Occipital cortical proton MRS at 4 Tesla in human moderate MDMA polydrug users
Ronald L Cowan1, Nicolas R Bolo, Mary Dietrich
1Psychiatric Neuroimaging Program, Department of Psychiatry, Vanderbilt University Medical Center, 1601 23rd Avenue South, Suite 3057, Nashville, TN 37212, USA. Ronald.L.Cowan@Vanderbilt.Edu
Abstract:
The recreational drug MDMA (3,4, methylenedioxymethamphetamine; sold under the street name of Ecstasy) is toxic to serotonergic axons in some animal models of MDMA administration. In humans, MDMA use is associated with alterations in markers of brain function that are pronounced in occipital cortex. Among neuroimaging methods, magnetic resonance spectroscopy (MRS) studies of brain metabolites N-acetylaspartate (NAA) and myoinositol (MI) at a field strength of 1.5 Tesla (T) reveal inconsistent results in MDMA users. Because higher field strength proton MRS has theoretical advantages over lower field strengths, we used proton MRS at 4.0 T to study absolute concentrations of occipital cortical NAA and MI in a cohort of moderate MDMA users (n=9) versus non-MDMA using (n=7) controls. Mean NAA in non-MDMA users was 10.47 mM (+/-2.51), versus 9.83 mM (+/-1.94) in MDMA users. Mean MI in non-MDMA users was 7.43 mM (+/-.68), versus 6.57 mM (+/-1.59) in MDMA users. There were no statistical differences in absolute metabolite levels for NAA and MI in occipital cortex of MDMA users and controls. These findings are not supportive of MDMA-induced alterations in NAA or MI levels in this small sample of moderate MDMA users. Limitations to this study suggest caution in the interpretation of these results.
Insights
This study found no significant differences in occipital cortex N-acetylaspartate (NAA) or myoinositol (MI) levels between moderate 3,4-methylenedioxymethamphetamine (MDMA) users and controls. Higher field strength magnetic resonance spectroscopy (MRS) did not reveal MDMA-induced metabolite alterations in this small sample.
Area of Science:
- Neuroscience
- Neuroimaging
- Neurotoxicology
Background:
- 3,4-methylenedioxymethamphetamine (MDMA), or Ecstasy, is a recreational drug with known neurotoxic effects on serotonergic axons in animal models.
- Human MDMA use is linked to functional brain alterations, particularly in the occipital cortex.
- Previous magnetic resonance spectroscopy (MRS) studies using 1.5 Tesla (T) have yielded inconsistent results regarding MDMA's impact on brain metabolites like N-acetylaspartate (NAA) and myoinositol (MI).
Purpose of the Study:
- To investigate potential MDMA-induced alterations in occipital cortical N-acetylaspartate (NAA) and myoinositol (MI) concentrations.
- To leverage the advantages of higher field strength proton MRS (4.0 T) for more precise metabolite quantification.
- To compare metabolite levels in moderate MDMA users versus non-using controls.
Main Methods:
- Utilized 4.0 T proton magnetic resonance spectroscopy (MRS) to measure absolute concentrations of NAA and MI.
- Recruited a cohort of moderate MDMA users (n=9) and a control group of non-MDMA users (n=7).
- Focused analysis on the occipital cortex, a region showing pronounced functional alterations in MDMA users.
Main Results:
- The mean concentration of NAA was 10.47 mM (+/-2.51) in controls and 9.83 mM (+/-1.94) in MDMA users.
- The mean concentration of MI was 7.43 mM (+/-0.68) in controls and 6.57 mM (+/-1.59) in MDMA users.
- No statistically significant differences were observed in absolute NAA or MI levels between the MDMA user group and the control group.
Conclusions:
- The findings do not support the hypothesis of MDMA-induced alterations in occipital cortical NAA or MI levels in this small sample of moderate users.
- Higher field strength MRS at 4.0 T did not detect significant metabolic changes.
- Caution is advised in interpreting these results due to study limitations and the small sample size.
