Recording Neuronal Field Excitatory Postsynaptic Potentials in Acute Hippocampal Slices

Place a mouse hippocampal slice into a submersion chamber filled with artificial cerebrospinal fluid, or aCSF.

Secure the slice with a holding mesh to prevent movement.

Continuously circulate oxygenated aCSF to maintain neuronal viability.

Install reference electrodes to provide a stable voltage reference.

Position the stimulation and recording electrodes in line with and parallel to the hippocampal CA1 stratum pyramidale.

Apply electrical pulses.

These pulses stimulate the neurons, causing voltage-gated ion channels to open, allowing positive ions to flow in, and triggering action potentials.

These action potentials propagate along the neurons and induce the release of excitatory neurotransmitters into the synaptic cleft.

The neurotransmitters bind to specific receptors on the postsynaptic neurons, allowing positive ion influx and resulting in a change in membrane potential — the excitatory postsynaptic potential, or EPSP.

The recording electrode measures the EPSP from a population of neurons within the recording region — the field EPSP.