BACKGROUND: Elevated brain levels of kynurenic acid (KYNA), a metabolite in the kynurenine pathway, are associated with cognitive dysfunctions, which are nowadays often considered as fundamental characteristics of several psychopathologies; however, the role of KYNA in mental illnesses, such as schizophrenia, is not fully elucidated. This study aimed to assess KYNA levels in the prefrontal cortex (PFC) of rats prenatally treated with methylazoxymethanol (MAM) acetate, i.e., a well-validated neurodevelopmental animal model of schizophrenia. The effects of an early pharmacological modulation of the endogenous cannabinoid system were also evaluated. METHODS: Pregnant Sprague-Dawley rats were treated with MAM (22 mg/kg, ip) or its vehicle at gestational day 17. Male offspring were treated with the cannabinoid CB1 receptor antagonist/inverse agonist AM251 (0.5 mg/kg/day, ip) or with the typical antipsychotic haloperidol (0.6 mg/kg/day, ip) from postnatal day (PND) 19 to PND39. The locomotor activity and cognitive performance were assessed in the novel object recognition test and the open field test in adulthood. KYNA levels in the PFC of prenatally MAM-treated rats were also assessed. RESULTS: A significant cognitive impairment was observed in prenatally MAM-treated rats (p < 0.01), which was associated with enhanced PFC KYNA levels (p < 0.05). The peripubertal AM251, but not haloperidol, treatment ameliorated the cognitive deficit (p < 0.05), by normalizing the PFC KYNA content in MAM rats. CONCLUSIONS: The present findings suggest that the cognitive deficit observed in MAM rats may be related to enhanced PFC KYNA levels which could be, in turn, mediated by the activation of cannabinoid CB1 receptor. These results further support the modulation of brain KYNA levels as a potential therapeutic strategy to ameliorate the cognitive dysfunctions in schizophrenia.

• Klíčová slova
• AM251, Haloperidol, Kynurenine Pathway, Novel object recognition test, Peripubertal treatment, Schizophrenia,
• MeSH
• antipsychotika farmakologie   MeSH
• haloperidol farmakologie   MeSH
• kognitivní dysfunkce metabolismus   farmakoterapie   MeSH
• krysa rodu Rattus MeSH
• kyselina kynurenová * metabolismus   MeSH
• methylazoxymethanolacetát * analogy a deriváty   MeSH
• modely nemocí na zvířatech MeSH
• piperidiny farmakologie   MeSH
• potkani Sprague-Dawley * MeSH
• prefrontální mozková kůra * metabolismus   účinky léků   MeSH
• pyrazoly farmakologie   MeSH
• receptor kanabinoidní CB1 metabolismus   MeSH
• schizofrenie * metabolismus   farmakoterapie   MeSH
• těhotenství MeSH
• zpožděný efekt prenatální expozice * 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
• Názvy látek
• AM 251 MeSH Prohlížeč
• antipsychotika MeSH
• haloperidol MeSH
• kyselina kynurenová * MeSH
• methylazoxymethanolacetát * MeSH
• piperidiny MeSH
• pyrazoly MeSH
• receptor kanabinoidní CB1 MeSH

AIM: Widely used second-generation antipsychotics are associated with adverse metabolic effects, contributing to increased cardiovascular mortality. To develop strategies to prevent or treat adverse metabolic effects, preclinical models have a clear role in uncovering underlying molecular mechanisms. However, with few exceptions, preclinical studies have been performed in healthy animals, neglecting the contribution of dysmetabolic features inherent to psychotic disorders. METHODS: In this study, methylazoxymethanol acetate (MAM) was prenatally administered to pregnant Sprague-Dawley rats at gestational day 17 to induce a well-validated neurodevelopmental model of schizophrenia mimicking its assumed pathogenesis with persistent phenotype. Against this background, the dysmetabolic effects of acute treatment with olanzapine and haloperidol were examined in female rats. RESULTS: Prenatally MAM-exposed animals exhibited several metabolic features, including lipid disturbances. Half of the MAM rats exposed to olanzapine had pronounced serum lipid profile alteration compared to non-MAM controls, interpreted as a reflection of a delicate MAM-induced metabolic balance disrupted by olanzapine. In accordance with the drugs' clinical metabolic profiles, olanzapine-associated dysmetabolic effects were more pronounced than haloperidol-associated dysmetabolic effects in non-MAM rats and rats exposed to MAM. CONCLUSION: Our results demonstrate metabolic vulnerability in female prenatally MAM-exposed rats, indicating that findings from healthy animals likely provide an underestimated impression of metabolic dysfunction associated with antipsychotics. In the context of metabolic disturbances, neurodevelopmental models possess a relevant background, and the search for adequate animal models should receive more attention within the field of experimental psychopharmacology.

• Klíčová slova
• adipokine, antipsychotic, lipid profile, methylazoxymethanol, schizophrenia,
• MeSH
• antipsychotika * terapeutické užití   MeSH
• haloperidol * toxicita   MeSH
• krysa rodu Rattus MeSH
• lipidy MeSH
• methylazoxymethanolacetát toxicita   analogy a deriváty   MeSH
• modely nemocí na zvířatech MeSH
• olanzapin toxicita   MeSH
• potkani Sprague-Dawley 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
• Názvy látek
• antipsychotika * MeSH
• haloperidol * MeSH
• lipidy MeSH
• methylazoxymethanol MeSH Prohlížeč
• methylazoxymethanolacetát MeSH
• olanzapin MeSH

Adolescent exposure to cannabinoids as a postnatal environmental insult may increase the risk of psychosis in subjects exposed to perinatal insult, as suggested by the two-hit hypothesis of schizophrenia. Here, we hypothesized that peripubertal Δ9-tetrahydrocannabinol (aTHC) may affect the impact of prenatal methylazoxymethanol acetate (MAM) or perinatal THC (pTHC) exposure in adult rats. We found that MAM and pTHC-exposed rats, when compared to the control group (CNT), were characterized by adult phenotype relevant to schizophrenia, including social withdrawal and cognitive impairment, as revealed by social interaction test and novel object recognition test, respectively. At the molecular level, we observed an increase in cannabinoid CB1 receptor (Cnr1) and/or dopamine D2/D3 receptor (Drd2, Drd3) gene expression in the prefrontal cortex of adult MAM or pTHC-exposed rats, which we attributed to changes in DNA methylation at key regulatory gene regions. Interestingly, aTHC treatment significantly impaired social behavior, but not cognitive performance in CNT groups. In pTHC rats, aTHC did not exacerbate the altered phenotype nor dopaminergic signaling, while it reversed cognitive deficit in MAM rats by modulating Drd2 and Drd3 gene expression. In conclusion, our results suggest that the effects of peripubertal THC exposure may depend on individual differences related to dopaminergic neurotransmission.

• Klíčová slova
• dopamine D2/D3 receptors, methylazoxymethanol acetate, psychopathology, Δ9-tetrahydrocannabinol,
• MeSH
• dopamin metabolismus   MeSH
• krysa rodu Rattus MeSH
• lidé MeSH
• modely nemocí na zvířatech MeSH
• prefrontální mozková kůra účinky léků   metabolismus   MeSH
• receptory dopaminu D3 metabolismus   MeSH
• schizofrenie * chemicky indukované   MeSH
• těhotenství MeSH
• tetrahydrokanabinol * toxicita   MeSH
• zpožděný efekt prenatální expozice * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• dopamin MeSH
• receptory dopaminu D3 MeSH
• tetrahydrokanabinol * MeSH