A MECHANOGENETIC STRATEGY TO RESTORE SYNAPTIC FUNCTION IN PCDH19-RELATED EPILEPSY

Early Infantile Epileptic Encephalopathy type 9 (EIEE9), caused by mosaic loss of PCDH19, is characterized by impaired synaptic adhesion and network hyperexcitability resulting from disrupted N-cadherin signalling. Because enhancing N-cadherin function rescues synaptic and plasticity deficits in mouse models, restoring cadherin-dependent pathways at defined synapses represents a promising strategy to normalize circuit activity. Building on these findings, we developed a mechanogenetic approach based on an engineered N-cadherin–SNAP chimeric receptor that enables covalent attachment of Magnetic Nanoparticles (MNPs) to the neuronal surface. In primary neurons, the chimera is efficiently expressed, enriched at dendritic spines, and predominantly localized at excitatory synapses. MNPs are selectively recruited to chimera-expressing dendrites and spines, demonstrating robust synapse-specific targeting and mechanical coupling. To bridge in vitro and in vivo conditions, we established murine organotypic hippocampal slices as an ex vivo platform for viral delivery, magnetic stimulation and circuit-level analysis. These preparations preserve tissue architecture and synaptic viability, support AAV-mediated expression of the chimera, and were coupled to multi-electrode array recordings to quantify changes in firing rate, burst structure and network synchrony during mechanogenetic stimulation. Finally, we will implement an in vivo pipeline combining stereotaxic hippocampal delivery of the construct and MNPs with patterned magnetic stimulation, behavioural assays and electrophysiological recordings in juvenile and adult EIEE9 mice to assess seizure burden, synaptic plasticity and circuit stability. Together, these data establish N-cadherin–based mechanogenetics as a scalable and synapse-specific neuromodulation strategy and position it as a candidate therapeutic approach for restoring circuit stability in PCDH19-related developmental epilepsy.