Sniffing and motivated behavior in the rat

The results suggest that measurement of respiration/sniffing frequency may have relevance to classical conditioning interpretations of motivated behavior.

Abstract

The effect of rewarding brain stimulation on inspiration rate in the rat was investigated using a temporal conditioning and a fixed-interval lever-pressing procedure. In early temporal conditioning trials, inspiration frequency was most pronounced following brain stimulation. With conditioning, inspiration frequency became most pronounced preceding brain stimulation. Inspiration frequency in the sniffing range remained part of the unconditional response to rewarding brain stimulation throughout both experiments of this study. In the fixed-interval procedure, inspiration frequency increased just prior to the first lever-press of an interval, and continued to increase until reinforcement was delivered. These results suggest that measurement of respiration/sniffing frequency may have relevance to classical conditioning interpretations of motivated behavior.