ИЗУЧЕНИЕ ВЛИЯНИЯ НЕОНАТАЛЬНОЙ ВОСПАЛИТЕЛЬНОЙ БОЛИ НА КОГНИТИВНЫЕ ПРОЦЕССЫ И РЕАКТИВНОСТЬ ГИПОТАЛАМО-ГИПОФИЗАРНО-АДРЕНОКОРТИКАЛЬНОЙ СИСТЕМЫ У КРЫС ПРЕПУБЕРТАТНОГО ВОЗРАСТА

Abstract

We investigated the effect of neonatal inflammatory pain on the plasma corticosterone level dynamics in newborn rat pups, as well as on the processes of spatial learning, short- and long-term memory, and the hypothalamic−pituitary−adrenal (HPA) axis reactivity to forced swim stress in prepubertal (45−53 days) rats of both sexes. We found a prolonged increase in the HPA axis reactivity in response to peripheral inflammatory pain induced by formalin injection to newborn rat pups, suggesting the developmental modification of the HPA axis and its possible involvement in the regulation of cognitive abilities. Neonatal pain caused deficits in spatial learning and memory, disclosing a sexual dimorphism in the implementation of spatial learning and memory. After long-term memory recording in 53-day-old rats in the forced swim test, the plasma corticosterone level was found to be increased compared to the basal level, but no differences in the hormone level between rats with neonatal pain and control animals, as well as no sex-related differences, were revealed. Thus, in the late prepubertal period, rats showed no straightforward relationship between neonatal pain-induced activation of the HPA axis and the indicators of spatial learning and memory, which may indicate the involvement of other neurobiological systems in the effect of neonatal pain on cognitive abilities.