(EN) Functional Magnetic Resonance Imaging in Abstinent MDMA Users: A Review, su eurekaselect.com. URL consultato il 9 maggio 2017.
«• Chronic MDMA use results in serotonergic toxicity, thereby altering the regional cerebral blood flow that can be studied using fMRI.
• The effects of chronic MDMA use have been analysed in various neurocognitive domains such as working memory, episodic memory, semantic memory, visual stimulation, motor function and impulsivity. Structural neuroimaging in MDMA users has shown reduction in brain 5-HT transporter (5-HTT) and 5-HT2a receptor levels using positron emission tomography (PET) or single photon emission computed tomography (SPECT) and reduced grey matter density in various brain regions using voxel based morphometry method (VBM). Chemical Neuroimaging, assaying the levels of myoinositol (MI) and N-acetylaspartate (NAA) in the brains of MDMA users using proton magnetic resonance spectroscopy (MRS), has not revealed any consistent results. Functional magnetic resonance imaging (fMRI) studies have shown task evoked differences in regional brain activation, measured as blood oxygen level dependent (BOLD) signal intensity and/or spatial extent of activation, in MDMA users and controls.
Neurocognitive studies, in MDMA users, have consistently revealed dose related memory and learning problems.
Serotonergic innervation is known to regulate the cerebral microvasculature. Chronic MDMA use results in serotonin toxicity, therefore MDMA users are expected to have altered regional blood flow detectable in fMRI.
Animal data has suggested that MDMA is selectively more toxic to the axons more distal to the brainstem cell bodies, that is, those present mainly in the occipital cortesemente.
Also, human PET and SPECT studies have revealed significant reductions in serotonin transporter binding, most evident in the occipital cortex. The effects of poly-drug exposure may result in additive neurotoxicity or mutual neuro-protection. MDMA is known to induce hyperthermia which is a prooxidant neurotoxic condition.
Hyperthermia is known to accentuate the neurotoxic potential of MDMA as well as methamphetamine. On the other hand, lowering of the core body temperature has been shown to have a neuroprotective effect."»