Abstract
In humans, exercises involving slowed respiratory rate (SRR) counter autonomic sympathetic bias and reduce responses to stressors, including in individuals with various degrees of autonomic dysfunction. In the rat, we examined whether operant conditioning could lead to reductions in respiratory rate (RR) and performed preliminary studies to assess whether conditioned SRR was sufficient to decrease physiological and behavioral responsiveness to stressors. RR was continuously monitored during 20 2-h sessions using whole body plethysmography. SRR conditioned, but not yoked control rats, were able to turn off aversive visual stimulation (intermittent bright light) by slowing their breathing below a preset target of 80 breaths/min. SRR conditioned rats greatly increased the incidence of breaths below the target RR over training, with average resting RR decreasing from 92 to 81 breaths/min. These effects were significant as a group and vs. yoked controls. Preliminary studies in a subset of conditioned rats revealed behavioral changes suggestive of reduced reactivity to stressful and nociceptive stimuli. In these same rats, intermittent sessions without visual reinforcement and a post-training priming stressor (acute restraint) demonstrated that conditioned rats retained reduced RR vs. controls in the absence of conditioning. In conclusion, we present the first successful attempt to operantly condition reduced RR in an animal model. Although further studies are needed to clarify the physio-behavioral concomitants of slowed breathing, the developed model may aid subsequent neurophysiological inquiries on the role of slow breathing in stress reduction.
Highlights
An emerging view is that mind-body techniques involving slowed deep breathing lead to considerable health benefits in humans
While we have not performed mechanistic studies to causally associate slow breathing with stress reduction, we did obtain some evidence of reduced sensitivity to experimental stressors in slowed respiratory rate (SRR) conditioned rats
In the series of basic tests we performed in a subset of conditioned rats, latency to enter the center of an open field was reduced (Figure 6A) to well below the normal range reported (Nam et al, 2014), respiratory rate (RR) elevation was attenuated in response to restraint (Figure 6C2), and pain sensitization was absent following formalin-induced inflammation (Figure 7C)
Summary
An emerging view is that mind-body techniques involving slowed deep breathing lead to considerable health benefits in humans. Conditioning Slowed Breathing in Rats variability by a factor of two or more (Lehrer et al, 1999; Elliott and Edmonson, 2005) and cuts self-reported depression in half (Janakiramaiah et al, 1998). This suggests volitional slowed deep breathing can reduce sympathetic tone with consequent reduction in stress (Jerath et al, 2006). Given previously described evidence of the therapeutic benefits of slowed respiratory rate (SRR), as well as the suggestion that high RR predicts a number of negative cardiopulmonary outcomes (Fieselmann et al, 1993; Hodgetts et al, 2002), RR appears to be an important index of stress and its deleterious impact on behavior
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
