Figure 1.

Preventing Neuronal Hyperexcitability during Embryogenesis Is Sufficient to Suppress Seizure

(A) Schematic representation of the experimental procedure. Embryos expressed eNpHR in cholinergic neurons and were exposed to light (λ565 nm, 100 or 600 ms/1 Hz) between 11 and 19 hr AEL. Subsequent L3 larvae were tested for seizure behavior by electroshock. AEH, after embryo hatching.

(B) Electroshock-induced seizure recovery time is significantly reduced in a genetic (bss) seizure mutant (bss/+; B19-GAL4/eNpHR) following inhibition of neural activity (600-ms light pulses) during embryogenesis (compare +LED₆₀₀ to −LED). By contrast, short duration light pulses of 100 ms (+LED₁₀₀), which are excitatory (see Figure S2), are without effect. The bss mutation is semi-dominant, conferring a weaker but still significant seizure phenotype in heterozygous progeny (bss/+).

(C) Inhibition of neural activity in embryos exposed to the proconvulsant PTx is sufficient to significantly prevent seizure (compare +LED₆₀₀ to −LED).

Data are represented as mean ± SEM. ^∗∗∗p < 0.001, Bonferroni’s post hoc test. Red and black dotted lines represent reference RTs (mean ± SEM) obtained from bss, bss/+ and WT, respectively.