Optogenetics: Control of Brain Using Light

neuronal cells communicate with each other by producing electrical signals or action potentials (APs). Different ion channels, including Na+, K+ and Ca2+ channels, are involved in generation of AP. Once an AP is generated in the soma, it travels down entire the axon length toward its terminal in a selfgenerating fashion that ultimately conveys information between neurons in the neural circuit. Depending on the neurotransmitter, each neuron inhibits or excites other neurons in a certain network. For instance, glutamate released from glutamatergic neurons, opens AMPA and NMDA channels permitting influx of Na+/Ca2+, which leads to postsynaptic depolarization. On the other hand, GABA released from GABAergic neurons results in Cl- influx and postsynaptic hyperpolarization. One of the major challenges in neuroscience is how actions of individual cells in the brain could underlie a certain behavior such as attention, food consumption, aggression, cognition, and movement.