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Biology subjects

Sargolini, F.

Publications and source records attributed to Sargolini, F..

3 recordsLinked to original sources

Dorsal striatum involvement in response conflict management - A lesion study in rats

Action control allows to respond to relevant stimuli while ignoring the non-relevant stimuli in the surrounding environment. In humans this process is generally studied in conflict tasks, such as the Simon task, in which participants respond with a left or right button press to the non-spatial relevant feature (e.g. the color) of a lateralized stimulus, while ignoring the stimulus position. In this study we used a visual version of the Simon task that we have previsously developed in rats to investigate the involvement of the dorsal striatum, a brain area that is central in action control processes. We tested the effect of excitotoxic lesions of the dorsomedial (DMS) and dorsolateral (DLS) areas in learning to control response interference. We showed that both DMS and DLS lesions negatively impacted rat performances, and this effect strongly depends on task practice. These results suggest an involvement of both areas in learning to manage response conflict.

neuroscience↗

At the roots of interference control: Conflict task in rats reveals the commonalities of onto- and phylo-genetic development

Responding to internal goals and filtering irrelevant environmental cues is essential for adapted behavior. To better understand their phylogenetic evolution, we explored the underlying mechanisms in rats, thanks to the adaptation of a well-established conflict task in Humans. Besides mean performance, state of the art data analysis based on distribution analysis and formal modeling (diffusion model adapted to conflict tasks that proved very powerful in Humans) revealed mechanisms similar to the ones observed in human adults, grounding any theoretical explanation into an evolutionary perspective. Besides, the dynamics of the underlying processes in this simple conflict task resembles the ones observed in human children performing a more challenging conflict task, including the tendency to loose goals. The present study bridges the gap between onto- and phylo-genetic development of cognitive control, opening new perspectives to understand both their functional and neural implementation.

animal behavior and cognition↗

Coding dynamics of the striatal networks during learning

The rat dorsomedial (DMS) and dorsolateral striatum (DMS), equivalent to caudate nucleus and putamen in primates, are generally required for goal-directed and habit behaviour, respectively. However, it is still unclear whether and how this functional dychotomy emerges in the course of learning. In this study we investigated this issue by recording DMS and DLS single neuron activity in rats performing a continuous spatial alternation task, from the acquisition to optimized performance. We first applied a classical analytical approach to identify task-related activity based on the modifications of single neuron firing rate in relation to specific task events or maze trajectories. We then used an innovative approach based on Hawkes process to reconstruct a directed connectivity graph of simultaneously recorded neurons, that was used to decode animal behavior. This approach enabled us to better unravel the role of DMS and DLS neural networks across learning stages. We showed that DMS and DLS display different task-related activity throughout learning stages, and the proportion of coding neurons over time decreases in the DMS and increases in the DLS. Despite theses major differences, the decoding power of both networks increases during learning. These results suggest that DMS and DLS neural networks gradually reorganize in different ways in order to progressively increase their control over the behavioral performance.

neuroscience↗