Despite the enormous diversity of glutamate (Glu) receptors and advances in understanding recombinant receptors, native Glu receptors underlying functionally-identified inputs in active systems are poorly defined in comparison. In the present study we use UBP-302, which antagonizes GluR5 subunit-containing Kainate (KA) receptors at 10 µM, but other KA and AMPA receptors at 100 µM, and rhythmically-active in vitro preparations of neonatal rat, to explore the contribution of nonNMDA receptor signaling in rhythm generating and motor output compartments of the inspiratory network. At 10 µM, UBP-302 had no effect on inspiratory burst frequency or amplitude. At 100 µM, burst amplitude recorded from XII, C1 and C4 nerve roots was significantly reduced, but frequency was unaffected. The lack of a frequency effect was confirmed when local application of UBP-302 (100 µM) into the preBötC did not affect frequency but substance P evoked a 2-fold increase. A UBP-302-sensitive (10 µM), ATPA-evoked frequency increase, however, established that preBötC networks are sensitive to GluR5 activation. Whole-cell recordings demonstrated that XII motoneurons also express functional GluR5-containing KA receptors that do not contribute to inspiratory drive, and confirmed the dose-dependence of UBP-302 actions on KA and AMPA receptors. Our data provide the first evidence that the nonNMDA (most likely AMPA) receptors mediating glutamatergic transmission within preBötC inspiratory rhythm generating networks are pharmacologically distinct from those transmitting drive to inspiratory motoneurons. This differential expression may ultimately be exploited pharmacologically to separately counteract depression of central respiratory rhythmogenesis or manipulate the drive to motoneurons controlling airway and pump musculature.