The brain is a dense network of precisely interconnected cells called neurons. Our thoughts and behaviors require communication between billions of individual neurons that occurs at special cellular junctions called synapses. During brain development, distinct types of neurons must identify each other to form synaptic connections. In this dissertation, I use mouse genetic tools to study the role of dystroglycan at inhibitory synapses in the forebrain. I show that CCK+ interneurons are present in the brains of mice that lack dystroglycan from the nervous system, but their axons are distributed abnormally in the hippocampus. These findings have important implications for understanding the molecular mechanisms that neurons use to wire together during brain development.