Biology subjects

Cecchi, R.

Publications and source records attributed to Cecchi, R..

3 recordsLinked to original sources

bioRxiv2023

Direct stimulation of anterior insula and ventromedial prefrontal cortex disrupts economic choices

Neural activities within the ventromedial prefrontal cortex and anterior insula are associated with economic choices. However, whether these brain regions are causally related to these processes remains unclear. To address this issue, we leveraged rare intracerebral electrical stimulation (iES) data in epileptic patients. We show that opposite effects of iES on choice depend on the location of stimulation on a dorso-ventral axis within each area, thus demonstrating dissociable neural circuits causally involved in accepting versus avoiding challenges.

neuroscience↗

bioRxiv2021

Intracerebral mechanisms explaining the impact of incidental feedback on mood state and risky choice

Identifying factors whose fluctuations are associated with choice inconsistency is a major issue for rational decision theory. Here, we investigated the neuro-computational mechanisms through which mood fluctuations may bias human choice behavior. Intracerebral EEG data were collected in a large group of participants (n = 30), while they were performing interleaved quiz and choice tasks. Neural baseline activity preceding choice onset was confronted first to mood level, estimated by a computational model integrating the feedbacks received in the quiz task, and then to the weighting of option attributes, in a computational model predicting risk attitude in the choice task. Results showed that 1) elevated broadband gamma activity (BGA) in the ventromedial prefrontal cortex (vmPFC) and dorsal anterior insula (daIns) was respectively signaling periods of high and low mood, 2) increased vmPFC and daIns BGA respectively promoted and tempered risk taking by overweighting gain versus loss prospects. Thus, incidental feedbacks induce brain states that correspond to different moods and bias the comparison of safe and risky options. More generally, these findings might explain why people experiencing positive (or negative) outcome in some part of their life tend to expect success (or failure) in any other.

neuroscience↗

bioRxiv2017

High-throughput creation and functional profiling of eukaryotic DNA sequence variant libraries using CRISPR/Cas9

Construction of genetic variant libraries with phenotypic measurement is central to advancing todays functional genomics, and remains a grand challenge. Here, we introduce a Cas9-based approach for generating pools of mutants with defined genetic alterations (deletions, substitutions and insertions), along with methods for tracking their fitness en masse. We demonstrate the utility of our approach in performing focused analysis of hundreds of mutants of a single protein and in investigating the biological function of an entire family of poorly characterized genetic elements. Our platform allows fundamental biology questions to be investigated in a quick, easy and affordable manner.

bioengineering↗