Visualization and Mapping of Neuronal Pathways in an Amygdala Brain Slice

In the mouse brain, the amygdala contains neurons that form synaptic connections with the medial prefrontal cortex, or mPFC neurons.

Take an amygdala brain slice in which the mPFC neurons express a light-sensitive channel rhodopsin fused to a fluorescent protein.

Place the slice in a recording chamber and visualize it under a fluorescence microscope to locate the mPFC neurons.

Switch to a brightfield view and introduce a patch pipette containing an internal solution.

Apply positive pressure to advance the pipette toward an amygdala neuron.

Upon neuronal contact, a dimple forms.

Apply suction to form a tight seal.

Continue suction to rupture the membrane, establishing contact with the cell's interior.

Illuminate the slice to activate the mPFC neuronal channelrhodopsin, triggering positive ion influx, action potential generation, and neurotransmitter release.

The neurotransmitters bind to postsynaptic amygdala neuron receptors, causing ion influx and current generation.

Record the postsynaptic neuronal current to analyze mPFC-amygdala connectivity.