Browsing by Subject "Resting-state functional connectivity"
Now showing 1 - 4 of 4
Results Per Page
Sort Options
Item Multimodal brain age estimates relate to Alzheimer disease biomarkers and cognition in early stages: a cross-sectional observational study(eLife Sciences, 2023-01-06) Millar, Peter R.; Gordon, Brian A.; Luckett, Patrick H.; Benzinger, Tammie L. S.; Cruchaga, Carlos; Fagan, Anne M.; Hassenstab, Jason J.; Perrin, Richard J.; Schindler, Suzanne E.; Allegri, Ricardo F.; Day, Gregory S.; Farlow, Martin R.; Mori, Hiroshi; Nübling, Georg; The Dominantly Inherited Alzheimer Network; Bateman, Randall J.; Morris, John C.; Ances, Beau M.; Neurology, School of MedicineBackground: Estimates of 'brain-predicted age' quantify apparent brain age compared to normative trajectories of neuroimaging features. The brain age gap (BAG) between predicted and chronological age is elevated in symptomatic Alzheimer disease (AD) but has not been well explored in presymptomatic AD. Prior studies have typically modeled BAG with structural MRI, but more recently other modalities, including functional connectivity (FC) and multimodal MRI, have been explored. Methods: We trained three models to predict age from FC, structural (S), or multimodal MRI (S+FC) in 390 amyloid-negative cognitively normal (CN/A-) participants (18-89 years old). In independent samples of 144 CN/A-, 154 CN/A+, and 154 cognitively impaired (CI; CDR > 0) participants, we tested relationships between BAG and AD biomarkers of amyloid and tau, as well as a global cognitive composite. Results: All models predicted age in the control training set, with the multimodal model outperforming the unimodal models. All three BAG estimates were significantly elevated in CI compared to controls. FC-BAG was significantly reduced in CN/A+ participants compared to CN/A-. In CI participants only, elevated S-BAG and S+FC BAG were associated with more advanced AD pathology and lower cognitive performance. Conclusions: Both FC-BAG and S-BAG are elevated in CI participants. However, FC and structural MRI also capture complementary signals. Specifically, FC-BAG may capture a unique biphasic response to presymptomatic AD pathology, while S-BAG may capture pathological progression and cognitive decline in the symptomatic stage. A multimodal age-prediction model improves sensitivity to healthy age differences.Item Oxytocin, PTSD, and Sexual Abuse are Associated with Attention Network Intrinsic Functional Connectivity(Elsevier, 2021) Crum, Kathleen I.; Flanagan, Julianne C.; Vaughan, Brandon; Aloi, Joseph; Moran-Santa Maria, Megan M.; Back, Sudie E.; Brady, Kathleen T.; Joseph, Jane E.; Psychiatry, School of MedicineChildhood maltreatment is linked to Posttraumatic Stress Disorder (PTSD) in adulthood. Neural attention network function contributes to resilience against PTSD following maltreatment; oxytocin administration alters functional connectivity differentially among resilient to PTSD groups. The present study examined intrinsic connectivity between ventral and dorsal neural attention networks (VAN and DAN) to clarify the nature of dysfunction versus resilience in the context of maltreatment-related PTSD, and to explore differential dysfunction related to varied aspects of maltreatment. Oxytocin administration was examined as a factor in these relationships. Resting-state functional connectivity data were collected from 39 adults with maltreatment histories, with and without PTSD, who were randomly assigned to receive oxytocin or placebo. We found that PTSD and sexual abuse (SA) were associated with reduced VAN-DAN connectivity. There were no significant effects with regard to physical abuse. Oxytocin was associated with greater VAN-DAN connectivity strength. These preliminary findings suggest dysfunction within attentional systems in PTSD, as well as following SA. Further, oxytocin may help ameliorate attentional neurocircuitry dysfunction in individuals with PTSD and those with maltreatment histories.Item Resting-State Functional Connectivity Disruption as a Pathological Biomarker in Autosomal Dominant Alzheimer Disease(Mary Ann Liebert, 2021) Smith, Robert X.; Strain, Jeremy F.; Tanenbaum, Aaron; Fagan, Anne M.; Hassenstab, Jason; McDade, Eric; Schindler, Suzanne E.; Gordon, Brian A.; Xiong, Chengjie; Chhatwal, Jasmeer; Jack, Clifford, Jr.; Karch, Celeste; Berman, Sarah; Brosch, Jared R.; Lah, James J.; Brickman, Adam M.; Cash, David M.; Fox, Nick C.; Graff-Radford, Neill R.; Levin, Johannes; Noble, James; Holtzman, David M.; Masters, Colin L.; Farlow, Martin R.; Laske, Christoph; Schofield, Peter R.; Marcus, Daniel S.; Morris, John C.; Benzinger, Tammie L. S.; Bateman, Randall J.; Ances, Beau M.; Neurology, School of MedicineAim: Identify a global resting-state functional connectivity (gFC) signature in mutation carriers (MC) from the Dominantly Inherited Alzheimer Network (DIAN). Assess the gFC with regard to amyloid (A), tau (T), and neurodegeneration (N) biomarkers, and estimated years to symptom onset (EYO). Introduction: Cross-sectional measures were assessed in MC (n = 171) and mutation noncarrier (NC) (n = 70) participants. A functional connectivity (FC) matrix that encompassed multiple resting-state networks was computed for each participant. Methods: A global FC was compiled as a single index indicating FC strength. The gFC signature was modeled as a nonlinear function of EYO. The gFC was linearly associated with other biomarkers used for assessing the AT(N) framework, including cerebrospinal fluid (CSF), positron emission tomography (PET) molecular biomarkers, and structural magnetic resonance imaging. Results: The gFC was reduced in MC compared with NC participants. When MC participants were differentiated by clinical dementia rating (CDR), the gFC was significantly decreased in MC CDR >0 (demented) compared with either MC CDR 0 (cognitively normal) or NC participants. The gFC varied nonlinearly with EYO and initially decreased at EYO = −24 years, followed by a stable period followed by a further decline near EYO = 0 years. Irrespective of EYO, a lower gFC associated with values of amyloid PET, CSF Aβ1–42, CSF p-tau, CSF t-tau, 18F-fluorodeoxyglucose, and hippocampal volume. Conclusions: The gFC correlated with biomarkers used for defining the AT(N) framework. A biphasic change in the gFC suggested early changes associated with CSF amyloid and later changes associated with hippocampal volume.Item Sex-specific frontal-striatal connectivity differences among adolescents with externalizing disorders(Elsevier, 2021) Chai, Ya; Chimelis-Santiago, José R.; Bixler, Kristy A.; Aalsma, Matthew; Yu, Meichen; Hulvershorn, Leslie A.; Psychiatry, School of MedicineBackground: Sex-specific neurobiological underpinnings of impulsivity in youth with externalizing disorders have not been well studied. The only report of functional connectivity (FC) findings in this area demonstrated sex differences in fronto-subcortical connectivity in youth with attention-deficit/hyperactivity disorder (ADHD). Methods: The current study used functional magnetic resonance imaging(fMRI) to examine sex differences in resting-state seed-based FC, self-rated impulsivity, and their interactions in 11-12-year-old boys (n = 43) and girls (n = 43) with externalizing disorders. Generalized linear models controlling for pubertal development were used. Seeds were chosen in the ventral striatum, medial prefrontal cortex, middle frontal gyrus and amygdala. Results: Impulsivity scores were greater in boys than girls (p < 0.05). Boys showed greater positive connectivity within a ventromedial prefrontal-ventral striatal network. In addition, boys demonstrated weaker connectivity than girls within two medial-lateral prefrontal cortical networks. However, only boys showed greater medial-lateral prefrontal connectivity correlated with greater impulsivity. Conclusions: The findings provide evidence supporting sex differences in both ventral striatal-ventromedial prefrontal and medial-lateral prefrontal functional networks in youth with externalizing disorders. These important networks are thought to be implicated in impulse control. Medial-lateral prefrontal connectivity may represent a male-specific biomarker of impulsivity.