The present study aimed to examine a weakly electric fish Gnathonemus petersii (G. petersii) as a candidate model organism of glutamatergic theory of schizophrenia. The idea of G. petersii elevating the modeling of schizophrenia symptoms is based on the fish's electrolocation and electrocommunication abilities. Fish were exposed to the NMDA antagonist ketamine in two distinct series differing in the dose of ketamine. The main finding revealed ketamine-induced disruption of the relationship between electric signaling and behavior indicating impairment of fish navigation. Moreover, lower doses of ketamine significantly increased locomotion and erratic movement and higher doses of ketamine reduced the number of electric organ discharges indicating successful induction of positive schizophrenia-like symptoms and disruption of fish navigation. Additionally, a low dose of haloperidol was used to test the normalization of the positive symptoms to suggest a predictive validity of the model. However, although successfully induced, positive symptoms were not normalized using the low dose of haloperidol; hence, more doses of the typical antipsychotic haloperidol and probably also of a representative of atypical antipsychotic drugs need to be examined to confirm the predictive validity of the model.
Schizophrenia is severe neuropsychiatric disease, which is commonly accompanied not only by positive or negative symptoms, but also by cognitive impairment. To study neuronal mechanisms underlying cognitive distortions and mechanisms underlying schizophrenia, animal pharmacological models of cognitive symptoms are commonly used. Between various cognitive impairments in schizophrenia patients, disturbed time perception has often been reported. Here, we examined temporal and spatial cognition in a modified Carousel maze task in the animal model of schizophrenia induced by non-competitive NMDA-receptor antagonists MK-801. Male Long-Evans rats (n = 18) first learned to avoid the aversive sector on a rotating arena in both dark and light intervals. We verified that during dark, rats used temporal cues, while during light they relied predominantly on spatial cues. We demonstrated that the timing strategy depends on the stable rotation speed of the arena and on the repositioning clues such as aversive stimuli. During testing (both in light and dark intervals), half of the rats received MK-801 and the control half received saline solution. We observed dose-dependent disruptions of both temporal and spatial cognition. Namely, both doses of MK-801 (0.1 and 0.12 mg/kg) significantly impaired timing strategy in the dark and increased locomotor activity. MK-801 dose 0.1 mg/kg, but not 0.12, also impaired spatial avoidance strategy in light. We found that the timing strategy is more sensitive to NMDA antagonist MK-801 than the spatial strategy. To conclude, a modified version of the Carousel maze is a useful and sensitive tool for detecting timing impairments in the MK-801 induced rodent model of schizophrenia.
- MeSH
- antagonisté excitačních aminokyselin aplikace a dávkování farmakologie MeSH
- bludiště - učení účinky léků MeSH
- chování zvířat účinky léků MeSH
- dizocilpinmaleát aplikace a dávkování farmakologie MeSH
- kognitivní dysfunkce chemicky indukované patofyziologie MeSH
- krysa rodu rattus MeSH
- modely nemocí na zvířatech MeSH
- potkani Long-Evans MeSH
- schizofrenie chemicky indukované MeSH
- učení vyhýbat se účinky léků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Antipsychotics are used in the treatment of schizophrenia and other psychiatric disorders. Generally, they are divided into typical and atypical ones, according to the fact that atypical antipsychotics induce fewer side effects and are more effective in terms of social and cognitive improvements. Their pharmacological effects are mediated via broad range of receptors that consequently influence different cellular signalling pathways. Antipsychotics produce undesirable side effects that range from relatively minor to life threatening. In vitro and in vivo studies have pointed to neurotoxic effect exerted by some antipsychotics and have shown that apoptosis might play role in some side effects induced by antipsychotics, including tardive dyskinesia, weight gain, agranulocytosis, osteoporosis, myocarditis, etc. Although cumulative data have suggested safety of atypical antipsychotics use during pregnancy, some of them have been shown to induce apoptotic neurodegenerative and structural changes in fetal brains with long-lasting impact on cognitive impairment of offspring. Typical antipsychotics seem to be more cytotoxic than atypical ones. Recently, epidemiological studies have shown lower incidence of cancer in schizophrenic patients that suggest the ability of antipsychotics to suppress risk of cancer development. Some antipsychotics have been reported to inhibit cancer cell proliferation and induce their apoptosis. Therefore, antipsychotics apoptotic effect may be used as a tool in the treatment of some types of cancer, especially in combinatorial therapies. In this mini-review, we focused on pro- and antiapoptotic or 'Dr. Jekyll and Mr. Hyde' effects of antipsychotics, which can be involved in their side effects, as well as their promising therapeutic indications.
- MeSH
- antipsychotika * škodlivé účinky MeSH
- apoptóza MeSH
- lidé MeSH
- schizofrenie * chemicky indukované farmakoterapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
In agreement with the neurodevelopmental hypothesis of schizophrenia, prenatal exposure of Sprague-Dawley rats to the antimitotic agent methylazoxymethanol acetate (MAM) at gestational day 17 produces long-lasting behavioral alterations such as social withdrawal and cognitive impairment in adulthood, mimicking a schizophrenia-like phenotype. These abnormalities were preceded at neonatal age both by the delayed appearance of neonatal reflexes, an index of impaired brain maturation, and by higher 2-arachidonoylglycerol (2-AG) brain levels. Schizophrenia-like deficits were reversed by early treatment [from postnatal day (PND) 2 to PND 8] with the CB1 antagonist/inverse agonist AM251 (0.5 mg/kg/day). By contrast, early CB1 blockade affected the behavioral performance of control rats which was paralleled by enhanced 2-AG content in the prefrontal cortex (PFC). These results suggest that prenatal MAM insult leads to premorbid anomalies at neonatal age via altered tone of the endocannabinoid system, which may be considered as an early marker preceding the development of schizophrenia-like alterations in adulthood.
- MeSH
- krysa rodu rattus MeSH
- methylazoxymethanolacetát * MeSH
- modely nemocí na zvířatech MeSH
- potkani Sprague-Dawley MeSH
- receptor kanabinoidní CB1 MeSH
- schizofrenie * chemicky indukované farmakoterapie genetika MeSH
- těhotenství MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The recent shift in socio-political debates and growing liberalization of Cannabis use across the globe has raised concern regarding its impact on vulnerable populations such as adolescents. Concurrent with declining perception of Cannabis harms, more adolescents are using it daily in several countries and consuming marijuana strains with high content of psychotropic delta (9)-tetrahydrocannabinol (THC). These dual, related trends seem to facilitate the development of compromised social and cognitive performance at adulthood, which are described in preclinical and human studies. Cannabis exerts its effects via altering signalling within the endocannabinoid system (ECS), which modulates the stress circuitry during the neurodevelopment. In this context early interventions appear to circumvent the emergence of adult neurodevelopmental deficits. Accordingly, Cannabis sativa second-most abundant compound, cannabidiol (CBD), emerges as a potential therapeutic agent to treat neuropsychiatric disorders. We first focus on human and preclinical studies on the long-term effects induced by adolescent THC exposure as a "critical window" of enhanced neurophysiological vulnerability, which could be involved in the pathophysiology of schizophrenia and related primary psychotic disorders. Then, we focus on adolescence as a "window of opportunity" for early pharmacological treatment, as novel risk reduction strategy for neurodevelopmental disorders. Thus, we review current preclinical and clinical evidence regarding the efficacy of CBD in terms of positive, negative and cognitive symptoms treatment, safety profile, and molecular targets.
- MeSH
- fytonutrienty * škodlivé účinky farmakologie terapeutické užití MeSH
- kanabinoidy * škodlivé účinky farmakologie terapeutické užití MeSH
- lidé MeSH
- mladiství MeSH
- schizofrenie * chemicky indukované farmakoterapie metabolismus prevence a kontrola MeSH
- toxické psychózy * farmakoterapie metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mladiství MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Mortality in psychiatric patients with severe mental illnesses reaches a 2-3 times higher mortality rate compared to the general population, primarily due to somatic comorbidities. A high prevalence of cardiovascular morbidity can be attributed to the adverse metabolic effects of atypical antipsychotics (atypical APs), but also to metabolic dysregulation present in drug-naïve patients. The metabolic aspects of neurodevelopmental schizophrenia-like models are understudied. This study evaluated the metabolic phenotype of a methylazoxymethanol (MAM) schizophrenia-like model together with the metabolic effects of three APs [olanzapine (OLA), risperidone (RIS) and haloperidol (HAL)] administered via long-acting formulations for 8 weeks in female rats. Body weight, feed efficiency, serum lipid profile, gastrointestinal and adipose tissue-derived hormones (leptin, ghrelin, glucagon and glucagon-like peptide 1) were determined. The lipid profile was assessed in APs-naïve MAM and control cohorts of both sexes. Body weight was not altered by the MAM model, though cumulative food intake and feed efficiency was lowered in the MAM compared to CTR animals. The effect of the APs was also present; body weight gain was increased by OLA and RIS, while OLA induced lower weight gain in the MAM rats. Further, the MAM model showed lower abdominal adiposity, while OLA increased it. Serum lipid profile revealed MAM model-induced alterations in both sexes; total, HDL and LDL cholesterol levels were increased. The MAM model did not exert significant alterations in hormonal parameters except for elevation in leptin level. The results support intrinsic metabolic dysregulation in the MAM model in both sexes, but the MAM model did not manifest higher sensitivity to metabolic effects induced by antipsychotic treatment.
- MeSH
- antipsychotika farmakologie terapeutické užití MeSH
- haloperidol farmakologie terapeutické užití MeSH
- metabolismus lipidů účinky léků MeSH
- metabolom účinky léků MeSH
- methylazoxymethanolacetát analogy a deriváty MeSH
- modely nemocí na zvířatech * MeSH
- olanzapin farmakologie terapeutické užití MeSH
- potkani Sprague-Dawley MeSH
- risperidon farmakologie terapeutické užití MeSH
- schizofrenie chemicky indukované farmakoterapie metabolismus MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Gestational methylazoxymethanol acetate (MAM) treatment produces offspring with adult phenotype relevant to schizophrenia, including positive- and negative-like symptoms, cognitive deficits, dopaminergic dysfunction, structural and functional abnormalities. Here we show that adult rats prenatally treated with MAM at gestational day 17 display significant increase in dopamine D3 receptor (D3) mRNA expression in prefrontal cortex (PFC), hippocampus and nucleus accumbens, accompanied by increased expression of dopamine D2 receptor (D2) mRNA exclusively in the PFC. Furthermore, a significant change in the blood perfusion at the level of the circle of Willis and hippocampus, paralleled by the enlargement of lateral ventricles, was also detected by magnetic resonance imaging (MRI) techniques. Peripubertal treatment with the non-euphoric phytocannabinoid cannabidiol (30 mg/kg) from postnatal day (PND) 19 to PND 39 was able to reverse in MAM exposed rats: i) the up-regulation of the dopamine D3 receptor mRNA (only partially prevented by haloperidol 0.6 mg/kg/day); and ii) the regional blood flow changes in MAM exposed rats. Molecular modelling predicted that cannabidiol could bind preferentially to dopamine D3 receptor, where it may act as a partial agonist according to conformation of ionic-lock, which is highly conserved in GPCRs. In summary, our results demonstrate that the mRNA expression of both dopamine D2 and D3 receptors is altered in the MAM model; however only the transcript levels of D3 are affected by cannabidiol treatment, likely suggesting that this gene might not only contribute to the schizophrenia symptoms but also represent an unexplored target for the antipsychotic activity of cannabidiol.
- MeSH
- antipsychotika farmakologie MeSH
- haloperidol chemie farmakologie MeSH
- kanabidiol chemie farmakologie MeSH
- magnetická rezonanční tomografie MeSH
- methylazoxymethanolacetát toxicita MeSH
- modely nemocí na zvířatech MeSH
- molekulární modely MeSH
- mozek diagnostické zobrazování účinky léků MeSH
- mozkový krevní oběh MeSH
- potkani Sprague-Dawley MeSH
- puberta MeSH
- receptory dopaminu D2 chemie genetika metabolismus MeSH
- receptory dopaminu D3 chemie genetika metabolismus MeSH
- regulace genové exprese MeSH
- schizofrenie chemicky indukované diagnostické zobrazování farmakoterapie genetika MeSH
- simulace molekulární dynamiky MeSH
- těhotenství MeSH
- zpožděný efekt prenatální expozice MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
In agreement with the neurodevelopmental hypothesis of schizophrenia, prenatal exposure of rats to the antimitotic agent methylazoxymethanol acetate (MAM) at gestational day 17 produced long-lasting behavioral alterations such as social withdrawal and cognitive impairment in the social interaction test and in the novel object recognition test, respectively. At the molecular level, an increased cannabinoid receptor type-1 (CB1) mRNA and protein expression, which might be due to reduction in DNA methylation at the gene promoter in the prefrontal cortex (PFC), coincided with deficits in the social interaction test and in the novel object recognition test in MAM rats. Both the schizophrenia-like phenotype and altered transcriptional regulation of CB1 receptors were reversed by peripubertal treatment (from PND 19 to PND 39) with the non-psychotropic phytocannabinoid cannabidiol (30 mg/kg/day), or, in part, by treatment with the cannabinoid CB1 receptor antagonist/inverse agonist AM251 (0.5 mg/kg/day), but not with haloperidol (0.6 mg/kg/day). These results suggest that early treatment with cannabidiol may prevent both the appearance of schizophrenia-like deficits as well as CB1 alterations in the PFC at adulthood, supporting that peripubertal cannabidiol treatment might be protective against MAM insult.
- MeSH
- endokanabinoidy metabolismus MeSH
- ethanolaminy metabolismus MeSH
- glyceridy metabolismus MeSH
- hipokampus metabolismus MeSH
- interpersonální vztahy MeSH
- kanabidiol farmakologie MeSH
- krysa rodu rattus MeSH
- kyseliny arachidonové metabolismus MeSH
- kyseliny olejové metabolismus MeSH
- kyseliny palmitové metabolismus MeSH
- messenger RNA metabolismus MeSH
- methylazoxymethanolacetát farmakologie MeSH
- modely nemocí na zvířatech MeSH
- piperidiny farmakologie MeSH
- pohybová aktivita účinky léků MeSH
- polynenasycené alkamidy metabolismus MeSH
- prefrontální mozková kůra metabolismus MeSH
- puberta MeSH
- pyrazoly farmakologie MeSH
- receptor kanabinoidní CB1 metabolismus MeSH
- rozpoznávání (psychologie) účinky léků MeSH
- schizofrenie chemicky indukované farmakoterapie metabolismus MeSH
- těhotenství MeSH
- zpožděný efekt prenatální expozice farmakoterapie metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Clinical studies consistently report structural impairments (i.e.: ventricular enlargement, decreased volume of anterior cingulate cortex or hippocampus) and functional abnormalities including changes in regional cerebral blood flow in individuals suffering from schizophrenia, which can be evaluated by magnetic resonance imaging (MRI) techniques. The aim of this study was to assess cerebral blood perfusion in several schizophrenia-related brain regions using Arterial Spin Labelling MRI (ASL MRI, 9.4 T Bruker BioSpec 94/30USR scanner) in rats. In this study, prenatal exposure to methylazoxymethanol acetate (MAM, 22 mg/kg) at gestational day (GD) 17 and the perinatal treatment with Δ-9-tetrahydrocannabinol (THC, 5 mg/kg) from GD15 to postnatal day 9 elicited behavioral deficits consistent with schizophrenia-like phenotype, which is in agreement with the neurodevelopmental hypothesis of schizophrenia. In MAM exposed rats a significant enlargement of lateral ventricles and perfusion changes (i.e.: increased blood perfusion in the circle of Willis and sensorimotor cortex and decreased perfusion in hippocampus) were detected. On the other hand, the THC perinatally exposed rats did not show differences in the cerebral blood perfusion in any region of interest. These results suggest that although both pre/perinatal insults showed some of the schizophrenia-like deficits, these are not strictly related to distinct hemodynamic features.
- MeSH
- circulus arteriosus Willisi diagnostické zobrazování účinky léků embryologie MeSH
- hipokampus krevní zásobení diagnostické zobrazování účinky léků embryologie MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- magnetická rezonanční angiografie metody MeSH
- methylazoxymethanolacetát toxicita MeSH
- modely nemocí na zvířatech MeSH
- mozkový krevní oběh účinky léků MeSH
- neurogeneze účinky léků MeSH
- schizofrenie chemicky indukované diagnóza MeSH
- senzorimotorický kortex krevní zásobení diagnostické zobrazování účinky léků embryologie MeSH
- techniky pozorování chování MeSH
- těhotenství MeSH
- tetrahydrokanabinol toxicita MeSH
- zpožděný efekt prenatální expozice chemicky indukované diagnostické zobrazování MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- mužské pohlaví MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
