Gamma (γ) oscillations arise from rhythmic synchronized synaptic activity in the γ frequency band (30–80 Hz) and are associated with higher brain functions such as learning and memory (Howard et al., 2003). γ oscillations can be recorded in many brain regions including the hippocampus, olfactory bulb, thalamus and neocortex (Mainy et al., 2007). Generated by the coordinated interaction of excitatory and inhibitory neurons within neural networks (van Vugt et al., 2010), γ oscillations are thought to provide a time frame for synchronized firing of principal neurons (Fisahn et al., 1998; Liu et al., 2004; Fries, 2007), which is critical for the integration of synaptic signals and facilitates synaptic plasticity (Wespatat et al., 2004; Bikbaev and Manahan-Vaughan, 2008).
