Optogenetics is a novel technology that combines optics and genetics by optical 
control of microbial opsins, targeted to living cell membranes. The versatility 
and the electrophysiologic characteristics of the light-sensitive ion-channels 
channelrhodopsin-2 (ChR2), halorhodopsin (NpHR), and the light-sensitive proton 
pump archaerhodopsin-3 (Arch) make these optogenetic tools potent candidates in 
controlling neuronal firing in models of epilepsy and in providing insights into 
the physiology and pathology of neuronal network organization and 
synchronization. Opsins allow selective activation of excitatory neurons and 
inhibitory interneurons, or subclasses of interneurons, to study their activity 
patterns in distinct brain-states in vivo and to dissect their role in 
generation of synchrony and seizures. The influence of gliotransmission on 
epileptic network function is another topic of great interest that can be 
further explored by using light-activated Gq protein-coupled opsins for 
selective activation of astrocytes. The ever-growing optogenetic toolbox can 
also be combined with emerging techniques that have greatly expanded our ability 
to record specific subtypes of cortical and hippocampal neurons in awake 
behaving animals such as juxtacellular recording and two-photon guided 
whole-cell recording, to identify the specific subtypes of neurons that are 
altered in epileptic networks. Finally, optogenetic tools allow rapid and 
reversible suppression of epileptic electroencephalography (EEG) activity upon 
photoactivation. This review outlines the most recent advances achieved with 
optogenetic techniques in the field of epilepsy by summarizing the presentations 
contributed to the 13th ILAE WONOEP meeting held in the Laurentian Mountains, 
Quebec, in June 2013.