Browsing by Subject "Hippocampus"
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Item A protein panel in cerebrospinal fluid for diagnostic and predictive assessment of alzheimer’s disease(American Association for the Advancement of Science, 2023) Haque, Rafi; Watson, Caroline M.; Liu, Jiaqi; Carter, E. Kathleen; Duong, Duc M.; Lah, James J.; Wingo, Aliza P.; Roberts, Blaine R.; Johnson, Erik C. B.; Saykin, Andrew J.; Shaw, Leslie M.; Seyfried, Nicholas T.; Wingo, Thomas S.; Levey, Allan I.; Radiology and Imaging Sciences, School of MedicineAlzheimer's disease (AD) is a neurodegenerative disease with heterogenous pathophysiological changes that develop years before the onset of clinical symptoms. These preclinical changes have generated considerable interest in identifying markers for the pathophysiological mechanisms linked to AD and AD-related disorders (ADRD). On the basis of our prior work integrating cerebrospinal fluid (CSF) and brain proteome networks, we developed a reliable and high-throughput mass spectrometry-selected reaction monitoring assay that targets 48 key proteins altered in CSF. To test the diagnostic utility of these proteins and compare them with existing AD biomarkers, CSF collected at baseline visits was assayed from 706 participants recruited from the Alzheimer's Disease Neuroimaging Initiative. We found that the targeted CSF panel of 48 proteins (CSF 48 panel) performed at least as well as existing AD CSF biomarkers (Aβ42, tTau, and pTau181) for predicting clinical diagnosis, FDG PET, hippocampal volume, and measures of cognitive and dementia severity. In addition, for each of those outcomes, the CSF 48 panel plus the existing AD CSF biomarkers significantly improved diagnostic performance. Furthermore, the CSF 48 panel plus existing AD CSF biomarkers significantly improved predictions for changes in FDG PET, hippocampal volume, and measures of cognitive decline and dementia severity compared with either measure alone. A potential reason for these improvements is that the CSF 48 panel reflects a range of altered biology observed in AD/ADRD. In conclusion, we show that the CSF 48 panel complements existing AD CSF biomarkers to improve diagnosis and predict future cognitive decline and dementia severity.Item Adult neurogenesis and neurodegenerative diseases: A systems biology perspective(Wiley, 2017-01) Horgusluoglu, Emrin; Nudelman, Kelly; Nho, Kwangsik; Saykin, Andrew J.; Medical and Molecular Genetics, School of MedicineNew neurons are generated throughout adulthood in two regions of the brain, the olfactory bulb and dentate gyrus of the hippocampus, and are incorporated into the hippocampal network circuitry; disruption of this process has been postulated to contribute to neurodegenerative diseases including Alzheimer's disease and Parkinson's disease. Known modulators of adult neurogenesis include signal transduction pathways, the vascular and immune systems, metabolic factors, and epigenetic regulation. Multiple intrinsic and extrinsic factors such as neurotrophic factors, transcription factors, and cell cycle regulators control neural stem cell proliferation, maintenance in the adult neurogenic niche, and differentiation into mature neurons; these factors act in networks of signaling molecules that influence each other during construction and maintenance of neural circuits, and in turn contribute to learning and memory. The immune system and vascular system are necessary for neuronal formation and neural stem cell fate determination. Inflammatory cytokines regulate adult neurogenesis in response to immune system activation, whereas the vasculature regulates the neural stem cell niche. Vasculature, immune/support cell populations (microglia/astrocytes), adhesion molecules, growth factors, and the extracellular matrix also provide a homing environment for neural stem cells. Epigenetic changes during hippocampal neurogenesis also impact memory and learning. Some genetic variations in neurogenesis related genes may play important roles in the alteration of neural stem cells differentiation into new born neurons during adult neurogenesis, with important therapeutic implications. In this review, we discuss mechanisms of and interactions between these modulators of adult neurogenesis, as well as implications for neurodegenerative disease and current therapeutic research.Item An assay to image neuronal microtubule dynamics in mice(Springer Nature, 2014-09-12) Kleele, Tatjana; Marinković, Petar; Williams, Philip R.; Stern, Sina; Weigand, Emily E.; Engerer, Peter; Naumann, Ronald; Hartmann, Jana; Karl, Rosa M.; Bradke, Frank; Bishop, Derron; Herms, Jochen; Konnerth, Arthur; Kerschensteiner, Martin; Godinho, Leanne; Misgeld, Thomas; Anatomy, Cell Biology and Physiology, School of MedicineMicrotubule dynamics in neurons play critical roles in physiology, injury and disease and determine microtubule orientation, the cell biological correlate of neurite polarization. Several microtubule binding proteins, including end-binding protein 3 (EB3), specifically bind to the growing plus tip of microtubules. In the past, fluorescently tagged end-binding proteins have revealed microtubule dynamics in vitro and in non-mammalian model organisms. Here, we devise an imaging assay based on transgenic mice expressing yellow fluorescent protein-tagged EB3 to study microtubules in intact mammalian neurites. Our approach allows measurement of microtubule dynamics in vivo and ex vivo in peripheral nervous system and central nervous system neurites under physiological conditions and after exposure to microtubule-modifying drugs. We find an increase in dynamic microtubules after injury and in neurodegenerative disease states, before axons show morphological indications of degeneration or regrowth. Thus increased microtubule dynamics might serve as a general indicator of neurite remodelling in health and disease.Item Apolipoprotein E4 influences amyloid deposition but not cell loss after traumatic brain injury in a mouse model of Alzheimer's disease(Society for Neuroscience, 2002-12) Hartman, Richard E.; Laurer, Helmut; Longhi, Luca; Bales, Kelly R.; Paul, Steven M.; McIntosh, Tracy K.; Holtzman, David M.; Pharmacology and Toxicology, School of MedicineThe epsilon4 allele of apolipoprotein E (APOE) and traumatic brain injury (TBI) are both risk factors for the development of Alzheimer's disease (AD). These factors may act synergistically, in that APOE4+ individuals are more likely to develop dementia after TBI. Because the mechanism underlying these effects is unclear, we questioned whether APOE4 and TBI interact either through effects on amyloid-beta (Abeta) or by enhancing cell death/tissue injury. We assessed the effects of TBI in PDAPP mice (transgenic mice that develop AD-like pathology) expressing human APOE3 (PDAPP:E3), human APOE4 (PDAPP:E4), or no APOE (PDAPP:E-/-). Mice were subjected to a unilateral cortical impact injury at 9-10 months of age and allowed to survive for 3 months. Abeta load, hippocampal/cortical volumes, and hippocampal CA3 cell loss were quantified using stereological methods. All of the groups contained mice with Abeta-immunoreactive deposits (56% PDAPP:E4, 20% PDAPP:E3, 75% PDAPP:E-/-), but thioflavine-S-positive Abeta (amyloid) was present only in the molecular layer of the dentate gyrus in the PDAPP:E4 mice (44%). In contrast, our previous studies showed that in the absence of TBI, PDAPP:E3 and PDAPP:E4 mice have little to no Abeta deposition at this age. After TBI, all of the Abeta deposits present in PDAPP:E3 and PDAPP:E-/- mice were diffuse plaques. In contrast to the effect of APOE4 on amyloid, PDAPP:E3, PDAPP:E4, and PDAPP:E-/- mice did not differ in the amount of brain tissue or cell loss. These data support the hypothesis that APOE4 influences the neurodegenerative cascade after TBI via an effect on Abeta.Item Associations between hippocampal morphometry and neuropathologic markers of Alzheimer's disease using 7 T MRI(Elsevier, 2017-04-21) Blanken, Anna E.; Hurtz, Sona; Zarow, Chris; Biado, Kristina; Honarpisheh, Hedieh; Somme, Johanne; Brook, Jenny; Tung, Spencer; Kraft, Emily; Lo, Darrick; Ng, Denise W.; Vinters, Harry V.; Apostolova, Liana G.; Department of Neurology, School of MedicineHippocampal atrophy, amyloid plaques, and neurofibrillary tangles are established pathologic markers of Alzheimer's disease. We analyzed the temporal lobes of 9 Alzheimer's dementia (AD) and 7 cognitively normal (NC) subjects. Brains were scanned post-mortem at 7 Tesla. We extracted hippocampal volumes and radial distances using automated segmentation techniques. Hippocampal slices were stained for amyloid beta (Aβ), tau, and cresyl violet to evaluate neuronal counts. The hippocampal subfields, CA1, CA2, CA3, CA4, and subiculum were manually traced so that the neuronal counts, Aβ, and tau burden could be obtained for each region. We used linear regression to detect associations between hippocampal atrophy in 3D, clinical diagnosis and total as well as subfield pathology burden measures. As expected, we found significant correlations between hippocampal radial distance and mean neuronal count, as well as diagnosis. There were subfield specific associations between hippocampal radial distance and tau in CA2, and cresyl violet neuronal counts in CA1 and subiculum. These results provide further validation for the European Alzheimer's Disease Consortium Alzheimer's Disease Neuroimaging Initiative Center Harmonized Hippocampal Segmentation Protocol (HarP).Item Associations between residential segregation, ambient air pollution, and hippocampal features in recent trauma survivors(medRxiv, 2025-02-20) Liang, Sophia S.; Roeckner, Alyssa R.; Ely, Timothy D.; Lebois, Lauren A. M.; van Rooij, Sanne J. H.; Bruce, Steven E.; Jovanovic, Tanja; House, Stacey L.; Beaudoin, Francesca L.; An, Xinming; Neylan, Thomas C.; Clifford, Gari D.; Linnstaedt, Sarah D.; Germine, Laura T.; Rauch, Scott L.; Haran, John P.; Storrow, Alan B.; Lewandowski, Christopher; Musey, Paul I., Jr.; Hendry, Phyllis L.; Sheikh, Sophia; Pascual, Jose L.; Seamon, Mark J.; Harris, Erica; Pearson, Claire; Peak, David A.; Merchant, Roland C.; Domeier, Robert M.; Rathlev, Niels K.; O'Neil, Brian J.; Sergot, Paulina; Sanchez, Leon D.; Sheridan, John F.; Harte, Steven E.; Kessler, Ronald C.; Koenen, Karestan C.; McLean, Samuel A.; Ressler, Kerry J.; Stevens, Jennifer S.; Webb, E. Kate; Harnett, Nathaniel G.; Emergency Medicine, School of MedicineBackground: Residential segregation is associated with differential exposure to air pollution. Hippocampus structure and function are highly susceptible to pollutants and associated with posttraumatic stress disorder (PTSD) development. Therefore, we investigated associations between residential segregation, air pollutants, hippocampal neurobiology, and PTSD in recent trauma survivors. Methods: Participants (N = 278; 34% non-Hispanic white, 46% Non-Hispanic Black, 16% Hispanic) completed multimodal neuroimaging two weeks after trauma. Yearly averages of air pollutants (PM2.5 and NO2) and racial/economic segregation (Index of Concentration at the Extremes) were derived from each participant's address. Linear models assessed if air pollutants mediated associations between segregation and hippocampal volume, threat reactivity, or parahippocampal cingulum fractional anisotropy (FA) after covarying for age, sex, income, and 2-week PTSD symptoms. Further models evaluated if pollutants or segregation prospectively predicted PTSD symptoms six months post-trauma. Results: Non-Hispanic Black participants lived in neighborhoods with significantly greater segregation and air pollution compared to Hispanic and non-Hispanic white participants (ps<.001). There was a significant indirect effect of NO2 between segregation and FA values (β = 0.08, 95% CI[0.01, 0.15]), and an indirect effect of PM2.5 between segregation and threat reactivity (β = -0.08, 95% CI[-0.14, -0.01]). There was no direct effect of segregation on hippocampal features. Pollutants and segregation were not associated with PTSD symptoms . Conclusion: Residential segregation is associated with greater air pollution exposure, which is in turn associated with variability in hippocampal features among recent trauma survivors. Further research is needed to assess relationships between other environmental factors and trauma and stress-related disorders.Item Awareness of Genetic Risk in the Dominantly Inherited Alzheimer Network (DIAN)(Wiley, 2020-01) Aschenbrenner, Andrew J.; James, Bryan D.; McDade, Eric; Wang, Guoqiao; Lim, Yen Ying; Benzinger, Tammie L.S.; Cruchaga, Carlos; Goate, Alison; Xiong, Chengjie; Perrin, Richard; Buckles, Virginia; Allegri, Ricardo; Berman, Sarah B.; Chhatwal, Jasmeer P.; Fagan, Anne; Farlow, Martin; O'Connor, Antoinette; Ghetti, Bernardino; Graff-Radford, Neill; Goldman, Jill; Gräber, Susanne; Karch, Celeste M.; Lee, Jae-Hong; Levin, Johannes; Martins, Ralph N.; Masters, Colin; Mori, Hiroshi; Noble, James; Salloway, Stephen; Schofield, Peter; Morris, John C.; Bateman, Randall J.; Hassenstab, Jason; Neurology, School of MedicineIntroduction: Although some members of families with autosomal dominant Alzheimer's disease mutations learn their mutation status, most do not. How knowledge of mutation status affects clinical disease progression is unknown. This study quantifies the influence of mutation awareness on clinical symptoms, cognition, and biomarkers. Methods: Mutation carriers and non-carriers from the Dominantly Inherited Alzheimer Network (DIAN) were stratified based on knowledge of mutation status. Rates of change on standard clinical, cognitive, and neuroimaging outcomes were examined. Results: Mutation knowledge had no associations with cognitive decline, clinical progression, amyloid deposition, hippocampal volume, or depression in either carriers or non-carriers. Carriers who learned their status mid-study had slightly higher levels of depression and lower cognitive scores. Discussion: Knowledge of mutation status does not affect rates of change on any measured outcome. Learning of status mid-study may confer short-term changes in cognitive functioning, or changes in cognition may influence the determination of mutation status.Item Coenzyme Q10 Prevents Scopolamine Associated Hippocampal-Dependent Memory Deficits in Mice(Elsevier, 2021) Kabir, Nadia; Pervin, Mst Shahnaj; Alam, Musrura Mefta; Mahmud, Waich; Zulfiker, Abu Hasanat Md.; Al Amin, Md. Mamun; Medical and Molecular Genetics, School of MedicineScopolamine has been widely used to induce pharmacological model of memory impairment. Scopolamine impairs cognitive function via mitochondrial dysfunction and oxidative stress beyond that of direct cholinergic antagonism. Coenzyme Q10 (CoQ10), a mitochondrial component, protects mitochondria from reactive oxygen species and assist in energy production. Mitochondrial dysfunction appears with CoQ10 deficiency in the neurodegenerative disease. It is unknown whether CoQ10 can prevent scopolamine-associated spatial working memory deficits. We treated adult Swiss albino mice either by saline (control) or scopolamine or scopolamine plus CoQ10 or CoQ10 alone for four weeks and subsequently assessed spatial memory formation and locomotor activity. We euthanized mice to determine oxidative stress markers including lipid and protein oxidation, superoxide dismutase and catalase activity in brain tissues.Scopolamine-treated mice showed impaired spatial learning and memory formation. Scopolamine significantly increased levels of lipid peroxidation, reduced activity of superoxide dismutase and catalase compared to the controls. On the contrary, concomitant administration of scopolamine and CoQ10 did not cause spatial memory deficits. Furthermore, combined treatment did not alter hippocampal lipid and protein oxidation and activity of superoxide dismutase and catalase. Surprisingly, only CoQ10 supplementation improves oxidative stress markers compared to the control.Our results strongly suggest a protective ability of CoQ10 on spatial memory formation when concomitantly given with scopolamine in mice. The observed protective activity was presumably via an increased level of superoxide dismutase enzyme. We propose a further study to measure hippocampal mitochondrial function to reveal the underlying mechanism of CoQ10 before trial in humans.Item Cognitive Function and its Relationship with Brain Structure in Myotonic Dystrophy Type 1(Wiley, 2021) Langbehn, Kathleen E.; van der Plas, Ellen; Moser, David J.; Long, Jeffrey D.; Gutmann, Laurie; Nopoulos, Peg; Neurology, School of MedicineStudies have shown relationships between white matter abnormalities and cognitive dysfunction in myotonic dystrophy type 1 (DM1), but comprehensive analysis of potential structure-function relationships are lacking. Fifty adult-onset DM1 individuals (33 female) and 68 unaffected adults (45 female) completed the Wechsler Adult Intelligence Scale-IV (WAIS-IV) to determine the levels and patterns of intellectual functioning. Neuroimages were acquired with a 3T scanner and were processed with BrainsTools. Regional brain volumes (regions of interest, ROIs) were adjusted for inter-scanner variation and intracranial volume. Linear regression models were conducted to assess if group by ROI interaction terms significantly predicted WAIS-IV composite scores. Models were adjusted for age and sex. The DM1 group had lower Perceptual Reasoning Index (PRI), Working Memory Index (WMI), and Processing Speed Index (PSI) scores than the unaffected group (PRI t(113) = -3.28, p = 0.0014; WMI t(114) = -3.49, p = 0.0007; PSI t(114) = -2.98, p = 0.0035). The group by hippocampus interaction term was significant for both PRI and PSI (PRI (t(111) = -2.82, p = 0.0057; PSI (t(112) = -2.87, p = 0.0049)). There was an inverse association between hippocampal volume and both PRI and PSI in the DM1 group (the higher the volume, the lower the intelligence quotient scores), but no such association was observed in the unaffected group. Enlarged hippocampal volume may underlie some aspects of cognitive dysfunction in adult-onset DM1, suggesting that increased volume of the hippocampus may be pathological.Item Cortical–striatal gene expression in neonatal hippocampal lesion (NVHL)-amplified cocaine sensitization(Wiley, 2013) Chambers, R. A.; McClintick, J. N.; Sentir, A. M.; Berg, S. A.; Runyan, M.; Choi, K. H.; Edenberg, H. J.; Biochemistry and Molecular Biology, School of MedicineCortical-striatal circuit dysfunction in mental illness may enhance addiction vulnerability. Neonatal ventral hippocampal lesions (NVHL) model this dual diagnosis causality by producing a schizophrenia syndrome with enhanced responsiveness to addictive drugs. Rat genome-wide microarrays containing >24 000 probesets were used to examine separate and co-occurring effects of NVHLs and cocaine sensitization (15 mg/kg/day × 5 days) on gene expression within medial prefrontal cortex (MPFC), nucleus accumbens (NAC), and caudate-putamen (CAPU). Two weeks after NVHLs robustly amplified cocaine behavioral sensitization, brains were harvested for genes of interest defined as those altered at P < 0.001 by NVHL or cocaine effects or interactions. Among 135 genes so impacted, NVHLs altered twofold more than cocaine, with half of all changes in the NAC. Although no genes were changed in the same direction by both NVHL and cocaine history, the anatomy and directionality of significant changes suggested synergy on the neural circuit level generative of compounded behavioral phenotypes: NVHL predominantly downregulated expression in MPFC and NAC while NVHL and cocaine history mostly upregulated CAPU expression. From 75 named genes altered by NVHL or cocaine, 27 had expression levels that correlated significantly with degree of behavioral sensitization, including 11 downregulated by NVHL in MPFC/NAC, and 10 upregulated by NVHL or cocaine in CAPU. These findings suggest that structural and functional impoverishment of prefrontal-cortical-accumbens circuits in mental illness is associated with abnormal striatal plasticity compounding with that in addictive disease. Polygenetic interactions impacting neuronal signaling and morphology within these networks likely contribute to addiction vulnerability in mental illness.