Faculty Bibliography

Small-animal diffusion MRI (dMRI) has been used for methodological development and validation, characterizing the biological basis of diffusion phenomena, and comparative anatomy. The steps from animal setup and monitoring, to acquisition, analysis, and interpretation are complex, with many decisions that may ultimately affect what questions can be answered using the resultant data. This work aims to present selected considerations and recommendations from the diffusion community on best practices for preclinical dMRI of in vivo animals. We describe the general considerations and foundational knowledge that must be considered when designing experiments. We briefly describe differences in animal species and disease models and discuss why some may be more or less appropriate for different studies. We, then, give recommendations for in vivo acquisition protocols, including decisions on hardware, animal preparation, and imaging sequences, followed by advice for data processing including preprocessing, model-fitting, and tractography. Finally, we provide an online resource that lists publicly available preclinical dMRI datasets and software packages to promote responsible and reproducible research. In each section, we attempt to provide guides and recommendations, but also highlight areas for which no guidelines exist (and why), and where future work should focus. Although we mainly cover the central nervous system (on which most preclinical dMRI studies are focused), we also provide, where possible and applicable, recommendations for other organs of interest. An overarching goal is to enhance the rigor and reproducibility of small animal dMRI acquisitions and analyses, and thereby advance biomedical knowledge.

BACKGROUND:Despite evidence supporting the efficacy of culturally tailored interventions in reducing stigma, such approaches are lacking for women living with HIV/AIDS (WLWHAs) in China. We conducted this study to determine the efficacy of the culturally tailored Helping Overcome Perceived Stigma (HOPES) intervention in reducing perceived stigma among WLWHAs in China. METHODS:A single-blinded, two-arm parallel-group randomized clinical trial was conducted from 2023 to 2024 in South and Southwest China. WLWHAs from four hospitals were assigned using a WeChat-embedded randomization application to the control group (usual care) or the HOPES intervention. Data analysts remained blinded. Interventions were conducted virtually using Leave No One Behind (LNOB) platform for 3 months. The primary outcome, perceived stigma score, was assessed at baseline, immediately after the intervention and at 3 months post-intervention using 7 items from the HIV/AIDS Stigma Experience Questionnaire (HASEQ), with data analyzed through repeated measures analysis. RESULTS:Of 136 WLWHAs screened, we randomized 101 WLWHAs (50 HOPES; 51 controls). The HOPES group demonstrated a statistically significant reduction in perceived stigma scores immediately after the intervention (-3.86 points, 95 % CI: 5.34 to -2.38, P < .001) and at three months post-intervention (-5.83 points, 95 % CI: 7.20 to -4.47, P < .001) compared to the control group. CONCLUSION/CONCLUSIONS:The findings demonstrate HOPES' efficacy in reducing perceived stigma in WLWHA. However, the clinical significance of these changes needs further investigation. Future research should focus on defining meaningful patient-reported thresholds, assessing long-term impact, and optimizing delivery methods.

BackgroundRespiratory impairment in neuromuscular disorders (NMDs) is generally assessed using forced vital capacity (FVC). Any improvement in FVC trajectory will delay ventilatory support; however, the change required for patients to perceive a noticeable clinical benefit, the clinically meaningful threshold (CMT), has not been defined in NMDs.ObjectiveTo derive the within-person and between-group CMTs for FVC (% predicted) in patients with late-onset Pompe disease (LOPD).MethodsThis analysis leverages data from the Phase 3 COMET trial (NCT02782741, registered 25 May 2016), which assessed the efficacy of avalglucosidase alfa (AVA) versus alglucosidase alfa (ALG) on upright FVC (% predicted) in LOPD. Anchor- and distribution-based methods were used to estimate the within-person and between-group CMTs for FVC at Weeks 49 and 97.ResultsCOMET enrolled 99 participants aged ≥18 years (52% male; mean age 48.0 years). The within-person CMT for absolute change in FVC expressed as % predicted was estimated as 3.0% [95% confidence interval (CI) 2.3, 3.8]. The proportion of patients with a meaningful increase in FVC was higher in the AVA versus ALG group across the CI of the estimated CMT (odds ratios: 2.3-2.6; nominal p-values: 0.026-0.058). The between-group CMT, needed to evaluate differences between treatment groups, was estimated as 2.1% predicted [95% CI 1.1, 3.1].ConclusionsWe identified a narrow range of within-person and between-group CMTs for upright FVC (% predicted) in LOPD. Post hoc application of these thresholds to COMET showed that a greater proportion of patients in the AVA group had clinically meaningful improvement in FVC versus ALG. These findings may aid in interpretation of data from studies in other NMDs.

Cortical GABAergic interneurons (INs) are comprised of distinct types that provide tailored inhibition to pyramidal cells (PCs) and other INs, thereby enabling precise control of cortical circuit activity. INs expressing the neuropeptide vasoactive-intestinal peptide (VIP) have attracted attention recently following the discovery that they predominantly function by inhibiting dendritic-targeting somatostatin (SST) expressing INs, thereby disinhibiting PCs. This VIP-SST disinhibitory circuit motif is observed throughout the neocortex from mice to humans, and serves as a key mechanism for top-down (feedback) and context-dependent information processing. Thus, VIP IN-mediated disinhibition has been found to play an important role in sensory processing, control of executive functions, attention, sensorimotor integration and other cortico-cortical and thalamocortical feedback interactions. Furthermore, VIP INs have been implicated in mediating the effects of reinforcement signals, both reward and aversive, via their responsiveness to neuromodulators such as acetylcholine (ACh), and in facilitating synaptic plasticity and learning. While it is evident from transcriptomic analyses that VIP INs are a molecularly heterogeneous group, the physiological significance of this diversity is unclear at present. Here, we have characterized the functional diversity of VIP INs in the primary somatosensory cortex by leveraging intersectional genetic approaches to study distinct VIP IN subtypes. We found that VIP INs can be divided into four different populations: a group that expresses the Ca²⁺-binding protein calretinin (CR), two distinct groups that express the neuropeptide cholecystokinin (CCK), and a group that does not express either CR or CCK (non-CCK non-CR; or nCCK nCR). VIP neurons in each group exhibit different laminar distributions, axonal and dendritic arbors, intrinsic electrophysiological properties, and efferent connectivity, VIP/CR INs target almost exclusively SST INs, VIP/nCCK nCR INs also mainly target SST INs but also have connections to parvalbumin (PV) expressing INs. These two groups have essentially no connectivity to pyramidal cells (PCs). On the other hand, the two types of VIP/CCK INs target PCs, but differ in the degree to which synaptic release from each type is modulated by endocannabinoids. We also found that long-range inputs differentially recruit distinct VIP IN groups. Intriguingly, we find that distinct VIP IN populations target distinct SST INs subtypes in turn, indicating the presence of specialized VIP-SST disinhibitory subcircuits. Activation of distinct VIP IN subpopulations in vivo results in differential effects on the cortical network, thus providing evidence for modularity in VIP IN-mediated actions during cortical information processing.

BACKGROUND:Hyperexcitability in Alzheimer's disease (AD) is proposed to emerge early and contribute to disease progression. The dentate gyrus (DG) and its primary cell type, granule cells (GCs) are implicated in hyperexcitability in AD. Hence, we hypothesized that mossy cells (MCs), important regulators of GC excitability, contribute to early hyperexcitability in AD. Indeed, MCs and GCs are linked to hyperexcitability in epilepsy. METHODS:Using the Tg2576 model of AD and WT mice (~ 1 month-old), we compared MCs and GCs electrophysiologically and morphologically, assessed the activity marker c-Fos, Aβ expression and a hippocampal- and MC-dependent memory task that is impaired at 3-4 months of age in Tg2576 mice. RESULTS:Tg2576 MCs had increased spontaneous excitatory events (sEPSP/Cs) and decreased spontaneous inhibitory currents (sIPSCs), increasing the excitation/inhibition ratio. Additionally, Tg2576 MC intrinsic excitability was enhanced. Consistent with in vitro results, Tg2576 MCs showed enhanced c-Fos protein expression. Tg2576 MCs had increased intracellular Aβ expression, suggesting a reason for increased excitability. GCs showed increased excitatory and inhibitory input without changes in intrinsic properties, consistent with effects of increased MC activity. In support, increased GC activity was normalized by an antagonist of MC input to GCs. Also in support, Tg2576 MC axons showed sprouting to the area of GC dendrites. These effects occurred before an impairment in the memory task, suggesting they are extremely early alterations. CONCLUSIONS:Alterations in Tg2576 MCs and GCs early in life suggest an early role for MCs in increased GC excitability. MCs may be a novel target to intervene in AD pathophysiology at early stages.

BACKGROUND:), can be self- or caregiver-administered at home with fixed-dosing for patients ≥ 12 years of age. This real-world study aimed to understand treatment preferences among individuals with PH1, highlighting challenges in administration of current treatments. METHODS:A cross-sectional web-based survey was conducted among U.S.-based adults (aged ≥ 18) diagnosed with PH1. The survey consisted of a 20-25 min questionnaire and was conducted from October to December 2023. RESULTS:The study participants (N = 39) included both male (N = 26) and female (N = 13) adults with PH1. Participants came from a range of community settings, including urban (46%), rural (39%), and suburban (15%); and were full- or part-time workers (56%) or students (41%). Most participants were on lumasiran therapy (95%) for an average of 1 year (range: 0.3-1.8 years). The survey revealed that the commonly reported factors important for treatment selection among participants living with PH1 were frequency of administration, treatment administrator, time required for treatment, and place of administration. The ability to self-administer was ranked as the top choice by most participants. Over half (56%) found quarterly injections easy or very easy. Similarly, 56-59% found home administration, whether self- or healthcare provider (HCP)-administered, easy or very easy. Nearly half (46%) considered injections at medical facilities challenging or very challenging. The majority indicated traveling > 15 min for injections would be burdensome (57%) and arranging appointments problematic (54%). When comparing administration methods, 72% preferred self-injection over HCP-administered injections. Regarding treatment regimens, 57% found it easy or very easy to receive monthly injections initially, before switching to quarterly. Additionally, 64% preferred a medication dosage that is not weight-based. While participants expressed a preference for less frequent treatments, 67% preferred self-injection at home over medical facility injections, and 67% preferred monthly injections at home over quarterly injections at a medical facility. CONCLUSIONS:This study shows that patients with PH1 value treatments that are convenient and fit their lifestyle.

This perspective proposes adapting video-text generative AI to 3D medical imaging (CT/MRI) and medical videos (endoscopy/laparoscopy) by treating 3D images as videos. The approach leverages modern video models to analyze multiple sequences simultaneously and provide real-time AI assistance during procedures. The paper examines medical imaging's unique characteristics (synergistic information, metadata, and world model), outlines applications in automated reporting, case retrieval, and education, and addresses challenges of limited datasets, benchmarks, and specialized training.

UNLABELLED:Research supports an association between diet and health, and emerging evidence suggests that diet is associated with neuropsychiatric symptoms. However, no human study has examined an anti-inflammatory diet across rigorously defined psychiatric diagnoses and its associations with symptom severity and cognition. As inflammation is implicated in mental illness, we investigated adherence to the Mediterranean diet (MD), an anti-inflammatory diet, and the standard American diet (SAD), and examined cross-sectional relationships with psychiatric symptoms and cognition. METHOD/METHODS:Participants included 54 individuals with psychotic disorders, 30 with non-psychosis affective disorders and 40 healthy controls. Participants underwent diagnostic interviews, PANSS symptom ratings, and MATRICS cognitive assessments. The self-report GBAQ was used to assess adherence to the MD versus SAD. RESULTS:The psychosis group was significantly more likely to consume the SAD than healthy controls (p = 0.007), with MD adherence predicting better working memory (r = 0.461, p < 0.001). In the non-psychosis affective disorders group, MD adherence predicted slower processing speed (r = -0.376, p = 0.049). In the non-psychosis affective disorders group, MD predicted reduced PANSS General Psychopathology scale (r = -0.449, p = 0.013), as well as the Activation (r = -0.362, p = 0.049), and Dysphoric Mood factors (r = -0.403, p = 0.027). DISCUSSION/CONCLUSIONS:This first-of-its kind study identified poor dietary choices in persons with psychosis, showing significantly lower symptoms and better cognition in association with the MD in transdiagnostic analyses. It supports the study of dietary interventions for prevention and treatment of psychiatric conditions.

The structure of compound eyes in arthropods has been the subject of many studies, revealing important biological principles. Until recently, these studies were constrained by the two-dimensional nature of available ultrastructural data. By taking advantage of the novel three-dimensional ultrastructural dataset obtained using volume electron microscopy, we present the first cellular-level reconstruction of the whole compound eye of an insect, the miniaturized parasitoid wasp Megaphragma viggianii. The compound eye of the female M. viggianii consists of 29 ommatidia and contains 478 cells. Despite the almost anucleate brain, all cells of the compound eye contain nuclei. As in larger insects, the dorsal rim area of the eye in M. viggianii contains ommatidia that are believed to be specialized in polarized light detection as reflected in their corneal and retinal morphology. We report the presence of three 'ectopic' photoreceptors. Our results offer new insights into the miniaturization of compound eyes and scaling of sensory organs in general.

This study investigated the potential of combining multiple MR parameters to enhance the characterization of myelin in the mouse brain. We collected ex vivo multiparametric MR data at 7 T from control and Gli1^-/- mice; the latter exhibit enhanced myelination at Postnatal Day 10 (P10) in the corpus callosum and cortex. The MR data included relaxivity, magnetization transfer, and diffusion measurements, each targeting distinct myelin properties. This analysis was followed by and compared to myelin basic protein (MBP) staining of the same samples. Although a majority of the MR parameters included in this study showed significant differences in the corpus callosum between the control and Gli1^-/- mice, only T₂, T₁/T₂, and radial diffusivity (RD) demonstrated a significant correlation with MBP values. Based on data from the corpus callosum, partial least square regression suggested that combining T₂, T₁/T₂, and inhomogeneous magnetization transfer ratio could explain approximately 80% of the variance in the MBP values. Myelin predictions based on these three parameters yielded stronger correlations with the MBP values in the P10 mouse brain corpus callosum than any single MR parameter. In the motor cortex, combining T₂, T₁/T₂, and radial kurtosis could explain over 90% of the variance in the MBP values at P10. This study demonstrates the utility of multiparametric MRI in improving the detection of myelin changes in the mouse brain.