Drosophila Optogenetica: een methode om neuronale circuits te manipuleren

- In Drosophilia flies, a looming visual stimulus signaling the approach of a predator activates neuronal circuits that trigger an escape response. To manipulate the neuronal circuit that controls such a response, express a transgenic light-sensitive opsin, like channelrhodopsin-2 in specific neurons within that circuit.

Channelrhodopsin is a photo-sensitive cation channel that opens when exposed to bright blue light. The subsequent inflow of sodium ions spikes an action potential that causes the neuron to fire and relay information along the circuit. In addition to the light stimulus, the cofactor all-trans-retinal is required for channelrhodopsin to open.

Therefore, provide all-trans-retinal in the fly food, since it is usually present in very small amounts. Additionally, when investigating the role of neurons in a neural circuit involved in a response to a visual stimulus, use flies that are visually blind to prevent other light responses.

Finally, use a blue LED light to trigger the same behavior that is caused by the looming stimulus. In the example protocol, we will see the food preparation and light-induced behavioral response of flies expressing channelrhodopsin in optic lo