This lecture covers the cellular mechanisms of inhibitory synaptic conductances in the brain, focusing on GABAergic inhibition, inhibitory postsynaptic potentials, shunting inhibition, and target structures of GABAergic inhibition. It explains how GABA receptors function as ligand-gated channels, the impact of GABA on membrane resistance, and the role of GABAA conductances in hyperpolarizing and shunting inhibition.