Optogenetic Control of Hippocampal Network Dynamics

Begin with a mouse hippocampal slice containing the target pyramidal cells connected to genetically modified light-sensitive interneurons.

Place the slice in a recording chamber.

Position a local field potential or LFP electrode in the desired region to record theta oscillations, a type of rhythmic brain activity.

Using a microelectrode, patch a nearby pyramidal cell to record its activity.

Place an optic fiber light above the hippocampal slice centered on the recording region.

Deliver blue light pulses at a set frequency to the slice to activate the light-sensitive ion channels in the interneuron.

The activation causes an influx of positive ions, leading to depolarization.

This triggers the release of inhibitory neurotransmitters onto the pyramidal neuron, thereby reducing excitability.

The light stimulation enhances the synchronization of the theta oscillations and the synaptic activity of the recorded neuron, suggesting effective modulation of the neural rhythms.