UA cloudflare authentication

Browsing by Author "O'Donnell, Brian F."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Does Chronic Cannabis Use Impact Risky Decision-Making: An Examination of fMRI Activation and Effective Connectivity?
    (Frontiers Media, 2020) Raymond, David R.; Paneto, Adrian; Yoder, Karmen K.; O'Donnell, Brian F.; Brown, Joshua W.; Hetrick, William P.; Newman, Sharlene D.; Indiana University System; Indiana University Bloomington; Indiana University-Purdue University Indianapolis; University of Alabama Tuscaloosa
    With the increase in use of cannabis and its shifting legal status in the United States, cannabis use has become an important research focus. While studies of other drug populations have shown marked increases in risky decision-making, the literature on cannabis users is not as clear. The current study examined the performance of 17 cannabis users and 14 non-users on the Balloon Analog Risk Task (BART) using behavioral, fMRI and effective connectivity methods. Significant attenuation was found in a functional pathway projecting from the dorsal anterior cingulate cortex (dACC) to the nucleus accumbens (NAc) in cannabis users compared to non-using controls as well as decreases in risk-taking behaviors. These findings suggest that cannabis users may process and evaluate risks and rewards differently than non-users.
  • Thumbnail Image
    Item
    The relationship between cannabis use and taurine: A MRS and metabolomics study
    (PLOS, 2022) Newman, Sharlene D.; Martin, Ashley M. Schnakenberg; Raymond, David; Cheng, Hu; Wilson, Landon; Barnes, Stephen; O'Donnell, Brian F.; University of Alabama Tuscaloosa; Yale University; US Department of Veterans Affairs; Veterans Health Administration (VHA); VA Connecticut Healthcare System; Indiana University of Pennsylvania; University of Alabama Birmingham; Indiana University Bloomington
    Taurine is an essential amino acid. It has been shown to be neuroprotective including protecting against the neurotoxic effects of glutamate. The goal of the current study was to examine the relationship between CB use and taurine measured in brain using magnetic resonance spectroscopy (MRS), and peripherally from a urine sample. Two experiments are presented. The first is a reanalysis of published data that examined taurine and glutamate in the dorsal anterior cingulate of a CB user group and non-user group using MRS. The second experiment, in a separate CB user group, used metabolomics analysis to measure taurine levels in urine. Because body composition has been associated with the pharmacokinetics of cannabis and taurine levels, a moderation model was examined with body composition included as the covariate. The MRS study found taurine levels were correlated with glutamate in both groups and taurine was correlated with frequency of CB use in the CB user group. The moderation model demonstrated significant effects of CB use and BMI; the interaction was marginally significant with lower BMI individuals showing a positive relationship between CB use and taurine. A similar finding was observed for the urine analysis. Both CB use and weight, as well as the interaction were significant. In this case, individuals with higher weight showed an association between CB use and taurine levels. This study shows the feasibility and potential importance of examining the relationship between taurine and CB use as it may shed light on a mechanism that underlies the neuroprotective effects of CB.