Effects of childhood adversity on the volumes of the amygdala subnuclei and hippocampal subfields in individuals with major depressive disorder.

Background: Reductions in total hippocampus volume have frequently been reported in MRI studies in major depressive disorder (MDD), but reports of differences in total amygdala volume have been inconsistent. Childhood maltreatment is an important risk factor for MDD in adulthood and may affect the volume of the hippocampus and amygdala. In the present study, we examined associations between the volumes of the amygdala subnuclei and hippocampal subfields and history of childhood maltreatment in participants with MDD.

Dopamine and light: effects on facial emotion recognition.

Bright light can affect mood states and social behaviours. Here, we tested potential interacting effects of light and dopamine on facial emotion recognition. Participants were 32 women with subsyndromal seasonal affective disorder tested in either a bright (3000 lux) or dim light (10 lux) environment.

Effects of cortisol on hippocampal subfields volumes and memory performance in healthy control subjects and patients with major depressive disorder.

Overactivity of the hypothalamic-pituitary-adrenal (HPA) axis in major depressive disorder (MDD) is among the most consistently replicated biological findings in psychiatry. Magnetic resonance imaging (MRI) studies have consistently demonstrated that hippocampal (HC) volume is decreased in patients with MDD. The improved spatial resolution of high field strength MRI has recently enabled measurements of HC subfield volumes in vivo.

Dentate gyrus volume and memory performance in major depressive disorder.

Background: Magnetic resonance imaging (MRI) has shown lower hippocampal volume in major depressive disorder (MDD). Patients with MDD have consistently demonstrated worse performance than healthy controls a number of memory tests. Memory functions within the hippocampus in healthy younger subjects appear to be linked to cornu ammonis (CA1-3) and dentate gyrus (DG) subfields.

Structural changes in hippocampal subfields in major depressive disorder: a high-field magnetic resonance imaging study.

Background: Magnetic resonance imaging (MRI) has shown lower hippocampal volume in major depressive disorder (MDD). Preclinical and postmortem studies show that chronic stress and MDD may affect hippocampal subfields differently, but MRI spatial resolution has previously been insufficient to measure subfield volumes.

Methods: Twenty MDD participants (9 unmedicated and 11 medicated, both > 6 months) and 27 healthy control subjects were studied.

Fronto-limbic volumetric changes in major depressive disorder.

Background: Fronto-limbic dysregulation in major depressive disorder (MDD) may be influenced by early life stress and antidepressant treatment. The present structural MRI study aimed to determine the relationship between amygdala, cingulate and subgenual prefrontal cortex volumes in MDD and their associations with child abuse and antidepressants.

Methods: Right-handed subjects (21-50 years), meeting DSM-IV criteria for MDD, either with (n=19) or without (n=20) childhood sexual or physical abuse.

Effects of trauma-related cues on pain processing in posttraumatic stress disorder: an fMRI investigation.

Background: Imaging studies of pain processing in primary psychiatric disorders are just emerging. This study explored the neural correlates of stress-induced analgesia in individuals with posttraumatic stress disorder (PTSD). It combined functional magnetic resonance imaging (fMRI) and the traumatic script-driven imagery symptom provocation paradigm to examine the effects of trauma-related cues on pain perception in individuals with PTSD.

Structural changes in the hippocampus in major depressive disorder: contributions of disease and treatment.

Background: Previous magnetic resonance imaging (MRI) studies of patients with major depressive disorder (MDD) have consistently shown bilateral and unilateral reductions in hippocampal volume relative to healthy controls. Recent structural MRI studies have addressed the question of whether changes in the volume of hippocampal subregions may be associated with MDD.

Methods: We used a comprehensive and reliable 3-dimensional tracing protocol that enables delineation of hippocampal subregions (head, body, tail) to study changes in the hippocampus of patients with MDD.

Measurement of glutathione in human brain at 3T using an improved double quantum filter in vivo.

A single voxel proton NMR double quantum filter (DQF) for measurement of glutathione (GSH) in human brain at 3T is reported. Yield enhancement for the CH(2) resonances of the cysteine moiety at 2.95ppm has been achieved by means of dual encoding.

Diffusion tensor imaging tractography and reliability analysis for limbic and paralimbic white matter tracts.

Diffusion tensor imaging (DTI) provides the opportunity to study white matter tracts in vivo. The goal was to estimate the reliability of DTI tractography for the analysis of limbic and paralimbic white matter. Normative data from 24 healthy subjects and reliability data from four healthy and four depressed subjects were acquired at 1.

Aging hippocampus and amygdala.

Earlier studies suggest that the anterior hippocampus may show resilience to age-associated volume loss. This study compared high-resolution magnetic resonance images obtained from younger (n=28; age range: 22-50 years) and older (n=39; age range: 65-84 years) healthy right-handed individuals to determine whether age-related volume changes varied between the hippocampal head, body and tail. Volumetric reductions were progressively more severe from hippocampal head to tail.

Measurement of glycine in human brain by triple refocusing 1H-MRS in vivo at 3.0T.

A new (1)H-MRS filtering strategy for selective measurement of glycine (Gly) in human brain in vivo at 3.0T is proposed. Investigation of multiple refocusing following a 90 degrees excitation pulse indicated that triple refocusing is most effective for suppression of the strongly coupled resonances of myo-inositol (mI) at the Gly 3.

Measurement of GABA and contaminants in gray and white matter in human brain in vivo.

A preliminary study of discrimination between GABA and macromolecules (MMs) in human brain by proton double quantum filtering (DQF) at 3.0 T in vivo is presented. GABA-tuned and MM-tuned DQ filters were designed with dual-band 180 degrees radiofrequency (RF) pulses that were tuned for selective refocusing of GABA (3.

Three-dimensional volumetric analysis and reconstruction of amygdala and hippocampal head, body and tail.

Volumetric changes in the amygdala and hippocampus are relevant to many disorders, but their close proximity makes it difficult to separate these structures by magnetic resonance imaging, leading many volumetric protocols to exclude problematic slices from analysis, or to analyze the amygdalo-hippocampal complex conjointly. The hippocampus tail is also often excluded, because of the difficulty in separating it from the thalamus. We have developed a reliable protocol for volumetric analysis and 3-D reconstruction of the amygdala and hippocampus (as a whole and in its anatomical parts).

T2 measurement and quantification of glutamate in human brain in vivo.

The proton NMR transverse relaxation time T(2) of glutamate (Glu) in human brain was measured by means of spectrally selective refocusing at 3.0 T in vivo. An 81.

Proton spectral editing for discrimination of lactate and threonine 1.31 ppm resonances in human brain in vivo.

A single-voxel proton NMR J-difference editing method for discriminating between the 1.31 ppm resonances of lactate (Lac) and threonine (Thr) in human brain in vivo at 3 T is reported. One double-band and two triple-band Gaussian 180 degrees RF pulses, all with a bandwidth of 15 Hz, were employed within an adiabatic-refocused double-echo localization sequence to induce the target signals of Lac and Thr and simultaneously acquire a creatine singlet in each subscan.

Measurement of brain glutamate and glutamine by spectrally-selective refocusing at 3 Tesla.

A new single-voxel proton NMR spectrally-selective refocusing method for measuring glutamate (Glu) and glutamine (Gln) in the human brain in vivo at 3T is reported. Triple-resonance selective 180 degrees RF pulses with a bandwidth of 12 Hz were implemented within point-resolved spectroscopy (PRESS) for selective detection of Glu or Gln, and simultaneous acquisition of creatine singlets for use as a reference in phase correction. The carriers of the spectrally-selective 180 degrees pulses and the echo times (TEs) were optimized with both numerical and experimental analyses of the filtering performance, which enabled measurements of the target metabolites with negligible contamination from N-acetylaspartate and glutathione.

Detection of the myo-inositol 4.06-ppm resonance by selective J rewinding: application to human prefrontal cortex in vivo.

A new proton NMR single-voxel spectral editing strategy for the rapid measurement of myo-inositol in human brain is proposed. The spectral editing detects the 4.06-ppm, weakly coupled resonance by means of selective J rewinding.

Brain gamma-aminobutyric acid measurement by proton double-quantum filtering with selective J rewinding.

An optimized single-shot proton double-quantum (DQ) filter for the quantification of gamma-aminobutyric acid (GABA) levels in human brain is reported. It is demonstrated that creation of DQ coherences following dual-resonance-selective refocusing gives a theoretical editing efficiency of 50% for the detection of the GABA resonance at 3.01 ppm.

Positive and negative affect differentially influence identification of facial emotions.

Positive and negative affects may bias behavior toward approach to rewards and withdrawal from threat, particularly when the contingencies are ambiguous. The hypothesis was that positive and negative affects would associate predictably with identification of happy, disgusted, or angry expressions that may signal potentially rewarding or aversive social interactions. Healthy volunteers (n=86) completed affect ratings and a facial emotion task that employed morphed continua in which emotional expressions gradually decreased in ambiguity.

Panic-related responses to pentagastrin, flumazenil, and thyrotropin-releasing hormone in healthy volunteers.

Thyrotropin-releasing hormone ( TRH) induces some somatic symptoms that resemble those of a panic attack, without being considered to be a laboratory panicogen in panic disorder (PD) patients. This study aimed to identify doses of TRH and the laboratory panicogens, pentagastrin and flumazenil, that would produce a similar intensity of panic-related somatic symptoms in healthy volunteers because comparison of the effects of these doses in PD patients could be used to test the hypothesis that these agents have specific panicogenic effects that are not explained solely by cognitively mediated reactions to somatic symptoms. Nine subjects were administered pentagastrin (0.

GABA X2 multiplet measured pre- and post-administration of vigabatrin in human brain.

This work demonstrates, in solution and in human brain at 3 tesla, that the X(2)-multiplet of the A(2)M(2)X(2) proton spin system of GABA at 2.315 ppm can be readily resolved from that of the overlapping background, particularly the glutamate multiplet, i.e.