Combined light and electrical stimulation of light-sensitive neural tissue

A method for stimulating neural tissue, the tissue including one or more neurons genetically modified to express a light-sensitive protein, the method comprising:

• applying a light stimulus to the neural tissue, wherein the light stimulus comprises light in the visible spectrum and is configured to activate the light-sensitive protein, wherein the light stimulus is applied as a series of pulses;
• and
• applying a respective electrical stimulus to the neural tissue at the same time as, or at a predetermined delay time after, the start of the applying of each pulse of the light stimulus, wherein each electrical stimulus comprises a pulse train;
• wherein the combination of the applying of the light stimulus and the applying of the electrical stimulus triggers membrane depolarisation in at least one of the neurons.