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Open Access Publications from the University of California

Scholarly Works (7 results)

  • Article
LBL Publications (1992)
    Cover page: A 50 mm Bore Superconducting Dipole with a Unique Iron Yoke Structure
    • Article
    • Peer Reviewed
    UCLA Previously Published Works (2014)
    Rationale: Findings from animal studies and human PET imaging indicate that nicotine and cigarette smoking affect glutamate (Glu) and related neurochemical markers in the brain and imply that smoking reduces extracellular Glu. As Glu release is mediated by nicotinic acetylcholine receptors (nAChRs), which are present at high concentrations in the thalamus, we examined the effects of smoking on thalamic Glu. Objective: To determine the effects of tobacco smoking on thalamic glutamate levels. Methods: Thalamic Glu levels were measured in vivo in 18 smokers and 16 nonsmokers using proton magnetic resonance spectroscopic imaging (1H MRSI) at 1.5 T. Results: Mean Glu levels did not differ significantly between the subject groups. However, within smokers, Glu levels were negatively correlated with self-reports of both cigarettes/day over the last 30 days (r=-0.64, p=0.006) and pack-years of smoking (r=-0.66, p=0.005). Conclusions: Consistent with expectations based on preclinical studies, within smokers, cigarettes/day and pack-years are associated with reduced Glu in thalamus, a brain region rich in nAchRs. These results encourage work on candidate glutamatergic therapies for smoking cessation and suggest a noninvasive metric for their action in the brain. © 2014 Springer-Verlag.
      • Article
      LBL Publications (2000)
        Cover page: The use of pressurized bladders for stress control of superconducting magnets
        • Article
        • Peer Reviewed
        UCLA Previously Published Works (2017)
        Cognitive-behavioral therapy (CBT) is effective for obsessive compulsive disorder (OCD); however, little is understood about its mechanisms related to brain network connectivity. We examined connectivity changes from resting-state functional magnetic resonance imaging data pre-to-post-CBT in 43 OCD participants, randomized to receive either 4 weeks of intensive CBT or 4 weeks waitlist followed by 4 weeks of CBT, and 24 healthy controls before and after 4 weeks of no treatment. Network-based-statistic analysis revealed large-magnitude increases in OCD connectivity in eight networks. Strongest increases involved connectivity between the cerebellum and caudate/putamen, and between the cerebellum and dorsolateral/ventrolateral prefrontal cortices. Connectivity increases were associated with increased resistance to compulsions. Mechanisms of CBT may involve enhanced cross-network integration, both within and outside of classical cortico-striatal-thalamo-cortical regions; those involving cerebellar to striatal and prefrontal regions may reflect acquisition of new non-compulsive goal-directed behaviors and thought patterns. Our findings have implications for identifying targets for enhancing treatment efficacy and monitoring treatment progress.
          Cover page: Mechanisms of cognitive-behavioral therapy for obsessive-compulsive disorder involve robust and extensive increases in brain network connectivity
          • Article
          • Peer Reviewed
          UCLA Previously Published Works (2004)

          In adult schizophrenia, magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) have revealed volumetric and metabolic defects in multiple brain regions, among them the anterior cingulate, frontal cortex, striatum, thalamus, parietal cortex, and frontal and parietal white matter. This study used proton magnetic resonance spectroscopic imaging (H-1 MRSI) to identify potential metabolic abnormalities in these regions in childhood-onset schizophrenia. H-1 MRSI was acquired at 1.5 T and 272 ins echo time in 11 children and adolescents with schizophrenia (aged 7-18 years; seven boys, four girls; all but two medicated) and 20 age-matched healthy controls (10 boys, 10 girls). Absolute levels of N-acetyl compounds (NAA), creatine plus phosphocreatine (Cr), and choline compounds (Cho) were compared among groups in each region. In schizophrenic patients relative to controls, Cr was 14.3% higher in superior anterior cingulate (mean of left and right hemispheres). Cho was higher in superior anterior cingulate (30.3%), frontal cortex (13.3%), and caudate head (13.5%). In the thalamus, there was also a diagnosis-by-gender interaction, whereby NAA was lower in patients for male but not for female subjects. Elevated Cr suggests abnormal local cell-energy demand and elevated Cho is consistent with a prior proposal that patients with early age-of-onset schizophrenia exhibit phospholipid membrane disturbances. Low NAA may reflect diminished neuronal integrity. (C) 2004 Elsevier Inc. All rights reserved.

            Cover page: H-1 MRSI evidence of metabolic abnormalities in childhood-onset schizophrenia
            • Article
            LBL Publications (1992)
              Cover page: A 50 mm Bore Superconducting Dipole with a Unique Iron Yoke StructureCreative Commons 'BY' version 4.0 license
              • Article
              Lawrence Berkeley National Laboratory (2001)
                Cover page: A new support structure for high field magnets
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