Extracellular Recording
Neural recording technique that measures electrical activity from outside cells, capturing action potentials and local field potentials.
Extracellular recording is a technique that measures electrical activity from outside individual cells using microelectrodes or silicon probes, typically capturing action potentials (spikes) and local field potentials (LFPs).
Why it matters: Extracellular recording is the primary method for monitoring neural activity in intact brains. Unlike intracellular methods, it allows simultaneous observation of many neurons over extended periods without damaging cells.
What it captures: Action potentials from individual neurons (high-frequency, >300 Hz) and local field potentials representing summed population activity (low-frequency, <300 Hz). The same electrode can capture both signal types with appropriate filtering.
Key considerations: Signal quality depends on electrode impedance, proximity to neurons, noise environment, and signal conditioning. Higher site density enables better spike sorting and more complete population sampling.