Rhythmic motor behaviors, such as breathing and walking, provide a straightforward behavioral context for extracting meaning from dynamic activity patterns produced in the underlying neural circuits. Neural circuits controlling rhythmic movements are known as central pattern generators (CPGs) and take tonic excitatory drive and generate rhythmic motor output. My general aim is to use the CPG controlling breathing to understand how physiological and pathophysiological changes in excitation and inhibition influence the dynamics of rhythmic neural circuits to control movements in mammals. I utilize novel, network-level approaches, focused on patterned manipulations of small networks of neurons, i.e., microcircuits, to significantly advance our understanding of diseases of motor control and reveal how the phenomenal diversity of behavior emerges from dynamic activity in the brain.