Figure 2.

On-demand optogenetic excitation of the fastigial nucleus contralateral to KA injection. A) Spontaneous seizures are recorded from the KA-injected hippocampus and blue (473nm) light is delivered in an on-demand fashion to the contralateral fastigial nucleus in VGluT2-ChR animals. B) Example seizure events detected on-line (denoted by purple bar) that were either randomly selected not to receive light (top trace) or receive light (bottom trace, 3 seconds of light delivery denoted by blue box). Scale bar: 5s, 0.05mV. Three seconds of pulsed light delivery (1000ms on, 50ms off) significantly reduces seizure duration. C) Post-detection seizure duration distributions for an example animal (93% reduction, p < 0.001, two sample Kolmogorov-Smirnov test). Blue bars: events receiving light intervention; hashed bars: no-light internal controls. Top trace illustrates pulsed light delivery paradigm. Inset: first 5s bin expanded, 1s bin size. D) No effect of light delivery on seizure duration in an opsin negative animal (p = 0.896, two sample Kolmogorov-Smirnov test). E) Light delivery produces a significant reduction of seizure duration in opsin positive VGluT2-ChR mice (each gray data point represents one animal, black data points represent mean). Similarly, 3 seconds of shorter light pulses (F-H) at 7Hz (50ms on, 100ms off), or (I-K) 10 Hz (50ms on, 50ms off), produce a significant reduction in seizure duration.