Proceedings of the National Academy of Sciences
April 13, 2020
Morten L. Kringelbach, Josephine Cruzat, Joana Cabral et al.
326 citations
By combining multimodal neuroimaging data, a framework was developed that demonstrates the fundamental principles of bidirectional coupling between neuronal and neurotransmitter dynamical systems. The work causally explains the functional effects of stimulating specific serotoninergic receptors (5-HT2AR) with psilocybin in healthy humans. This could lead to a better understanding of why psilocybin shows promise as a therapeutic intervention for neuropsychiatric disorders such as depression, anxiety, and addiction.
Curr Biol
September 27, 2018
Gustavo Deco, Josephine Cruzat, Joana Cabral et al.
246 citations
A whole-brain model integrating anatomical, functional, and neurotransmitter data explains how serotonin 2A receptor stimulation with LSD alters brain dynamics. The model combines diffusion MRI, functional MRI, and PET scans of serotonin 2A receptor density to simulate resting-state activity and music listening effects. It shows that LSD's effects arise from non-linear interactions between anatomical connectivity, the brainwide distribution of 5-HT2A receptors, and neuromodulation of neuronal gain. Accounting for neuromodulatory activity in brain models can yield insights into brain function and aid drug discovery for neuropsychiatric disorders.
Current Biology
February 20, 2016
Raphael Kaplan, Mohit H. Adhikari, Rikkert Hindriks et al.
127 citations
Hippocampal sharp-wave ripples, brief high-frequency oscillations linked to memory consolidation, are followed by a dramatic increase in fMRI signal within the default mode network (DMN) of anesthetized monkeys. This effect was specific to ripples and did not occur after other hippocampal events or in other resting-state networks. The findings link circuit-level neural dynamics—ripples—to network-level fluctuations in the DMN, providing mechanistic support for the DMN's role in memory consolidation.
bioRxiv Preprint Server
January 29, 2020
Abhilash Dwarakanath, Vishal Kapoor, Joachim Werner et al.
15 citations
preprint
Access of sensory information to consciousness depends on neural activity crossing a threshold in the prefrontal cortex (PFC), yet how brain state fluctuations interact with conscious content is unclear. Using multielectrode recordings during a no-report binocular rivalry task in animals, two distinct prefrontal states were identified: low-frequency (1-9 Hz) bursts that precede spontaneous switches in conscious perception (perceptual update), and beta-band (20-40 Hz) bursts correlated with stable perception. Beta bursts synchronize neural ensembles coding the perceived stimulus. Similar fluctuations occur during rest, suggesting they are endogenous. The findings indicate that global cortical states, not selective spiking, drive internal switches in conscious perception.
bioRxiv Preprint Server
January 28, 2020
Vishal Kapoor, Abhilash Dwarakanath, Shervin Safavi et al.
preprint
The prefrontal cortex can represent the contents of conscious perception even when no overt report is required. Recordings from macaque monkeys during binocular rivalry—where perception alternates between two conflicting images—showed that neural ensemble activity in the prefrontal cortex decoded which image the animal was seeing as accurately as when images were presented without competition. This decoding remained significant even when eye movements were suppressed, indicating that the signals were not solely due to oculomotor confounds. The findings suggest that prefrontal population dynamics reflect internally driven changes in conscious perception during multistable vision.