Prenatal exposure to methamphetamine (METH) increases nociceptive sensitivity in adult rats. As the strong analgesics have high abuse potential and drugs of abuse are known to have analgesic properties, the aim was to study analgesic effect of different psychostimulants in control and prenatally METHexposed rats. Latencies of withdrawal reflexes of hind limbs and the tail on thermal nociceptive stimuli were repeatedly measured in 15-min intervals after the application of 5 mg/kg s.c. of amphetamine (AMPH), methamphetamine (METH), cocaine (COC), 3,4-methylenedioxymethamphetamine (MDMA) or morphine (MOR). In all groups, AMPH induced on hind limbs stronger analgesia than METH and MDMA whereas COC and MOR were practically without any effect. On the tail, effect of AMPH did not differ from that of MOR. All psychostimulants increased defecation in comparison with MOR and in all groups the number of defecation boluses positively correlated with analgesia of the hind limbs. We did not confirm that prenatal exposure to METH makes adult rats more sensitive either to same drug or to other psychostimulants. The different analgesic potencies of psychostimulants and MOR at different body sites indicate the possible existence of a somatotopic organization of pain inhibition, which is controlled by different mechanisms., A. Yamamotová, R. Šlamberová., and Obsahuje seznam literatury
Animal models are important for the investigation of mechanisms and therapeutic approaches in various human diseases, including schizophrenia. Recently, two neurodevelopmental rat models of this psychosis were developed based upon the use of subunit selective N-methyl-D-aspartate receptor agonists - quinolinic acid (QUIN) and N-acetyl-aspartyl-glutamate (NAAG). The aim of this study was to evaluate pain perception in these models. QUIN or NAAG was infused into lateral cerebral ventricles neonatally. In the adulthood, the pain perception was examined. The rats with neonatal brain lesions did not show any significant differences in acute mechanical nociception and in formalin test compared to controls. However, the neonatally lesioned rats exhibited significantly higher pain thresholds in thermal nociception. Increased levels of mechanical hyperalgesia, accompanying the sciatic nerve constriction (neuropathic pain), were also observed in lesioned rats. Although hyperalgesia was more pronounced in QUIN-treated animals, the number of c-Fos-immunoreactive neurons of the lumbar spinal cord was similar in experimental and control rats. We conclude that neonatal brain lesions attenuated the thermal perception in both nociceptive and neuropathic pain whereas mechanical pain was increased in the model of neuropathic pain only. Thus, nociceptive and neuropathic pain belongs - in addition to behavioral changes - among the parameters which are affected in described animal models of schizophrenia., M. Franěk ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
This review, which summarizes our findings concerning the long-term effects of pre-, peri- and postnatal factors affecting development, nociception and sensorimotor functions, focuses on three areas: 1) perinatal factors influencing nociception in adult rats were examined in rats with hippocampal lesions, after the administration of stress influencing and psychostimulant drugs (dexamethasone, indomethacine and methamphetamine); 2) the effect of pre- and early postnatal methamphetamine administration was shown to impair the development of sensorimotor functions tested in rat pups throughout the preweaning period; 3) the effect of extensive dorsal rhizotomy of the brachial plexus during the early postnatal period was studied with respect to neuropathic pain development and sensorimotor functions. The present study indicates that prenatal or neonatal stress, as well as various drugs, may disturb the development of the nociceptive system and cause long-term behavioral changes persisting to adulthood and that some types of neuropathic pain cannot be induced during the first two postnatal weeks at all. A mature nervous system is required for the development of the described pathological behaviors., R. Rokyta, A. Yamamotová, R. Šlamberová, M. Franěk, Š. Vaculín, L. Hrubá, B. Schutová, M. Pometlová., and Obsahuje bibliografii a bibliografické odkazy
Since close relationship was shown between drug addiction and memory formation, the aim of the present study was to investigate the effects of interaction between prenatal methamphetamine (MA) exposure and MA treatment in adulthood on spatial and non-spatial memory and on the structure of the N-methyl-D-aspartate (NMDA) receptors in the hippocampus. Adult male rats prenatally exposed to MA (5 mg/kg) or saline were tested in adulthood. Non-spatial memory was examined in the Object Recognition Test (ORT) and spatial memory in the Object Location Test (OLT) and in the Memory Retention Test (MRT) conducted in the Morris Water Maze (MWM), respectively. Based on the type of the memory test animals were injected either acutely (ORT, OLT) or long-term (MWM) with MA (1 mg/kg). After each testing, animals were sacrificed and brains were removed. The hippocampus was then examined in Western Blot analysis for occurrence of different NMDA receptors’ subtypes. Our results demonstrated that prenatal MA exposure affects the development of the NMDA receptors in the hippocampus that might correspond with improvement of spatial memory tested in adulthood in the MWM. On the other hand, the effect of prenatal MA exposure on nonspatial memory examined in the ORT was the opposite. In addition, we showed that the effect of MA administration in adulthood on NMDA receptors is influenced by prenatal MA exposure, which seems to correlate with the spatial memory examined in the OLT., R. Šlamberová, M. Vrajová, B. Schutová, M. Mertlová, E. Macúchová, K. Nohejlová, L. Hrubá, J. Puskarčíková, V. bubeníková-Valešová, A. Yamamotová., and Obsahuje bibliografii