Novel inductively coupled ear-bars (ICEs) to enhance restored fMRI signal from susceptibility compensation in rats.

Functional magnetic resonance imaging faces inherent challenges when applied to deep-brain areas in rodents, e.g. entorhinal cortex, due to the signal loss near the ear cavities induced by susceptibility artifacts and reduced sensitivity induced by the long distance from the surface array coil. Given the pivotal roles of deep brain regions in various diseases, optimized imaging techniques are needed. To mitigate susceptibility-induced signal losses, we introduced baby cream into the middle ear. To enhance the detection sensitivity of deep brain regions, we implemented inductively coupled ear-bars, resulting in approximately a 2-fold increase in sensitivity in entorhinal cortex. Notably, the inductively coupled ear-bar can be seamlessly integrated as an add-on device, without necessitating modifications to the scanner interface. To underscore the versatility of inductively coupled ear-bars, we conducted echo-planner imaging-based task functional magnetic resonance imaging in rats modeling Alzheimer's disease. As a proof of concept, we also demonstrated resting-state-functional magnetic resonance imaging connectivity maps originating from the left entorhinal cortex-a central hub for memory and navigation networks-to amygdala hippocampal area, Insular Cortex, Prelimbic Systems, Cingulate Cortex, Secondary Visual Cortex, and Motor Cortex. This work demonstrates an optimized procedure for acquiring large-scale networks emanating from a previously challenging seed region by conventional magnetic resonance imaging detectors, thereby facilitating improved observation of functional magnetic resonance imaging outcomes.

Aberrant memory system connectivity and working memory performance in subjective cognitive decline.

Subjective cognitive decline, a perceived worsening of cognitive functioning without objective deficit on assessment, could indicate incipient dementia. However, the neural correlates of subjective cognitive decline as assessed by magnetic resonance imaging remain somewhat unclear. Here, we evaluated differences in functional connectivity across memory regions, and cognitive performance, between healthy older adults aged 50 to 85 with (n = 35, Age = 68.5 ±â€¯7.7, 22 female), and without (n = 48, Age = 67.0 ±â€¯8.8, 29 female) subjective cognitive decline. We also evaluated neurite density, fractional anisotropy, and mean diffusivity of the parahippocampal cingulum, cingulate gyrus cingulum, and uncinate fiber bundles in a subsample of participants (n = 37). Participants with subjective cognitive decline displayed lower average functional connectivity across regions of a putative posterior memory system, and lower retrosplenial-precuneus functional connectivity specifically, than those without memory complaints. Furthermore, participants with subjective cognitive decline performed poorer than controls on visual working memory. However, groups did not differ in cingulum or uncinate diffusion measures. Our results show differences in functional connectivity and visual working memory in participants with subjective cognitive decline that could indicate potential incipient dementia.

Functional connectivity of cortical resting-state networks is differentially affected by rest conditions.

Optimal conditions for resting-state functional magnetic resonance imaging (rs-fMRI) are still highly debated. Here, we comprehensively assessed the effects of various rest conditions on all cortical resting-state networks (RSNs) defined by an established atlas. Twenty-two healthy college students (22 ± 4 years old, 12 females) were scanned on a GE 3T MRI scanner. Rs-fMRI datasets were collected under four different conditions for each subject: (1) eyes open in dim light (Eyes-Open), (2) eyes closed and awake (Eyes-Closed), (3) eyes closed while remembering four numbers through the scan session (Eyes-Closed-Number) and (4) asked to watch a movie (Movie). We completed a thorough examination of the 17 functional RSNs defined by Yeo and colleagues. Importantly, the movie led to changes in global connectivity and should be avoided as a rest condition. Conversely, there were no significant connectivity differences between conditions within the frontoparietal control and limbic networks and the following subnetworks as defined by Yeo et al.: default-B, dorsal-attention-B and salience/ventral-attention-B. These were not even significant when compared to the highly stimulative Movie condition. A significant difference was not found between Eyes-Closed and Eyes-Closed-Number conditions in whole-brain, within-network and between-network comparisons. When considering other rest conditions, however, we observed connectivity changes in some subnetworks, including those of the default-mode network. Overall, we found conditions with more external stimulation led to more changes in functional connectivity during rs-fMRI. In conclusion, the comprehensive results of our study can aid in choosing rest conditions for the study of overall and specific functional networks.

Implementation of a Healthy Food and Beverage Policy at a Public University.

University nutrition policies are a useful step toward improving the food environment for students, faculty, and staff, leading to improved health outcomes for the campus community. As 1 of the first universities to adopt and implement a campus-wide nutrition policy, the objective of this report is to share the university's experience with policy development, implementation, monitoring and evaluation, challenges, facilitators, and recommendations to inform these processes for future university nutrition policies.