VENTILATORY CONDITIONING BY SELF-STIMULATION IN RATS - A PILOT-STUDY

This article describes an experimental attempt to condition breathing pattern in rats. In this experiment, a freely moving rat was first rew arded by an electrical stimulation of the medial forebrain bundle when ever inspiratory duration (TI) exceeded 300 ms. A bidirectional contro l was then used: TIs longer than 400 ms were rewarded, and then TIs sh orter than 300 ms were rewarded. The frequency of TIs longer than 300 ms increased when this event was rewarded, further increased when TIs above 400 ms were rewarded, and decreased during reversal conditioning (TI < 300 ms). At the beginning of the experiment, stimulation caused increased arousal and motor activity, but after prolonged conditionin g, the brain stimulation was associated with quiet wakefulness. Althou gh the general procedure appears to be well-suited to the experimental study of voluntary breathing, some possible improvements are suggeste d for further, more extensive investigations.