Practice question

Single-unit recording aims to isolate action potentials from one neuron amidst surrounding activity. Sharp metal microelectrodes or glass micropipettes are advanced under stereotaxic guidance until tip impales membrane or lies juxtacellularly, producing high-resistance coupling that reveals large fast spikes attributable to single cell. Spike sorting separates waveforms by amplitude and shape, enabling analysis of tuning and connectivity. EEG averages thousands of synaptic currents at scalp, patch-clamp studies membrane channels not whole-cell spiking, PET measures tracer metabolism, none involve direct impalement for single-cell resolution.