Maternal deprivation alters nociceptive response in a gender-dependent manner in rats. Issue 76 (August 2019)

• Record Type: Journal Article
• Authors: Ströher, Roberta; de Oliveira, Carla; Costa Lopes, Bettega; da Silva, Lisiane Santos; Regner, Gabriela Gregory; Richardt Medeiros, Helouise; de Macedo, Isabel Cristina; Caumo, Wolnei; Torres, Iraci L.S.
• Is Part Of: International journal of developmental neuroscience. Issue 76(2019:Aug.)
• Page Start: 25
• Page End: 33
• Publication Date: 2019-08
• Subjects: Analgesia -- Development -- Female -- Male -- Maternal separation -- Rodent; Developmental neurobiology -- Periodicals; Neurology -- Periodicals; Neurologie du développement -- Périodiques; Developmental neurobiology; Periodicals; 612.8
• DOI: 10.1016/j.ijdevneu.2019.05.001
• Languages: English
• ISSNs: 0736-5748

Abstract

Highlights: Maternal deprivation (MD) promoted thermal hyperalgesia at P21. At P42 MD affected the anxiety-like behavior in a gender dependent manner. At P43, MD promoted thermal analgesia in males rats. Abstract: The present study aimed at investigating both the early and long-term effects of maternal deprivation as well as gender on neuromotor reflexes, anxiety behavior and thermal nociceptive responses. A total of 64 Wistar rats pups (32 males, 32 females) were utilized and were deprived of their mother for 3 h/daily, from postnatal day 1 (P1) until P10. Successively, animals were divided into 2 groups: control group (C) - pups no subjected to intervention; and the maternal-deprived group (MD): pups subjected to maternal deprivation. The neuromotor reflexes were evaluated through the righting reflex and negative geotaxis tests; the exploratory behavior by open field test (OFT); the anxiety-like behavior by elevated plus-maze test (EPM); the thermal nociceptive responses byhot plate (HP) and tail-flick (TFL) tests. All the animals subjected to maternal deprivation showed a delayed reflex response at P8 in the negative geotaxis test. In contrast, the OFT at P20 identified an effect of gender on the outer crossings and grooming as well as an interaction between gender and maternal deprivation on latency. Additionally, effect of maternal deprivation in the open and closed arms as well as gender effect in the protected head-dipping (PHD) and non-protected head-dipping (NPHD) were observed at P20 (EPM). In contrast, there were a gender effect on latency and an interaction between gender and maternal deprivation on rearing at P42. Moreover, in nociceptive tests was observed an analgesic effect induced by maternal deprivation; however, in the TFL test, only deprived females showed this effect. Surprisingly, only control animals presented an ontogeny nociceptive effect in the HP testat P21 and P43, which may be related to an increase in the inhibitory nociceptive pathways throughout life. In this way, we suggest maternal deprivation to be able to anticipate the maturation of the inhibitory nociceptive pathway. In conclusion, maternal deprivation induced a delayed reflex response at P8 and altered the anxiety and nociceptive behaviors according to the time after exposure to this stressor, in a gender-specific manner.