To elucidate the importance of telencephalic structures and the effects of metabolic rate in the production of locomotor-respiratory coupling, we examined the relationship between locomotor and ventilatory patterns in: (1) intact trained geese, and (2) brainstem-stimulated (medullary reticular formation) decerebrate geese, that were walking on a treadmill. The decerebrate geese, however, were not completely self supporting. Thus, while the two groups walked with similar stride frequencies (fs), they did so at two different work rates.
While at rest, tidal volume (VT), breathing frequency (fv) and minute ventilation (VE) were very similar in the two groups. VE increased 120% during walking in the intact geese, primarily as a result of increases VE, while both VT and fv increased to produce a smaller 40 % increase in VE in the decerebrate birds. Although the magnitude of the increase in VE was three times greater in the intact geese, the relationships between VE and oxygen uptake (VO2) and VE and CO2 output (VCOCO2) were similar in the two groups.
Significant coupling between locomotor and respiratory patterns was found in both intact (28.3%) and decerebrate birds (28.9%), suggesting that the telencephalon is not essential for the coupling of locomotor and respiratory rhythms during walking in geese. In addition, the incidence of locomotor-respiratory synchrony was virtually identical in the two groups in spite of a threefold difference in metabolic work rate.