Autism spectrum disorder (ASD) is a neurodevelopmental condition causing a range of social and communication impairments. Although the role of multiple genes and environmental factors has been reported, the effects of the interplay between genes and environment on the onset and progression of the disease remains elusive. We housed wild-type (Tsc2+/+) and tuberous sclerosis 2 deficient (Tsc2+/-) Eker rats (ASD model) in individually ventilated cages or enriched conditions and conducted a series of behavioural tests followed by the histochemical analysis of dendritic spines and plasticity in three age groups (days 45, 90 and 365). The elevated plus-maze test revealed a reduction of anxiety by enrichment, whereas the mobility of young and adult Eker rats in the open field was lower compared to the wild type. In the social interaction test, an enriched environment reduced social contact in the youngest group and increased anogenital exploration in 90- and 365-day-old rats. Self-grooming was increased by environmental enrichment in young and adult rats and decreased in aged Eker rats. Dendritic spine counts revealed an increased spine density in the cingulate gyrus in adult Ekers irrespective of housing conditions, whereas spine density in hippocampal pyramidal neurons was comparable across all genotypes and groups. Morphometric analysis of dendritic spines revealed age-related changes in spine morphology and density, which were responsive to animal genotype and environment. Taken together, our findings suggest that under TSC2 haploinsufficiency and mTORC1 hyperactivity, the expression of behavioural signs and neuroplasticity in Eker rats can be differentially influenced by the developmental stage and environment.
- MeSH
- hipokampus metabolismus MeSH
- krysa rodu rattus MeSH
- modely nemocí na zvířatech MeSH
- mTORC1 metabolismus MeSH
- neuroplasticita MeSH
- poruchy autistického spektra * genetika metabolismus MeSH
- pyramidové buňky metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Dopamine type 2 receptors (D2Rs) constitute the main molecular target in the pharmacotherapy of schizophrenia. However, the second and third generation of antipsychotics comprises multi-target ligands, also binding serotonin type 3 receptors (5-HT3Rs) and other receptor classes as well. Here, we examined two experimental compounds (marked compound K1697 and K1700) from the group of 1,4-di-substituted aromatic piperazines, previously described in the study of Juza et al., 2021, and compared them with the chosen reference antipsychotic, aripiprazole. Their efficacy against schizophrenia-like behavior was tested in two different models of psychosis in the rat, induced by acute administration of either amphetamine (1.5 mg/kg) or dizocilpine (0.1 mg/kg), reflecting the dopaminergic and glutamatergic hypotheses of schizophrenia. The two models exhibited broadly similar behavioral manifestations: hyperlocomotion, disrupted social behavior and impaired prepulse inhibition of the startle response. However, they differed in their treatment responses as hyperlocomotion and prepulse inhibition deficit in the dizocilpine model were resistant to antipsychotic treatment, unlike the amphetamine model. One of the experimental compounds, K1700, ameliorated all the observed schizophrenia-like behaviors in the amphetamine model with an efficacy comparable to or greater than aripiprazole. Whereas social impairments caused by dizocilpine were strongly suppressed by aripiprazole, K1700 was less efficient. Taken together, K1700 showed antipsychotic properties comparable to those of aripiprazole, although the efficacy of the two drugs differed in specific domains of behavior and was also model-dependent. Our present results highlight the differences in these two schizophrenia models and their responsiveness to pharmacotherapy, and confirm compound K1700 as a promising drug candidate.
- MeSH
- amfetamin MeSH
- antipsychotika * terapeutické užití MeSH
- aripiprazol MeSH
- chinolony * MeSH
- dizocilpinmaleát MeSH
- dopamin metabolismus MeSH
- krysa rodu rattus MeSH
- psychotické poruchy * farmakoterapie MeSH
- receptory serotoninové MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
We designed a behavioral task called One-Trial Trace Escape Reaction (OTTER), in which rats incidentally associate two temporally discontinuous stimuli: a neutral acoustic cue (CS) with an aversive stimulus (US) which occurs two seconds later (CS-2s-US sequence). Rats are first habituated to two similar environmental contexts (A and B), each consisting of an interconnected dark and light chamber. Next, rats experience the CS-2s-US sequence in the dark chamber of one of the contexts (either A or B); the US is terminated immediately after a rat escapes into the light chamber. The CS-2s-US sequence is presented only once to ensure the incidental acquisition of the association. The recall is tested 24 h later when rats are presented with only the CS in the alternate context (B or A), and their behavioral response is observed. Our results show that 59% of the rats responded to the CS by escaping to the light chamber, although they experienced only one CS-2s-US pairing. The OTTER task offers a flexible high throughput tool to study memory acquired incidentally after a single experience. Incidental one-trial acquisition of association between temporally discontinuous events may be one of the essential components of episodic memory formation.
- MeSH
- krysa rodu rattus MeSH
- rozpomínání MeSH
- strach fyziologie MeSH
- úniková reakce MeSH
- vydry * MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The amyloid cascade hypothesis, focusing on pathological proteins aggregation, has so far failed to uncover the root cause of Alzheimer's disease (AD), or to provide an effective therapy. This traditional paradigm essentially explains a mechanism involved in the development of sporadic AD rather than its cause. The failure of an overwhelming majority of clinical studies (99.6%) demonstrates that a breakthrough in therapy would be difficult if not impossible without understanding the etiology of AD. It becomes more and more apparent that the AD pathology might originate from brain infection. In this review, we discuss a potential role of bacteria, viruses, fungi, and eukaryotic parasites as triggers of AD pathology. We show evidence from the current literature that amyloid beta, traditionally viewed as pathological, actually acts as an antimicrobial peptide, protecting the brain against pathogens. However, in case of a prolonged or excessive activation of a senescent immune system, amyloid beta accumulation and aggregation becomes damaging and supports runaway neurodegenerative processes in AD. This is paralleled by the recent study by Alam and colleagues (2022) who showed that alpha-synuclein, the protein accumulating in synucleinopathies, also plays a critical physiological role in immune reactions and inflammation, showing an unforeseen link between the 2 unrelated classes of neurodegenerative disorders. The multiplication of the amyloid precursor protein gene, recently described by Lee and collegues (2018), and possible reactivation of human endogenous retroviruses by pathogens fits well into the same picture. We discuss these new findings from the viewpoint of the infection hypothesis of AD and offer suggestions for future research.
- MeSH
- Alzheimerova nemoc * metabolismus MeSH
- amyloidní beta-protein metabolismus MeSH
- amyloidový prekurzorový protein beta metabolismus MeSH
- antibakteriální látky terapeutické užití MeSH
- antiinfekční látky * metabolismus MeSH
- lidé MeSH
- mozek patologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Schizophrenia is a serious mental disorder without a fully understood pathomechanism, but which involves dysregulation of neurotransmitters and their receptors. The best option for the management of schizophrenia comprises so-called multi-target ligands, similar to the third generation of neuroleptics. Dopamine type 2 receptors (D2Rs) are the main target in the treatment of schizophrenia, in particular for mitigation of the positive symptoms. Due to the high expression of 5-hydroxytryptamine type 3 receptors (5-HT3Rs) in human brain areas responsible for emotional behavior, motivation, and cognitive function, 5-HT3Rs represent a potential target for modulating the cognitive and negative symptoms of schizophrenia. Here we present the design, synthesis, and both in vitro and in vivo biological evaluation of 1,4-disubstituted aromatic piperazines. Screening of in vitro properties revealed the two most promising drug candidates (21 and 24) which were found to be potent D2Rs and moderate 5-HT3R antagonists, and which were forwarded to in vivo studies in Wistar rats. Considering toxicity, administration of the maximal feasible dose of 21 (2 mg/kg) did not produce any side effects. By contrast, the higher solubility of 24 led to revelation of mild and temporary side effects at the dose of 20 mg/kg. Importantly, both 21 and 24 showed facile crossing of the blood-brain barrier, even exerting higher levels in the brain in comparison to plasma. In a behavioral study using the acute amphetamine model of psychosis, we showed that compound 24 ameliorated both positive and negative effects of amphetamine including hyperlocomotion, social impairments, and disruption of prepulse inhibition. The effect of the highest dose (10 mg/kg) was comparable to the effect of the reference dose of aripiprazole (1 mg/kg).
Maternal immune activation has been identified as a significant risk factor for schizophrenia. Using rodent models, past work has demonstrated various behavioral and brain impairments in offspring after immune-activating events. We applied 5 mg/kg of poly(I:C) on gestation day 9 to pregnant mouse dams, whose offspring were then stressed during puberty. We show impairments in attentional set-shifting in a T-maze, and a decreased number of parvalbumin-positive interneurons in the hippocampus as a result of peripubertal stress specifically in females.
- MeSH
- chování zvířat fyziologie MeSH
- exekutivní funkce fyziologie MeSH
- hipokampus cytologie MeSH
- infekční komplikace v těhotenství * chemicky indukované imunologie MeSH
- interneurony cytologie MeSH
- kognitivní dysfunkce etiologie patologie patofyziologie MeSH
- modely nemocí na zvířatech MeSH
- myši inbrední C57BL MeSH
- poly I-C aplikace a dávkování MeSH
- pozornost fyziologie MeSH
- psychický stres komplikace patologie patofyziologie MeSH
- schizofrenie etiologie imunologie patologie patofyziologie MeSH
- těhotenství MeSH
- zpožděný efekt prenatální expozice chemicky indukované patologie patofyziologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Závěrečná zpráva o řešení grantu Agentury pro zdravotnický výzkum MZ ČR
Nestr.
Poruchy kognitivních funkcí jsou považovány za klíčový příznak schizofrenie a předpovídají terapeutický výsledek. Velmi významně narušují denní fungování pacientů se schizofrenií, a přesto dosud neexistuje cílená léčba kognitivního deficitu u schizofrenie. V tomto translačním projektu plánujeme objasnit kauzální roli hipokampálně-prefrontálních projekcí v kognitivní koordinace a flexibilitě. Rovněž ukážeme na příčinnou roli frontotemporální theta koherence a synchronie pomocí optogenetické kontroly aktivity PV+ interneuronů u volně pohyblivých potkanů. V klinické části otestujeme vliv frontotemporální synchronizace na kognitivní koordinaci a flexibilitu ve skupině 35 pacientů v remisi a u 35 zdravých kontrol s využitím hrEEG/fMRI měření a testů virtuální reality. Hlavním cílem je objasnění neurobiologického substrátu kognitivního deficitu u schizofrenie, které umožní inteligentní design nových léčebných postupů. Výsledky projektu jednoznačně ukážou složky frontotemporální dysfunkce u schizofrenie a otevřou cestu pro budoucí specifickou terapii kognitivního deficitu.; Disturbances of cognitive functions have been recognized as hallmarks of schizophrenia and predictors of therapeutic outcome. They significantly limit patient ́s functioning, yet there are no specific treatments for cognitive deficits in this disease. In this translational project, we seek to determine the causal role of hippocampal-prefrontal projections in cognitive coordination and flexibility. Moreover, causative role of frontotemporal theta coherence and synchrony will be revealed by controlling PV+ interneuron activity in freely-moving rats. The human part will test relations of frontotemporal synchrony to coordination and flexibility in 35 remitted schizophrenia patients and 35 matched healthy controls using a hrEEG/fMRI measurements and tests of the virtual reality. The overall aim is to elucidate a neuronal substrate for cognitive deficits in schizophrenia for an intelligent design of new treatments. Results of this project will unequivocally show the constituents of frontotemporal dysfunction in schizophrenia and open way for future treatment of cognitive deficits.
- MeSH
- elektroencefalografie MeSH
- hipokampus MeSH
- kognitivní dysfunkce etiologie patofyziologie MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- modely nemocí na zvířatech MeSH
- nervový přenos MeSH
- neurozobrazování MeSH
- optogenetika MeSH
- prefrontální mozková kůra MeSH
- schizofrenie diagnóza MeSH
- translační biomedicínský výzkum MeSH
- virtuální realita MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- zvířata MeSH
- Konspekt
- Patologie. Klinická medicína
- NLK Obory
- neurologie
- psychiatrie
- NLK Publikační typ
- závěrečné zprávy o řešení grantu AZV MZ ČR
In this pilot study, a series of new 3,4-dihydroquinolin-2(1H)-one derivatives as potential dopamine receptor D2 (D2R) modulators were synthesized and evaluated in vitro. The preliminary structure-activity relationship disclosed that compound 5e exhibited the highest D2R affinity among the newly synthesized compounds. In addition, 5e showed a very low cytotoxic profile and a high probability to cross the blood-brain barrier, which is important considering the observed affinity. However, molecular modelling simulation revealed completely different binding mode of 5e compared to USC-D301, which might be the culprit of the reduced affinity of 5e toward D2R in comparison with USC-D301.
- MeSH
- aripiprazol chemická syntéza farmakologie MeSH
- buněčná smrt MeSH
- centrální nervový systém účinky léků MeSH
- chinolony chemická syntéza chemie farmakologie MeSH
- CHO buňky MeSH
- Cricetulus MeSH
- hematoencefalická bariéra účinky léků patologie MeSH
- ligandy MeSH
- molekulární modely MeSH
- racionální návrh léčiv MeSH
- receptory dopaminu D2 chemie metabolismus MeSH
- vazebná místa MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Chronic sensitization to serotonin 1A and 7 receptors agonist 8-OH-DPAT induces compulsive checking and perseverative behavior. As such, it has been used to model obsessive-compulsive disorder (OCD)-like behavior in mice and rats. In this study, we tested spatial learning in the 8-OH-DPAT model of OCD and the effect of co-administration of memantine and riluzole-glutamate-modulating agents that have been shown to be effective in several clinical trials. Rats were tested in the active place avoidance task in the Carousel maze, where they learned to avoid the visually imperceptible shock sector. All rats were subcutaneously injected with 8-OH-DPAT (0.25 mg/kg) or saline (control group) during habituation. During acquisition, they were pretreated with riluzole (1 mg/kg), memantine (1 mg/kg), or saline solution 30 min before each session and injected with 8-OH-DPAT ("OH" groups) or saline ("saline" groups) right before the experiment. We found that repeated application of 8-OH-DPAT during both habituation and acquisition significantly increased locomotion, but it impaired the ability to avoid the shock sector. However, the application of 8-OH-DPAT in habituation had no impact on the learning process if discontinued in acquisition. Similarly, memantine and riluzole did not affect the measured parameters in the "saline" groups, but in the "OH" groups, they significantly increased locomotion. In addition, riluzole increased the number of entrances and decreased the maximum time avoided of the shock sector. We conclude that monotherapy with glutamate-modulating agents does not reduce but exacerbates cognitive symptoms in the animal model of OCD.
- MeSH
- 8-hydroxy-2-(di-N-propylamino)tetralin škodlivé účinky farmakologie MeSH
- chování zvířat účinky léků MeSH
- krysa rodu rattus MeSH
- memantin farmakologie MeSH
- modely nemocí na zvířatech MeSH
- obsedantně kompulzivní porucha * chemicky indukované farmakoterapie patofyziologie MeSH
- paměť účinky léků MeSH
- potkani Long-Evans MeSH
- prostorové učení účinky léků MeSH
- riluzol farmakologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: Tuberous sclerosis complex (TSC), a multi-system genetic disorder often associated with autism spectrum disorder (ASD), is caused by mutations of TSC1 or TSC2, which lead to constitutive overactivation of mammalian target of rapamycin (mTOR). In several Tsc1+/- and Tsc2+/- animal models, cognitive and social behavior deficits were reversed by mTOR inhibitors. However, phase II studies have not shown amelioration of ASD and cognitive deficits in individuals with TSC during mTOR inhibitor therapy. We asked here if developmental epilepsy, common in the majority of individuals with TSC but absent in most animal models, could explain the discrepancy. METHODS: At postnatal day P12, developmental status epilepticus (DSE) was induced in male Tsc2+/- (Eker) and wild-type rats, establishing four experimental groups including controls. In adult animals (n = 36), the behavior was assessed in the paradigms of social interaction test, elevated plus-maze, light-dark test, Y-maze, and novel object recognition. The testing was carried out before medication (T1), during a 2-week treatment with the mTOR inhibitor everolimus (T2) and after an 8-week washing-out (T3). Electroencephalographic (EEG) activity was recorded in a separate set of animals (n = 18). RESULTS: Both Tsc2+/- mutation and DSE caused social behavior deficits and epileptiform EEG abnormalities (T1). Everolimus led to a persistent improvement of the social deficit induced by Tsc2+/-, while deficits related to DSE did not respond to everolimus (T2, T3). CONCLUSIONS: These findings may contribute to an explanation why ASD symptoms in individuals with TSC, where comorbid early-onset epilepsy is common, were not reliably ameliorated by mTOR inhibitors in clinical studies.
- MeSH
- autistická porucha * MeSH
- haploinsuficience MeSH
- krysa rodu rattus MeSH
- status epilepticus * MeSH
- TOR serin-threoninkinasy genetika MeSH
- tuberin genetika MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH