Acoustic Perturbation of Breathing: A Newly Discovered Response to Soft Sounds in Rats Using an Approach of Image Analysis
Abstrakt
Whether soft sounds are effective in eliciting any reflexive body movements remains unknown. To detect the possible sound-induced changes of body movements in unconstrained rats, we had developed and tested a novel method of image analysis based on a modified optical flow algorithm.
Data collection involved a digital camera that captured from above body images of an unrestrained rat, while a short-duration noise burst was presented unexpectedly at different intensities. Positive responses of acoustic perturbation of breathing were successfully detected over the chest or abdominal area in all 6 rats studied, and reported here for the first time.
The reflex change was a relatively small sound-induced perturbation in the amplitude of breathing and/or in the inter-breath interval exceeding a statistical threshold of the pre-stimulus levels. Results showed that such acoustic perturbation of breathing could be elicited rather robustly (> 90%) even with very soft sounds (< 30 dB SPL, or Sound Pressure Level).
We concluded that our method of image analysis was powerful enough to detect these subtle changes of breathing pattern in freely moving rats.