Banca de QUALIFICAÇÃO: ALEX SANDRO DA SILVA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : ALEX SANDRO DA SILVA
DATE: 28/07/2025
TIME: 10:00
LOCAL: meet.google.com/xyz-xkgm-hdg
TITLE:

DISTINCT AND SHARED FUNCTIONAL CONNECTIVITY ALTERATIONS IN SCHIZOPHRENIA AND AYAHUASCA-INDUCED STATES: A DIRECT FMRI COMPARISON

KEY WORDS:

schizophrenia, psychedelics, ayahuasca, functional connectivity, thalamo-cortical, DMN

PAGES: 32
BIG AREA: Ciências Biológicas
AREA: Fisiologia
SUMMARY:

Resting-state functional brain connectivity (rs-fMRI) patterns were investigated across four groups: healthy controls (n = 19), patients with schizophrenia (n = 18), and healthy volunteers under the influence of ayahuasca (acute: n = 9; subacute: n = 21). Our aim was to directly compare neural dynamics, given the ongoing uncertainty regarding similarities and differences between schizophrenia and psychedelic-induced states. Results revealed that both schizophrenia and the acute ayahuasca state are characterized by alterations in thalamo-cortical communication and Default Mode Network (DMN) connectivity. In schizophrenia, we observed thalamo-cortical hyperconnectivity (involving temporal, sensorimotor, and occipital regions) and hypoconnectivity within the DMN and between occipital, somatosensory, and temporal cortices. The acute ayahuasca state similarly exhibited thalamo-cortical hyperconnectivity (encompassing auditory, somatosensory areas), DMN hypoconnectivity, and increased interhemispheric limbic connectivity. Congruence analysis confirmed several similarities, such as thalamo-temporal/somatosensory hyperconnectivity and DMN hypoconnectivity. However, crucial differences emerged: thalamo-cortical hyperconnectivity under acute ayahuasca was more pronounced in the superior temporal cortex, whereas in schizophrenia it was more diffuse, associated with reduced functional integration. Moreover, schizophrenia exhibited diminished frontotemporal connectivity, contrasting with the enhanced integration observed during the acute ayahuasca state. These findings underscore the need to expand models such as the cortico-striato-thalamo-cortical (CSTC) circuit framework for schizophrenia, incorporating structural alterations and the chronic nature of the condition, in contrast to the transient effects of ayahuasca

COMMITTEE MEMBERS:
Presidente - 1243905 - DRAULIO BARROS DE ARAUJO
Externa ao Programa - ***.458.574-** - FERNANDA PALHANO XAVIER DE FONTES - UFRN
Interna - 1871878 - KERSTIN ERIKA SCHMIDT