Gender specific effects of neonatal limited nesting on viscerosomatic sensitivity and anxiety-like behavior in adult rats.
BACKGROUND
Evidence exists to suggest that early life stress (ELS), such as neglect or abuse has profound effects on the developing brain. The current study tests the hypothesis that ELS in the form of neonatal limited nesting (LN) may serve as a predisposing factor for the development of altered nociceptive processing and comorbid increases in anxiety-like behavior in adulthood.


METHODS
Both male and female neonatal Sprague-Dawley rats were subjected to LN from postnatal day (PND) 2-9, while a control group was exposed to standard cage bedding. In adulthood, visceral sensitivity was assessed by quantifying a visceromotor behavioral response to graded isobaric pressures of colorectal distension. Hindpaw withdrawal thresholds in response to von Frey filaments were used to measure somatic sensitivity. Anxiety-like behavior was assessed in adult life using both the elevated plus maze and open field assay.


RESULTS
Early life stress in the form of neonatal LN induced visceral and somatic hypersensitivity in adult male rats and augmented anxiety-like behavior. However, in adult cycling females, neonatal LN did not alter nociceptive processing or lead to changes in the levels of anxiety-like behavior.


CONCLUSIONS
Our findings suggest that in male rats the LN model is a novel tool to investigate the long-term consequences of adverse early life experience on adult health.
Oklahoma Center for Neuroscience, University of Oklahoma Health Science Center, Oklahoma City, OK, USA.
D K
DK
Prusator
B
B
Greenwood-Van Meerveld
D000818:Animals; D000831:Animals, Newborn; D001007:Anxiety / Q000209:etiology*; D003106:Colon / Q000473:pathology; D004108:Dilatation, Pathologic; D005260:Female; D008297:Male; D009425:Nesting Behavior; D059225:Nociception; D010147:Pain Measurement; D051381:Rats; D017207:Rats, Sprague-Dawley; D012007:Rectum / Q000473:pathology; D012737:Sex Factors; D013315:Stress, Psychological / Q000150:complications*
early life stress; pain; rat