Smaller Hippocampus Research Articles

Brain structure and clinical profile point to neurodevelopmental factors involved in pedophilic disorder.

ObjectivePedophilic disorder (PD) is characterized bypersistent, intense sexual attraction to prepubertal children that the individual has acted on, or causes marked distress or interpersonal difficulty. Although prior research suggests that PD has neurodevelopmental underpinnings, the evidence remains sparse. To aid the understanding of etiology and treatment development, we quantified neurobiological and clinical correlates of PD.MethodWe compared 55 self‐referred, help‐seeking, non‐forensic male patients with DSM‐5 PD with 57 age‐matched, healthy male controls (HC) on clinical, neuropsychological, and structural brain imaging measures (cortical thickness and surface area, subcortical and white matter volumes). Structural brain measures were related to markers for aberrant neurodevelopment including IQ, and the 2nd to 4th digit ratio (2D:4D).ResultsPD was associated with psychiatric disorder comorbidity and ADHD and autism spectrum disorder symptoms. PD patients had lower total IQ than HC. PD individuals exhibited cortical surface area abnormalities in regions belonging to the brain's default mode network and showed abnormal volume of white matter underlying those regions. PD subjects had smaller hippocampi and nuclei accumbens than HC. Findings were not related to history of child‐related sexual offending. IQ correlated negatively with global expression of PD‐related brain features and 2D:4D correlated with surface area in PD.ConclusionsIn the largest single‐center study to date, we delineate psychiatric comorbidity, neurobiological and cognitive correlates of PD. Our morphometric findings, their associations with markers of aberrant neurodevelopment, and psychiatric comorbidities suggest that neurodevelopmental mechanisms are involved in PD. The findings may need consideration in future development of clinical management of PD patients.

Brain-derived neurotrophic factor Val66Met variant on brain volumes in infants.

The brain-derived neurotrophic factor (BDNF) has many important roles in neurogenesis and neuronal health. BDNF is also involved in learning and memory. Individuals with BDNF-Val66Met variant (Met +) are at higher risk for neuropsychiatric disorders and have smaller hippocampi and amgydalae compared to those without this variant (Met-). Whether these smaller brain volumes are already present at birth is unknown and were evaluated. 66 newborn infants were genotyped for BDNF-rs6265 and had brain MRI scans. The T1-weighted images were automatically parcellated for hippocampus and amygdala, as well as the intracranial volume (ICV), total brain volume, total gray and white matter, using a multi-atlas label fusion method implemented in the MRICloud ( https://braingps.anatomyworks.org ). The segmented brain volumes were normalized to the ICV for group comparisons. The two infant groups were not different in their demographics and birth characteristics. However, compared to Met- infants, the Met + infants had smaller hippocampi (p = 0.013), smaller amygdalae (p = 0.041), and less steep age-related declines in total brain volume and % white matter volume. The smaller relative hippocampal and amygdala volumes in Met + infants suggest that the Met + genotype affected prenatal developmental processes. In addition, the slower age-dependent declines in the relative total brain and white matter volumes of the Met + group in this cross-sectional dataset suggest the BDNF-Val66Met variant might have an ongoing negative influence on the postnatal developmental processes.

The relationship between duration of abstinence and gray-matter brain structure in chronic methamphetamine users

ABSTRACT Background: Brain structural findings in chronic methamphetamine users have been inconsistent. Identifying contributing influences (e.g., sex, abstinence duration) can help clarify the clinical course of recovery. Objectives: We studied the effects of long-term methamphetamine abstinence on gray-matter volume. Our hypothesis was that smaller volume early in abstinence would precede long-term recovery. Methods: Individuals who used methamphetamine (≥100 g lifetime use, mandated to residential treatment for methamphetamine-positive urine; 40 men, 21 women), undergoing supervised abstinence (men: 12–400 days; women: 130–594 days), were compared to healthy controls (49 men, 36 women) using T1-weighted MRI. Volumes of orbitofrontal, anterior cingulate and parietal cortex, hippocampus, and striatum were measured using Freesurfer software. Associations of volumes with abstinence duration were tested in males and females separately because their abstinence times differed (121.5 ± 124.5 vs. 348.0 ± 128.6 days, p < 0.001); only males were studied in early abstinence. The General Linear Model was used to test effects of abstinence duration and group (methamphetamine users vs. controls). Results: In males, duration of abstinence was multivariate significant for gray-matter volumes (p = 0.017). Abstinence duration was associated with increases in volumes of the orbitofrontal and parietal cortices (ps = 0.031, 0.016) and hippocampi (ps = 0.044). Irrespective of abstinence, male methamphetamine users had smaller hippocampi than male controls (p = 0.008). Females showed no significant effects of group or abstinence. Conclusions: In males, abstinence from methamphetamine appears to result in volumetric increases in regions important for cognitive function, which may affect recovery during the course of treatment. Data from the period of early abstinence are required to evaluate volumetric changes in females.

Air pollution exposure during pregnancy and childhood and brain morphology in preadolescents

BackgroundStudies investigating the relationship between exposure to air pollution and brain development using magnetic resonance images are emerging. However, most studies have focused only on prenatal exposures, and have included a limited selection of pollutants. Here, we aim to expand the current knowledge by studying pregnancy and childhood exposure to a wide selection of pollutants, and brain morphology in preadolescents. MethodsWe used data from 3133 preadolescents from a birth cohort from Rotterdam, the Netherlands (enrollment: 2002–2006). Concentrations of nitrogen oxides, coarse, fine, and ultrafine particles, and composition of fine particles were estimated for participant's home addresses in pregnancy and childhood, using land use regression models. Structural brain images were obtained at age 9–12 years. We assessed the relationships of air pollution exposure, with brain volumes, and surface-based morphometric data, adjusting for socioeconomic and life-style characteristics, using single as well as multi-pollutant approach. ResultsNo associations were observed between air pollution exposures and global volumes of total brain, and cortical and subcortical grey matter. However, we found associations between higher pregnancy and childhood air pollution exposures with smaller corpus callosum, smaller hippocampus, larger amygdala, smaller nucleus accumbens, and larger cerebellum (e.g. -69.2mm3 hippocampal volume [95%CI -129.1 to -9.3] per 1ng/m3 increase in pregnancy exposure to polycyclic aromatic hydrocarbons). Higher pregnancy exposure to air pollution was associated with smaller cortical thickness while higher childhood exposure was associated with predominantly larger cortical surface area. ConclusionHigher pregnancy or childhood exposure to several air pollutants was associated with altered volume of several brain structures, as well as with cortical thickness and surface area. Associations showed some similarity to delayed maturation and effects of early-life stress.

Multiple Endocrine Deficiencies are Common in Hypoparathyroidism–Retardation–Dysmorphism Syndrome

The rare hypoparathyroidism-retardation-dysmorphism (HRD) syndrome (OMIM #241410) is caused by the mutated tubulin chaperone E (TBCE) gene. This gene encodes a critical protein in the microtubule assembly pathway. To evaluate the endocrine profile of patients with HRD. The study used a retrospective analysis of a large cohort of patients in a single university medical center. Sixty-three patients were diagnosed with HRD during 1990 to 2019; 58 of them had an endocrine evaluation. We investigated somatic growth parameters, the prevalence of hypoglycemia, growth hormone deficiency, hypothyroidism, hypogonadism, and cortisol deficiency. All patients were born small for gestational age, and severe growth retardation was found in all patients with mean height standard deviation score (SDS) of -8.8 (range: -5.1 to -15.1) and weight SDS -18 (range: -5.1 to -61.2). Serum insulin-like growth factor-1 concentrations were very low among the 21 studied patients: -2.32 SDS (range: -0.6 to -2.7). Four out of 14 (28%) investigated patients had growth hormone deficiency, and 55% of patients were hospitalized due to symptomatic hypoglycemia. Adrenal glucocorticoid insufficiency was diagnosed in 22% of those tested. Hypothyroidism was found in 36% of patients. Both hypogonadotrophic and hypergonadotrophic hypogonadism were observed. The main magnetic resonance imaging findings were small anterior pituitary gland, small hippocampus, brain atrophy, thin corpus callosum, Chiari type I malformation, and septo-optic dysplasia. Multiple endocrine abnormalities are common in patients with HRD syndrome. Periodic screening of thyroid and adrenal functions is recommended.

Association of Poor Family Functioning From Pregnancy Onward With Preadolescent Behavior and Subcortical Brain Development

The association of poor family functioning, a potent stressor, with child behavior is potentially long term and relevant for a person's well-being later in life. Whether changes in brain development underlie the associations with preadolescent behavior and help identify periods of vulnerability is unclear. To assess the associations of poor family functioning from pregnancy onward with cortical, white matter, and subcortical volumes, and to examine the extent to which, in particular, hippocampal volume mediates the association of prenatal parental environmental exposures with child problem behavior in preadolescence. This population-based cohort study, conducted from April 2002 to January 2006, was embedded in Generation R, a multiethnic population-based cohort from fetal life onward. All pregnant women living in Rotterdam, the Netherlands, with an expected delivery date between April 2002 and January 2006 were invited to participate. Of the 8879 pregnant women enrolled during pregnancy, 1266 mothers with no partner data and 490 with missing family functioning data were excluded, as well as 1 sibling of 32 twin pairs. After excluding an additional 657 children with poor imaging data quality or incidental findings, the final sample consisted of 2583 mother-child pairs. Data analysis was performed from March 1, 2019, to June 28, 2019. Mother- and father-rated poor family functioning was repeatedly measured by the General Functioning subscale of the Family Assessment Device. Our primary hypothesis, formulated after data collection but before analysis, was that poor prenatal family functioning would be associated with smaller hippocampal and amygdala volumes in late childhood. High-resolution structural neuroimaging data of children aged 10 years were collected with a single 3-T magnetic resonance imaging system. Child emotional and behavioral problems were assessed with the Child Behavior Checklist. Data were available for 2583 children (mean [SD] age, 10.1 [0.6] years; 1315 girls [50.9%]). Data for parents included 2583 mothers (mean [SD] age, 31.1 [4.7] years; 1617 Dutch race/ethnicity [62.6%]) and 1788 fathers (mean [SD] age, 33.5 [5.3] years; 1239 Dutch race/ethnicity [69.3%]). Children exposed to prenatal maternal-reported poor family functioning had smaller hippocampal (B = -0.08; 95% CI, -0.13 to -0.02) and occipital lobe (B = -0.70; 95% CI, -1.19 to -0.21) volumes in preadolescence. There was no evidence for an association of exposure to poor family functioning at mid- or late childhood with brain morphology. Hippocampal volumes partially mediated the association of prenatal maternal-reported poor family functioning with preadolescent problem behavior (B = 0.08; 95% CI, 0.03-0.13), even after adjusting for prior child problems at age 1.5 years. Analyses of combined maternal and paternal family functioning ratings showed similar results, but associations were largely driven by maternal family functioning reports. In this population-based cohort study, prenatal maternal-reported poor family functioning was associated with a smaller hippocampus in preadolescents. This difference in brain structure may underlie behavioral problems and is a possible neurodevelopmental manifestation of the long-term consequences of poor family functioning for the child.

Effect Modifiers of TDP-43-Associated Hippocampal Atrophy Rates in Patients with Alzheimer's Disease Neuropathological Changes.

Transactive response DNA-binding protein of 43 kDa (TDP-43) is associated with hippocampal atrophy in Alzheimer's disease (AD), but whether the association is modified by other factors is unknown. To evaluate whether the associations between TDP-43 and hippocampal volume and atrophy rate are affected by age, gender, apolipoprotein E (APOE) ɛ4, Lewy bodies (LBs), amyloid-β (Aβ), or Braak neurofibrillary tangle (NFT) stage. In this longitudinal neuroimaging-clinicopathological study of 468 cases with AD neuropathological changes (Aβ-positive) that had completed antemortem head MRI, we investigated how age, gender, APOEɛ4, presence of LBs, Aβ, TDP-43, and Braak NFT stages are associated with hippocampal volumes and rates of atrophy over time. We included field strength in the models since our cohort included 1.5T and 3T scans. We then determined whether the associations between hippocampal atrophy and TDP-43 are modified by these factors using mixed effects models. Older age, female gender, APOEɛ4, higher field strength, higher TDP-43, and Braak NFT stages were associated with smaller hippocampi. Rate of atrophy was greater with higher TDP-43 and Braak NFT stage, but lower in older patients. The association of TDP-43 with greater rate of atrophy was enhanced in APOEɛ4 carriers (p = 0.04). Neurodegenerative effects of TDP-43 seem to be independent of most factors except perhaps APOE in cases with AD neuropathological changes. TDP-43 and tau appear to behave independently of one another.

Hippocampal Volume in Psychiatric Diagnoses: Should Psychiatry Biomarker Research Account for Comorbidities?

Background Many research papers claim that patients with specific psychiatric disorders (major depressive disorder, posttraumatic stress disorder, borderline personality disorder, alcohol use disorder, and others) have smaller hippocampi, but most of those reports compared patients to healthy controls. We hypothesized that if psychiatrically matched controls (psychiatric control, matched for demographics and psychiatric comorbidities) were used, much of the biomarker literature in psychiatric research would not replicate. We used hippocampus and amygdala volume only as examples, as these are very commonly replicated results in psychiatry biomarker research. We propose that psychiatry biomarker research could benefit from using psychiatric controls, as the use of healthy controls results in data that are not disorder-specific. Method Hippocampus/amygdala volumes were compared between major depressive disorder, sex-/age-/race-matched healthy control, and psychiatric control (N = 126/group). Similar comparisons were performed for posttraumatic stress disorder (N = 67), borderline personality disorder (N = 111), and alcohol use disorder (N = 136). Results Major depressive disorder patients had smaller left (p = 8.79 × 10−3) and right (p = 3.13 × 10−3) hippocampal volumes than healthy control. Posttraumatic stress disorder had smaller left (p = 0.018) and right (p = 8.64 × 10−4) hippocampi than healthy control. Borderline personality disorder had smaller right hippocampus (p = 7.90 × 10−3) and amygdala (p = 1.49 × 10−3) than healthy control. Alcohol use disorder had smaller right hippocampus (p = 0.034) and amygdala (p = .024) than healthy control. No differences were found between any of the four diagnostic groups and psychiatric control. Conclusion When psychiatric controls were used, there was no difference in hippocampal or amygdalar volume between any of the diagnoses studied and controls. This strategy (keeping all possible relevant variables matched between experimental groups) has been used to advance science for hundreds of years, and we propose should also be used in biomarker psychiatry research.

Neuroanatomical Risk Factors for Posttraumatic Stress Disorder in Recent Trauma Survivors

BackgroundLow hippocampal volume could serve as an early risk factor for posttraumatic stress disorder (PTSD) in interaction with other brain anomalies of developmental origin. One such anomaly may well be the presence of a large cavum septum pellucidum (CSP), which has been loosely associated with PTSD. We performed a longitudinal prospective study of recent trauma survivors. We hypothesized that at 1 month after trauma exposure the relation between hippocampal volume and PTSD symptom severity will be moderated by CSP volume, and that this early interaction will account for persistent PTSD symptoms at subsequent time points. MethodsOne hundred seventy-one adults (87 women, average age 34.22 years [range, 18–65 years of age]) who were admitted to a general hospital’s emergency department after a traumatic event underwent clinical assessment and structural magnetic resonance imaging within 1 month after trauma. Follow-up clinical evaluations were conducted at 6 (n = 97) and 14 (n = 78) months after trauma. Hippocampal and CSP volumes were measured automatically by FreeSurfer software and verified manually by a neuroradiologist (D.N.). ResultsAt 1 month after trauma, CSP volume significantly moderated the relation between hippocampal volume and PTSD severity (p = .026), and this interaction further predicted symptom severity at 14 months posttrauma (p = .018). Specifically, individuals with a smaller hippocampus and larger CSP at 1 month posttrauma showed more severe symptoms at 1 and 14 months after trauma exposure. ConclusionsOur study provides evidence for an early neuroanatomical risk factors for PTSD, which could also predict the progression of the disorder in the year after trauma exposure. Such a simple-to-acquire neuroanatomical signature for PTSD could guide early management as well as long-term monitoring.

Smaller Limbic Structures Are Associated with Immunosuppression and Viral Load in Over 1000 HIV-Infected Adults Across Five Continents: Findings from the ENIGMA-HIV Working Group

Background: Despite more widely accessible combination antiretroviral therapy (cART), the human immunodeficiency virus type-1 (HIV) infection remains a global public health challenge. Even in treated and chronically HIV-infected (HIV+) individuals, neurocognitive impairment often persists, affecting quality of life. Identifying the neuroanatomical pathways associated with infection in-vivo may delineate the neuropathological processes underlying these deficits. However, to date, neuroimaging findings are inconsistent. Methods: We established the ENIGMA-HIV Working Group to retrospectively pool and harmonize heterogeneous data from 12 HIV neuroimaging studies across Africa, Asia, Australia, Europe, and North America. Volume estimates for eight subcortical brain regions were extracted from T1- weighted MRI from 1,044 HIV+ adults (aged 22-81 years; 72·4% on cART; 70·3% male; 41·6% with detectable viral load; dVL), to identify associations with plasma markers reflecting current immunosuppression (CD4+ T-cell counts) or dVL. Follow-up analyses stratified data by cART status and sex. Findings: After Bonferroni correction, lower current CD4+ counts were associated with smaller hippocampal (β=20·3 mm3 per 100 cells/mm3; p=0·0001) and thalamic volumes (β=29.3; p=0·003); in participants not on cART, they were associated with smaller putamen volumes (β=65·1; p=0·0009). dVLs were associated with smaller hippocampi (Cohen's d=0·24; p=0·0003) and amygdala (d=0·18; p=0·0058). Interpretation: In a globally representative population of HIV+ individuals, volumes of structures in the limbic system were consistently associated with current plasma markers. Deficits in these regions may represent a generalizable brain signature of HIV-infection in the cART era. Our findings support the role of viral suppression and immune restoration in maintaining brain health. Funding Statement: Funding for the ENIGMA Center for Worldwide Medicine Imaging and Genomics was provided by the NIH Big Data to Knowledge Program (BD2K; U54 EB020403). Additional funding for this work was provided by NIH grants R01AG059874 (NJ), R01MH117601 (NJ), T32AG058507 (TMN and CRKC), 5T32MH073526 (CRKC), MH083553 (CHH), MH19535 (CHH), R01HL095135 (KJK), MH095661 (TK), UL1RR033176 (TK), UL1TR000124 (TK), MH19535 (TK), NS080655 (BAN), K01AA025306 (ECP), R01HL095135 (CMS), U54MD007584 (CMS), K23MH095661 (ADT), K23AG032872 (VV), R01NS061696 (VV), K24MH098759 (VV), K01AG050707 (AJW), P01AA019072 (RAC), R01MH074368 (RAC), P30 AI042853 (RAC), and by R01MH085604 (RP). This study was also supported by the SA Medical Research Council (DJS), NHMRC APP568746 and APP1045400 (LAC), and the European Research Council Advanced Grant MedYMA 2011- 291080 (XP). Declaration of Interests: PMT, TMN, NJ, and CRKC received partial research support from Biogen, Inc., for work unrelated to the topic of this manuscript. BKN has received an honorarium from MedLink Neurology. VV has served as a consultant for Merck and ViiV Healthcare in the past 3 years, not related to this work. JA has received honoraria for participating in advisory meetings for ViiV Healthcare, Gilead, Merck, Roche and AbbVie. The remaining authors all declare no conflicts of interest. Ethics Approval Statement: Each study obtained approval from their local ethics committee or institutional review board; participants signed an informed consent form at each participating site.

Common Brain Volume Signatures Associated with Immunosuppression and Viral Load in Over 1000 Adults Living with HIV Across 5 Continents: Findings from the ENIGMA-HIV Working Group

Background: Despite more widely accessible combination antiretroviral therapy (cART), the human immunodeficiency virus type-1 (HIV) infection remains a global public health challenge. Even in treated and chronically HIV-infected (HIV+) individuals, neurocognitive impairment often persists, affecting quality of life. Identifying the neuroanatomical pathways associated with infection in-vivo may delineate the neuropathological processes underlying these deficits. However, to date, neuroimaging findings are inconsistent. Methods: We established the ENIGMA-HIV Working Group to retrospectively pool and harmonize heterogeneous data from 12 HIV neuroimaging studies across Africa, Asia, Australia, Europe, and North America. Volume estimates for eight subcortical brain regions were extracted from T1- weighted MRI from 1,044 HIV+ adults (aged 22-81 years; 72·4% on cART; 70·3% male; 41·6% with detectable viral load; dVL), to identify associations with plasma markers reflecting current immunosuppression (CD4+ T-cell counts) or dVL. Follow-up analyses stratified data by cART status and sex. Findings: After Bonferroni correction, lower current CD4+ counts were associated with smaller hippocampal (β=20·3 mm3 per 100 cells/mm3; p=0·0001) and thalamic volumes (β=29.3; p=0·003); in participants not on cART, they were associated with smaller putamen volumes (β=65·1; p=0·0009). dVLs were associated with smaller hippocampi (Cohen's d=0·24; p=0·0003) and amygdala (d=0·18; p=0·0058). Interpretation: In a globally representative population of HIV+ individuals, volumes of structures in the limbic system were consistently associated with current plasma markers. Deficits in these regions may represent a generalizable brain signature of HIV-infection in the cART-era. Our findings support the role of viral suppression and immune restoration in maintaining brain health. Funding Statement: Funding for the ENIGMA Center for Worldwide Medicine Imaging and Genomics was provided by the NIH Big Data to Knowledge Program (BD2K; U54 EB020403). Additional funding for this work was provided by NIH grants R01AG059874 (NJ), R01MH117601 (NJ), T32AG058507 (TMN and CRKC), 5T32MH073526 (CRKC), MH083553 (CHH), MH19535 (CHH), R01HL095135 (KJK), MH095661 (TK), UL1RR033176 (TK), UL1TR000124 (TK), MH19535 (TK), NS080655 (BAN), K01AA025306 (ECP), R01HL095135 (CMS), U54MD007584 (CMS), K23MH095661 (ADT), K23AG032872 (VV), R01NS061696 (VV), K24MH098759 (VV), K01AG050707 (AJW), P01AA019072 (RAC), R01MH074368 (RAC), P30 AI042853 (RAC), and by R01MH085604 (RP). This study was also supported by the SA Medical Research Council (DJS), NHMRC APP568746 and APP1045400 (LAC), and the European Research Council Advanced Grant MedYMA 2011- 291080 (XP). Declaration of Interests: PMT, TMN, NJ, and CRKC received partial research support from Biogen, Inc., for work unrelated to the topic of this manuscript. BKN has received an honorarium from MedLink Neurology. VV has served as a consultant for Merck and ViiV Healthcare in the past 3 years, not related to this work. JA has received honoraria for participating in advisory meetings for ViiV Healthcare, Gilead, Merck, Roche and AbbVie. The remaining authors all declare no conflicts of interest. Ethics Approval Statement: Each study obtained approval from their local ethics committee or institutional review board; participants signed an informed consent form at each participating site.

Role of intestinal flora disturbance in perioperative neurocognitive disorders in aged mice

Objective To evaluate the role of intestinal flora disturbance in perioperative neurocognitive disorders in aged mice. Methods Sixty SPF healthy male C57BL/6J mice, aged 18 months, were divided into 4 groups (n=15 each) by a random number table method: control group (group C), operation group (group O), operation plus lactobacillus rhamnosus group (group OL) and operation plus fecal microbiota transplantation group (group OF). Exploratory laparotomy was performed in O, OL and OF groups.In group PL, lactobacillus rhamnosus 200 μl (1×109 CFU/ml, 200 μl/day) was given by gavage once a day for 10 days starting from the end of surgery, and mice received about 0.2×109 CFU probiotics per day.In group OF, broad-spectrum antibiotic mixture (ampicillin and sulbactam 1.5 g/L, vancomycin 500 mg/L, ciprofloxacin 200 mg/L, imipenem cilastatin 250 mg/L and metronidazole 1 g/L) was added to the drinking water at 7 weeks prior to operation and replaced with sterile tap water at 72 h before operation, and fecal filtrates 200 μl was given by gavage once a day for 10 days starting the end of operation.Five mice were sacrificed at day 10 after operation in each group, and Evans blue extravasation test was used to measure the vascular permeability of jejunum and ileum.Five mice were sacrificed at day 10 after operation in each group, and the small intestinal and hippocampal tissues and orbital venous blood samples were obtained for determination of interleukin-6 (IL-6), IL-17, tumor necrosis factor-alpha (TNF-α), interferon gamma (IFN-γ), IL-4 and IL-10 levels by enzyme-linked immunosorbent assay.Five mice were selected at day 10 after operation in each group, and the Morris water maze test was used to assess the cognitive function. Results Compared with group C, the vascular permeability of jejunum and ileum was significantly increased, the levels of IL-6, IL-17, TNF-α and IFN-γ in the small intestine, peripheral blood and hippocampus were increased, the levels of IL-4 and IL-10 were decreased, the swimming distance and escape latency were prolonged, and the time spent in the target quadrant was shortened in group O (P 0.05). Compared with group O, the vascular permeability of jejunum and ileum was significantly decreased, the levels of IL-6, IL-17, TNF-α and IFN-γ in the small intestine, peripheral blood and hippocampus were decreased, the levels of IL-4 and IL-10 were increased, the swimming distance and escape latency were shortened, and the time spent in the target quadrant was prolonged in OL and OF groups (P<0.05). Conclusion Intestinal flora disturbance can mediate inflammatory responses in the hippocampus and cause perioperative neurocognitive disorders in aged mice. Key words: Gastrointestinal microbiome; Neurocognitive disorders; Aged

Unresolved–Disorganized Attachment is Associated With Smaller Hippocampus and Increased Functional Connectivity Beyond Psychopathology

Loss and abuse in children can lead to unresolved–disorganized (UD) attachment. How this condition relates to brain structure and functional connectivity (FC) is unknown. We therefore aimed to investigate gray matter volume (GMV) and resting state functional connectivity (RSFC) correlates of UD attachment in adolescents. Based on previous neuroimaging studies of trauma effects, we hypothesized that the structure of the amygdala and hippocampus and the FC of the latter would be linked to UD attachment. Anatomical and RSFC data were collected from a mixed group of adolescents (N = 74) with symptoms of posttraumatic stress disorder (PTSD) related to childhood sexual abuse (CSA), anxiety/depressive symptoms, and without psychiatric disorder as part of the Emotional Pathways’ Imaging Study in Clinical Adolescents (EPISCA). Bilateral volumes of the amygdala and hippocampus were measured using the FMRIB Software Library, and RSFC of the hippocampus was assessed using seed‐based correlation. UD attachment was measured using the Adult Attachment Interview. Hierarchical regression and correlation were used to assess the associations between UD status (continuous and categorical), brain structure, and FC, adjusting for a general psychopathology factor, puberty stage, gender, age, and IQ. UD attachment was associated with a smaller left hippocampal volume, R 2 = .23, and a higher level of FC between the hippocampus and the middle temporal gyrus and lateral occipital cortex. The associations among UD attachment, specific brain structure, and FC across psychopathological classifications shows promise for dimensional complements to the dominant classificatory approach in clinical research and practice.

Detecting biological heterogeneity patterns in ADNI amnestic mild cognitive impairment based on volumetric MRI.

There is substantial biological heterogeneity among older adults with amnestic mild cognitive impairment (aMCI). We hypothesized that this heterogeneity can be detected solely based on volumetric MRI measures, which potentially have clinical implications and can improve our ability to predict clinical outcomes. We used latent class analysis (LCA) to identify subgroups among persons with aMCI (n = 696) enrolled in the Alzheimer's Disease Neuroimaging Initiative (ADNI), based on baseline volumetric MRI measures. We used volumetric measures of 10 different brain regions. The subgroups were validated with respect to demographics, cognitive performance, and other AD biomarkers. The subgroups were compared with each other and with normal and Alzheimer's disease (AD) groups with respect to baseline cognitive function and longitudinal rate of conversion. Four aMCI subgroups emerged with distinct MRI patterns: The first subgroup (n = 404), most similar to normal controls in volumetric characteristics and cognitive function, had the lowest incidence of AD. The second subgroup (n = 230) had the most similar MRI profile to early AD, along with poor performance in memory and executive function domains. The third subgroup (n = 36) had the highest global atrophy, very small hippocampus and worst overall cognitive performance. The fourth subgroup (n = 26) had the least amount of atrophy, however still had poor cognitive function specifically in in the executive function domain. Individuals with aMCI who were clinically categorized within one group other showed substantial heterogeneity based on MRI volumetric measures.

Schizophrenia-like reduced sensorimotor gating in intact inbred and outbred rats is associated with decreased medial prefrontal cortex activity and volume.

Prepulse inhibition (PPI) of startle response is a measure of sensorimotor gating that is impaired in schizophrenia and in many other clinical conditions. Rat models using pharmacological or surgical strategies reveal that PPI is modulated by the cortico-striatal-pallido-thalamic (CSPT) circuit. Here, we explore whether spontaneous variation in PPI in intact inbred and outbred rats is associated with functional and structural differences in the CSPT circuit. Inbred Roman High-(RHA) and Low-avoidance (RLA) and outbred heterogeneous stock (HS) rats were assessed for PPI, brain activity, andbrain volume. Brain activity was assessed by c-Fos expression and brain volume by magnetic resonance imaging. Relevant structures of the CSPT circuit were evaluated, such as the medial prefrontal cortex (mPFC), cingulate cortex, hippocampus (HPC), amygdala, nucleus accumbens (NAc), and dorsal striatum. RHA showed lower PPI than RLA rats, while HS rats were stratified by their PPI levels in three groups. Reduced PPI was accompanied by decreased mPFC activity in Roman and HS rats and increased NAc shell activity in HS rats. Low PPI was also associated with decreased mPFC and HPC volumes in Roman and HS rats. This study reports a consistent relationship between decreased function and volume of the mPFC and spontaneous low-PPI levels in inbred and outbred intact rats. Moreover, our findings suggest that, apart from a hypoactive and smaller mPFC, a hyperactive NAc and smaller HPC may underlie reduced PPI levels. Our results support the notion that sensorimotor gating is modulated by forebrain structures and highlight the importance of the mPFC in its regulation.

SU61 - ASSESSING BEHAVIOR AND ANXIETY IN THE DHCR7Δ3-5/T93M MOUSE MODEL OF SMITH-LEMLI-OPITZ SYNDROME

Background Smith-Lemli-Opitz Syndrome (SLOS) is an autosomal recessive inborn error of cholesterol synthesis caused by mutation of the 7-dehydrocholesterol reductase (DHCR7) gene. This results in abnormal sterol levels, increased 7-dehydrocholesterol and typically decreased cholesterol. Although SLOS has a characteristic physical phenotype, with the most common finding being 2-3 toe syndactyly, there are also multiple behavioral abnormalities. These include cognitive deficits, anxiety, hyper-activity, sleep cycle disturbance, language impairment and autism spectrum behaviors. Methods There are currently two main mouse models of SLOS; a homozygous null, Dhcr7Δ3-5/Δ3-5, and a model combining the null mutation and the common p.T93M missense mutation, Dhcr7Δ3-5/T93M. Unlike the null model, the hypomorphic Dhcr7T93M/Δ3-5 mice can live to adulthood and are therefore suitable for behavioral studies. Anxiety can be measured via multiple commonly used protocols; elevated plus maze (EPM), open field test and assessing burrowing and nesting behavior. Results Although there was variation in all genders and genotypes, overall the Dhcr7T93M/Δ3-5 mice were marginally more likely to have increased burrowing compared to controls. However, this was only significant at 4 months in the overnight study. In contrast, the Nestlet test and EPM are both suggestive of decreased anxiety in the Dhcr7T93M/Δ3-5 mice. Additional histological analysis showed that Dhcr7T93M/Δ3-5 mice tended to have a smaller hippocampus and anterior commissure than age and gender matched controls. Discussion The increased burrowing could be showing the increased anxiety phenotype or hyperactivity, which is also noted in the increased gait speed of the Dhcr7T93M/Δ3-5 mice in the open field test. However, the results of the Nestlet test and EPM are opposite to what is typically observed in patients, therefore these findings are either the result of a secondary defect or suggest that the Dhcr7T93M/Δ3-5 model does not replicate the behavioral traits of patients. The hippocampus is the part of the brain responsible for learning, memory and spatial awareness. As such, the changes seen in the hippocampus could explain the decreased shredding observed in the Nestlet test and the potential delayed learning of the Dhcr7T93M/Δ3-5 mice, observed by the normalization of the behaviors in the EPM and open field tasks. These results are suggestive of subtle structural defects and justify further analysis, particularly using mice with an isogenic background where the differences may be more distinct. As SLOS does not have an optimal treatment pathway, if the results suggested by these tests are accurate, it could help aid the development of therapeutic interventions.

MRI load of cerebral microvascular lesions and neurodegeneration, cognitive decline, and dementia.

ObjectiveTo explore the differential associations of neurodegeneration and microvascular lesion load with cognitive decline and dementia in older people and the modifying effect of the APOE genotype on these associations.MethodsA sample of 436 participants (age ≥ 60 years) was derived from the population-based Swedish National study on Aging and Care in Kungsholmen, Stockholm, and clinically examined at baseline (2001–2003) and 3 occasions during the 9-year follow-up. At baseline, we assessed microvascular lesion load using a summary score for MRI markers of lacunes, white matter hyperintensities (WMHs), and perivascular spaces and neurodegeneration load for markers of enlarged ventricles, smaller hippocampus, and smaller gray matter. We assessed cognitive function using the Mini-Mental State Examination (MMSE) test and diagnosed dementia following the Diagnostic and Statistical Manual of Mental Disorders, 4th edition criteria. We analyzed data using linear mixed-effects, mediation, and random-effects Cox models.ResultsDuring the follow-up, 46 participants were diagnosed with dementia. Per 1-point increase in microvascular lesion and neurodegeneration score (range 0–3) was associated with multiple adjusted β-coefficients of −0.35 (95% confidence interval, −0.51 to −0.20) and −0.44 (−0.56 to −0.32), respectively, for the MMSE score and multiple adjusted hazard ratios of 1.68 (1.12–2.51) and 2.35 (1.58–3.52), respectively, for dementia; carrying APOE ε4 reinforced the associations with MMSE decline. WMH volume changes during the follow-up mediated 66.9% and 12.7% of the total association of MMSE decline with the baseline microvascular score and neurodegeneration score, respectively.ConclusionsBoth cerebral microvascular lesion and neurodegeneration loads are strongly associated with cognitive decline and dementia. The cognitive decline due to microvascular lesions is exacerbated by APOE ε4 and is largely attributed to progression and development of microvascular lesions.

Hippocampal Subfield Volumetry: Differential Pattern of Atrophy in Different Forms of Genetic Frontotemporal Dementia.

Background:Frontotemporal dementia (FTD) is a heterogeneous neurodegenerative disorder, with a strong genetic component. Previous research has shown that medial temporal lobe atrophy is a common feature of FTD. However, no study has so far investigated the differential vulnerability of the hippocampal subfields in FTD.Objectives:We aimed to investigate hippocampal subfield volumes in genetic FTD.Methods:We in6/2/2018vestigated hippocampal subfield volumes in a cohort of 75 patients with genetic FTD (age: mean (standard deviation) 59.3 (7.7) years; disease duration: 5.1 (3.4) years; 29 with MAPT, 28 with C9orf72, and 18 with GRN mutations) compared with 97 age-matched controls (age: 62.1 (11.1) years). We performed a segmentation of their volumetric T1-weighted MRI scans to extract hippocampal subfields volumes. Left and right volumes were summed and corrected for total intracranial volumes.Results:All three groups had smaller hippocampi than controls. The MAPT group had the most atrophic hippocampi, with the subfields showing the largest difference from controls being CA1-4 (24–27%, p < 0.0005). For C9orf72, the CA4, CA1, and dentate gyrus regions (8–11%, p < 0.0005), and for GRN the presubiculum and subiculum (10–14%, p < 0.0005) showed the largest differences from controls.Conclusions:The hippocampus was affected in all mutation types but a different pattern of subfield involvement was found in the three genetic groups, consistent with differential cortical-subcortical network vulnerability.

16.2 CHILDHOOD TRAUMA ENGAGES OXIDATIVE STRESS, HIPPOCAMPUS ALTERATIONS, AND POORER CLINICAL OUTCOME IN EARLY PSYCHOSIS PATIENTS

BackgroundExposure to childhood trauma (CT) is a global major public-health and social-welfare problem worldwide. CT increases the vulnerability to major psychiatric conditions including psychosis and is associated with poorer clinical outcome. CT affects the development of brain structures such as hippocampus, possibly through oxidative stress and neuroinflammation, two mechanisms linked to psychosis. We therefore hypothesized that there is an interplay between oxidative stress and CT in psychosis patients. We thus explored in early psychosis patients the relationships between CT and i) hippocampal volume, ii) antioxidant systems; and iii) clinical and cognitive outcomes.MethodsWe studied a cohort of 118 early psychosis patients, 36 were exposed to CT (experiences of physical, sexual, or emotional abuse/neglect before16 years old). In a subgroup of 48 patients (18 CT), hippocampal volume was determined by MRI. Antioxidant systems were quantified in blood for the whole cohort. Markers were: glutathione peroxidases (GPx) activity which appeared as a peripheral correlate of brain GSH levels (Xin &al, 2016); peroxiredoxine levels (Prx); Thioredoxine (Trx). Psychopathology (PANSS) and neuropsychology (MCCB) were assessed. The various groups were segregated by linear discriminant analysis.ResultsThe previously observed decreased hippocampal volume in patients and association of small hippocampal volume with high blood GPx activity (reflecting high oxidative status) (Baumann &al, 2016) was due to the contribution of the traumatized group. Indeed, this association was absent in the no-trauma group, suggesting that the smaller hippocampus is linked to a redox dysregulation. To explore that point further, four groups were then formed, according to trauma and oxidative status: (i) noCT-lowGPx, (ii) noCT-highGPx, (iii) CT-lowGPx and (iv) CT-highGPx. Group CT-highGPx only had smaller hippocampi.In CT patients, small hippocampal volume was associated with high GPx activity, while hippocampal volume was similar in CT patients with low GPx activity (CT-lowGPx) and in patients not exposed to CT. Interestingly, other antioxidant defense systems such as Trx and oxidized Prx levels correlated negatively with GPx in CT-lowGPx group, suggesting that the Trx/Prx system is able to compensate for changes/decreases in GPx activity. Moreover, CT-lowGPx patients perform better than the other patients on speed of processing, verbal memory and attention tests.In contrast, hippocampal volume was decreased in CT patients with high GPx activity (CT-highGPx) compared with CT-lowGPx patients and patients not exposed to CT. There was no correlation between GPx and Trx/Prx system in this group. CT-highGPx patients had more severe positive, negative and disorganized symptoms than the other patients.DiscussionWe report that traumatized psychosis patients with high peripheral oxidation status (high GPx) had smaller hippocampal volumes and more severe clinical symptoms, while those with lower oxidation status (low GPx) had better cognition and appear to activate a compensatory antioxidant regulation by the Trx/Prx system.These results suggest that, in early psychosis patients, traumatic experiences during childhood interact with different redox systems and have long term neuroanatomical and clinical impacts. Therefore, redox pathways such as GPx, Trx and Prx systems represent important translational biomarkers for patient selection and stratification in order to aid in diagnostics and treatment decision at early stages of the disease.

O6.1. HIPPOCAMPAL VOLUME IN ADOLESCENTS WITH PERSISTENT PSYCHOTIC EXPERIENCES: A LONGITUDINAL POPULATION-BASED MRI STUDY

BackgroundIndividuals with schizophrenia show significant brain morphological abnormalities. The ENIGMA consortium identified that patients with schizophrenia had smaller hippocampus, amygdala, thalamus, accumbens and intracranial volumes.1 Reduced hippocampal volume is one of the most consistent findings in schizophrenia research.2–4 Also, Previous research has reported differences in hippocampal volume and white matter integrity in young adolescents who report psychotic experiences.5,6 However there has been little longitudinal research to investigate the developmental trajectory of these regions in adolescence with an increased susceptibility to psychotic disorders.Aimsto investigate two-year longitudinal changes in hippocampal volume in a sample of adolescents who reported psychotic experiences relative to their peers. To investigate the role of presence of co-morbid DSM IV mental disorders and stressful life events in influencing hippocampal volume and study the differences in hippocampus volume between adolescents who were having persistent symptoms versus adolescents with remitting symptoms.MethodsA longitudinal case-control study of 50 community-based adolescents aged 13–16 years (25 with psychotic experiences and a matched sample of 25 without psychotic experiences), compared hippocampal volume. All participants were assessed at baseline and two years follow up. T1 weighted anatomical high-resolution imaging and high angular resolution diffusion imaging data were used to conduct quantitative anatomical volumetric evaluations of global hippocampal volume. Clinical interviews also provided information on psychotic experiences, co-morbid disorders and adverse life events.ResultsThere were significant differences in the Right and Left Whole hippocampus between PE and Control group at baseline and 2-year follow up (p≤ 0.05). There were significant differences between PE persist and Control group in the left and right whole hippocampus (p≤ 0.05).DiscussionThe differences identified in our study suggest that early hippocampal reductions, may play a role in increasing vulnerability to psychosis.