Neurodynamic Impacts of Meditation Combined with Ayahuasca Constituents DMT and Harmine
Poster No:
1717
Submission Type:
Abstract Submission
Authors:
Klemens Egger1,2,3, Daniel Meling1, Firuze Polat1, Mihai Avram4, Milan Scheidegger1,2
Institutions:
1Psychiatric University Hospital Zurich, Zurich, Switzerland, 2Neuroscience Center Zurich (ZNZ), Zurich, Switzerland, 3Inselspital Bern, Bern, Switzerland, 4University of Lübeck, Lübeck, Germany
First Author:
Klemens Egger
Psychiatric University Hospital Zurich|Neuroscience Center Zurich (ZNZ)|Inselspital Bern
Zurich, Switzerland|Zurich, Switzerland|Bern, Switzerland
Psychiatric University Hospital Zurich|Neuroscience Center Zurich (ZNZ)|Inselspital Bern
Zurich, Switzerland|Zurich, Switzerland|Bern, Switzerland
Co-Author(s):
Milan Scheidegger
Psychiatric University Hospital Zurich|Neuroscience Center Zurich (ZNZ)
Zurich, Switzerland|Zurich, Switzerland
Psychiatric University Hospital Zurich|Neuroscience Center Zurich (ZNZ)
Zurich, Switzerland|Zurich, Switzerland
Introduction:
Meditation and psychedelic substances, such as psilocybin, LSD, or DMT, exert profound effects on human consciousness. Current models of biological mechanisms of action of both meditation and psychedelics hint toward synergistic effects on brain functioning when the two are combined. Building on a prior study exploring the effects of meditation combined with psilocybin [Smigielski et al., 2019], we conducted a double-blind, placebo-controlled between-subject study, investigating the combined impact of meditation and a novel ayahuasca-derived formulation containing N,N-Dimethyltryptamine (DMT) and harmine. Functional brain scans (fMRI) were conducted before and after a three-day psychedelic-enhanced meditation retreat, and changes in resting-state fMRI data were compared between the two groups.
Methods:
Forty trained meditators (22 m, 18 f) participated in one of two three-day meditation retreats, receiving either DMT and harmine (120 mg each) or placebo on day two of the retreat. Resting-state fMRI scans (7.5 minutes, closed eyes) were acquired one day before and one day after the retreat, i.e., two days pre- and two days post-drug administration. Functional data were preprocessed using the nipype-based fMRIprep pipeline (v23.0.2) and analyzed with the Conn Toolbox (v22.a) in Matlab. Denoising involved 24 head motion parameters [Friston et al., 1996], component-based noise reduction (aCompCor), and scrubbing (FD<0.5 mm). Analyses included seed-to-voxel analyses of seven resting-state networks (RSN), as defined by Yeo and colleagues [Yeo et al., 2011], between- and within-network changes, and global connectivity.
For between- and within-network changes, mean timeseries of each network were extracted and correlated with each voxel of the brain (between-network approach) or with each voxel of the network (within-network approach). The full GLM design matrix included both conditions (verum-placebo) and both timepoints (post-pre). We also analyzed pre to post changes in the placebo and verum group independently, as well as changes between the two groups in the post-intervention scans.
Global correlation maps were used to calculate network centrality at each voxel and analyzed with a GLM at the second level using the approach from above.
All voxel-thresholds were set to p < 0.001, cluster-thresholds were set to p < 0.05, FDR-corrected.
For between- and within-network changes, mean timeseries of each network were extracted and correlated with each voxel of the brain (between-network approach) or with each voxel of the network (within-network approach). The full GLM design matrix included both conditions (verum-placebo) and both timepoints (post-pre). We also analyzed pre to post changes in the placebo and verum group independently, as well as changes between the two groups in the post-intervention scans.
Global correlation maps were used to calculate network centrality at each voxel and analyzed with a GLM at the second level using the approach from above.
All voxel-thresholds were set to p < 0.001, cluster-thresholds were set to p < 0.05, FDR-corrected.
Results:
The comparison of post-pre scans for the placebo condition revealed significantly reduced connectivity changes between 5 out of 7 (except the sensory-motor and limbic networks) RSNs and other clusters in the brain. Within-network analyses did not yield significance. Global correlation analysis revealed three clusters with decreased connectivity for the post-pre contrast of placebo scans in the precentral gyrus, the inferior frontal gyrus and the precuneus.
Post-pre comparisons of the verum group revealed significantly increased connectivity from the visual, dorsal attention and salience network to the left occipital pole. Within-network and global correlation analyses did not yield significance.
No differences were found between the two groups' pre-intervention scans for any measure.
Regarding the verum-placebo post-pre contrast, we observed significantly increased salience network connectivity to bilateral occipital poles, bilateral cuneal cortex and lateral occipital cortex, while the visual network showed increased functional connectivity to left and right insula.
Post-pre comparisons of the verum group revealed significantly increased connectivity from the visual, dorsal attention and salience network to the left occipital pole. Within-network and global correlation analyses did not yield significance.
No differences were found between the two groups' pre-intervention scans for any measure.
Regarding the verum-placebo post-pre contrast, we observed significantly increased salience network connectivity to bilateral occipital poles, bilateral cuneal cortex and lateral occipital cortex, while the visual network showed increased functional connectivity to left and right insula.
Conclusions:
Our findings suggest that subacute effects of combining DMT and harmine in a meditation retreat setting enhance connectivity between various brain networks, in contrast to the opposing effects observed without pharmacological intervention. Furthermore, subacute effects of the psychedelic did not alter within-network or global connectivity. This underscores distinctions in neurodynamics between altered states induced by the psychedelic ayahuasca-derived formulation and contemplative practice alone.
Emotion, Motivation and Social Neuroscience:
Self Processes
Modeling and Analysis Methods:
fMRI Connectivity and Network Modeling 1
Novel Imaging Acquisition Methods:
BOLD fMRI
Perception, Attention and Motor Behavior:
Consciousness and Awareness
Physiology, Metabolism and Neurotransmission :
Pharmacology and Neurotransmission 2
Keywords:
FUNCTIONAL MRI
Neurotransmitter
Pharmacotherapy
Seretonin
Other - Psychedelics, consciousness, ayahuasca, DMT
1|2Indicates the priority used for review
Provide references using author date format
Smigielski L, (2019), 'Psilocybin-assisted mindfulness training modulates self-consciousness and brain default mode network connectivity with lasting effects', Neuroimage, vol. 196, pp. 207–215.
Yeo BTT, (2011), 'The organization of the human cerebral cortex estimated by intrinsic functional connectivity', Journal of Neurophysiology, vol. 106, no. 3, pp. 1125–65.