Optogenetic Stimulation and Electrophysiological Recording of Synaptic Events in Rat Brain Slices

Begin with a rat brain slice containing the target neuron region connected with a light-sensitive axon from a different brain region.

Place the slice into the submerged recording chamber and secure it with a slice anchor.

Under a microscope, locate the desired layer and identify the target pyramidal neuron.

Raise the microscope objective to create a meniscus with the slice surface.

Lower a glass micropipette filled with intracellular recording solution into this meniscus.

Touch the identified pyramidal cell with the pipette tip to create an indent in the membrane.

Apply suction to form a seal.

Increase the suction until the membrane ruptures, establishing a whole-cell configuration.

Using a mounted light source, apply light pulses to the slice.

These light pulses trigger an action potential in the light-sensitive axon, releasing neurotransmitters at the synaptic cleft.

Record the pyramidal neuron's responses to these releases to analyze synaptic efficiency.