Abstract
The definition of critical development periods has been intensively shaped over the last two centuries. On the basis of existing knowledge, it can be summarized that this term refers to different phenomena, depending on the particular subject of research and the focus of each author.
According to the theory of ontogenetic physiologist Jiří Křeček, the critical development periods may take some time, they do not occur for all functions at the same time, and developmental changes may not appear immediately after the intervention. From previous preclinical studies in animals monitoring the effect of psychostimulants on the development of offspring of exposed mothers, it is clear that not only the use of the drug as such, but also the route of administration, the dose and also the timing of application during the various stages of fetal development play an important role.
Methamphetamine (MA) interferes with the maturation of brain structures, which are gradually beginning to develop during the second half of the gestational period until weaning of the rat, which correlates with prenatal development in humans during the second and third trimesters. Statistical studies indicate that 84,3 % of pregnant, drug-dependent women use MA during the first trimester, 56,0 % during the second trimester, and 42,4 % of these women continue to use MA during the third trimester.
The stage at which of the offspring's neurodevelopment, during gestation and/or lactation period, is the most sensitive to MA is still not known. The paper summarizes the current knowledge in the field of neuroontogenesis related to the identification of critical developmental periods for MA effects.