The study is a pre-clinical study in animals that investigated visceral pain changes before and after PENFS in an animal model of irritable bowel syndrome. The animals received daily PENFS therapy for 4hrs per day, for a total of 5 days compared to a sham (inactive) device.

Baseline findings

1. After colonic inflammation, animals developed a visceral hypersensitivity to mechanical distension.
2. After colonic inflammation, there was also an increase in somatic sensitivity (compression of the hind paw).
3. Electrophysiology recordings from single neurons of the spinal cord and central nucleus of the amygdala showed normal baseline activity and increase to mild compression of the paw.

Post-PENFS treatment

1. PENFS prevented the development of visceral hyperalgesia if applied at the same time the colon was inflamed.
2. PENFS decreased post-inflammatory visceral and somatic hyperalgesia compared to sham.
3. A significant decrease in baseline activity of spinal (47%) and amygdala (57%) neurons was observed 15 minutes after PENFS device was applied.

Significance

1. This is the first report demonstrating that the development of post-inflammatory visceral and somatic hyperalgesia can be altered by PENFS.
2. The results also show that the response characteristics of amygdala and lumbar spinal neurons can be modulated by the PENFS.