MDMA modulates human sensorimotor cortical pathways during gentle touch.
Hanna Molla, Giovanni Novembre, Anya Bershad, Linda Handlin, Irene Perini, Harriet de Wit, India Morrison
Imaging neuroscience (Cambridge, Mass.) January 1, 2024 DOI: 10.1162/imag_a_00316 via PubMed
Summary
AI-generated from the abstractMDMA increases the perceived pleasantness of touch, but the neural mechanisms are not well understood. In a double-blind, randomized, within-subject fMRI study with 18 healthy participants, MDMA (1.5 mg/kg) compared to placebo enhanced affective ratings of gentle touch at both a slower, more pleasant speed (3 cm/s) and a faster, less pleasant speed (30 cm/s). Plasma oxytocin levels also increased more during the MDMA session. On the neural level, primary sensorimotor areas showed greater hemodynamic changes during MDMA for both touch speeds, indicating an early influence within somatosensory pathways. Changes in oxytocin levels interacted with the drug in area MT+, associated with motion perception. However, the posterior insula did not show preferential activation for the slower stroking speed.
Study at a glance
| Characteristics | Randomized controlled trial Double-blind Peer reviewed |
|---|---|
| Sample size | 18 |
| Population | Healthy participants |
| Interventions | MDMA lactose placebo |
| Dose | 1.5 mg/kg |
| Topics | MDMA |
| Keywords | Affective touch FMRI Oxytocin Social touch |
| Key finding | MDMA enhances affective ratings of touch and increases plasma oxytocin levels, with greater hemodynamic changes in primary sensorimotor areas for both touch speeds. |
Abstract
The stimulant ± 3,4-methylenedioxymethamphetamine (MDMA) has been shown to enhance the perceived pleasantness of touch. However, the underlying neural processes contributing to touch-related effects of MDMA are not well understood. Using a double-blind, randomized, within-subject design, this study used fMRI to examine hemodynamic changes following MDMA (1.5 mg/kg) vs. lactose placebo administration during gentle touch stimulation in a healthy sample (N= 18). Participants were stroked on the forearm at a slower, more pleasant (3 cm/s), and a faster (30 cm/s), less pleasant speed. For the MDMA session, participants' affective ratings of touch stimulation were higher than their placebo ratings. Increase in plasma oxytocin (OT) levels was also greater during the MDMA session. On the neural level, primary sensorimotor areas showed greater hemodynamic changes during the MDMA than during the placebo session for both touch speeds, indicating a relatively early influence within somatosensory pathways. Changes in OT levels showed an interaction with drug in an occipitotemporal region, area MT+, associated with motion perception. However, posterior insula did not show preferential activation for the slower stroking speed. These initial findings provide a basis for extending our knowledge of the neural processes underlying the effect of MDMA on affective touch.