This chapter introduces methods for detecting and analyzing extracellularly recorded action potentials from individual neurons, also known as unit spikes. It describes the settings of appropriate recording frequency band, sampling rate and resolution for spike recordings. It introduces window-based detection and multiple-channel sorting algorithms for spikes, along with analysis methods for spike sequences (including inter-spike-interval histogram, autocorrelation histogram, cross-correlation histogram, and so on). The chapter also covers spectrum analysis methods for local field potentials and EEG signals. Finally, it presents the current source density analysis for tracking transmembrane current during neuronal activation and provides methods for removing stimulation artifacts from both sinusoidal and pulse electrical stimulations.