Figure 9.

Lamotrigine and Gabapentin restore neural development membrane voltage prepattern in nicotine-exposed embryos. (A–D) Representative CC2-DMPE membrane voltage reporter dye images of stage ~15 Xenopus embryos: Control (untreated and uninjected) and nicotine-treated embryos with or without lamotrigine (stage 10 onwards) or gabapentin (stage 10 onwards) treatment. Solid yellow arrows indicate characteristic hyperpolarization in the neural plate as previously reported (Pai et al., 2015b, 2018). Hollow yellow arrows indicate significantly reduced signal (depolarization) within the neural plate in comparison to controls. Magenta arrows indicate significantly enhanced hyperpolarization in the neural plate compared to controls. (E,F) Quantification of fluorescence from CC2-DMPE images of stage ~15 Xenopus embryos along with electrophysiology-based membrane voltage approximations [as previously reported in references (Pai et al., 2015b, 2018)] for the indicated conditions (LT-lamotrigine, GP-gabapentin). (E) Quantification obtained along the magenta dotted line indicated in the illustration. (F) Quantification at the point of intersection of the magenta and black dotted line indicated in the illustration. Data represented as mean ± SD, **p < 0.01, ****p < 0.0001 (one-way ANOVA with Tukey’s post hoc test for N > 10 embryos for each treatment group at each point of the indicated spatial distance).