New, improved in vivo and in vitro approaches have led to a better und
erstanding of the mechanisms that generate respiratory rhythm, which d
epends on a complex interaction between network and intrinsic membrane
properties. The pre-Botzinger complex in the ventrolateral medulla is
particularly important for respiratory rhythm generation. This comple
x can be studied in isolation, and it contains all the known types of
respiratory neurons that are now amenable to detailed cellular and mol
ecular analyses.