Figure 5.

PGPC17-Derived Sensory Neurons Are Predominately Non-peptidergic

(A) Sensory neuron differentiation scheme. The LDN and SB drug combination was applied between D0 and D5 with the CHIR, DAPT, SU, and NGF combination starting on D2 through D11. Starting on D4, N2 medium was added in increasing 25% increments replacing mTeSR1. Dividing cells were eliminated using Ara-C on D10. N2 medium was changed twice weekly thereafter.

(B–E) Representative spiking patterns to sustained somatic current injection (B). At 2 weeks, all cells spike transiently (independent experiments = 3; technical replicates ≥5), whereas at 4 weeks there is a significant increase in the proportion of repetitively spiking neurons (independent experiments = 4; technical replicates ≥2) compared with transiently spiking neurons (independent experiments = 4; technical replicates ≥2) (p < 0.0001, chi-squared test). The action potential waveform experienced a significant increase in amplitude (C) and a significant decrease in width (D) between 2 and 4 weeks post-induction. Rheobase was significantly lower in repetitive spiking neurons than in transient spiking neurons at 2 or 4 weeks post-induction (E). ^∗p < 0.05 based on Mann-Whitney U tests.

(F) Ca²⁺ revealed a significant decrease in the proportion of neurons responsive to capsaicin between 2 and 4 weeks (p < 0.00001, chi-squared test), whereas the proportion of neurons responsive to GABA (p = 0.0001) or ATP (p = 0.042) significantly increased.