It is known that psychostimulants including methamphetamine (MA) have neurotoxic effect, especially, if they are targeting CNS during its critical periods of development. The present study was aimed on evaluation of cognitive changes following scheduled prenatal MA exposure in combination with long-term exposure in adulthood of male rats. Two periods of gestation were targeted: 1st half - the embryonic day (ED) 1-11 and 2nd half - ED 12-22. Rat mothers received subcutaneously a daily injection of MA (5 mg/kg) or saline (SAL, 1 ml/kg) throughout scheduled periods. Male offspring were tested for cognitive changes in the Morris Water Maze (MWM) in adulthood. Each day of the experiment animals received an injection of MA (1 mg/kg) or SAL (1 ml/kg) during 12 days. Our results demonstrated that in the group of animals exposed to the drug during ED 1-11, neither prenatal MA exposure, nor adult MA treatment changed the performance in the MWM test. Only the velocity was increased in group with long-term MA treatment (SAL/MA and MA/MA). In the group of animals exposed to the drug during ED 12-22, rats exposed to MA prenatally and also in adulthood (MA/MA) swam faster but learned the position of the platform slower in the Place Navigation Test than animals exposed to SAL in adulthood (MA/SAL). In the Probe Test, MA/SAL had decreased velocity and swam shorter distance than MA/MA or SAL/SAL rats suggesting increased floating of these animals. In the Memory Retention Test, SAL/MA rats swam shorter distance than SAL/SAL or MA/MA animals suggesting changes in used strategies in memory recall. As conclusion, our results suggest differences in the effect of combination of prenatal and adult exposure to MA. These effects further depend on the stage of CNS development and schedule of MA exposure affecting intrauterine development in male rats., I. Hrebíčková, M. Malinová-Ševčíková, E. Macúchová, K. Nohejlová, R. Šlamberová., and Obsahuje bibliografii
The observations of Sunda pangolin reproductive parameters in this paper were based on the wild-caught animals and those that had spent time in captive environments, however, when analyzing the results, we did not consider differences in terms of breeding habits between the two. Still, this research has led to an increase in knowledge of the breeding habits of the Sunda pangolin. Our results suggest that there is no breeding season or season of parturition for the Sunda pangolin, which breeds all year round. We estimated the gestation period in this species to be around six months. Sexual maturity occurred at one year old or as early as six-seven months
old in some individuals, and requires further investigation. Each Sunda pangolin in this study gave birth to one offspring at a time. The sex ratio at birth was 0.875:1 (♀:♂) (n = 15); and the weaning age was estimated at four months with a weight of 1.19 ± 0.50 kg (n = 3), which concurs with recent research. Findings in this study will contribute to future analyses of population dynamics, species conservation, and both in situ and ex situ management of the Sunda pangolin. Despite this contribution, further studies are needed on the reproductive parameters of Sunda pangolin.