Pochopení vztahu mezi senzomotorickými proměnnými a exerkiny, které ovlivňují funkci mozku a kognici, nám umožňuje hlouběji porozumět biologickému procesu stárnutí. Hlavním cílem této studie bylo zjistit, jak silně jsou mozkový neurotrofický faktor (brain-derived neurotrophic factor, BDNF), irisin, svalová hmota a svalová síla asociovány s výsledky testů vybraných kognitivních funkcí u starších žen a jak dobře je predikují. Padesát sedm starších žen (průměrný věk 70,4 ± 4,1 roku) absolvovalo baterii neuropsychologických testů, měření izometrické dynamometrie a bioelektrické impedance. Hladiny v krevním séru sledovaných exerkinů byly stanoveny enzymatickým imunosorbentním testem (ELISA). Pro testování predikcí byly využity hierarchické vícenásobné regresní modely. Odhadli jsme, že rozptyl 46,1 % v krátkodobé paměti byl zapříčiněn hladinami BDNF v séru, přičemž druhým statisticky významným prediktorem byl věk (beta = –0,22; p = 0,030). Síla dolních končetin (lower limb strength, LLS) prokázala významnou prediktivní sílu jak u paměti – bezprostřední vybavení (beta = 0,39; p = 0,004), tak u paměti – oddálené vybavení (beta = 0,45; p = 0,001). Hladiny BDNF v séru byly významným prediktorem u oddáleného vybavení (beta = 0,29; p = 0,048). Přidání hladin BDNF do modelu prokázalo významné zvýšení jeho prediktivní síly o přibližně 5,6 % (p = 0,048) u paměti – oddálené vybavení. Index kosterní svalové hmoty (skeletal muscle index, SMI) a úroveň vzdělání byly významnými prediktory mentální flexibility. Byla zjištěna silná pozitivní asociace mezi hladinami BDNF, irisinem, svalovou silou a kognitivní funkcí, přičemž irisin a svalová síla jsou silnými prediktory hladin BDNF u starších žen. Studie byla realizována s podporou grantu Univerzity Karlovy – PRIMUS/19/HUM/012, Specifického vysokoškolského výzkumu SVV 260599, projektu COOPERATIO a Grantové agentury UK číslo grantu 268321. Korespondenční adresa: PhDr. Veronika Holá Katedra gymnastiky a úpolových sportů FTVS UK José Martího 269/31 162 52 Praha 6-Veleslavín e-mail: veronika.hola@ftvs.cuni.cz
Understanding the relationship between sensorimotor variables and exerkines related to brain function and cognition may help better understand biological ageing. The main aim of this study was to determine how strongly brain-derived neurotrophic factor (BDNF), irisin, muscle mass and muscle strength are associated and predict scores on selected cognitive domain tests in older women. Fifty seven older women (mean age 70.4 ± 4.1 years) underwent a battery of cognitive and psychological tests and measurements of isometric dynamometry and bioelectrical impedance. Serum exerkines levels were measured by enzyme-linked immunosorbent assay (ELISA). Hierarchical multiple regression models were used to test the predictions. We estimated that 46.1% of the variance in short-term memory was accounted for by serum BDNF levels, with age being the second statistically significant predictor (Beta = -0.22; p = 0.030). Lower limb strength (LLS) showed significant predictive power in both immediate (Beta = 0.39; p = 0.004) and delayed memory (Beta = 0.45; p = 0.001), serum BDNF levels were a significant predictor in delayed memory (Beta = 0.29; p = 0.048). Adding serum BDNF levels to the model showed a significant increase in predictive power of approximately 5.6% (p = 0.048) in delayed memory. Skeletal muscle index (SMI) and education level were significant predictors of mental flexibility. A strong positive association between BDNF levels, irisin, muscle strength, and cognitive function was found, with irisin and muscle strength being strong predictors of BDNF levels in older women.
- Klíčová slova
- irisin,
- MeSH
- fibronektinová doména typu III fyziologie MeSH
- kognice fyziologie MeSH
- kognitivní stárnutí * fyziologie MeSH
- lidé MeSH
- mozkový neurotrofický faktor krev MeSH
- neuropsychologické testy * statistika a číselné údaje MeSH
- paměť fyziologie MeSH
- prognóza MeSH
- průřezové studie MeSH
- regresní analýza MeSH
- senioři MeSH
- svalová atrofie etiologie MeSH
- svalová síla fyziologie MeSH
- Check Tag
- lidé MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- práce podpořená grantem MeSH
The interaction between the main psychotropic ingredient of Cannabis, Δ9- tetrahydrocannabinol (THC), with the endogenous cannabinoid system (ECS) is a critical and underrated issue that deserves utmost attention. The ECS, indeed, contributes to the formation and regulation of excitatory and inhibitory (E/I) neuronal networks that in the hippocampus underly spatial memory. This study explored sex-specific consequences of prenatal exposure to THC in hippocampus-dependent memory and the underlying cellular and molecular contributors of synaptic plasticity and E/I homeostasis. Sprague Dawley dams were exposed to THC (2 mg/kg) or vehicle, from gestational day 5-20. The adolescent progeny of both sexes was tested for: spatial memory retrieval and flexibility in the Barnes Maze; mRNA expression of relevant players of hippocampal synaptic plasticity; density of cholecystokinin-positive basket cells (CCK+BCs) - a major subtype of hippocampal inhibitory interneurons; mRNA expression of the excitatory and inhibitory synaptic proteins neuroligins (Nlgns), as a proxy of synaptic efficiency. Our results show a sex-specific disruption in spatial memory retrieval and flexibility, a male-specific decrease in CCK+BCs density and increase in the expression of markers of neuroplasticity, and consistent changes in the expression of Nlgn-1 and 3 isoforms. Despite a delay in memory retrieval, flexibility of memory was spared in prenatally-THC-exposed female offspring as well as most of the markers of neuroplasticity; a sex-specific increase in CCK+BCs density, and a consistent expression of Nlgn-3 was observed. The current results highlight a major vulnerability to prenatal exposure to THC on memory processing in the male progeny, and sex-specific alterations in the E/I balance and synaptic plasticity.
- MeSH
- bludiště - učení účinky léků MeSH
- cholecystokinin metabolismus MeSH
- hipokampus * účinky léků metabolismus MeSH
- krysa rodu rattus MeSH
- neuroplasticita * účinky léků MeSH
- pohlavní dimorfismus * MeSH
- potkani Sprague-Dawley * MeSH
- prostorová paměť * účinky léků MeSH
- těhotenství MeSH
- tetrahydrokanabinol * farmakologie toxicita MeSH
- zpožděný efekt prenatální expozice * chemicky indukované MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Semantic and short-term episodic memory are impaired in some brain disorders including Alzheimer's disease. OBJECTIVE: Development and validation of an almost self-administered, but cognitively demanding four-minute test identifying very mild cognitive impairment (vMCI). METHODS: The innovative hedgehog PICture Naming and Immediate Recall (PICNIR) consisted of two parts. The first task was to write down the names of 20 black-and-white pictures to evaluate long-term semantic memory and language. The second task involves immediate recall and writing the names of as many previously named pictures as possible in one minute. The PICNIR is assessed using the number of naming errors (NE) and correctly recalled picture names (PICR). The PICNIR and a neuropsychological battery were administered to 190 elderly individuals living independently in the community. They were divided into those with vMCI (n = 43 with Montreal Cognitive Assessment (MoCA) 24 ± 3 points) and sociodemographically matched cognitively normal (CN) individuals (n = 147 with MoCA 26 ± 3). Both subgroups had predicted mean Mini-Mental State Examination scores of 28-29 points. RESULTS: Compared to CN, vMCI participants made more NE (0.3 ± 0.6 versus 0.6 ± 0.9; p = 0.02) and recalled fewer PICR (8.9 ± 2.2 versus 6.8 ± 2.2; p < 0.000001). Discriminative validity was satisfactory using the area under the ROC curve (AUC): 0.76 for PICR, 0.74 for MoCA, 0.67 for MoCA-five-word recall, and 0.59 for NE. The AUCs of PICR and MoCA were comparable and larger than those of MoCA five-point recall or NE. Logical Memory scores, RAVLT scores, Digit symbol, and animal fluency correlated with PICR. CONCLUSIONS: The picture-based PICNIR is an ultra-brief, sensitive cognitive test valid for assessing very mild cognitive impairment. Its effectiveness should be validated for other languages and cultures.
- MeSH
- epizodická paměť * MeSH
- kognitivní dysfunkce * diagnóza psychologie MeSH
- krátkodobá paměť fyziologie MeSH
- lidé MeSH
- neuropsychologické testy * statistika a číselné údaje MeSH
- reprodukovatelnost výsledků MeSH
- rozpomínání * fyziologie MeSH
- sémantika MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- testy pro posouzení mentálních funkcí a demence statistika a číselné údaje MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
The relationship between working memory (WM) and neuronal oscillations can be studied in detail using brain stimulation techniques, which provide a method for modulating these oscillations and thus influencing WM. The endogenous coupling between the amplitude of gamma oscillations and the phase of theta oscillations is crucial for cognitive control. Theta/gamma peak-coupled transcranial alternating current stimulation (TGCp-tACS) can modulate this coupling and thus influence WM performance. This study investigated the effects of TGCp-tACS on WM in older adults and compared their responses with those of younger participants from our previous work who underwent the same experimental design. Twenty-eight older subjects underwent both TGCp-tACS and sham stimulation sessions at least 72 h apart. Resting-state electroencephalography (EEG) was recorded before and after the interventions, and a WM task battery with five different WM tasks was performed during the interventions to assess various WM components. Outcomes measured included WM task performance (e.g., accuracy, reaction time (RT)) and changes in power spectral density (PSD) in different frequency bands. TGCp-tACS significantly decreased accuracy and RT on the 10- and 14-point Sternberg tasks and increased RT on the Digit Symbol Substitution Test in older adults. In contrast, younger participants showed a significant increase in accuracy only on the 14-item Sternberg task. Electrophysiological analysis revealed a decrease in delta and theta PSD and an increase in high gamma PSD in both younger and older participants after verum stimulation. In conclusion, theta-gamma coupling is essential for WM and modulation of this coupling affects WM performance. The effects of TGCp-tACS on WM vary with age due to natural brain changes. To better support older adults, the study suggests several strategies to improve cognitive function, including: Adjusting stimulation parameters, applying stimulation to two sites, conducting multiple sessions, and using brain imaging techniques for precise targeting.
- MeSH
- dospělí MeSH
- elektroencefalografie MeSH
- gama rytmus EEG * fyziologie MeSH
- krátkodobá paměť * fyziologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- přímá transkraniální stimulace mozku * MeSH
- reakční čas fyziologie MeSH
- senioři MeSH
- stárnutí fyziologie MeSH
- theta rytmus EEG * fyziologie MeSH
- zdraví MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Genetic variations in a common single nucleotide polymorphism in the ninth intron of the KIBRA gene have been linked to memory performance and risk of Alzheimer's disease (AD). OBJECTIVE: We examined the risk of AD related to presence of KIBRA T allele (versus CC homozygote) and to memory performance. The role of established genetic risk factors APOE ε4 and BDNF Met was also considered. METHODS: Participants were cognitively healthy individuals (n = 19), participants with amnestic mild cognitive impairment (aMCI) due to AD (n = 99) and AD dementia (n = 37) from the Czech Brain Aging Study. Binary and multinomial logistic regressions compared odds of belonging to a certain diagnostic category and multivariate linear regressions assessed associations with memory. RESULTS: KIBRA T allele was associated with increased AD dementia risk (odds ratio [OR] = 5.98, p = 0.012) compared to KIBRA CC genotype. In APOE ε4 negative individuals, KIBRA T allele was associated with a greater risk of both aMCI due to AD (OR = 6.68, p = 0.038) and AD dementia (OR = 15.75, p = 0.009). In BDNF Met positive individuals, the KIBRA T allele was associated with a greater risk of AD dementia (OR = 10.98, p = 0.050). In AD dementia, the association between KIBRA T allele and better memory performance approached significance (β = 0.42; p = 0.062). The link between possessing the KIBRA T allele and better memory reached statistical significance only among BDNF Met carriers (β = 1.21, p = 0.027). CONCLUSIONS: Findings suggest that KIBRA T allele may not fully protect against AD dementia but could potentially delay progression of post-diagnosis cognitive deficits.
- MeSH
- alely MeSH
- Alzheimerova nemoc * genetika MeSH
- apolipoprotein E4 genetika MeSH
- genetická predispozice k nemoci genetika MeSH
- genotyp MeSH
- intracelulární signální peptidy a proteiny genetika MeSH
- jednonukleotidový polymorfismus * genetika MeSH
- kognitivní dysfunkce * genetika MeSH
- lidé MeSH
- mozkový neurotrofický faktor genetika MeSH
- neuropsychologické testy MeSH
- paměť fyziologie MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: The hippocampal representation of space, formed by the collective activity of populations of place cells, is considered as a substrate of spatial memory. Alzheimer's disease (AD), a widespread severe neurodegenerative condition of multifactorial origin, typically exhibits spatial memory deficits among its early clinical signs before more severe cognitive impacts develop. OBJECTIVE: To investigate mechanisms of spatial memory impairment in a double transgenic rat model of AD. METHODS: In this study, we utilized 9-12-month-old double-transgenic TgF344-AD rats and age-matched controls to analyze the spatial coding properties of CA1 place cells. We characterized the spatial memory representation, assessed cells' spatial information content and direction-specific activity, and compared their population coding in familiar and novel conditions. RESULTS: Our findings revealed that TgF344-AD animals exhibited lower precision in coding, as evidenced by reduced spatial information and larger receptive zones. This impairment was evident in maps representing novel environments. While controls instantly encoded directional context during their initial exposure to a novel environment, transgenics struggled to incorporate this information into the newly developed hippocampal spatial representation. This resulted in impairment in orthogonalization of stored activity patterns, an important feature directly related to episodic memory encoding capacity. CONCLUSIONS: Overall, the results shed light on the nature of impairment at both the single-cell and population levels in the transgenic AD model. In addition to the observed spatial coding inaccuracy, the findings reveal a significantly impaired ability to adaptively modify and refine newly stored hippocampal memory patterns.
- MeSH
- Alzheimerova nemoc * patofyziologie MeSH
- amyloidový prekurzorový protein beta genetika MeSH
- hipokampální oblast CA1 patofyziologie MeSH
- hipokampus patofyziologie MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- modely nemocí na zvířatech * MeSH
- poruchy paměti etiologie patofyziologie MeSH
- potkani inbrední F344 MeSH
- potkani transgenní * MeSH
- prostorová paměť fyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Working memory (WM) is essential for the temporary storage and processing of information required for complex cognitive tasks and relies on neuronal theta and gamma oscillations. Given the limited capacity of WM, researchers have investigated various methods to improve it, including transcranial alternating current stimulation (tACS), which modulates brain activity at specific frequencies. One particularly promising approach is theta-gamma peak-coupled-tACS (TGCp-tACS), which simulates the natural interaction between theta and gamma oscillations that occurs during cognitive control in the brain. The aim of this study was to improve WM in healthy young adults with TGCp-tACS, focusing on both behavioral and neurophysiological outcomes. Thirty-one participants completed five WM tasks under both sham and verum stimulation conditions. Electroencephalography (EEG) recordings before and after stimulation showed that TGCp-tACS increased power spectral density (PSD) in the high-gamma region at the stimulation site, while PSD decreased in the theta and delta regions throughout the cortex. From a behavioral perspective, although no significant changes were observed in most tasks, there was a significant improvement in accuracy in the 14-item Sternberg task, indicating an improvement in phonological WM. In conclusion, TGCp-tACS has the potential to promote and improve the phonological component of WM. To fully realize the cognitive benefits, further research is needed to refine the stimulation parameters and account for individual differences, such as baseline cognitive status and hormonal factors.
- MeSH
- chování fyziologie MeSH
- dospělí MeSH
- elektrická stimulace MeSH
- elektroencefalografie MeSH
- gama rytmus EEG fyziologie MeSH
- krátkodobá paměť * fyziologie MeSH
- lidé MeSH
- mladý dospělý MeSH
- přímá transkraniální stimulace mozku * metody MeSH
- theta rytmus EEG fyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Despite advances in understanding the cellular and molecular processes underlying memory and cognition, and recent successful modulation of cognitive performance in brain disorders, the neurophysiological mechanisms remain underexplored. High frequency oscillations beyond the classic electroencephalogram spectrum have emerged as a potential neural correlate of fundamental cognitive processes. High frequency oscillations are detected in the human mesial temporal lobe and neocortical intracranial recordings spanning gamma/epsilon (60-150 Hz), ripple (80-250 Hz) and higher frequency ranges. Separate from other non-oscillatory activities, these brief electrophysiological oscillations of distinct duration, frequency and amplitude are thought to be generated by coordinated spiking of neuronal ensembles within volumes as small as a single cortical column. Although the exact origins, mechanisms and physiological roles in health and disease remain elusive, they have been associated with human memory consolidation and cognitive processing. Recent studies suggest their involvement in encoding and recall of episodic memory with a possible role in the formation and reactivation of memory traces. High frequency oscillations are detected during encoding, throughout maintenance, and right before recall of remembered items, meeting a basic definition for an engram activity. The temporal coordination of high frequency oscillations reactivated across cortical and subcortical neural networks is ideally suited for integrating multimodal memory representations, which can be replayed and consolidated during states of wakefulness and sleep. High frequency oscillations have been shown to reflect coordinated bursts of neuronal assembly firing and offer a promising substrate for tracking and modulation of the hypothetical electrophysiological engram.
- MeSH
- elektroencefalografie MeSH
- kognice * fyziologie MeSH
- lidé MeSH
- mozek fyziologie MeSH
- mozkové vlny fyziologie MeSH
- paměť fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Episodic memory, the ability to recall specific events and experiences, is a cornerstone of human cognition with profound clinical implications. While animal studies have provided valuable insights into the neuronal underpinnings of episodic memory, research has largely relied on a limited subset of tasks that model only some aspects of episodic memory. In this narrative review, we provide an overview of rodent episodic-like memory tasks that expand the methodological repertoire and diversify the approaches used in episodic-like memory research. These tasks assess various aspects of human episodic memory, such as integrated what-where-when or what-where memory, source memory, free recall, temporal binding, and threshold retrieval dynamics. We review each task's general principle and consider whether alternative non-episodic mechanisms can account for the observed behavior. While our list of tasks is not exhaustive, we hope it will guide researchers in selecting models that align with their specific research objectives, leading to novel advancements and a more comprehensive understanding of mechanisms underlying specific aspects of episodic memory.
- MeSH
- epizodická paměť * MeSH
- lidé MeSH
- neurovědy metody MeSH
- rozpomínání fyziologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
