Scientists from St. Petersburg found that fetal hypoxia in combination with maternal stress can cause the fruit of nicotine addiction in adulthood, TASS reported, referring to the press service of St. Petersburg State University.
Scientists conducted experiments on rats and were the first in the world to find out how lack of oxygen and maternal stress during pregnancy affect fetal brain development. The study showed that fetal hypoxia combined with the stress it causes in the mother can lead to nicotine addiction in the child in adulthood.
Fetal hypoxia is a condition in which the embryo lacks oxygen, which negatively affects its development. As a rule, this condition is accompanied by a stress reaction of the mother's body. The consequences of hypoxia manifest themselves in early childhood as a violation of the child's physical, emotional and mental development, and also continue and can worsen with age.
The brains of rodents and humans are similar, so the subjects of the study were female rats and their offspring. Scientists created fetal hypoxia in two ways: surgically and naturally. To create systemic maternal and fetal hypoxia during pregnancy, rats were periodically placed in a barochamber with oxygen deficiency.
After two weeks of nicotine consumption, rats that were exposed to prenatal hypoxia in combination with maternal stress, unlike control rats, developed a withdrawal or abstinence syndrome. Thus, the rats experienced stress associated with the cessation of nicotine use. As part of the study, the scientists also tested the rats' response speed to the acoustic startle reflex. Rats exposed to hypoxia before birth responded more slowly to a sharp sound than control animals. At the same time, under the influence of nicotine, the reaction speed of the studied rats normalized, becoming comparable to the control group. Furthermore, the scientists note that fetal hypoxia without a maternal hormonal stress response causes neither impairments in reaction speed nor propensity for nicotine addiction in adulthood.