Short- and long-term influences of hypoxia during early postnatal period of development on behavioral and hormonal responses in rats.

Hypoxia is a common neonatal stress that leads to essential long-lasting complications in the brain development. The aim of this study was to determine short- and long-term effects of early postnatal hypoxia (on day 7) on depression- and pain-related behaviors and the plasma corticosterone levels. The plasma corticosterone levels increased after 3-h severe hypoxia in 7-day-old rat pups (hypoxic rats) as compared to basal corticosterone in naïve pups and corticosterone levels in pups removed from the experimental chamber without hypoxia (normoxic rats).

Heterogeneity of the infant stage of rat development: inflammatory pain response, depression-related behavior, and effects of prenatal stress.

The infant stage of rat development is a very important period for potential correction of adverse consequences produced by negative prenatal events. However the age limit for this correction needs to be investigated. The last prenatal and first two weeks after birth are "critical" for maturation of the nociceptive and emotional systems.

Increased formalin-induced pain and expression of fos neurons in the lumbar spinal cord of prenatally stressed infant rats.

When pregnant dams are stressed, there is a resultant alteration in brain development and behavior in their offspring. Prior work has shown increased nociceptive responses in adolescent or adult rats born of stressed dams. However, the age at which those changes first occur is not known.

Reduced serotonin synthesis during early embryogeny changes effect of subsequent prenatal stress on persistent pain in the formalin test in adult male and female rats.

The considerable evidence supporting a role for serotonin (5-HT) in the embryonic formation of CNS, mediation of prenatal stress, and pain processing is reviewed. Long-term influences of prenatal 5-HT depletion as well as its combination with prenatal stress effects on tonic nociceptive system in 90-day-old Wistar rats were studied in the formalin test. Pregnant dams were injected with para-chlorophenylalanine (pCPA, 400 mg/kg/2 ml, ip), producing 5-HT depletion during the early period of fetal serotonergic system development.

Decreased serotonin level during pregnancy alters morphological and functional characteristics of tonic nociceptive system in juvenile offspring of the rat.

Serotonin (5-HT) contributes to the prenatal development of the central nervous system, acting as a morphogen in the young embryo and later as a neurotransmitter. This biologically active agent influences both morphological and biochemical differentiation of raphe neurons, which give rise to the descending serotonergic paths that regulate the processing of acutely evoked nociceptive inputs. The involvement of 5-HT in the prenatal development of tonic nociceptive system has not been studied.