Fig. 5. Synaptic impairments in PD patient reprogrammed neurons.

A GSEA shows significant enrichment (FDR-q < 0.0001) of the Human Phenotype Ontology gene set for “abnormality of central nervous system electrophysiology” (HP:0030178) among the genes dysregulated in PD patient-derived neurons. B Example image of a typical neuronal culture used for patch-clamping electrophysiology in DIC (top image) or filled with Rhodamine (bottom image). Cells with characteristic neuronal morphology and brightest Synapsin:GFP expression were selected for patch-clamp recordings after a minimum of three weeks (average 43 days) of maturation in BrainPhys™ neuronal medium. Cells were patched from a total of 76 coverslips. C, D All patch-clamped neurons included in the analysis (n = 80 healthy subject-derived, n = 89 PD patient-derived) were classified as “Type 5” cells⁴⁰, indicating equivalent functional maturity (see Methods for details). C Typical evoked action potential (AP) traces from PD patient and control-derived neurons following a 500-ms depolarizing current step. D The maximum firing frequency of evoked APs with amplitudes above -10 mV was similar between PD and control neurons. E Voltage-dependent sodium current characteristics were similar between PD and control neurons. F–M Synaptic properties of patch-clamped midbrain neurons from PD and healthy controls. F Typical recordings of excitatory postsynaptic synaptic currents mediated by AMPA receptors (left) and superimposed detected events and average trace (right). Data are presented as mean ± SEM. P values determined via nonparametric Mann-Whitney test (two-tailed, unpaired).