Classical fear conditioning is one of the most powerful models for studying the neuronal substrates of associative learning and for investigating how plasticity in defined neuronal circuits causes behavioral changes. In my talk, I will focus on the organization and function of the neuronal circuitry of fear. I will discuss how functionally, anatomically, and genetically defined types of amygdala neuron are precisely connected within the local circuitry and within larger-scale neuronal networks, and how they contribute to the acquisition and expression of conditioned fear behavior.