The present study examined the hypothesis that the extension of noxious effect of methamphetamine (MA) on maternal behavior and postnatal development on the pups may differ in dependence with time of application. Female rats were injected with MA (5 mg/kg) or saline during first (embryonic day (ED) 1-11) or second (ED 12-22) half of gestation. Our results demonstrated that MA exposure on ED 12-22 led to decreased birth weight and weight gained during lactation period relative to rats treated on ED 1-11. Both sexes treated prenatally with MA on ED 1-11 opened eyes earlier compared to animals treated on ED 12-22. As a matter of sensorimotor development application of MA on ED 1-11 impaired the righting reflex, while MA exposure on ED 12-22 impaired the performance of beam balance test in male rats. There were no differences in maternal behavior. Therefore, it seems that MA exposure in the first half of the gestation impaired the early sensorimotor development that is under control of the brain stem, while the MA exposure in the second half of gestation affected the beam balance performance that is dependent on the function of the cerebellum., M. Malinová-Ševčíková, I. Hrebíčková, E. Macúchová, E. Nová, M. Pometlová, R. Šlamberová., and Obsahuje bibliografii
Psychostimulants, including methamphetamine (MA), haveneurotoxic effect,
especially, if they are targeting CNS during its critical periods of development. The present study was aimed to examine cognitive changes after prenatal and neonatal MAtreatment in combination with chronic MA
exposure in adulthoodof male rats. Eight groups of male rats were tested in adulthood:males whose mothers were exposed to MA (5 mg/kg) or saline(SA, 1 ml/kg) during the first half of gestation period (GD 1-11),the second half of gestation period (GD 12-22) and neonatalperiod (PD 1-11). In addition, we compared indirect neonatalapplication via the breast milk
with the group of rat pups that received MA or SA directly by injection
(PD 1-11). Males weretested in adulthood for cognitive changes in the
Morris WaterMaze (MWM). MWM experiment lasted for 12 days: Learning(Day 1-6), Probe test (Day 8) and Retrieval Memory test
(Day 12). Each day of the MWM animals were injected with MA(1 mg/kg)
or SA (1 ml/kg). Prenatal MA exposure did not inducechanges in learning abilities of male rats, but neonatal exposureto MA leads to an increase search errorsand latencies to find thehidden platform. Prenatal and also
neonatal MA exposureimpaired cognitive ability to remember the position of the platform in Retrieval Memory test in adulthood. Animals exposed to the
prenatal treatment within the second half of gestation(ED 12-22) swam longer, slower and spent more time to find the hidden platform in Retrieval Memory test than animals exposedthroughout other periods. The present
study demonstrated thatstage of development is crucial for determination
the cognitivedeficits induced by prenatal or neonatal MA exposure.
Methamphetamine (MA) is an addictive psychostimulant with significant potential for abuse. Previous rat studies have demonstrated that MA use during pregnancy impairs maternal behavior and induced delayed development of affected pups. The
offspring of drug-addictive mothers were often neglected and exposed to neonatal stressors. The present study therefore examines the effect of perinatal stressors combined with exposure to prenatal MA on the development of pups and maternal behavior. Dams were divided into three groups according to drug treatment during pregnancy: controls (C); saline (SA, s.c., 1 ml/kg); MA (s.c., 5 mg/ml/kg). Litters were divided into four groups according to postnatal stressors: controls (N); maternal separation (S); maternal cold-water stress (W); maternal separation plus cold-water stress (SW). The pup-retrieval test showed differences among postnatally stressed mothers and non-stressed controls. The righting reflex on
a surface revealed delayed development of pups prenatally exposed to MA/SA and postnatal stress. Negative geotaxis and Rotarod results confirmed that the MA group was the most affected. Overall, our data suggests that a combination of perinatal stress and prenatal MA can have a detrimental effect on maternal behavior as well as on the sensorimotor development of pups. However, MA exposure during pregnancy seems to be the decisive factor for impairment.
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 aim of the present study was to compare effect of three low doses of morphine (MOR) and delta9-tetrahydrocannabinol (THC) on social behavior tested in Social interaction test (SIT). 45 min prior to testing adult male rats received one of the drugs or solvents: MOR (1; 2.5; 5 mg/kg); saline as a solvent for MOR; THC (0.5; 1; 2 mg/kg); ethanol as a solvent for THC. Occurrence and time spent in specific patterns of social interactions (SI) and non-social activities (locomotion and rearing) was video-recorded
for 5 min and then analyzed. MOR in doses of 1 and 2.5 mg/kg
displayed decreased SI in total. Detailed analysis of specific patterns of SI revealed decrease in mutual sniffing and allo-grooming after all doses of MOR. The highest dose (5 mg/kg) of MOR decreased following and increased genital investigation. Rearing activity was increased by lower doses of MOR (1 and 2.5 mg/kg). THC, in each of the tested doses, did not induce any specific changes when compared to matching control group (ethanol). However, an additional statistical analysis showed differences between all THC groups and their
ethanol control group when compared to saline controls. There was lower SI in total, lower mutual sniffing and allo-grooming, but higher rearing in THC and ethanol groups than in saline control group. Thus, changes seen in THC and ethanol groups are seemed to be attributed mainly to the effect of the ethanol. Based on the present results we can assume that opioids affect SI more than cannabinoid.