Novel insights about the mechanism of visceral hypersensitivity in maternally separated rats.

Visceral hypersensitivity (VHS) is one of the most important characteristics of functional gastrointestinal disorders, including irritable bowel syndrome (IBS). Stress, whether physical or psychological, is known to be a crucial factor for inducing and maintaining visceral sensitivity in humans and rodents, but how stress induces VHS is not fully understood. In a recent study published in Neurogastroenterology and Motility, Wouters et al. demonstrate, for the first time, that maternal separation induces activation of periaqueductal gray (PAG), the hippocampus and the somatosensory cortex concomitantly with increased deactivation of the pre-frontal cortex. The findings provide insight on the role of maternal separation in inducing regional cerebral blood flow changes and cerebral plasticity. These novel insights on the role of central activation in the modulation of stress-induced VHS add to our growing understanding of the mechanisms that underlie VHS and suggest potential new drug development targets in stress-related diseases, including IBS.