TGF-β signaling induces epileptiform activity. A , Photograph of a brain slice displaying electrode positioning. The stimulating electrode was placed at the white–gray matter border. B , Extracellular recordings showing spontaneous interictal-like epileptiform activity after treatment with aSERUM containing albumin. Asterisk refers to the region corresponding to the slower time scale shown in the lower trace. C , Evoked responses from slices treated with aCSF, albumin, albumin plus TGF-β receptor blockers, TGF-β1, or TGF-β1 plus TGF-β receptor blockers. TGF-β receptor blockers prevent epileptiform activity induced by albumin or TGF-β1 treatment. D , Comparison of mean event integral (black bars) in the 50–500 ms time range (after stimulation) shows a significant increase in the integral of the delayed epileptiform field potential in the albumin and TGF-β1-treated slices but not in slices treated with TGF-β receptor blockers. The white bars represent the percentage of slices with paroxysmal, epileptiform activity. Error bars indicate SEM. Asterisks indicate p < 0.05.
