Neural components enabling flexible cognition and behavior are well-established, and depend mostly on proper intercommunication within the prefrontal cortex (PFC) and striatum. However, dense projections from the ventral hippocampus (vHPC) alter the functioning of the medial PFC (mPFC). Dysfunctional hippocampo-prefrontal connectivity negatively affects the integrity of flexible cognition, especially in patients with schizophrenia. In this study, we aimed to test the role of the vHPC and mPFC in a place avoidance task on a rotating arena using two spatial flexibility task variants - reversal learning and set-shifting. To achieve this, we inactivated each of these structures in adult male Long-Evans rats by performing bilateral local muscimol (a GABAA receptor agonist) injections. A significantly disrupted performance was observed in reversal learning in the vHPC-inactivated, but not in the mPFC-inactivated rats. These results confirm the notion that the vHPC participates in some forms of behavioral flexibility, especially when spatial cues are needed. It seems, rather unexpectedly, that the mPFC is not taxed in these flexibility tasks on a rotating arena.

• Klíčová slova
• Behavioral flexibility, Carousel, Muscimol, Prefrontal cortex, Rotating arena, Ventral hippocampus,
• MeSH
• agonisté receptorů GABA-A farmakologie   MeSH
• hipokampus účinky léků   fyziologie   MeSH
• krysa rodu Rattus MeSH
• muscimol farmakologie   MeSH
• pozornost účinky léků   fyziologie   MeSH
• prefrontální mozková kůra účinky léků   fyziologie   MeSH
• prostorové vidění účinky léků   fyziologie   MeSH
• reverzní učení účinky léků   fyziologie   MeSH
• učení vyhýbat se účinky léků   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• agonisté receptorů GABA-A MeSH
• muscimol MeSH

It is well known that communication between the medial prefrontal cortex (mPFC) and the ventral hippocampus (vHPC) is critical for various cognitive and behavioral functions. However, the exact role of these structures in spatial coordination remains to be clarified. Here we sought to determine the involvement of the mPFC and the vHPC in the spatial retrieval of a previously learned active place avoidance task in adult male Long-Evans rats, using a combination of unilateral and bilateral local muscimol inactivations. Moreover, we tested the role of the vHPC-mPFC pathway by performing combined ipsilateral and contralateral inactivations. Our results showed not only bilateral inactivations of either structure, but also the combined inactivations impaired the retrieval of spatial memory, whereas unilateral one-structure inactivations did not yield any effect. Remarkably, muscimol injections in combined groups exerted similar deficits, regardless of whether the inactivations were contralateral or ipsilateral. These findings confirm the importance of these structures in spatial cognition and emphasize the importance of the intact functioning of the vHPC-mPFC pathway.

• Klíčová slova
• active place avoidance, hippocampo-prefrontal pathway, muscimol, rotating arena, spatial memory,
• MeSH
• hipokampus * MeSH
• krysa rodu Rattus MeSH
• muscimol farmakologie   MeSH
• potkani Long-Evans MeSH
• prefrontální mozková kůra MeSH
• prostorová paměť * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• muscimol MeSH

Schizophrenia research has increased in recent decades and focused more on its neural basis. Decision-making and cognitive flexibility are the main cognitive functions that are impaired and considered schizophrenia endophenotypes. Cognitive impairment was recently connected with altered functions of N-methyl-d-aspartate (NMDAR) glutamatergic receptors, which increased cortical activity. Selective NMDAR antagonists, such as MK-801, have been used to model cognitive inflexibility in schizophrenia. Decreased GABAergic inhibitory activity has been shown elsewhere with enhanced cortical activity. This imbalance in the excitatory/inhibitory may reduce the entrainment of prefrontal gamma and hippocampal theta rhythms and result in gamma/theta band de-synchronization. The current study established an acute MK-801 administration model of schizophrenia-like cognitive inflexibility in rats and used the attentional set-shifting task in which rats learned to switch/reverse the relevant rule. During the task, we used in vivo optogenetic stimulations of parvalbumin-positive interneurons at specific light pulses in the prefrontal cortex and ventral hippocampus. The first experiments showed that acute dizocilpine in rats produced schizophrenia-like cognitive inflexibility. The second set of experiments demonstrated that specific optogenetic stimulation at specific frequencies of parvalbumin-positive interneurons in the prefrontal cortex and ventral hippocampus rescued the cognitive flexibility rats that received acute MK-801. These findings advance our knowledge of the pivotal role of parvalbumin interneurons in schizophrenia-like cognitive impairment and may guide further research on this severe psychiatric disorder.

• Klíčová slova
• Attentional set-shifting task, Excitatory/inhibitory ratio, Gamma waves, MK-801, theta waves,
• MeSH
• dizocilpinmaleát * farmakologie   MeSH
• hipokampus metabolismus   MeSH
• interneurony metabolismus   MeSH
• kognice MeSH
• krysa rodu Rattus MeSH
• optogenetika MeSH
• parvalbuminy metabolismus   MeSH
• prefrontální mozková kůra metabolismus   MeSH
• receptory N-methyl-D-aspartátu metabolismus   MeSH
• schizofrenie * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• dizocilpinmaleát * MeSH
• parvalbuminy MeSH
• receptory N-methyl-D-aspartátu MeSH

Objective. Changes in the brain derived neurotrophic factor (BDNF) and glucocorticoid receptor (GR) expression in the prefrontal cortex (PFC) and hippocampus (HIP) are associated with psychiatric diseases and stress response. Chronic mild stress (CMS) may alter BDNF as well as GR levels in both the PFC and the HIP. The aim of the present study was to find out whether chronic treatment with a typical antipsychotic haloperidol (HAL) and an atypical antipsychotic aripiprazole (ARI) may modify the CMS effect on the BDNF and GR expression in the above-mentioned structures. Methods. The rats were exposed to CMS for 3 weeks and from the 7th day of CMS injected with vehicle (VEH), HAL (1 mg/kg) or ARI (10 mg/kg) for 4 weeks. BDNF and GR mRNA levels were established in the PFC and the HIP by Real Time PCR, whereas, PFC and HIP samples were obtained by punching them from 500 µm thick frozen sections. C-Fos immunoreactivity was analyzed in the PFC and the HIP on 30 µm thick paraformaldehyde fixed sections. Weight gain and corticosterone (CORT) levels were also measured. Results. The CMS and HAL suppressed the BDNF and GR mRNA levels in the PFC. In the HIP, CMS elevated BDNF mRNA levels that were suppressed by HAL and ARI treatments. The CMS decreased the c-Fos immunoreactivity in the PFC in both HAL- and ARI-treated animals. In the HIP, HAL increased the c-Fos immunoreactivity that was again diminished in animals exposed to CMS. Stressed animals gained markedly less weight until the 7th day of CMS, however, later their weight gain did not differ from the unstressed ones or was even higher in CMS+HAL group. Un-stressed HAL and ARI animals gained less weight than the VEH ones. Neither CMS nor HAL/ARI affected the plasma CORT levels. Conclusion. The present data indicate that HAL and ARI in the doses 1 mg/kg or 10 mg/kg, respectively, does not modify the effect of the CMS preconditioning on the BDNF and GR mRNA levels in the PFC or the HIP. However, HAL seems to modify the CMS effect on the HIP activation.

• Klíčová slova
• aripiprazole, brain derived neurotrophic factor, c-Fos-immunohisto-chemistry, glucocorticoid receptors, haloperidol, hippocampus, prefrontal cortex, rat,
• MeSH
• antipsychotika * farmakologie   MeSH
• aripiprazol farmakologie   MeSH
• haloperidol * MeSH
• hipokampus MeSH
• krysa rodu Rattus MeSH
• mozkový neurotrofický faktor genetika   MeSH
• prefrontální mozková kůra MeSH
• receptory glukokortikoidů genetika   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antipsychotika * MeSH
• aripiprazol MeSH
• haloperidol * MeSH
• mozkový neurotrofický faktor MeSH
• receptory glukokortikoidů MeSH

The hyperpolarization-activated cyclic-nucleotide-gated non-selective cation (HCN) channels play a potential role in the neurological basis underlying drug addiction. However, little is known about the role of HCN channels in methamphetamine (METH) abuse. In the present study, we examined the changes in working memory functions of METH re-exposed mice through Morris water maze test, and investigated the protein expression of HCN1 channels and potential mechanisms underlying the modulation of HCN channels by Western blotting analysis. Mice were injected with METH (1 mg/kg, i.p.) once per day for 6 consecutive days. After 5 days without METH, mice were re-exposed to METH at the same concentration. We found that METH re-exposure caused an enhancement of working memory, and a decrease in the HCN1 channels protein expression in both hippocampus and prefrontal cortex. The phosphorylated extracellular regulated protein kinase 1/2 (p-ERK1/2), an important regulator of HCN channels, was also obviously reduced in hippocampus and prefrontal cortex of mice with METH re-exposure. Meanwhile, acute METH exposure did not affect the working memory function and the protein expressions of HCN1 channels and p-ERK1/2. Overall, our data firstly showed the aberrant protein expression of HCN1 channels in METH re-exposed mice with enhanced working memory, which was probably related to the down-regulation of p-ERK1/2 protein expression.

• MeSH
• down regulace účinky léků   fyziologie   MeSH
• draslíkové kanály biosyntéza   MeSH
• hipokampus účinky léků   metabolismus   MeSH
• hyperpolarizační iontové kanály řízené cyklickými nukleotidy antagonisté a inhibitory   biosyntéza   MeSH
• krátkodobá paměť účinky léků   fyziologie   MeSH
• lokomoce účinky léků   fyziologie   MeSH
• methamfetamin aplikace a dávkování   toxicita   MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• náhodné rozdělení MeSH
• prefrontální mozková kůra účinky léků   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• draslíkové kanály MeSH
• Hcn1 protein, mouse MeSH Prohlížeč
• hyperpolarizační iontové kanály řízené cyklickými nukleotidy MeSH
• methamfetamin MeSH

Quinpirole (QNP) sensitization is a well-established model of stereotypical checking relevant to obsessive-compulsive disorder. Previously, we found that QNP-treated rats display deficits in hippocampus-dependent tasks. The present study explores the expression of immediate early genes (IEG) during QNP-induced stereotypical checking in the hippocampus, anterior cingulate cortex (ACC), orbitofrontal cortex (OFC), and medial prefrontal cortex (mPFC). Adult male rats were injected with QNP (0.5 mg/mL/kg; n = 15) or saline (n = 14) daily for 10 days and exposed to an arena enriched with two objects. Visits to the objects and the corners of the arena were recorded. QNP-treated rats developed an idiosyncratic pattern of visits that persisted across experimental days. On day 11, rats were exposed to the arena twice for 5 min and sacrificed. The expression of IEGs Arc and Homer1a was determined using cellular compartment analysis of temporal activity by fluorescence in situ hybridization. IEG-positive nuclei were counted in the CA1 area of the hippocampus, ACC, OFC, and mPFC. We found significantly fewer IEG-positive nuclei in the CA1 in QNP-treated rats compared to controls. The overlap between IEG expressing neurons was comparable between the groups. We did not observe significant differences in IEG expression between QNP treated and control rats in ACC, OFC, and mPFC. In conclusion, treatment of rats with quinpirole decreases plasticity-related activity in the hippocampus during stereotypical checking.

• Klíčová slova
• Arc, Homer1, hippocampus, obsessive-compulsive disorder, quinpirole, stereotypical checking,
• MeSH
• antagonisté dopaminu D2 farmakologie   MeSH
• chinpyrol farmakologie   MeSH
• cingulární gyrus účinky léků   fyziologie   MeSH
• hipokampus účinky léků   fyziologie   MeSH
• krysa rodu Rattus MeSH
• neurony účinky léků   metabolismus   MeSH
• neuroplasticita účinky léků   fyziologie   MeSH
• okamžité časné geny MeSH
• pohybová aktivita účinky léků   MeSH
• potkani Long-Evans MeSH
• prefrontální mozková kůra účinky léků   fyziologie   MeSH
• receptory dopaminu D2 metabolismus   MeSH
• receptory dopaminu D3 antagonisté a inhibitory   MeSH
• regulace genové exprese účinky léků   MeSH
• stereotypní chování 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
• Názvy látek
• antagonisté dopaminu D2 MeSH
• chinpyrol MeSH
• receptory dopaminu D2 MeSH
• receptory dopaminu D3 MeSH

Psychosis is a state of altered thoughts which often accompanies schizophrenia. It was suggested that changes in energetic metabolism accompany psychosis and post-psychosis states. Here, we use the N-methyl-D-aspartate (NMDA) receptor antagonist MK-801 to experimentally induce psychosis-like behavior in rats. We addressed an effect of single and repeated (5×) MK-801 application (0.3 mg/kg; i.p.) on the energy metabolism in homogenates and crude mitochondrial fraction (CMF) of the striatum (STR), prefrontal cortex (PFC), and the hippocampus (HIP) of the adult male Wistar rat (n = 39). In each brain region, we assessed activity of glycolytic (hexokinase (HK) and lactate dehydrogenase (LDH)) and Krebs cycle enzymes (citrate synthase (CS) and malate dehydrogenase (MDH)) 2 h and 3 days (3d) after the last MK-801 application together with relative respiratory rates assessment in tissue homogenate. In STR, a single MK-801 application led to a decrease in the LDH (p = 0.0035) and the increase of the MDH (p = 0.0043) activities following 3d. Therein, repeated MK-801 doses evoked increased LDH (p = 0.0204) and CS (p = 0.0019) activities in the homogenate 2 h and increased HK (p = 0.0007) 3d after the last application. Elevated HK activity within CMF was observed after 3d (p = 0.0054). In PFC, repeated MK-801 application decreased HK activity in the homogenate 3d after the final application (p = 0.0234). Correspondingly, PFC HK activity in CMF of repeated administration samples dropped (p = 0.003). In HIP, repeated MK-801 administration led to increased respiration of SDH (p = 0.0475) only 2 h after the last application and decreased CS activity (p = 0.0160) was observed 3d after the last application. Our results indicate a progressive metabolic dysregulation of glycolytic and Krebs cycle enzymes following repeated inhibition of NMDA receptors activity in a region-specific manner. Energetic alterations may form a basis for persisting cognitive problems during and following a psychosis in schizophrenia patients.

• Klíčová slova
• Citrate synthase, Energy metabolism, Hexokinase, Lactate dehydrogenase, Malate dehydrogenase, Schizophrenia,
• MeSH
• citrátový cyklus MeSH
• citrátsynthasa metabolismus   farmakologie   MeSH
• dizocilpinmaleát * farmakologie   MeSH
• hexokinasa metabolismus   farmakologie   MeSH
• hipokampus MeSH
• krysa rodu Rattus MeSH
• L-laktátdehydrogenasa metabolismus   MeSH
• lidé MeSH
• N-methylaspartát * farmakologie   MeSH
• potkani Wistar MeSH
• prefrontální mozková kůra MeSH
• receptory N-methyl-D-aspartátu metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• citrátsynthasa MeSH
• dizocilpinmaleát * MeSH
• hexokinasa MeSH
• L-laktátdehydrogenasa MeSH
• N-methylaspartát * MeSH
• receptory N-methyl-D-aspartátu MeSH

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by the loss of cognitive functions, reflecting pathological damage to the medial prefrontal cortex (mPFC) as well as to the hippocampus and the entorhinal cortex. Astrocytes maintain the internal homeostasis of the CNS and are fundamentally involved in neuropathological processes, including AD. Here, we analysed the astrocytic cytoskeletal changes within the mPFC of a triple transgenic mouse model of AD (3 × Tg-AD) by measuring the surface area and volume of glial fibrillary acidic protein (GFAP)-positive profiles in relation to the build-up and presence of amyloid-β (Aβ), and compared the results with those found in non-transgenic control animals at different ages. 3 × Tg-AD animals showed clear astroglial cytoskeletal atrophy, which appeared at an early age (3 months; 33% and 47% decrease in GFAP-positive surface area and volume, respectively) and remained throughout the disease progression at 9, 12 and 18 months old (29% and 36%; 37% and 35%; 43% and 37%, respectively). This atrophy was independent of Aβ accumulation, as only a few GFAP-positive cells were localized around Aβ aggregates, which suggests no direct relationship with Aβ toxicity. Thus, our results indicate that the progressive reduction in astrocytic branching and domain in the mPFC can account for the integrative dysfunction leading to the cognitive deficits and memory disturbances observed in AD.

• MeSH
• Alzheimerova nemoc patologie   MeSH
• amyloidní beta-protein metabolismus   MeSH
• astrocyty cytologie   metabolismus   patologie   MeSH
• atrofie patologie   MeSH
• cytoskelet patologie   MeSH
• imunohistochemie MeSH
• modely nemocí na zvířatech MeSH
• myši transgenní MeSH
• myši MeSH
• prefrontální mozková kůra cytologie   metabolismus   patologie   MeSH
• progrese nemoci MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• amyloidní beta-protein MeSH

Hypofunctioning of NMDA receptors, and the resulting shift in the balance between excitation and inhibition, is considered a key process in the pathophysiology of schizophrenia. One important manifestation of this phenomenon is changes in neural oscillations, those above 30 Hz (i.e., gamma-band oscillations), in particular. Although both preclinical and clinical studies observed increased gamma activity following acute administration of NMDA receptor antagonists, the relevance of this phenomenon has been recently questioned given the reduced gamma oscillations typically observed during sensory and cognitive tasks in schizophrenia. However, there is emerging, yet contradictory, evidence for increased spontaneous gamma-band activity (i.e., at rest or under baseline conditions). Here, we use the sub-chronic phencyclidine (PCP) rat model for schizophrenia, which has been argued to model the pathophysiology of schizophrenia more closely than acute NMDA antagonism, to investigate gamma oscillations (30-100 Hz) in the medial prefrontal cortex of anesthetized animals. While baseline gamma oscillations were not affected, oscillations induced by train stimulation of the posterior dorsal CA1 (pdCA1) field of the hippocampus were enhanced in PCP-treated animals (5 mg/kg, twice daily for 7 days, followed by a 7-day washout period). This effect was reversed by pharmacological enhancement of endocannabinoid levels via systemic administration of URB597 (0.3 mg/kg), an inhibitor of the catabolic enzyme of the endocannabinoid anandamide. Intriguingly, the pharmacological blockade of CB1 receptors by AM251 unmasked a reduced gamma oscillatory activity in PCP-treated animals. The findings are consistent with the observed effects of URB597 and AM251 on behavioral deficits reminiscent of the symptoms of schizophrenia and further validate the potential for cannabinoid-based drugs as a treatment for schizophrenia.

• Klíčová slova
• CB1 receptors, Endocannabinoids, Hippocampus, Prefrontal cortex, URB597,
• MeSH
• amidohydrolasy * antagonisté a inhibitory   metabolismus   MeSH
• antagonisté excitačních aminokyselin farmakologie   aplikace a dávkování   MeSH
• benzamidy * farmakologie   MeSH
• endokanabinoidy metabolismus   MeSH
• fencyklidin * farmakologie   MeSH
• gama rytmus EEG fyziologie   účinky léků   MeSH
• karbamáty * farmakologie   MeSH
• krysa rodu Rattus MeSH
• kyseliny arachidonové metabolismus   farmakologie   MeSH
• modely nemocí na zvířatech MeSH
• piperidiny * farmakologie   MeSH
• polynenasycené alkamidy metabolismus   farmakologie   MeSH
• potkani Sprague-Dawley MeSH
• prefrontální mozková kůra účinky léků   metabolismus   patofyziologie   MeSH
• pyrazoly farmakologie   MeSH
• schizofrenie * patofyziologie   metabolismus   farmakoterapie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• AM 251 MeSH Prohlížeč
• amidohydrolasy * MeSH
• anandamide MeSH Prohlížeč
• antagonisté excitačních aminokyselin MeSH
• benzamidy * MeSH
• cyclohexyl carbamic acid 3'-carbamoylbiphenyl-3-yl ester MeSH Prohlížeč
• endokanabinoidy MeSH
• fatty-acid amide hydrolase MeSH Prohlížeč
• fencyklidin * MeSH
• karbamáty * MeSH
• kyseliny arachidonové MeSH
• piperidiny * MeSH
• polynenasycené alkamidy MeSH
• pyrazoly MeSH

The formation of memories is a complex, multi-scale phenomenon, especially when it involves integration of information from various brain systems. We have investigated the differences between a novel and consolidated association of spatial cues and amphetamine administration, using an in situ hybridisation method to track the short-term dynamics during the recall testing. We have found that remote recall group involves smaller, but more consolidated groups of neurons, which is consistent with their specialisation. By employing machine learning analysis, we have shown this pattern is especially pronounced in the VTA; furthermore, we also uncovered significant activity patterns in retrosplenial and prefrontal cortices, as well as in the DG and CA3 subfields of the hippocampus. The behavioural propensity towards the associated localisation appears to be driven by the nucleus accumbens, however, further modulated by a trio of the amygdala, VTA and hippocampus, as the trained association is confronted with test experience. Moreover, chemogenetic analysis revealed central amygdala as critical for linking appetitive emotional states with spatial contexts. These results show that memory mechanisms must be modelled considering individual differences in motivation, as well as covering dynamics of the process.

• MeSH
• amfetamin farmakologie   MeSH
• amygdala fyziologie   metabolismus   MeSH
• hipokampus fyziologie   metabolismus   MeSH
• konsolidace paměti * fyziologie   účinky léků   MeSH
• krysa rodu Rattus MeSH
• mozek fyziologie   MeSH
• neurony fyziologie   MeSH
• nucleus accumbens fyziologie   MeSH
• odměna MeSH
• paměť fyziologie   MeSH
• podněty MeSH
• prefrontální mozková kůra fyziologie   MeSH
• rozpomínání * fyziologie   účinky léků   MeSH
• strojové učení MeSH
• tegmentum mesencephali - area ventralis fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• amfetamin MeSH