This lecture covers the cellular mechanisms underlying postsynaptic potentials, focusing on excitatory postsynaptic currents (EPSCs) and potentials (EPSPs). It explains the role of glutamate in EPSPs, the differences between AMPA and NMDA receptors, and the voltage-dependence of EPSPs. The lecture also discusses dendrites' contribution to EPSP generation and the concept of unitary EPSPs. Additionally, it explores the interplay between presynaptic action potentials and postsynaptic responses, emphasizing the importance of synaptic summation in reaching the action potential threshold.