When dopamine-producing neurons die, the brain can spontaneously grow 'pseudo-dopamine' neurons to try and fix the damage.
April 1, 2026
Original Paper
Loss of Synaptojanin 1 in dopamine neurons triggers synaptic degeneration and striatal TH interneuron compensation
bioRxiv · 2025.05.14.653914
The Takeaway
In a model of Parkinson's-like loss, researchers discovered the brain has a hidden 'backup' plan where it induces existing interneurons to transform and start producing dopamine. This reveals an incredible level of adaptive plasticity that could change how we treat neurodegeneration.
From the abstract
Synaptic dysfunction is an early feature of Parkinson's disease (PD). Synaptojanin 1 (SJ1), a phosphoinositide phosphatase linked to early-onset parkinsonism, is essential for clathrin-mediated endocytosis and synaptic vesicle recycling. While constitutive SJ1 mutant mice recapitulate patient-like phenotypes, their broad systemic effects obscure the cell type-specific functions of SJ1. Here, we report the first dopamine neuron-specific SJ1 conditional knockout (SJ1-DA cKO) mice. Complete and sel