Recording Synaptic Currents at the Drosophila Larval Neuromuscular Junction

Place a Petri dish containing a dissected Drosophila larva with exposed muscles and nerve branches onto the microscope stage.

Insert a reference electrode into a bath solution within the Petri dish.

Fill a recording electrode with an isotonic solution.

Using a micromanipulator, position this electrode over an abdominal muscle innervated by motor neurons.

Place the electrode tip on a synaptic bouton, a structure at the axon tip containing neurotransmitters.

Continuously record miniature excitatory junctional currents or mEJCs, which are responses to spontaneous neurotransmitter release.

The correct range of mEJC amplitude confirms the proper electrode positioning.

Next, position a stimulation electrode near the axon that innervates the targeted muscle.

Apply negative pressure to pull the axon inside the electrode.

Gradually increase the stimulation current to induce an action potential.

This triggers the axon to release neurotransmitters at the neuromuscular junction, which are recorded as synaptic currents.

Place the petri dish with the preparation on the microscope stage. Insert the reference electrode in the bath. Fill the recording electrode with HL3 solution. Under the 10x obje