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Journal of Affective Disorders Feb 2022We previously found that blood pressure (BP) is elevated, and associated with poorer neurocognition, in youth with bipolar disorder (BD). While higher BP is associated...
BACKGROUND
We previously found that blood pressure (BP) is elevated, and associated with poorer neurocognition, in youth with bipolar disorder (BD). While higher BP is associated with smaller brain structure in adults, studies have not examined this topic in BD or youth.
METHODS
Participants were 154 youth, ages 13-20 (n = 81 BD, n = 73 HC). Structural magnetic resonance imaging and diastolic (DBP), and systolic (SBP) pressure were obtained. Region of interest (ROI; anterior cingulate cortex [ACC], insular cortex, hippocampus) and vertex-wise analyses controlling for age, sex, body-mass-index, and intracranial volume investigated BP-neurostructural associations; a group-by-BP interaction was also assessed.
RESULTS
In ROI analyses, higher DBP in the overall sample was associated with smaller insular cortex area (β=-0.18 p = 0.007) and was associated with smaller ACC area to a significantly greater extent in HC vs. BD (β=-0.14 p = 0.015). In vertex-wise analyses, higher DBP and SBP were associated with smaller area and volume in the insular cortex, frontal, parietal, and temporal regions in the overall sample. Additionally, higher SBP was associated with greater thickness in temporal and parietal regions. Finally, higher SBP was associated with smaller area and volume in frontal, parietal, and temporal regions to a significantly greater extent in BD vs. HC.
LIMITATIONS
Cross-sectional design, single assessment of BP.
CONCLUSION
BP is associated with brain structure in youth, with variability related to structural phenotype (volume vs. thickness) and psychiatric diagnosis (BD vs. HC). Future studies evaluating temporality of these findings, and the association of BP changes on brain structure in youth, are warranted.
Topics: Adolescent; Adult; Bipolar Disorder; Blood Pressure; Brain; Cross-Sectional Studies; Humans; Insular Cortex; Magnetic Resonance Imaging; Young Adult
PubMed: 34920038
DOI: 10.1016/j.jad.2021.12.028 -
Psychiatry Research. Neuroimaging Oct 2021Repetitive negative thinking (RNT) is a cognitive process characterised by intrusive, repetitive, and difficult-to-disengage-from negative thoughts. Heightened RNT... (Review)
Review
Repetitive negative thinking (RNT) is a cognitive process characterised by intrusive, repetitive, and difficult-to-disengage-from negative thoughts. Heightened RNT levels are prevalent across clinical disorders and have been associated with ill-health (e.g. cardiovascular disease), even at lower, non-clinical levels. Identifying the neuroanatomical correlates of RNT could help characterise structural alterations that transcend diagnostic boundaries and further understanding of the pathogenesis of clinical disorders. We therefore conducted a systematic review to investigate associations between RNT and brain morphology. Following title/abstract and full-text screening, 24 studies were included. We found evidence that RNT severity is associated with grey and white matter volumes/microstructure, particularly in the dorsolateral prefrontal cortex, anterior cingulate cortex and superior longitudinal fasciculus, regions heavily implicated in cognitive control, and emotional processing and regulation. However, inconsistent associations, potentially due to the heterogeneity of included studies (e.g. methodological differences, type of RNT assessed), preclude specific conclusions being reached regarding any one region's association with RNT. Further, given the defuse nature of thoughts, it may be that RNT is associated with distributed brain regions operating within large-scale networks, rather than with a single structure. High quality longitudinal studies, investigating structural networks, are required to confirm the neuroanatomical basis of RNT and elucidate the direction of relationships.
Topics: Brain; Humans; Longitudinal Studies; Pessimism; Prefrontal Cortex; Surveys and Questionnaires
PubMed: 34390952
DOI: 10.1016/j.pscychresns.2021.111353 -
Journal of Alzheimer's Disease : JAD 2022Olfactory deficits are early features of preclinical Alzheimer's disease (AD). Whether olfaction is associated with PET biomarkers among community-dwelling older adults...
BACKGROUND
Olfactory deficits are early features of preclinical Alzheimer's disease (AD). Whether olfaction is associated with PET biomarkers among community-dwelling older adults is less clear.
OBJECTIVE
Investigate cross-sectional and longitudinal associations of olfaction with mild cognitive impairment (MCI) and amyloid-β (Aβ) and tau deposition.
METHODS
We analyzed 364 initially cognitively normal participants (58% women, 24% black) who had baseline olfaction data and subsequent cognitive assessments during an average 2.4-year. A subset of 129 had PET-PiB (Aβ) (n = 72 repeated) and 105 had 18F-flortaucipir (FTP)-PET (tau) (n = 44 repeated). Olfaction was measured using a 16-item Sniffin' Sticks Odor Identification Test. The association of olfaction with incident MCI was examined using Cox regression. Associations with PiB-distribution volume ratio (DVR) and FTP-standardized uptake value ratio (SUVR) were examined using partial correlation. We tested whether PiB+/-status modified these associations. Analyses were adjusted for demographics and olfactory test version.
RESULTS
17 (5%) participants developed MCI. Each unit lower odor identification score was associated with 22% higher risk of developing MCI (p = 0.04). In the PET subset, lower scores were associated with higher mean cortical DVR and DVR in orbitofrontal cortex (OFC), precuneus, and middle temporal gyrus (p≤0.04). The "olfaction*PiB+/-" interaction in OFC DVR was significant (p = 0.03), indicating the association was limited to PiB positive individuals. Greater decline in odor identification score was associated with greater increase in anterior OFC DVR and entorhinal tau SUVR (p≤0.03).
CONCLUSION
Among community-dwelling older adults, poorer olfaction predicts incident MCI and is associated with overall and regional Aβ. Greater olfaction decline is associated with faster Aβ and tau accumulation in olfaction-related regions. Whether olfaction predicts AD-related neurodegenerative changes warrants further investigations.
Topics: Aged; Alzheimer Disease; Amyloid beta-Peptides; Biomarkers; Cognitive Dysfunction; Cross-Sectional Studies; Female; Humans; Independent Living; Male; Positron-Emission Tomography; Smell; tau Proteins
PubMed: 35180111
DOI: 10.3233/JAD-210636 -
Nature Communications Oct 2023Associative learning is crucial for adapting to environmental changes. Interactions among neuronal populations involving the dorso-medial prefrontal cortex (dmPFC) are...
Associative learning is crucial for adapting to environmental changes. Interactions among neuronal populations involving the dorso-medial prefrontal cortex (dmPFC) are proposed to regulate associative learning, but how these neuronal populations store and process information about the association remains unclear. Here we developed a pipeline for longitudinal two-photon imaging and computational dissection of neural population activities in male mouse dmPFC during fear-conditioning procedures, enabling us to detect learning-dependent changes in the dmPFC network topology. Using regularized regression methods and graphical modeling, we found that fear conditioning drove dmPFC reorganization to generate a neuronal ensemble encoding conditioned responses (CR) characterized by enhanced internal coactivity, functional connectivity, and association with conditioned stimuli (CS). Importantly, neurons strongly responding to unconditioned stimuli during conditioning subsequently became hubs of this novel associative network for the CS-to-CR transformation. Altogether, we demonstrate learning-dependent dynamic modulation of population coding structured on the activity-dependent formation of the hub network within the dmPFC.
Topics: Male; Mice; Animals; Conditioning, Classical; Learning; Prefrontal Cortex; Fear; Neurons; Association Learning
PubMed: 37803014
DOI: 10.1038/s41467-023-41547-5 -
Neurobiology of Learning and Memory Mar 2020In rodents, the anterior cingulate (ACC), prelimbic (PL), and infralimbic cortex (IL) comprise the medial prefrontal cortex (mPFC). Through extensive connections with... (Review)
Review
In rodents, the anterior cingulate (ACC), prelimbic (PL), and infralimbic cortex (IL) comprise the medial prefrontal cortex (mPFC). Through extensive connections with cortical and subcortical structures, the mPFC plays a key modulatory role in the neuronal circuits underlying associative fear and reward learning. In this article, we have compiled the evidence that associative learning induces plasticity in both the intrinsic and synaptic excitability of mPFC neurons to modulate conditioned fear and cocaine seeking behavior. The literature highlights the accumulating evidence that plasticity in the intrinsic excitability of mPFC neurons represents a major cellular mechanism that interacts with synaptic changes to alter the impact of the mPFC on fear and reward circuits.
Topics: Action Potentials; Animals; Association Learning; Conditioning, Classical; Drug-Seeking Behavior; Extinction, Psychological; Fear; Humans; Neuronal Plasticity; Neurons; Prefrontal Cortex; Reward
PubMed: 31765801
DOI: 10.1016/j.nlm.2019.107117 -
European Journal of Internal Medicine Feb 2024Hypertension has been recognized as a significant risk factor for cerebrovascular diseases and cognitive decline. However, the specific impact of hypertension,...
BACKGROUND
Hypertension has been recognized as a significant risk factor for cerebrovascular diseases and cognitive decline. However, the specific impact of hypertension, systolic/diastolic blood pressure, pulse pressure (PP) and mean arterial pressure (MAP) on brain cortical structure remains unclear. Mendelian randomization (MR) provides a robust approach to investigate the causal relationship between blood pressure components and brain cortical changes.
METHODS
In this MR study, data from large-scale genome-wide association studies for blood pressure components and neuroimaging were utilized to conduct our analyses. We leveraged genetic variants associated specifically with hypertension (122,620 cases and 332,683 controls), systolic (469,767 individuals), diastolic (490,469 individuals) blood pressure, PP (810,865 individuals) and MAP (over 1 million individuals) to evaluate their effects on brain cortex surficial area (51,665 individuals) and cortex thickness (51,665 individuals).
RESULTS
Our findings revealed a significant correlation between systolic blood pressure and abnormal reduction in brain cortex surficial area (β=-1330.69, 95% confident interval [CI]: -2655.35 to -6.02, p = 0.0489); however, no significant relationship was found between systolic blood pressure and brain cortex thickness (β=-0.0078, 95% CI: -0.0178 to 0.0022, p = 0.1287). Additionally, no significant associations were observed between hypertension (β=-200.05, p = 0.6884; β=-0.0051, p = 0.1179, respectively), diastolic blood pressure (β=-460.63, p = 0.5160; β=0.0047, p = 0.2448, respectively), PP (β=1041.84, p = 0.3725; β=-0.0112, p = 0.2212, respectively), MAP (β=-18.84, p = 0.8841; β=0.0002, p = 0.7654, respectively) and both brain cortex surficial area and brain cortex thickness.
CONCLUSION
Our MR study provides evidence supporting the hypothesis that systolic blood pressure, rather than diastolic blood pressure, PP or MAP, is associated with abnormal changes in brain cortical structure.
Topics: Humans; Blood Pressure; Genome-Wide Association Study; Mendelian Randomization Analysis; Hypertension; Brain
PubMed: 37852841
DOI: 10.1016/j.ejim.2023.10.018 -
The Journal of Neuroscience : the... May 2023A crucial ability of the human brain is to learn and exploit probabilistic associations between stimuli to facilitate perception and behavior by predicting future...
A crucial ability of the human brain is to learn and exploit probabilistic associations between stimuli to facilitate perception and behavior by predicting future events. Although studies have shown how perceptual relationships are used to predict sensory inputs, relational knowledge is often between concepts rather than percepts (e.g., we learned to associate cats with dogs, rather than specific images of cats and dogs). Here, we asked if and how sensory responses to visual input may be modulated by predictions derived from conceptual associations. To this end we exposed participants of both sexes to arbitrary word-word pairs (e.g., car-dog) repeatedly, creating an expectation of the second word, conditional on the occurrence of the first. In a subsequent session, we exposed participants to novel word-picture pairs, while measuring fMRI BOLD responses. All word-picture pairs were equally likely, but half of the pairs conformed to the previously formed conceptual (word-word) associations, whereas the other half violated this association. Results showed suppressed sensory responses throughout the ventral visual stream, including early visual cortex, to pictures that corresponded to the previously expected words compared with unexpected words. This suggests that the learned conceptual associations were used to generate sensory predictions that modulated processing of the picture stimuli. Moreover, these modulations were tuning specific, selectively suppressing neural populations tuned toward the expected input. Combined, our results suggest that recently acquired conceptual priors are generalized across domains and used by the sensory brain to generate category-specific predictions, facilitating processing of expected visual input. Perceptual predictions play a crucial role in facilitating perception and the integration of sensory information. However, little is known about whether and how the brain uses more abstract, conceptual priors to form sensory predictions. In our preregistered study, we show that priors derived from recently acquired arbitrary conceptual associations result in category-specific predictions that modulate perceptual processing throughout the ventral visual hierarchy, including early visual cortex. These results suggest that the predictive brain uses prior knowledge across various domains to modulate perception, thereby extending our understanding of the extensive role predictions play in perception.
Topics: Male; Female; Humans; Animals; Cats; Dogs; Learning; Magnetic Resonance Imaging; Brain; Concept Formation; Brain Mapping
PubMed: 37059461
DOI: 10.1523/JNEUROSCI.1874-22.2023 -
Translational Psychiatry Jul 2021Anhedonia is a core symptom of multiple psychiatric disorders and has been associated with alterations in brain structure. Genome-wide association studies suggest that...
Anhedonia is a core symptom of multiple psychiatric disorders and has been associated with alterations in brain structure. Genome-wide association studies suggest that anhedonia is heritable, with a polygenic architecture, but few studies have explored the association between genetic loading for anhedonia-indexed by polygenic risk scores for anhedonia (PRS-anhedonia)-and structural brain imaging phenotypes. Here, we investigated how anhedonia and PRS-anhedonia were associated with brain structure within the UK Biobank cohort. Brain measures (including total grey/white matter volumes, subcortical volumes, cortical thickness (CT) and white matter integrity) were analysed using linear mixed models in relation to anhedonia and PRS-anhedonia in 19,592 participants (9225 males; mean age = 62.6 years, SD = 7.44). We found that state anhedonia was significantly associated with reduced total grey matter volume (GMV); increased total white matter volume (WMV); smaller volumes in thalamus and nucleus accumbens; reduced CT within the paracentral cortex, the opercular part of inferior frontal gyrus, precentral cortex, insula and rostral anterior cingulate cortex; and poorer integrity of many white matter tracts. PRS-anhedonia was associated with reduced total GMV; increased total WMV; reduced white matter integrity; and reduced CT within the parahippocampal cortex, superior temporal gyrus and insula. Overall, both state anhedonia and PRS-anhedonia were associated with individual differences in multiple brain structures, including within reward-related circuits. These associations may represent vulnerability markers for psychopathology relevant to a range of psychiatric disorders.
Topics: Anhedonia; Biological Specimen Banks; Brain; Genome-Wide Association Study; Gray Matter; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Phenotype; United Kingdom; White Matter
PubMed: 34282121
DOI: 10.1038/s41398-021-01522-4 -
Maedica Mar 2020This study aims to evaluate the effects of obesity on the structure of axillary lymph nodes in women with no evidence of breast or axilla pathology. In this...
This study aims to evaluate the effects of obesity on the structure of axillary lymph nodes in women with no evidence of breast or axilla pathology. In this prospective study, we documented the body mass index of 204 women who were referred for screening mammography. Two radiologists have independently viewed the mammograms to find the largest axillary lymph node and reported its dimensions. Independent sample T-test was used to evaluate the association of the above indices with participants' body mass index. Associations between indices were investigated using multiple regression analyses. All measurements of axillary lymph nodes and hilo-cortical ratio were significantly increased with increasing body mass index (p<0.001), except for cortex width (p=0.15). There were strong associations (p < 0.001) between increasing hilum length and increasing lymph node length (R²=0.90), increasing hilum width and increasing lymph node width (R²=0.85), and increasing hilum width and decreasing cortex width (R²=0.12). There was no association between cortex width and lymph node width (R²=0.0001). Inter-rater reliability ranged from 0.49 to 0.70. Our study demonstrated that axillary lymph nodes with a bigger hilum width had a smaller cortex width in obese but apparently normal population. Considering the important role of axillary lymph node cortex in their immune function, this may be a cause for immune dysfunction of axillary lymph nodes in obesity and explain the worse prognosis of breast cancer in obese women. The limited number of participants, the 2-dimensional nature of mammograms and the difficulty of measuring the dimensions of axillary lymph nodes using mammography were important limitations of this study. Obesity may result in structural change and dysfunction of axillary lymph nodes. Dysfunction of axillary lymph nodes may have a role in worse prognosis of breast cancer in obese patients.
PubMed: 32419869
DOI: 10.26574/maedica.2020.15.1.99 -
Neuropsychopharmacology : Official... Dec 2022Racial discrimination (RD) has been consistently linked to adverse brain health outcomes. These may be due in part to RD effects on neural networks involved with threat...
Racial discrimination (RD) has been consistently linked to adverse brain health outcomes. These may be due in part to RD effects on neural networks involved with threat appraisal and regulation; RD has been linked to altered activity in the rostral anterior cingulate cortex (rACC) and structural decrements in the anterior cingulum bundle and hippocampus. In the present study, we examined associations of RD with cingulate, hippocampus and amygdala gray matter morphology in a sample of trauma-exposed Black women. Eighty-one Black women aged 19-62 years were recruited as part of an ongoing study of trauma. Participants completed assessments of RD, trauma exposure, and posttraumatic stress disorder (PTSD), and underwent T1-weighted anatomical imaging. Cortical thickness, surface area and gray matter volume were extracted from subregions of cingulate cortex, and gray matter volume was extracted from amygdala and hippocampus, and entered into partial correlation analyses that included RD and other socio-environmental variables. After correction for multiple comparisons and accounting for variance associated with other stressors and socio-environmental factors, participants with more RD exposure showed proportionally lower cortical thickness in the left rACC, caudal ACC, and posterior cingulate cortex (ps < = 0.01). These findings suggest that greater experiences of RD are linked to compromised cingulate gray matter thickness. In the context of earlier findings indicating that RD produces increased response in threat neurocircuitry, our data suggest that RD may increase vulnerability for brain health problems via cingulate cortex alterations. Further research is needed to elucidate biological mechanisms for these changes.
Topics: Humans; Female; Gyrus Cinguli; Racism; Magnetic Resonance Imaging; Brain Mapping; Gray Matter; Stress Disorders, Post-Traumatic
PubMed: 36100659
DOI: 10.1038/s41386-022-01445-8