The article discusses the crucial role of inhibition in shaping cortical activity, both during spontaneous and sensory-evoked processes. Synaptic excitation and inhibition are interdependent, with rapid changes in one often accompanied by changes in the other. Inhibition is generated by GABAergic interneurons, which form local circuits with excitatory glutamatergic principal cells. These circuits, including feedforward and feedback loops, regulate the membrane potential and excitability of neurons, influencing their output. The balance between excitation and inhibition is essential for proper cortical function, and disruptions can lead to epileptiform or comatose states. Inhibition also plays a key role in gain control, dynamic range, and tuning of cortical neurons to specific stimuli. Additionally, inhibition is involved in generating and synchronizing oscillations, such as gamma oscillations, which are thought to facilitate information transmission across cortical areas. The article highlights the need for further research to understand the specific contributions of different inhibitory cell types and circuits to cortical function and their roles in neurological and cognitive disorders.The article discusses the crucial role of inhibition in shaping cortical activity, both during spontaneous and sensory-evoked processes. Synaptic excitation and inhibition are interdependent, with rapid changes in one often accompanied by changes in the other. Inhibition is generated by GABAergic interneurons, which form local circuits with excitatory glutamatergic principal cells. These circuits, including feedforward and feedback loops, regulate the membrane potential and excitability of neurons, influencing their output. The balance between excitation and inhibition is essential for proper cortical function, and disruptions can lead to epileptiform or comatose states. Inhibition also plays a key role in gain control, dynamic range, and tuning of cortical neurons to specific stimuli. Additionally, inhibition is involved in generating and synchronizing oscillations, such as gamma oscillations, which are thought to facilitate information transmission across cortical areas. The article highlights the need for further research to understand the specific contributions of different inhibitory cell types and circuits to cortical function and their roles in neurological and cognitive disorders.