title: Lower Left Thalamic Myo-Inositol Levels Associated with Greater Cognitive Impulsivity in Marijuana-Dependent Young Men: Preliminary Spectroscopic Evidence at 4T.
abstract: The effects of chronic marijuana (MRJ) use on neurochemistry are not well characterized. Previously, altered global myo-Inositol (mI) concentrations and distribution in white matter were associated with impulsivity and mood symptoms in young MRJ-dependent men. The objective of this study was to retrospectively examine previously collected data, to investigate the potential regional specificity of metabolite levels in brain regions densely packed with cannabinoid receptors. Spectra were acquired at 4.0 Tesla using 2DJ-resolved proton magnetic resonance spectroscopic imaging (MRSI) to quantify the entireJ-coupled spectral surface of metabolites from voxels in regions of interest. For the current regional spectral analyses, a 2D-JMRSI grid was positioned over the central axial slice and shifted in thexandydimensions to optimally position voxels over regions containing thalamus, temporal lobe, and parieto-occipital cortex. MRJ users exhibited significantly reduced mI levels in the left thalamus (lThal), relative to non-using participants, which were associated with elevated cognitive impulsivity. Other regional analyses did not reveal any significant group differences. The current findings indicate that reduced mI levels are regionally specific to the lThal in MRJ users. Furthermore, findings suggest that mI and the lThal uniquely contribute to elevated impulsivity.
authors.affiliation: McLean Hospital/Harvard Medical School, 115 Mill St., Belmont, MA 02478, USA.
authors.forename: Yasmin
authors.initials: Y
authors.lastname: Mashhoon
authors.affiliation: McLean Hospital/Harvard Medical School, 115 Mill St., Belmont, MA 02478, USA.
authors.forename: J Eric
authors.initials: JE
authors.lastname: Jensen
authors.affiliation: McLean Hospital/Harvard Medical School, 115 Mill St., Belmont, MA 02478, USA.
authors.forename: Jennifer T
authors.initials: JT
authors.lastname: Sneider
authors.affiliation: Brain Institute, University of Utah School of Medicine, Salt Lake City, UT 84108, USA.
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Yurgelun-Todd
authors.affiliation: McLean Hospital/Harvard Medical School, 115 Mill St., Belmont, MA 02478, USA.
authors.forename: Marisa M
authors.initials: MM
authors.lastname: Silveri
keywords: Impulsivity; Marijuana; Myo-Inositol; Neurochemistry; Proton; Spectroscopy; Thalamus