Gamma oscillations, occurring in the 30–90 Hz range, are fundamental to brain function and are generated by complex interactions between excitatory and inhibitory neurons. These oscillations are closely tied to perisomatic inhibition, particularly from fast-spiking interneurons, and are often associated with irregular neuronal firing. Gamma oscillations emerge from coordinated excitation and inhibition, detectable as local field potentials, and their frequency varies depending on the underlying mechanism. They are modulated by slower rhythms through cross-frequency coupling, which helps synchronize cortical circuits. Gamma oscillations are crucial for cognitive functions and are closely linked to the operational modes of local circuits, providing insights into neuronal population dynamics in health and disease. Key mechanisms include the I-I model, where inhibitory interneurons generate oscillations through mutual inhibition, and the E-I model, involving reciprocal connections between excitatory and inhibitory neurons. Both models contribute to gamma oscillations, with the I-I model emphasizing perisomatic inhibition and the E-I model highlighting phase shifts between excitatory and inhibitory spikes. Gamma oscillations also play a role in long-range synchronization, with cross-frequency coupling enabling coordination between different brain regions. Understanding these mechanisms is essential for elucidating the complex dynamics of brain circuits and their functions in both normal and pathological conditions.Gamma oscillations, occurring in the 30–90 Hz range, are fundamental to brain function and are generated by complex interactions between excitatory and inhibitory neurons. These oscillations are closely tied to perisomatic inhibition, particularly from fast-spiking interneurons, and are often associated with irregular neuronal firing. Gamma oscillations emerge from coordinated excitation and inhibition, detectable as local field potentials, and their frequency varies depending on the underlying mechanism. They are modulated by slower rhythms through cross-frequency coupling, which helps synchronize cortical circuits. Gamma oscillations are crucial for cognitive functions and are closely linked to the operational modes of local circuits, providing insights into neuronal population dynamics in health and disease. Key mechanisms include the I-I model, where inhibitory interneurons generate oscillations through mutual inhibition, and the E-I model, involving reciprocal connections between excitatory and inhibitory neurons. Both models contribute to gamma oscillations, with the I-I model emphasizing perisomatic inhibition and the E-I model highlighting phase shifts between excitatory and inhibitory spikes. Gamma oscillations also play a role in long-range synchronization, with cross-frequency coupling enabling coordination between different brain regions. Understanding these mechanisms is essential for elucidating the complex dynamics of brain circuits and their functions in both normal and pathological conditions.