) accumulation in the brain’s ventricles and can be associated with ventricular enlargement, increased intracranial pressure, and injury to surrounding tissue. The article describes CSF shunting and endoscopic procedures as current treatments that can have complications. Because the choroid plexus produces CSF, the study tested whether targeted ablation of its epithelial cells could reduce CSF volume and hydrocephalus-associated effects. The study also assessed developmental findings after neonatal ablation.

Data Highlights

Study element	Reported finding
Intervention	AAV5-CMV-DTR delivered the diphtheria toxin receptor gene to choroid plexus epithelial cells; subsequent diphtheria toxin administration enabled targeted cell ablation.
Vector targeting	In neonatal and adult mice, the vector targeted choroid plexus epithelial cells with minimal expression in surrounding brain tissue.
Neonatal ventricular outcome	The approach reduced ventricular CSF volume in neonatal mice, where the ROSA26-iDTR genetic ablation model had been ineffective.
Adult hydrocephalus model and timing	In adult mice with kaolin-induced hydrocephalus, treatment initiated within 6–10 hours of induction reduced parenchymal edema and corpus callosum MRI signal abnormalities.
Ventricular outcome	The adult hydrocephalus findings occurred without substantial reduction in ventricular enlargement or ventricular collapse.
Neonatal findings	Choroid plexus ablation reduced neuroblast populations in the subventricular zone and hippocampal subgranular zone, and was associated with reduced hippocampal and overall brain volumes and modestly lower exploratory locomotor activity.
Cell measures	Cell proliferation and apoptosis measurements showed no significant differences at the examined time points.

Key Findings

AAV5-CMV-DTR targeted choroid plexus epithelial cells in neonatal and adult mice, with minimal expression in surrounding brain tissue.
In neonatal mice, the approach reduced ventricular CSF volume where the ROSA26-iDTR genetic ablation model had been ineffective.
In adult mice with kaolin-induced hydrocephalus, treatment begun within 6–10 hours reduced brain parenchymal edema and corpus callosum MRI signal abnormalities.
The adult hydrocephalus findings were not accompanied by substantial reduction in ventricular enlargement or ventricular collapse.
Neonatal choroid plexus ablation reduced neuroblast populations in the subventricular zone and hippocampal subgranular zone; the reduction was more pronounced in the subventricular zone.
Neonatal ablation was also associated with reduced hippocampal and overall brain volumes and modest decreases in exploratory locomotor activity. Proliferation and apoptosis measures did not differ significantly at the time points examined.

Clinical Implications

The study reports that choroid plexus ablation reduced edema in a mouse hydrocephalus model while ventricular enlargement persisted. The authors state that further studies are needed to assess long-term neurological consequences, optimal treatment timing, and the approach’s translational potential and therapeutic window.

Conclusion

In mice, targeted choroid plexus ablation reduced hydrocephalus-associated parenchymal edema without substantially reducing ventricular enlargement. Neonatal ablation was associated with changes in neuroblast populations, brain volumes, and exploratory locomotor activity. The authors identify long-term effects, treatment timing, and translational potential as questions for further study.