BACKGROUND: Limited research has explored the effect of cardiovascular risk and amyloid interplay on cognitive decline in East Asians.METHODS: Vascular burden was quantified using Framingham's General Cardiovascular Risk Score (FRS) in 526 Korean Brain Aging Study (KBASE) participants. Cognitive differences in groups stratified by FRS and amyloid positivity were assessed at baseline and longitudinally.RESULTS: Baseline analyses revealed that amyloid‐negative (Aβ–) cognitively normal (CN) individuals with high FRS had lower cognition compared to Aβ– CN individuals with low FRS (p < 0.0001). Longitudinally, amyloid pathology predominantly drove cognitive decline, while FRS alone had negligible effects on cognition in CN and mild cognitive impairment (MCI) groups.CONCLUSION: Our findings indicate that managing vascular risk may be crucial in preserving cognition in Aβ– individuals early on and before the clinical manifestation of dementia. Within the CN and MCI groups, irrespective of FRS status, amyloid‐positive individuals had worse cognitive performance than Aβ– individuals.Highlights: Vascular risk significantly affects cognition in amyloid‐negative older Koreans. Amyloid‐negative CN older adults with high vascular risk had lower baseline cognition. Amyloid pathology drives cognitive decline in CN and MCI, regardless of vascular risk. The study underscores the impact of vascular health on the AD disease spectrum.

Like many social behaviors, aggression can be rewarding, leading to behavioral plasticity. One outcome of reward-induced aggression is the long-term increase in the speed in which future aggression-based encounters is initiated. This form of aggression impacts dendritic structure and excitatory synaptic neurotransmission in the nucleus accumbens, a brain region well known to regulate motivated behaviors. Yet, little is known about the intracellular signaling mechanisms that drive these structural/functional changes and long-term changes in aggressive behavior. This study set out to further elucidate the intracellular signaling mechanisms regulating the plasticity in neurophysiology and behavior that underlie the rewarding consequences of aggressive interactions. Female Syrian hamsters experienced zero, two or five aggressive interactions and the phosphorylation of proteins in reward-associated regions was analyzed. We report that aggressive interactions result in a transient increase in the phosphorylation of extracellular-signal related kinase 1/2 (ERK1/2) in the nucleus accumbens. We also report that aggressive interactions result in a transient decrease in the phosphorylation of mammalian target of rapamycin (mTOR) in the medial prefrontal cortex, a major input structure to the nucleus accumbens. Thus, this study identifies ERK1/2 and mTOR as potential signaling pathways for regulating the long-term rewarding consequences of aggressive interactions. Furthermore, the recruitment profile of the ERK1/2 and the mTOR pathways are distinct in different brain regions.

INTRODUCTION: Higher adherence to the Mediterranean‐DASH (Dietary Approaches to Stop Hypertension) Intervention for Neurodegenerative Delay (MIND) diet has been associated with reduced Alzheimer's disease (AD) risk. This study assessed the validity of a brief 15‐item MIND diet screener compared to a comprehensive food frequency questionnaire (FFQ). METHODS: The validity of an adapted MIND diet screener relative to the VioScreen FFQ was evaluated in 92 older adults from the Indiana Alzheimer's Disease Research Center (IADRC). Correlation coefficients and tertile‐based classification statistics were used, and FFQ nutrient profiles were examined across screener‐based MIND diet tertiles. RESULTS: MIND diet scores from the screener showed strong positive correlation ( r = 0.71, ρ = 0.70, p < 0.001) and comparable ranking ability (63% correctly classified, 1% grossly misclassified, k _w  = 0.67) compared to those from the FFQ, as well as significant associations with nutrient profiles. CONCLUSION: The MIND diet screener is an acceptable, time‐efficient tool for estimating MIND diet scores in older adults. Highlights: The MIND diet screener effectively differentiated participants by diet quality. Agreement between instrument scores was consistent across diagnostic groups. Reliability of the screener over approximately 1 year was comparable to the FFQ. The MIND diet screener is an acceptable tool for use in time‐constrained settings. Future studies should confirm validity using objective biomarkers.

The BrainAGE method is used to estimate biological brain age using structural neuroimaging. However, the stability of the model across different scan parameters and races/ethnicities has not been thoroughly investigated. Estimated brain age was compared within- and across-MRI field strength and across voxel sizes. Estimated brain age gap (BAG) was compared across demographically matched groups of different self-reported races and ethnicities in ADNI and IMAS cohorts. Longitudinal ComBat was used to correct for potential scanner effects. The brain age method was stable within field strength, but less stable across different field strengths. The method was stable across voxel sizes. There was a significant difference in BAG between races, but not ethnicities. Correction procedures are suggested to eliminate variation across scanner field strength while maintaining accurate brain age estimation. Further studies are warranted to determine the factors contributing to racial differences in BAG.

Traumatic brain injury (TBI) has been discussed as a risk factor for Alzheimer’s disease (AD) due to its association with dementia risk and earlier cognitive symptom onset. However, the mechanisms behind this relationship are unclear. Some studies have suggested TBI may increase pathological protein deposition in an AD-like pattern; others have failed to find such associations. This review covers literature that uses positron emission tomography (PET) of amyloid-β and/or tau to examine subjects with history of TBI who are at risk for AD due to advanced age. A comprehensive literature search was conducted on January 9, 2023, and 24 resulting citations met inclusion criteria. Common methodological concerns included small samples, limited clinical detail about subjects’ TBI, recall bias due to reliance on self-reported TBI, and an inability to establish causation. For both amyloid and tau, results were widespread but inconsistent. The regions which showed the most compelling evidence for increased amyloid deposition were the cingulate gyrus, cuneus/precuneus, and parietal lobe. Evidence for increased tau was strongest in the medial temporal lobe, entorhinal cortex, precuneus, and frontal, temporal, parietal, and occipital lobes. However, conflicting findings across most regions of interest in both amyloid- and tau-PET studies indicate the critical need for future work in expanded samples and with greater clinical detail to offer a clearer picture of the relationship between TBI and protein deposition in older subjects at risk for AD.

Background: The Mediterranean diet has been associated with decreased brain atrophy (Staubo et al. 2016,Alz&Dem), but the MIND (Mediterranean‐Dietary Approaches to Stop Hypertension (DASH) Intervention for Neurodegenerative Delay) diet, designed for dementia prevention (Morris et al. 2015, Alz&Dem), remains underexplored for its impact on brain atrophy. We investigated the MIND diet’s association with cortical thickness (CT) in the Indiana Alzheimer’s Disease Research Center (IADRC) sample.Methods: 134 participants (49 CN, 45 SCD, 30 MCI, 10 AD/other) completed a self‐report MIND diet questionnaire at the IADRC, which was coded into high, medium, or low intake groups for each food (5 ‘unhealthy’ food groups were reverse scored) and completed an MRI scan on a 3T scanner. The cortical surface was parcellated using FreeSurfer v6. We selected two regions of interest (ROIs) reflecting AD‐associated neurodegeneration: temporal and global CT. We examined the association of MIND diet scores (0‐15) and food groups with CT using regression models adjusted for age, sex, race, education, and diagnosis.Results: Higher MIND diet scores were associated with greater mean temporal CT (r = 0.269, p = 0.002) and greater mean global CT (r = 0.230, p = 0.008). In multivariable‐adjusted models, the association persisted for temporal but not global CT. Among the 15 food components, greater olive oil (r = 0.034, p<0.001), fish (r = 0.181, p = 0.040), beans (r = 0.237, p = 0.008), and nuts (r = 0.214, p = 0.014), and reduced fast food intake (r = 0.188, p = 0.035) were significantly associated with temporal CT. These associations, except for nuts, remained significant in multivariable‐adjusted models, with an additional relationship found for chicken (r = 0.189, p = 0.038). Among the 15 food components, greater olive oil (r = 0.243, p = 0.008), and beans (0.180, p = 0.044), and reduced fast food (r = 0.212, p = 0.017) were significantly associated with global CT. Only reduced fast food retained significance in the multivariable‐adjusted models.Conclusions: Greater adherence to the MIND diet was associated with greater CT in both global and temporal regions. Specific components, including increased olive oil, beans, nuts, fish, and reduced fast food, showed significant associations with CT, suggesting elements within the diet driving this association. These findings highlight the potential neuroprotective effects of the MIND diet, emphasizing the importance of dietary patterns in preserving brain health during aging.