Animals and humans receive the most critical information from parts of the environment that are immediately inaccessible and highly dynamic. The brain must effectively process potential interactions between elements in such an environment to make appropriate decisions in critical situations. We trained male Long-Evans rats to discriminate static and dynamic spatial stimuli and to generalize novel dynamic spatial stimuli displayed on an inaccessible computer screen. We provide behavioral evidence indicating that rats encode dynamic visuospatial situations by constructing internal static representations that capture meaningful future interactions between objects. These observations support previous findings in humans that such internal static representations can encapsulate relevant spatiotemporal information of dynamic environments. This mechanism would allow animals and humans to process complex time-changing situations neatly.

• MeSH
• chování zvířat MeSH
• krysa rodu Rattus MeSH
• potkani Long-Evans MeSH
• vnímání prostoru * fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Path integration, the ability to track one's position using self-motion cues, is critically dependent on the grid cell network in the entorhinal cortex, a region vulnerable to early Alzheimer's disease pathology. In this study, we examined path integration performance in individuals with subjective cognitive decline (SCD), a group at increased risk for Alzheimer's disease, and healthy controls using an immersive virtual reality task. We developed a Bayesian computational model to decompose path integration errors into distinct components. SCD participants exhibited significantly higher path integration error, primarily driven by increased memory leak, while other modelling-derived error sources, such as velocity gain, sensory and reporting noise, remained comparable across groups. Our findings suggest that path integration deficits, specifically memory leak, may serve as an early marker of neurodegeneration in SCD and highlight the potential of self-motion-based navigation tasks for detecting pre-symptomatic Alzheimer's disease-related cognitive changes.

• Publikační typ
• časopisecké články MeSH
• preprinty MeSH

BACKGROUND: The apolipoprotein E (APOE) ɛ4 allele is associated with episodic memory and spatial navigation deficits. The brain-derived neurotrophic factor (BDNF) Met allele may further worsen memory impairment in APOEɛ4 carriers but its role in APOEɛ4-related spatial navigation deficits has not been established. OBJECTIVE: We examined influence of APOE and BDNF Val66Met polymorphism combination on spatial navigation and volumes of selected navigation-related brain regions in cognitively unimpaired (CU) older adults and those with amnestic mild cognitive impairment (aMCI). METHODS: 187 participants (aMCI [n = 116] and CU [n = 71]) from the Czech Brain Aging Study were stratified based on APOE and BDNF Val66Met polymorphisms into four groups: ɛ4-/BDNFVal/Val, ɛ4-/BDNFMet, ɛ4+/BDNFVal/Val, and ɛ4+/BDNFMet. The participants underwent comprehensive neuropsychological examination, brain MRI, and spatial navigation testing of egocentric, allocentric, and allocentric delayed navigation in a real-space human analogue of the Morris water maze. RESULTS: Among the aMCI participants, the ɛ4+/BDNFMet group had the least accurate egocentric navigation performance (p < 0.05) and lower verbal memory performance than the ɛ4-/BDNFVal/Val group (p = 0.007). The ɛ4+/BDNFMet group had smaller hippocampal and entorhinal cortical volumes than the ɛ4-/BDNFVal/Val (p≤0.019) and ɛ4-/BDNFMet (p≤0.020) groups. Among the CU participants, the ɛ4+/BDNFMet group had less accurate allocentric and allocentric delayed navigation performance than the ɛ4-/BDNFVal/Val group (p < 0.05). CONCLUSION: The combination of APOEɛ4 and BDNF Met polymorphisms is associated with more pronounced egocentric navigation impairment and atrophy of the medial temporal lobe regions in individuals with aMCI and less accurate allocentric navigation in CU older adults.

• Klíčová slova
• Alzheimer’s disease, Morris water maze, apolipoproteins E, brain-derived neurotrophic factor, entorhinal cortex, episodic memory, gene polymorphism, magnetic resonance imaging, mild cognitive impairment, spatial navigation,
• MeSH
• apolipoprotein E4 genetika   MeSH
• kognitivní dysfunkce genetika   patofyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mozkový neurotrofický faktor genetika   MeSH
• polymorfismus genetický MeSH
• prostorová navigace fyziologie   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• apolipoprotein E4 MeSH
• BDNF protein, human MeSH Prohlížeč
• mozkový neurotrofický faktor MeSH

PURPOSE: Identification of demographic, physical/physiological, lifestyle and genetic factors contributing to the onset of dementia, specifically Alzheimer disease (AD), and implementation of novel methods for early diagnosis are important to alleviate prevalence of dementia globally. The Czech Brain Aging Study (CBAS) is the first large, prospective study to address these issues in Central/Eastern Europe by enrolling non-demented adults aged 55+ years, collecting a variety of personal and biological measures and tracking cognitive function over time. PARTICIPANTS: The CBAS recruitment was initiated in 2011 from memory clinics at Brno and Prague University Hospitals, and by the end of 2018, the study included 1228 participants. Annual follow-ups include collection of socioeconomic, lifestyle and personal history information, neurology, neuropsychology, laboratory, vital sign and brain MRI data. In a subset, biomarker assessment (cerebrospinal fluid (CSF) and amyloid positron emission tomography) and spatial navigation were performed. Participants were 69.7±8.1 years old and had 14.6±3.3 years of education at baseline, and 59% were women. By the end of 2018, 31% finished three and more years of follow-up; 9% converted to dementia. Apolipoprotein E status is available from 95% of the participants. The biological sample bank linked to CBAS database contained CSF, serum and DNA. FINDINGS TO DATE: Overall, the findings, mainly from cross-sectional analyses, indicate that spatial navigation is a promising marker of early AD and that it can be distinguished from other cognitive functions. Specificity of several standard memory tests for early AD pathology was assessed with implications for clinical practice. The relationship of various lifestyle factors to cognition and brain atrophy was reported. FUTURE PLANS: Recruitment is ongoing with secured funding. Longitudinal data analyses are currently being conducted. Proposals for collaboration on specific data from the database or biospecimen, as well as collaborations with similar cohort studies to increase sample size, are welcome. Study details are available online (www.cbas.cz).

• Klíčová slova
• dementia, epidemiology, mental health,
• MeSH
• Alzheimerova nemoc epidemiologie   MeSH
• demence epidemiologie   MeSH
• hodnocení rizik MeSH
• kohortové studie MeSH
• lidé středního věku MeSH
• lidé MeSH
• ochranné faktory MeSH
• prospektivní studie MeSH
• senioři MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH