Miguel Castelo‐branco

University of Coimbra

2 papers in the library · 34 citations · publishing 2021-2025

Papers

The Effects of Tryptamine Psychedelics in the Brain: A meta-Analysis of Functional and Review of Molecular Imaging Studies

Frontiers in Pharmacology September 29, 2021 João Castelhano, Gisela Lima, Marta Teixeira et al. 34 citations

Tryptamine psychedelics such as LSD, psilocybin, DMT, and ayahuasca alter brain activation and connectivity in regions that match the distribution of 5HT2A and 5HT1A receptors, including visual cortex, cingulate cortex, medial prefrontal cortex, temporal cortex, and the right amygdala. These effects involve areas supporting mental imagery, theory of mind, and emotional regulation, suggesting potential therapeutic applications. The analysis confirms that changes occur in regions with high 5HT2A receptor density, but also in other areas like the dorsolateral prefrontal cortex. However, too few PET studies exist to meta-analyze receptor occupancy directly.

DOI: 10.3389/fphar.2021.739053 5-ht2a receptor Psilocybin Serotonin Neuroscience +13

Inhaled N, N-dimethyltryptamine diminishes connectivity between the ventral tegmental area and the nucleus accumbens: relevance to pathologies of mesolimbic and mesocortical pathways

Scientific Reports December 12, 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 preliminary pharmacoimaging study, 11 healthy participants with prior psychedelic experience self-administered inhaled DMT immediately before MRI scanning, with a no-administration control condition. DMT decreased connectivity between the right nucleus accumbens and left ventral tegmental area, increased connectivity between the right nucleus accumbens and anterior cingulate cortex, and increased connectivity between medial prefrontal cortex and anterior cingulate cortex. These connectivity changes correlated with altered volition and perception. Reduced midbrain-NAc connectivity, often increased in addiction, suggests potential therapeutic value for reward-related disorders.

DOI: 10.1038/s41598-025-31431-1 Full text Ventral tegmental area Nucleus accumbens Anterior cingulate cortex Dopamine +13