[The control of respiratory volume by instrumental feedback under hypoxia and hypercapnia in rats]. / Upravlenie dykhatel'nym ob''emom posredstvom instrumental'noi obratnoi sviazi v usloviiakh gipoksii i giperkapnii u krys.

The biofeedback was used in the training of rats to decrease their spontaneous tidal volume in conditions of normoxia, hypoxia and hypercapnia. All rats decreased tidal volume in the ranges equal to 1.0 VT and 0.8 VT in the air and hypoxic conditions. It was difficult for them to decrease tidal volume in hypercapnia. The role of hypoxic and hypercapnic drives in respiratory responses to a breathing regimen and its abolition, is discussed.

[Features of the respiration of the rat at a given tidal volume]. / Osobennosti dykhaniia krys v usloviiakh zadannogo dykhatel'nogo ob"ema.

Intact rats were trained to breathe in a given tidal volume equal to VT; 0.8 VT; 0.6 VT; 0.4 VT. To decrease their spontaneous tidal volume rats were automatically punished with electric current for exceeding the given volume. All rats could breathe in the ranges VT and 0.8 VT maintaining the obligatory level of lung ventilation. It was difficult for them to breathe in the ranges 0.6 VT and 0.4 VT. In these cases the lung ventilation was lower than the obligatory one and the breathing was interrupted with hyperpnoea. Rats respiratory reactions depend on the range of the restriction. Three types of respiratory responses to the tidal volume restriction were found. The ability of rats to breathe in given ranges of the restriction are discussed.