Generation of Spontaneous and On-Demand Ictal Events in Mouse Brain Cortical Slices

Source: Chang, M. et al. Generation and On-Demand Initiation of Acute Ictal Activity in Rodent and Human Tissue. J. Vis. Exp. (2019) This video demonstrates the induction of ictal events in coronal cortical slices from a transgenic mouse expressing light-activated cation channels in cortical excitatory pyramidal neurons. The slice is placed in a recording chamber, and a recording electrode is inserted into the superficial cortical layer. Upon perfusion with a seizure-inducing drug that blocks potassium channels, the neurons become hyperexcitable and generate spontaneous ictal events. To generate on-demand ictal events, a brief light pulse is used to activate the cation channels in pyramidal neurons, triggering the release of excitatory neurotransmitters, which induce the postsynaptic neurons to generate ictal events for a short duration.