Physiological Effects of Acute Neonatal Normobaric Hypoxia in C57BL/6 Mice

Abstract

Perinatal hypoxia (PH) is one of the main factors having adverse influences on the development of the central nervous system. The sequelae of PH and the mechanisms of its development have been studied in animal experiments, mainly in rodents, such that there is still a need to develop more appropriate experimental models. The aim of the present work was to study the effects of single episodes of normobaric hypoxia in the offspring of C57BL/6 mice of both sexes. Mice aged two days were subjected to hypoxia for 2 h using an oxygen content of 8%. Control mice were kept in the same conditions but with a normal oxygen content. Levels of physical and motor development, motor and exploratory activity, and anxiety levels were determined from day 3 to day 31 of life. These studies showed that exposure led to higher levels of mortality in C57BL/6 mice, producing impairments to the establishment of sensorimotor reflexes, changes in behavior in the open field test, and a minor increase in anxiety in the elevated plus maze test. These results lead to the conclusion that models based on single episodes of normobaric hypoxia in mice can be used to study the pathophysiological and neurochemical mechanisms underlying neurological impairments in perinatal hypoxia.