Research Interests: Psychology and Gynecology
Metabolic changes in the hippocampus formation can be investigated with in vivo magnetic resonance spectroscopy (MRS). Learned helplessness (LH) is a well validated animal model of depression which we established in Sprague-Dawley rats... more
Metabolic changes in the hippocampus formation can be investigated with in vivo magnetic resonance spectroscopy (MRS). Learned helplessness (LH) is a well validated animal model of depression which we established in Sprague-Dawley rats defining some as "learned helpless" (LH) or not "learned helpless" (NLH). Helpless and non-helpless rats received a course of daily administered electroconvulsive shocks (ECS) for 6 days. MRS measurements were performed on a 4.7 T animal scanner with an average voxel size within the rat hippocampus of 10 microl. In LH rats hippocampal creatine/NAA rose significantly (14%) whereas creatine/NAA of NLH rats showed no increase at all. A possible connection between hippocampal creatine levels and major depressive disorders as a reflection of changes in energy metabolism is discussed.
Research Interests: Endocrinology, Neuroscience, Psychology, Cognitive Science, Animal Behavior, and 15 moreDepression, Creatine, Magnetic Resonance Spectroscopy, Medicine, Electroconvulsive therapy, Hippocampus, Internal Medicine, Animals, Male, Animal Model, Learned Helplessness, Mental Disorders, Mood Disorders, Neurosciences, and Hippocampal formation
Recent evidence suggests that alterations in hippocampal glutamate and γ-aminobutyric acid (GABA) are associated with the pathomechanism of depression and treatment effects of electroconvulsive therapy (ECT). Thus, proton magnetic... more
Recent evidence suggests that alterations in hippocampal glutamate and γ-aminobutyric acid (GABA) are associated with the pathomechanism of depression and treatment effects of electroconvulsive therapy (ECT). Thus, proton magnetic resonance spectroscopy (¹H MRS) at a 9.4 T animal system seems a promising tool to study underlying mechanisms since it allows for an accurate quantification of metabolites with distinction of glutamate, GABA and glutamine, as well as separation of taurine from choline. A well-validated animal model of treatment resistant depression (congenital learned helpless rats = cLH) was investigated by hippocampal in vivo ¹H MRS with and without a 1-week course of electroconvulsive shocks (ECS), an animal model of ECT, and compared to wild type (WT) animals, while saline and clomipramine injections served as additional controls. Untreated cLH rats showed significantly lower glucose and higher taurine concentrations compared to WT animals. Besides alterations on these metabolites, ECS increased glutamate in WT and cLH and choline in cLH rats. Moreover, correlations between glutamate and GABA concentrations with learned helpless behaviour were revealed. These findings support the idea of disordered hippocampal metabolism in an animal model of treatment resistant depression and suggest an early impact of ECS on MR-detectable hippocampal metabolites.
Research Interests: Neuroscience, Psychology, Chemistry, Depression, Magnetic Resonance Spectroscopy, and 15 moreMedicine, Electroconvulsive therapy, Hippocampus, Glucose, Animals, Male, Learned Helplessness, Clinical Sciences, Rats, Glutamine, Choline, Neurosciences, Glutamic Acid, Glutamate Receptor, and Hippocampal formation
The theory of depression is dominated by the monoamine hypothesis but there is increasing evidence that beyond monoamines, glutamate (Glu) and gamma-aminobutyric acid (GABA) play an essential role in the pathogenesis of depression. In... more
The theory of depression is dominated by the monoamine hypothesis but there is increasing evidence that beyond monoamines, glutamate (Glu) and gamma-aminobutyric acid (GABA) play an essential role in the pathogenesis of depression. In this study, the effect of alterations of GABA and Glu were investigated in the congenital learned helplessness paradigm. Proton magnetic resonance spectroscopy is an important monitoring tool to bridge the findings in clinical and preclinical studies. We found increased Glu/GABA ratios in the hippocampus and prefrontal cortex of placebo-treated (saline intraperitoneally) congenital learned helplessness rats versus wild-type rats, and a treatment-induced (desipramine 10 mg/kg intraperitoneally or electroconvulsive shock) decrease of this monoamine ratio in both brain regions. Our results corroborate previous findings of an amino-acid influence on the pathomechanisms of mood disorders.
Research Interests: Endocrinology, Cognitive Science, Depression, Biology, Magnetic Resonance Spectroscopy, and 15 moreMedicine, Prefrontal Cortex, Glutamate, Brain, Internal Medicine, Animal, Animals, Learned Helplessness, Mental Disorders, Mood Disorders, Butyric Acid, Neurosciences, Glutamic Acid, Model organism, and Glutamate Receptor
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Research Interests: Addiction, Magnetic Resonance Imaging, Medicine, Brain Mapping, Humans, and 15 moreCues, Alcoholism, Functional Magnetic Resonance Imaging, Female, Alcohol Drinking, Male, Craving, Middle Aged, Adult, Alcoholic Beverages, Basal ganglia, Alcohol Use, Corpus striatum, Cue reactivity, and Medical and Health Sciences
Research Interests: Neuroscience, Psychology, Cognition, Addiction (Biology), Medicine, and 14 morePrefrontal Cortex, Functional Connectivity, Insula, Functional Magnetic Resonance Imaging, Orbitofrontal cortex, Posterior Cingulate, Control Management, Ventral Striatum, Anterior cingulate cortex, Dorsolateral Prefrontal Cortex, Cue reactivity, Psychology and Cognitive Sciences, Alcohol use disorder, and Medical and Health Sciences
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Research Interests: Computer Science, Artificial Intelligence, Computer Vision, Computed Tomography, Computational Complexity, and 15 moreMagnetic Resonance Imaging, Nuclear Magnetic Resonance, Functional MRI, Medicine, Multidisciplinary, Brain, Humans, Computer Systems, Functional Imaging, Heart, Informatik, Neurosciences, Direct Volume Rendering, Magnetic resonance image, and Motion Artifact
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Introduction Since the finding of an altered phosophomono and -diester metabolism in cell membranes of postmortem brains of schizophrenic patients [1] several studies have used P-MRS for in vivo investigation of schizophrenic groups [2-4]... more
Introduction Since the finding of an altered phosophomono and -diester metabolism in cell membranes of postmortem brains of schizophrenic patients [1] several studies have used P-MRS for in vivo investigation of schizophrenic groups [2-4] in different brain regions, partly with contradictory results. Because of the scalar coupling between H and P in the molecules the resonances of phospho-monoand/or phosphodiester (Phosphorylethanolamine PE, Phosphocholine PC and Gylcero-phosphorylethanolamine GPE, Glycerophosphocholine GPC) show a multiplet structure overlying the broad phospholipid-component, their concentrations are difficult to quantify reliably. We used a 3D-whole head RINEPT sequence together with point-spread function (PSF) corrected tissue segmentation for robust absolute quantification.
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Objective Brain atlases are important research tools enabling researchers to focus their investigations on specific anatomically defined brain regions and are used in many MRI applications, e.g. in fMRI, morphometry, whole brain... more
Objective Brain atlases are important research tools enabling researchers to focus their investigations on specific anatomically defined brain regions and are used in many MRI applications, e.g. in fMRI, morphometry, whole brain spectroscopy, et cetera. Despite their extensive use and numerous versions they usually consist of predefined rigid brain regions with a given level of detail often degrading them to a non-ideal tool in special research topics. Result To overcome this intrinsic weakness we present a graphical user interface application which allows researchers to easily create mouse brain atlases with an adjustable user-defined level of detail and coverage to match specific research questions.
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Deleterious effects of adverse childhood experiences (ACE) on human brain volume are widely reported. First evidence points to differential effects of ACE on brain volume in terms of timing of ACE. Upcoming studies additionally point... more
Deleterious effects of adverse childhood experiences (ACE) on human brain volume are widely reported. First evidence points to differential effects of ACE on brain volume in terms of timing of ACE. Upcoming studies additionally point towards the impact of different types (i.e., neglect and abuse) of ACE in terms of timing. The current study aimed to investigate the correlation between retrospectively reported severity of type (i.e., the extent to which subjects were exposed to abuse and/or neglect, respectively) and timing of ACE on female brain volume in a sample of prolonged traumatized subjects. A female sample with ACE (N = 68) underwent structural magnetic resonance imaging and a structured interview exploring the severity of ACE from age 3 up to 17 using the “Maltreatment and Abuse Chronology of Exposure” (MACE). Random forest regression with conditional interference trees was applied to assess the impact of ACE severity as well as the severity of ACE type, (i.e. to what exten...
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Real-time functional magnetic resonance imaging neurofeedback training of amygdala hemodynamic activity directly targets a neurobiological mechanism, which contributes to emotion regulation problems in borderline personality disorder... more
Real-time functional magnetic resonance imaging neurofeedback training of amygdala hemodynamic activity directly targets a neurobiological mechanism, which contributes to emotion regulation problems in borderline personality disorder (BPD). However, it remains unknown which outcome measures are suited to assess changes in emotion regulation and affective instability associated with amygdala down-regulation in a clinical trial. The current study directly addresses this question. 24 female patients with a DSM-IV BPD diagnosis underwent a four-session amygdala neurofeedback training. Before and after the training as well as at a six weeks follow-up, participants completed measures of emotion dysregulation and affective instability at diverse levels of analysis (verbal report, clinical interview, ecological momentary assessment, emotion-modulated startle, heart rate variability and fMRI). Participants were able to down-regulate their amygdala BOLD response with neurofeedback. There was ...
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Brain–computer interfaces provide conscious access to neural activity by means of brain‐derived feedback (“neurofeedback”). An individual's abilities to monitor and control feedback are two necessary processes for effective... more
Brain–computer interfaces provide conscious access to neural activity by means of brain‐derived feedback (“neurofeedback”). An individual's abilities to monitor and control feedback are two necessary processes for effective neurofeedback therapy, yet their underlying functional neuroanatomy is still being debated. In this study, healthy subjects received visual feedback from their amygdala response to negative pictures. Activation and functional connectivity were analyzed to disentangle the role of brain regions in different processes. Feedback monitoring was mapped to the thalamus, ventromedial prefrontal cortex (vmPFC), ventral striatum (VS), and rostral PFC. The VS responded to feedback corresponding to instructions while rPFC activity differentiated between conditions and predicted amygdala regulation. Control involved the lateral PFC, anterior cingulate, and insula. Monitoring and control activity overlapped in the VS and thalamus. Extending current neural models of neurofe...
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We explored brain volume recovery in terms of cortical thickness (CTh; gyral, sulcal pattern) and surface area (SA), as well as subcortical volume recovery in the first 2 weeks of abstinence in 49 alcohol-dependent patients (ADPs). A... more
We explored brain volume recovery in terms of cortical thickness (CTh; gyral, sulcal pattern) and surface area (SA), as well as subcortical volume recovery in the first 2 weeks of abstinence in 49 alcohol-dependent patients (ADPs). A widespread reduction of CTh in ADPs at day 1 of abstinence compared to healthy controls, with more pronounced differences in sulci relative to gyri was found. After 2 weeks of abstinence, partial recovery to varying degrees of CTh loss in ADPs was observed for several regions. The longitudinal CTh changes were greater in sulci than in gyri of affected regions. No longitudinal change in SAs and subcortical volumes was found. Alterations of CTh contribute to brain volume loss in alcoholism and recovery during early abstinence. Sulci seem to be more vulnerable to excessive alcohol consumption and to drive abstinence-induced volume recovery. During the initial 2 weeks of abstinence no subcortical volume regain was observed. Either the time span was too shor...
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Heating of gradient coils and passive shim components is a common cause of instability in the B0 field, especially when gradient intensive sequences are used. The aim of the study was to set a benchmark for typical drift encountered... more
Heating of gradient coils and passive shim components is a common cause of instability in the B0 field, especially when gradient intensive sequences are used. The aim of the study was to set a benchmark for typical drift encountered during MR spectroscopy (MRS) to assess the need for real-time field-frequency locking on MRI scanners by comparing field drift data from a large number of sites. A standardized protocol was developed for 80 participating sites using 99 3T MR scanners from 3 major vendors. Phantom water signals were acquired before and after an EPI sequence. The protocol consisted of: minimal preparatory imaging; a short pre-fMRI PRESS; a ten-minute fMRI acquisition; and a long post-fMRI PRESS acquisition. Both pre- and post-fMRI PRESS were non-water suppressed. Real-time frequency stabilization/adjustment was switched off when appropriate. Sixty scanners repeated the protocol for a second dataset. In addition, a three-hour post-fMRI MRS acquisition was performed at one site to observe change of gradient temperature and drift rate. Spectral analysis was performed using MATLAB. Frequency drift in pre-fMRI PRESS data were compared with the first 5:20 minutes and the full 30:00 minutes of data after fMRI. Median (interquartile range) drifts were measured and showed in violin plot. Paired t-tests were performed to compare frequency drift pre- and post-fMRI. A simulated in vivo spectrum was generated using FID-A to visualize the effect of the observed frequency drifts. The simulated spectrum was convolved with the frequency trace for the most extreme cases. Impacts of frequency drifts on NAA and GABA were also simulated as a function of linear drift. Data from the repeated protocol were compared with the corresponding first dataset using Pearson's and intraclass correlation coefficients (ICC). Of the data collected from 99 scanners, 4 were excluded due to various reasons. Thus, data from 95 scanners were ultimately analyzed. For the first 5:20 min (64 transients), median (interquartile range) drift was 0.44 (1.29) Hz before fMRI and 0.83 (1.29) Hz after. This increased to 3.15 (4.02) Hz for the full 30 min (360 transients) run. Average drift rates were 0.29 Hz/min before fMRI and 0.43 Hz/min after. Paired t-tests indicated that drift increased after fMRI, as expected (p < 0.05). Simulated spectra convolved with the frequency drift showed that the intensity of the NAA singlet was reduced by up to 26%, 44 % and 18% for GE, Philips and Siemens scanners after fMRI, respectively. ICCs indicated good agreement between datasets acquired on separate days. The single site long acquisition showed drift rate was reduced to 0.03 Hz/min approximately three hours after fMRI. This study analyzed frequency drift data from 95 3T MRI scanners. Median levels of drift were relatively low (5-min average under 1 Hz), but the most extreme cases suffered from higher levels of drift. The extent of drift varied across scanners which both linear and nonlinear drifts were observed.
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Zusammenfassung Eine elegante Methode fur die lokalisierte in vivo 31 P-MR-Spektroskopie am Gehirn des Menschen ist das Chemical-Shift-Imaging. Eine signifikante Verbesserung des Signal-Rausch-Verhaltnisses bei gleichbleibender Meszeit... more
Zusammenfassung Eine elegante Methode fur die lokalisierte in vivo 31 P-MR-Spektroskopie am Gehirn des Menschen ist das Chemical-Shift-Imaging. Eine signifikante Verbesserung des Signal-Rausch-Verhaltnisses bei gleichbleibender Meszeit wurde von uns mit der Doppelresonanztechnik erzielt. Durch zusatzliche Hochfrequenz-Einstrahlung auf der Protonenfrequenz wird ein Kern-Overhauser-Effekt im dipolar gekoppelten 31P-1 H-Spinsystem induziert. In Probandenmessungen wurde ein Signalgewinn von bis zu 42 % beobachtet. Das 31P-Chemical-Shift-Imaging wird in einer klinischen Studie zur Kontrolle der prachirurgischen Embolisation von Meningeomen eingesetzt.
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Introduction Dysfunction and deficits in the structure of the anterior cingulate cortex (ACC) as well as increased impulsivity have been reported in borderline personality disorder (BPD) [1-3]. γ-Aminobutyric acid (GABA) is the main... more
Introduction Dysfunction and deficits in the structure of the anterior cingulate cortex (ACC) as well as increased impulsivity have been reported in borderline personality disorder (BPD) [1-3]. γ-Aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the human cerebral cortex. Loss or dysfunction of GABAergic neurotransmission is associated with many neurological and psychiatric conditions, e.g. decreased GABA was found in schizophrenia by Yoon [4]. We are not aware of any study investigating GABA in BPD. Methods In vivo single voxel 1H MRS was performed at a 3.0 T MR scanner with a thirty-two channel head coil (Siemens Magnetom TIM Trio) in 20 female patients with BPD (26.9 ± 5.2ys) and 24 female age matched healthy controls (27.9 ± 6.9ys). The ACC voxel (40x30x20mm3) was placed based on an isotropic 1 mm3 mprage data set with reconstructed coronal and transverse planes aligned with the shape of the corpus callosum (see Fig. 1). Approval for this study had been obtained from the local ethics committee. Spectra were acquired with a Point Resolved Spectroscopy (PRESS) Sequence using the following parameters: TE = 68ms, TR = 3000ms, 96 averages, 2048 acquisition points. Measurements of GABA were obtained using a MEGA-PRESS editing sequence which uses the J-coupling between the GABA-H4 resonance at 3.01 ppm and GABA-H3 resonance at 1.89 ppm to reveal the GABA resonance [5] (see Fig. 1). Two subsequent editing acquisitions were made. First with the frequency of the editing pulse switching between 1.9 ppm and 7.5 ppm (editing center 4.7 ppm) and second switching between 1.9 and 1.5 ppm (editing center 1.7 ppm). The latter diminishes contamination by nearby macromolecule (MM) resonances [6, 7]. For quantification of GABA the acquired spectra were analyzed using the jMRUISoftware. For the other metabolites, LCModel was used. A fully automated segmentation of the high resolution T1-weighted mprage data into gray matter (GM), white matter (WM) and cerebrospinal fluid (CSF) using SPM 5 algorithms and MATLAB 7.9 was performed to determine the composition of each spectroscopic voxel [8]. All metabolites were corrected for CSF content and scaled with the water signal at TE = 30ms. The GABA signal was quantified based on GABA phantom measurements. The calculation of the GABA concentration in vivo is as follows conc = S S S S ∗ conc ∗ ρ ρ where S and S are the peak areas of the corresponding in vivo and phantom measurement, respectively. conc is the GABA concentration of the phantom and the term ρ ρ ⁄ describes the density correction for water and GABA, respectively, due to the voxels tissue content. Since no relaxation corrections were applied the values are to be regarded as semi-quantitative.
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Both chronic alcohol consumption and alcohol withdrawal lead to neural tissue damage which partly recovers during abstinence. This study investigated withdrawal-associated changes in glutamatergic compounds, markers of neuronal integrity,... more
Both chronic alcohol consumption and alcohol withdrawal lead to neural tissue damage which partly recovers during abstinence. This study investigated withdrawal-associated changes in glutamatergic compounds, markers of neuronal integrity, and gray matter volumes during acute alcohol withdrawal in the hippocampus, a key region in development and maintenance of alcohol dependence in humans and rats. Alcohol-dependent patients (N = 39) underwent magnetic resonance imaging (MRI) and MR spectroscopy (MRS) measurements within 24 hours after the last drink and after 2 weeks of abstinence. MRI and MRS data of healthy controls (N = 34) were acquired once. Our thorough quality criteria resulted in N = 15 available spectra from the first and of N = 21 from the second measurement in patients, and of N = 19 from healthy controls. In a translational approach, chronic intermittent ethanol-exposed rats and respective controls (8/group) underwent 5 MRS measurements covering baseline, intoxication, 1...
Research Interests: Magnetic Resonance Imaging, Biomarkers, Magnetic Resonance Spectroscopy, Medicine, Hippocampus, and 15 moreHumans, Internal Medicine, Alcoholism, Female, Animals, Male, Abstinence, Clinical Sciences, Middle Aged, Alcohol dependence, Adult, Gray Matter, Glutamic Acid, Glutamate Receptor, and Hippocampal formation
Beneficial effects of voluntary wheel running on hippocampal neurogenesis, morphology and hippocampal-dependent behavior have widely been studied in rodents, but also serious side effects and similarities to stereotypy have been reported.... more
Beneficial effects of voluntary wheel running on hippocampal neurogenesis, morphology and hippocampal-dependent behavior have widely been studied in rodents, but also serious side effects and similarities to stereotypy have been reported. Some mouse strains run excessively when equipped with running wheels, complicating the comparability to human exercise regimes. Here, we investigated how exercise restriction to 6h/day affects hippocampal morphology and metabolism, stereotypic and basal behaviors, as well as the endocannabinoid system in wheel running C57BL/6 mice; the strain most commonly used for behavioral analyses and psychiatric disease models. Restricted and unrestricted wheel running had similar effects on immature hippocampal neuron numbers, thermoregulatory nest building and basal home-cage behaviors. Surprisingly, hippocampal gray matter volume, assessed with magnetic resonance (MR) imaging at 9.4 Tesla, was only increased in unrestricted but not in restricted runners. Moreover, unrestricted runners showed less stereotypic behavior than restricted runners did. However, after blockage of running wheels for 24h stereotypic behavior also increased in unrestricted runners, arguing against a long-term effect of wheel running on stereotypic behavior. Stereotypic behaviors correlated with frontal glutamate and glucose levels assessed by (1)H-MR spectroscopy. While acute running increased plasma levels of the endocannabinoid anandamide in former studies in mice and humans, we found an inverse correlation of anandamide with the daily running distance after long-term running. In conclusion, although there are some diverging effects of restricted and unrestricted running on brain and behavior, restricted running does not per se seem to be a better animal model for aerobic exercise in mice.
Research Interests: Neuroscience, Psychology, Animal Behavior, Neurogenesis, Running, and 15 moreMedicine, Biological Sciences, Hippocampus, Brain, Humans, Mice, Animals, Male, Endocannabinoid System, Endocannabinoids, Anandamide, Hippocampal formation, Motor activity, Stereotyped behavior, and Medical and Health Sciences
Attention Deficit Hyperactivity Disorder (ADHD) is a neurobiological disorder of early childhood onset. Defining symptoms are chronic impairments of attention, impulse control and motor hyperactivity that frequently persist until... more
Attention Deficit Hyperactivity Disorder (ADHD) is a neurobiological disorder of early childhood onset. Defining symptoms are chronic impairments of attention, impulse control and motor hyperactivity that frequently persist until adulthood. Miscellaneous causes of the disorder have been discussed. Accumulating evidence from imaging- and molecular genetic studies strengthened the theory of ADHS being a predominantly inherited disorder of neurobiological origin. In the last 15 years, non-invasive brain imaging methods were successfully implemented in pediatric research. Functional magnetic resonance imaging studies gave major insight into the neurobiological correlates of executive malfunction, inhibitory deficits and psychomotoric soft signs. These findings are in good accordance with brain morphometric data indicating a significant volumetric decrease of major components of striato-thalamo-cortical feedback loops, primarily influencing prefrontal executive functioning (e.g. basal ga...
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Growing evidence indicates that physical exercise increases hippocampal volume. This has consistently been shown in mice and men using magnetic resonance imaging. On the other hand, histological studies have reported profound alterations... more
Growing evidence indicates that physical exercise increases hippocampal volume. This has consistently been shown in mice and men using magnetic resonance imaging. On the other hand, histological studies have reported profound alterations on a cellular level including increased adult hippocampal neurogenesis after exercise. A combined investigation of both phenomena has not been documented so far although a causal role of adult neurogenesis for increased hippocampal volume has been suggested before. We investigated 20 voluntary wheel running and 20 sedentary mice after a period of 2 month voluntary wheel running. Half of each group received focalized hippocampal irradiation to inhibit neurogenesis prior to wheel running. Structural MRI and histological investigations concerning newborn neurons (DCX), glial cells (GFAP), microglia, proliferating and pyknotic cells, neuronal activation, as well as blood vessel density and arborisation were performed. In a regression model, neurogenesis...
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The interplay of amyloid and mitochondrial function is considered crucial in the pathophysiology of... more
The interplay of amyloid and mitochondrial function is considered crucial in the pathophysiology of Alzheimer&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s disease (AD). We tested the association of the putative marker of mitochondrial function N-acetylaspartate (NAA) as measured by proton magnetic resonance spectroscopy within the medial temporal lobe and cerebrospinal fluid amyoid-β42 (Aβ42), total Tau and pTau181. 109 patients were recruited in a multicenter study (40 mild AD patients, 14 non-AD dementia patients, 29 mild cognitive impairment (MCI) AD-type patients, 26 MCI of non-AD type patients). NAA correlated with Aβ42 within the AD group. Since the NAA concentration is coupled to neuronal mitochondrial function, the correlation between NAA and Aβ42 may reflect the interaction between disrupted mitochondrial pathways and amyloid production.
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Physical activity (PA) was found to influence human brain morphology. However, the impact of PA on brain morphology was mainly demonstrated in seniors. We investigated healthy individuals across a broad age range for the relation between... more
Physical activity (PA) was found to influence human brain morphology. However, the impact of PA on brain morphology was mainly demonstrated in seniors. We investigated healthy individuals across a broad age range for the relation between habitual PA and brain morphology. Ninety-five participants (19-82 years) were assessed for self-reported habitual PA with the &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;Baecke habitual physical activity questionnaire&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;, and T1-weighted magnetic resonance images were evaluated with whole brain voxel based morphometry for gray and white matter volumes and densities. Regression analyses revealed a positive relation between the extent of physical activity and gray matter volume bilaterally in the anterior hippocampal and parahippocampal gyrus independent of age and gender. Age as well as leisure and locomotion activities were linked to enhanced white matter volumes in the posterior cingulate gyrus and precuneus, suggesting a positive interaction especially in seniors. Habitual physical activity is associated with regional volumetric gray and white matter alterations. The positive relation of hippocampal volume and physical activity seems not to be restricted to seniors. Thus, habitual physical activity should be generally considered as an influencing factor in studies investigating medial temporal lobe volume and associated cognitive functions (memory), especially in psychiatric research.
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Recent evidence suggests that alterations in hippocampal glutamate and γ-aminobutyric acid (GABA) are associated with the pathomechanism of depression and treatment effects of electroconvulsive therapy (ECT). Thus, proton magnetic... more
Recent evidence suggests that alterations in hippocampal glutamate and γ-aminobutyric acid (GABA) are associated with the pathomechanism of depression and treatment effects of electroconvulsive therapy (ECT). Thus, proton magnetic resonance spectroscopy (¹H MRS) at a 9.4 T animal system seems a promising tool to study underlying mechanisms since it allows for an accurate quantification of metabolites with distinction of glutamate, GABA and glutamine, as well as separation of taurine from choline. A well-validated animal model of treatment resistant depression (congenital learned helpless rats = cLH) was investigated by hippocampal in vivo ¹H MRS with and without a 1-week course of electroconvulsive shocks (ECS), an animal model of ECT, and compared to wild type (WT) animals, while saline and clomipramine injections served as additional controls. Untreated cLH rats showed significantly lower glucose and higher taurine concentrations compared to WT animals. Besides alterations on these metabolites, ECS increased glutamate in WT and cLH and choline in cLH rats. Moreover, correlations between glutamate and GABA concentrations with learned helpless behaviour were revealed. These findings support the idea of disordered hippocampal metabolism in an animal model of treatment resistant depression and suggest an early impact of ECS on MR-detectable hippocampal metabolites.
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Impulsivity is central to borderline personality disorder (BPD). Response inhibition, addressing the ability to suppress or stop actions, is one aspect of behavioral impulse control which is frequently used to assess impulsivity. BPD... more
Impulsivity is central to borderline personality disorder (BPD). Response inhibition, addressing the ability to suppress or stop actions, is one aspect of behavioral impulse control which is frequently used to assess impulsivity. BPD patients display deficits in response inhibition under stress condition or negative emotions. We assessed whether response inhibition and its neural underpinnings are impaired in BPD when tested in an emotionally neutral setting and when co-morbid attention-deficit/hyperactivity disorder (ADHD) is excluded. To this end, we studied response inhibition in unmedicated BPD patients and healthy controls (HC) in two independent samples using functional magnetic resonance imaging during Simon-, Go/nogo-, and Stopsignal tasks. BPD patients and HC did not differ significantly in their performance in the Go/nogo and the Stopsignal tasks. Response interference in the Simon task was increased in BPD patients in one sample, but this could not be replicated in the second sample. In both samples, no significant differences in brain activation patterns during any of the tasks were present while the neural impulse control network was robustly activated during the inhibition tasks in both groups. Our results provide evidence that under emotionally neutral conditions response inhibition is not impaired in patients with BPD without co-occurring ADHD.