Repeated neonatal needle-prick stimulation increases inflammatory mechanical hypersensitivity in adult rats.

Background And Aims: Newborn infants are vulnerable to procedural stress and pain exposure on the first weeks of life that represents a critical period for the development of nociceptive, sensory, emotional, and social functions. We evaluated the nociceptive behavior of adult male and female rats that were submitted to nociceptive experience in the neonatal period and the maternal behavior in the postnatal period.

Methods: The animals were submitted to repetitive needle pricking from the second to the fifteenth postnatal day (PND 2-15).