Biology subjects

Ferro, D.

Publications and source records attributed to Ferro, D..

5 recordsLinked to original sources

bioRxiv2026

Dynamic interactions between sensory and decision-making circuits shape temporal evidence weighting

Perceptual decisions require the brain to integrate sensory evidence over time, yet the temporal weighting of evidence can be flexibly adjusted according to task demands. How such flexibility emerges from interactions between sensory and decision circuits remains unclear. Here, we combined behavioral and neural measurements with recurrent network modeling to investigate the mechanisms underlying temporal weighting of sensory evidence. Macaques performed a motion-discrimination task in which the temporal statistics of sensory evidence favored early, late or uniform integration. Behavioral psychophysical kernels revealed corresponding shifts in the influence of evidence across time, accompanied by systematic changes in motion discriminability and choice-related activity modulation in visual area MT. We developed a recurrent sensory-decision network incorporating reciprocal feedforward and feedback interactions and a temporally structured modulatory input, resembling an urgency signal. The model reproduced the observed behavioral and neural signatures across temporal weighting conditions. Mechanistically, shifting the onset and dynamics of modulatory inputs systematically reconfigured the temporal profile of evidence weighting without substantially altering sensory response dynamics. Choice-related activity in MT can be decomposed in a bottom-up component with the same time-course as the psychophysical kernel, and a top-down component reflecting the decision build-up. These findings suggest that flexible temporal integration can emerge from dynamic interactions between sensory transmission, recurrent decision circuits and temporally structured urgency modulation, providing a mechanistic framework for how neural systems adapt the computation of sensory evidence to changing task demands.

neuroscience↗

bioRxiv2026

Gut microbiome changes over the course of multiple sclerosis differentially influence autoimmune neuroinflammation

Multiple sclerosis (MS) is the leading inflammatory and demyelinating disease of the central nervous system (CNS). MS begins with systemic inflammation and over time is compartmentalized within the CNS. Studies in humans, supported by animal experiments, suggest that the gut microbiome plays an important role in MS development. However, despite the dynamic nature of the disease, little is known on how the microbiome evolves over the course of MS and how these microbiome changes influence immune responses and disease progression. Here, using high-throughput sequencing, we identified distinct gut microbial communities with differential functional potential in MS patients stratified by time since disease onset. Importantly, using a humanized mouse model, we demonstrate that differences in microbial composition significantly impact disease outcomes. Microbiota from more recently diagnosed MS patients induced severe neuroimmune disease in mice, whereas microbiota from long-term MS patients and healthy individuals elicited only mild disease. Accordingly, we found that microbiota from earlier diagnosed MS patients exhibit a higher inflammatory potential. This was characterized by a reduced capacity to induce regulatory T cells in mice and an increased induction of pro-inflammatory cytokines in human peripheral blood mononuclear cells. Together, our results suggest that the ability of the gut microbiome to promote systemic inflammation and trigger MS pathology shifts over the course of the disease and is primarily critical during its early stages. These findings indicate that a limited therapeutic window should be considered when designing microbiome-based interventions for MS.

immunology↗

bioRxiv2025

Accumulation of virtual tokens towards a jackpot reward enhances performance and value encoding in dorsal anterior cingulate cortex

Normatively, our decisions ought to be made relative to our total wealth, but in practice, we make our decisions relative to variable, decision-time-specific set points. This predilection introduces a major behavior bias that is known as reference-point dependence in Prospect Theory, and that has close links to mental accounting. Here we examined neural activity in the dorsal anterior cingulate cortex (dACC) of macaques performing a token-based risky choice task, in which the acquisition of six tokens (accumulated over several trials) resulted in a jackpot reward. We find that subjects make faster and more accurate choices, and that they are less prone to risk-taking as offer contingencies are easier and the jackpot reward becomes more likely to be achieved. By comparing alternative models that accounted for progressive token accumulation, we found that subjective evaluations are best explained by a reference-dependent value RDV model where offer values are considered as potential gains or losses with respect to a token-dependent reference. The reference-dependent model allows to implement a dynamical comparison of the two offered values to each other and to the number of missing tokens to reach the six tokens threshold as jackpot approached. In dACC, we find that gains in subjective values entail higher fractions of encoding cells than losses, and that the encoding tuning of expected utility variables is best aligned to choices in gains than in losses. These results suggest a neural basis of reference dependence biases in shaping decision-making behavior and highlight the critical role of value representations in dACC in driving evaluations.

neuroscience↗

bioRxiv2023

Gaze-centered gating and re-activation of value encoding in orbitofrontal cortex

During economic choice, we often consider options in alternation, until we commit to one. Nonetheless, neuroeconomics typically ignores the dynamic aspects of deliberation. We trained macaques to perform a value-based decision-making task where two risky offers were presented in sequence at different locations of the visual field, each followed by a delay epoch where offers were invisible. Subjects looked at the offers in sequence, as expected. Surprisingly, during the delay epochs, we found that subjects still tend to look at empty locations where the visual offers were formerly presented; and, moreover, longer fixation to given empty location increases the probability of choosing the associated offer, even after controlling for the offer values. We show that activity in orbitofrontal cortex (OFC) reflects the value of the gazed offer, but also the value of the offer associated to the gazed spatial location, even if it is not the most recently viewed. This reactivation reflects a reevaluation process, as fluctuations in neural spiking during offer stimuli presentation and delays correlate with upcoming choice. Our results suggest that look-at-nothing gazing triggers the reactivation of a previously seen offer for further reevaluation, revealing novel aspects of deliberation.

neuroscience↗

bioRxiv2020

Directed information exchange between cortical layers in macaque V1 and V4 and its modulation by selective attention

Achieving behavioral goals requires integration of sensory and cognitive information, across cortical laminae and cortical regions. How this computation is performed remains unknown. Using local field potential recordings and spectrally resolved conditional Granger causality (cGC) analysis, we mapped visual information flow, and its attentional modulation, between cortical layers within and between macaque areas V1 and V4. Stimulus induced inter-laminar information flow within V1 dominated upwardly, channeling information towards supragranular cortico-cortical output layers. Within V4, information flow dominated from granular to supragranular layers, but interactions between supragranular and infragranular layers dominated downwardly. Low-frequency across-area communication was stronger from V4 to V1, with little layer specificity. Gamma-band communication was stronger in the feedforward V1 to V4 direction. Attention to the receptive field of V1 decreased communication between all V1 layers, except for granular to supragranular layers interactions. Communication within V4, and from V1 to V4, increased with attention across all frequencies. While communication from V4 to V1 was stronger in lower frequency bands (4-25 Hz), attention modulated cGCs from V4 to V1 across all investigated frequencies. Our data show that top down cognitive processes result in reduced communication within cortical areas, increased feedforward communication across all frequency bands and increased gamma band feedback communication.

neuroscience↗