In
neuroscience,
single-unit recordings provide a method of measuring the electro-physiological responses of single
neurons using a
microelectrode system. When a neuron generates an
action potential, the signal propagates down the neuron as a current which flows in and out of the cell through excitable membrane regions in the
soma and
axon. A microelectrode is inserted into the brain, where it can record the rate of change in voltage with respect to time. These microelectrodes must be fine-tipped, high-impedance conductors; they are primarily glass micro-pipettes or metal microelectrodes made of platinum or tungsten. Microelectrodes can be carefully placed within (or close to) the
cell membrane, allowing the ability to record
intracellularly or
extracellularly.