Frontiers in pharmacology
January 1, 2024
Carla Soares, Gisela Lima, Marta Lapo Pais et al.
13 citations
A pharmacoimaging study in eleven healthy experienced users found that inhaled DMT increases functional connectivity between brain regions involved in social cognition and emotional processing. Specifically, DMT strengthened connections between the supramarginal gyrus and the precuneus, posterior cingulate gyrus, amygdala, and orbitofrontal cortex, as well as between the amygdala and orbitofrontal cortex. These changes occurred in socio-emotional and affective-value circuits, offering insight into how psychedelics may alter brain function and potentially contribute to therapeutic effects in disorders involving social and reward processing deficits.
PLoS ONE
June 14, 2016
João Martins, Miguel Castelo-Branco, Ana Batista et al.
10 citations
A single dose of MDMA (ecstasy) given to rats temporarily alters retinal function, as measured by electroretinograms. Three hours after administration, both MDMA-treated and high-temperature control rats showed larger and faster retinal responses, suggesting that the acute effects are partly due to MDMA-induced hyperthermia. After 24 hours, MDMA-treated animals still had increased responses in the outer retinal layers (photoreceptors and bipolar cells), even after temperature effects subsided, indicating a direct subacute effect of the drug. These changes returned to normal within seven days. The findings provide direct evidence that MDMA can enhance outer retinal activity, which may help explain visual disturbances reported by human users.
NeuroImage
August 15, 2024
Marta Lapo Pais, Marta Teixeira, Carla Soares et al.
8 citations
Inhaled DMT, a psychedelic acting on 5-HT2A serotonin receptors, increases the size of neural population receptive fields (pRFs) in the peripheral visual field of the primary visual cortex (V1). This change, measured with MRI and pRF mapping in a within-subject design, occurred during visual effects documented by the Hallucinogen Rating Scale and was not explained by differences in eye or head movements. The enlarged pRFs may underlie perceptual distortions such as field blurring, tunnel vision, and enlargement of nearby visual space. The findings suggest that 5-HT2A receptor activation controls gain in visual cortex, linking neural population responses to psychedelic visual phenomena.
British journal of clinical pharmacology
December 1, 2024
Gisela Lima, Carla Soares, Marta Teixeira et al.
4 citations
Psychedelics are being explored for physical and mental health applications beyond psychiatry, including chronic pain, palliative care, and neuroprotection in ischemia. This article reviews dimethyltryptamine (DMT) and ayahuasca pharmacology, effects, safety, and toxicity, and details the anaesthetist's role in clinical and experimental research—covering participant screening, dosing sessions, adverse effect management, and toxicity treatment. It draws on a current neuroimaging study protocol. The authors argue that anaesthetists are uniquely positioned to manage psychedelic therapy in medically complex, polymedicated patients, but note that non-mental medical applications remain underexplored.
Social cognitive and affective neuroscience
January 31, 2026
Carla Soares, Gisela Lima, Marta Teixeira et al.
1 citation
A pharmacoimaging study examined how ayahuasca affects a brain region involved in social perception, the posterior superior temporal sulcus (pSTS), which is part of the third visual pathway. Twelve healthy volunteers received two doses of ayahuasca (0.5 mg/kg and 0.8 mg/kg DMT) or a placebo in a crossover design. The higher dose increased connectivity of the right pSTS with visual and mirror-neuron brain regions. This enhanced connectivity correlated with stronger perspective-taking experiences. Participants also reported improved social relationships one week later, even though acute effects were minimal. The findings suggest ayahuasca strengthens early social information processing through the third visual pathway and mirror-neuron systems, offering a basis for its prosocial therapeutic effects.
Research Square
September 17, 2025
Gisela Lima, Carla Soares, Marta Teixeira et al.
Reward processing involves learning, liking, and wanting, and its disruption in mesolimbic and mesocortical pathways underlies many disorders. In a within-subject pharmacoimaging study with 11 healthy participants experienced with psychedelics, inhaled N,N-dimethyltryptamine (DMT) altered connectivity within the mesocorticolimbic circuitry. Connectivity decreased between the right nucleus accumbens and left ventral tegmental area, while it increased between the right nucleus accumbens and anterior cingulate cortex, and between the medial prefrontal cortex and anterior cingulate cortex. These changes correlated with shifts in volition and perception. The findings suggest DMT may have therapeutic potential for disorders affecting reward processing.