| 1. |
- Naghavi, Hamid Reza, et al.
(author)
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Personality traits predict response to novel and familiar stimuli in the hippocampal region
- 2009
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In: Psychiatry Research. - : Elsevier. - 0165-1781 .- 1872-7123 .- 0925-4927 .- 1872-7506. ; 173:2, s. 94-99
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Journal article (peer-reviewed)abstract
- Current evidence from genetic, neurochemical, and clinical research supports the notion that a combination of high novelty seeking and low harm avoidance traits (NS-ha) is reliably dissociable from the opposite personality profile (i.e., low novelty seeking and high harm avoidance, ns-HA). Little is known, however, about how the differences between these two types of personality are regulated by brain function. Here we used functional magnetic resonance imaging (fMRI) and recruited two groups of individuals, one group with the NS-ha profile and the other group with the ns-HA profile, to examine whether there is a difference between the two groups in their brain response to novel versus familiar word stimuli. Results revealed a differential pattern of response in an area in the hippocampal region, with the NS-ha group showing a greater sensitivity to novel stimuli and the ns-HA group demonstrating a greater response to familiar stimuli. We conclude that the response pattern to novel and familiar stimuli in the hippocampal region has a role in mediating differences between the NS-ha and ns-HA temperamental profiles.
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| 2. |
- Åhs, Fredrik, 1972-, et al.
(author)
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Disentangling the web of fear : amygdala reactivity and functional connectivity in spider and snake phobia
- 2009
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In: Psychiatry Research. - : Elsevier BV. - 0925-4927 .- 1872-7506 .- 0165-1781 .- 1872-7123. ; 172:2, s. 103-108
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Journal article (peer-reviewed)abstract
- The objective was to study effects of fear on brain activity, functional connectivity and brain-behavior relationships during symptom provocation in subjects with specific phobia. Positron emission tomography (PET) and (15)O water was used to measure regional cerebral blood flow (rCBF) in 16 women phobic of either snakes or spiders but not both. Subjects watched pictures of snakes and spiders serving either as phobic or fear-relevant, but non-phobic, control stimuli depending on phobia type. Presentation of phobic as compared with non-phobic cues was associated with increased activation of the right amygdala and cerebellum as well as the left visual cortex and circumscribed frontal areas. Activity decreased in the prefrontal, orbitofrontal and ventromedial cortices as well as in the primary somatosensory cortex and auditory cortices. Furthermore, amygdala activation correlated positively with the subjective experience of distress. Connectivity analyses of activity in the phobic state revealed increased functional couplings between voxels in the right amygdala and the periamygdaloid area, fusiform gyrus and motor cortex. During non-phobic stimulation, prefrontal activity correlated negatively with amygdala rCBF, suggesting a phobia-related functional decoupling. These results suggest that visually elicited phobic reactions activate object recognition areas and deactivate prefrontal areas involved in cognitive control over emotion-triggering areas like the amygdala, resulting in motor readiness to support fight or flight.
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| 3. |
- Eriksson, Olle, et al.
(author)
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Mood changes correlate to changes in brain serotonin precursor trapping in women with premenstrual dysphoria.
- 2006
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In: Psychiatry research. - : Elsevier BV. - 0165-1781 .- 0925-4927 .- 1872-7506. ; 146:2, s. 107-16
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Journal article (peer-reviewed)abstract
- The cardinal mood symptoms of premenstrual dysphoria can be effectively treated by serotonin-augmenting drugs. The aim of the study was to test the serotonin hypothesis of this disorder, i.e. of an association between premenstrual decline in brain serotonin function and concomitant worsening of self-rated cardinal mood symptoms. Positron emission tomography was used to assess changes in brain trapping of 11C-labeled 5-hydroxytryptophan, the immediate precursor of serotonin, in the follicular and premenstrual phases of the menstrual cycle in eight women with premenstrual dysphoria. Changes in mood and physical symptoms were assessed from daily visual analog scale ratings. Worsening of cardinal mood symptoms showed significant inverse associations with changes in brain serotonin precursor trapping; for the symptom "irritable", r(s)=-0.83, and for "depressed mood" r(s)=-0.81. Positive mood variables showed positive associations, whereas physical symptoms generally displayed weak or no associations. The data indicate strong inverse associations between worsening of cardinal symptoms of premenstrual dysphoria and brain serotonin precursor (11C-labeled 5-hydroxytryptophan) trapping. The results may in part support a role for serotonin in premenstrual dysphoria and may provide a clue to the effectiveness of serotonin-augmenting drugs in this disorder but should, due to small sample size and methodological shortcomings, be considered preliminary.
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| 4. |
- Henriksson, Karin, et al.
(author)
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A morphometric magnetic resonance method for measuring cranial, facial and brain characteristics for application to schizophrenia : Part 1
- 2006
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In: Psychiatry Research. - : Elsevier BV. - 0925-4927 .- 1872-7506 .- 0165-1781. ; 147:2-3, s. 173-186
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Journal article (peer-reviewed)abstract
- Serious psychopathology in adulthood may be associated with disturbed foetal brain development, which potentially shows lingering "fossil marks" in the cranial and facial regions. Several methods exist for assessing external craniofacial and internal brain distances but, to our knowledge, no method yet provides simultaneous measurement of cranial, facial and brain dimensions in live subjects. In this article we describe a method to identify landmarks on magnetic resonance images (MRI) for simultaneous measurement of cranial, facial and brain characteristics potentially associated with psychosis. To test the method itself, 30 patients with chronic schizophrenia and 31 healthy comparison subjects, mean age 41 years, were randomly selected from a larger cohort recruited at the Karolinska Hospital, Sweden. Participants were investigated with MRI, and 60 landmarks in the cranial, facial and brain regions were identified in the images. An independent anthropometric examination measured external craniofacial characteristics for study in relation to measurements produced through MRI. High inter-scorer and re-test reliabilities were obtained for two independent scorers of the landmarks in the MR images. Measurements of potentially comparable craniofacial distances showed high alignment with an established anthropometric method. This new method can provide simultaneous investigation of multiple aspects of cranial, facial and brain morphology in MR images originally collected for other purposes. In a second article we will use this method to compare 3D craniofacial measurements and shape between schizophrenia patients and healthy controls.
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| 5. |
- Vannini, Patrizia, et al.
(author)
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Reduced neuronal efficacy in progressive mild cognitive impairment : A prospective fMRI study on visuospatial processing
- 2007
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In: Psychiatry Research. - : Elsevier BV. - 0925-4927 .- 1872-7506 .- 0165-1781. ; 156:1, s. 43-57
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Journal article (peer-reviewed)abstract
- Mild cognitive impairment (MCI) often refers to the preclinical stage of dementia, where the majority develop Alzheimer's disease (AD). Given that neurodegenerative burden and compensatory mechanisms might exist before accepted clinical symptoms of AD are noticeable, the current prospective study aimed to investigate the functioning of brain regions in the visuospatial networks responsible for preclinical symptoms in AD using event-related functional magnetic resonance imaging (fMRI). Eighteen MCI patients were evaluated and clinically followed for approximately 3 years. Five progressed to AD (PMCI) and eight remained stable (SMCI). Thirteen age-, gender- and education-matched controls also participated. An angle discrimination task with varying task demands was used. Brain activation patterns as well as task demand-dependent and -independent signal changes between the groups were investigated by using an extended general linear model including individual performance (reaction time [RT]) of each single trial. Similar behavioral (RT and accuracy) responses were observed between MCI patients and controls. A network of bilateral activations, e.g. dorsal pathway, which increased linearly with increasing task demand, was engaged in all subjects. Compared with SMCI patients and controls, PMCI patients showed a stronger relation between task demand and brain activity in left superior parietal lobules (SPL) as well as a general task demand-independent increased activation in left precuneus. Altered brain function can be detected at a group level in individuals that progress to AD before changes occur at the behavioral level. Increased parictal activation in PMCI could reflect a reduced neuronal efficacy due to accumulating AD pathology and might predict future clinical decline in patients with MCI.
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| 6. |
- Anckarsäter, Henrik, 1966, et al.
(author)
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Persistent regional frontotemporal hypoactivity in violent offenders at follow-up.
- 2007
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In: Psychiatry research. - : Elsevier BV. - 0165-1781 .- 0925-4927 .- 1872-7123. ; 156:1, s. 87-90
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Journal article (peer-reviewed)abstract
- Since cross-sectional brain-imaging studies demonstrating frontotemporal cerebral hypoactivity in violent offenders have generally been carried out around the time of trial and sentencing, the findings might be influenced by the stressful situation of the subjects. It seems that no group of offenders with this finding has yet been followed longitudinally. We have re-examined nine offenders convicted of lethal or near-lethal violence in whom single photon emission tomography (SPECT) previously had demonstrated frontotemporal hypoperfusion. The mean interval between the initial and the follow-up examination was 4 years. The initially observed hypoactivity was found to have remained virtually unchanged at follow-up: no mean change in the group exceeded 5% in 12 assessed regions of interest. Although preliminary due to the small sample size, this study suggests that frontotemporal brain hypoactivity is a trait rather than a state in perpetrators of severe violent crimes.
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| 7. |
- Bah Rösman, Jessica, 1975, et al.
(author)
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Serotonin transporter gene polymorphisms: Effect on serotonin transporter availability in the brain of suicide attempters
- 2008
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In: Psychiatry Research: Neuroimaging. - : Elsevier BV. - 0925-4927 .- 0165-1781. ; 162:3, s. 221-229
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Journal article (peer-reviewed)abstract
- The efficacy of serotonin reuptake inhibitors in depression and anxiety disorders suggests the gene coding for the serotonin transporter (5-HTT), SLC6A4, as a candidate of importance for these conditions. Positive findings regarding associations between polymorphisms in SLC6A4 have been reported, indicating that these polymorphisms may influence anxiety-related personality traits, as well as the risk of developing depression and suicidality. Serotonin 5-HTT availability was assessed with single photon emission computed tomography (SPECT), using I-123-beta-CIT as ligand, in a population of unmedicated male suicide attempters (n=9) and in matched controls (n=9). Two polymorphisms in SLC6A4 were assessed, including the 5-HTTLPR located in the promoter region and a variable number of tandem repeats (VNTR) polymorphism in intron 2 (STin2). In suicide attempters, but not in controls, low 5-HTT availability was associated with the S allele of 5-HTTLPR and with the 12 repeat allele of STin2. Data suggest that polymorphisms in SLC6A4 may influence the expression of the brain serotonin transporter in suicide attempters.
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| 8. |
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| 9. |
- Henriksson, Karin, et al.
(author)
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A pilot study of facial, cranial and brain MRI morphometry in men with schizophrenia: Part 2.
- 2006
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In: Psychiatry Research. - : Elsevier BV. - 1872-7123 .- 0925-4927 .- 0165-1781. ; 147:2-3, s. 187-195
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Journal article (peer-reviewed)abstract
- This pilot study applies a new 3D morphometric MR method to test the hypothesis that men with schizophrenia (vs. controls) have deviant facial shapes and landmark relations in cranio/facialibrain (CFB) regions. This constitutes Part 2 of paired articles in this issue of Psychiatry Research: Neuroimaging, in which Part 1 presents the new method in detail. MRI coordinates from CFB landmarks of 23 patients and 15 controls were identified and then aligned with the Procrustes model, leaving shape as the only unitless geometrical information. Men with schizophrenia had significantly longer mid- and lower-facial heights, and greater lower (left) facial depth, with a tendency toward rotation along the facial midline. This supports findings from earlier anthropometric and 3D studies of the "exterior" (face). In contrast, none of the patient-control differences for the new "interior" (cranial-brain) distances reached statistical significance. These results need to be retested on a larger sample of both sexes. (c) 2006 Elsevier Ireland Ltd. All rights reserved.
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| 10. |
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