Biology subjects

Lenzi, I.

Publications and source records attributed to Lenzi, I..

3 recordsLinked to original sources

bioRxiv2025

Cortex-wide circuits for multisensory evidence accumulation and choice formation

Accurate decisions in natural environments require integrating sensory information across modalities. To determine where and when multisensory signals are integrated within the cortical hierarchy, we trained mice in a visuotactile evidence-accumulation task and used widefield and two-photon calcium imaging together with optogenetic perturbations to map cortical circuits. Mice showed enhanced performance in multisensory trials that matched an additive combination of the total unisensory evidence. Cortical imaging also revealed superadditive multisensory responses in parietal and frontal regions, but visual and tactile evidence was accumulated in distinct regions, with the rostrolateral visual area (RL) being more selective for visual and the frontal medial motor cortex (MM) for tactile inputs. This modality-specific segregation persisted beyond stimulus presentation with convergence into a modality-independent choice emerging only late in the trial in the anterolateral motor cortex (ALM). Two-photon imaging confirmed that ALM neurons predominantly encoded modality-independent choices with few neurons responding to specific sensory stimuli. Optogenetic inactivation of RL and frontal cortex during the stimulus or choice period further validated their respective roles in sensory evidence accumulation and choice formation. These findings reveal a hierarchical organization in which modality-specific evidence is maintained until late in the decision process, with frontal cortex turning multisensory signals into unified choices.

neuroscience↗

bioRxiv2025

Fine-scale animal proximity detection and localization via multi-sensor biologgers

O_LIAccurately quantifying spatial interactions is central to understanding social behavior, information flow, predator-prey dynamics, and disease transmission. Proximity loggers that record received signal strength indicator (RSSI) offer a promising approach for estimating pairwise distances, particularly in environments where GPS is unavailable or imprecise. However, RSSI is often dismissed as too noisy for fine-scale inference, with performance that depends on environmental conditions, tag orientation, and between-device variability. Incorporating additional tag-measured data may improve RSSI performance and enable its use as a continuous measure of distance in variable environments. C_LIO_LIHere, we assess the utility of continuous RSSI as a fine-scale distance estimator and localization tool using a novel multi-sensor WiFi biologger (WildFi). We conducted four experiments: (1) testing how tag orientation affects RSSI-distance relationships; (2) evaluating whether environmental covariates measured by onboard sensors improve proximity estimates; (3) assessing the accuracy of trilateration-based tag localization using fixed gateway arrays; and (4) comparing RSSI- and GPS-inferred proximity in free-ranging Egyptian fruit bats (Rousettus aegyptiacus). C_LIO_LIWhile RSSI alone could predict distance with reasonable accuracy, incorporating additional tag-sensed information (e.g., temperature, humidity, barometric pressure) and accounting for tag-level heterogeneity significantly improved predictive accuracy. Based on RSSI predictions, we could estimate tag location with a median error of 2.6 meters, accurate enough to indirectly estimate proximity networks without tag-to-tag communication. In deployments on free-flying bats, we found that RSSI and GPS were only weakly concordant, with GPS unreliable for detecting fine-scale interactions (<50 m). In contrast, RSSI could capture both fine-scale and some long-range interactions up to [~]250m. C_LIO_LIThese findings highlight RSSIs potential as a robust metric for proximity logging, particularly when combined with multi-sensor data and pre-deployment validations. Integrating multi-sensor data streams further enhances RSSI interpretability. Future biologger designs should prioritize synergy among data streams for integrated insights into proximity and animal behavior. C_LI Data and code for peer review statementData and code to reproduce the results of the paper are provided in a zip folder for peer review. We also provided our compiled code.

ecology↗

bioRxiv2021

Optical mini-stroke of thalamic networks impairs sleep stability, topography and cognition.

Modelling stroke in animals remains a challenge for translational research, especially for the infraction of small subcortical arteries. Using combined fibre optics and photothrombosis technologies, we developed a novel model of optically-induced infarcts (Opto-STROKE). Combining our model with electrophysiological recordings in freely-behaving mice, we studied early and late consequent patho-physiological changes in the dynamics of sleep-wake circuits and cognitive performance. Here, focusing on inducing Opto-STROKE lesions in the intralaminar thalamus (IL), which in humans cause severe impairments of arousal, cognition, and affective symptoms, our model recapitulated important deficits on sleep disorders presented in humans including arousal instability, concurrent to an augmented slow-wave activity and a reduction gamma power bands during wakefulness. Moreover, during NREM sleep, spindle density was decreased and topographically shifted to frontal cortices when compared to control animals. Remarkably, gamma power and spindle density were correlated with decreased pain threshold and impaired prefrontal cortex-dependent working memory in Opto-STROKE mice relative to controls. Collectively, our combined method influences both anatomical and functional outcomes of the classical stroke procedures and offers new insights on the fundamental role of the media thalamus as a hub for the regulation of both sleep-wake architecture and cognition. O_FIG_DISPLAY_L [Figure 1] M_FIG_DISPLAY C_FIG_DISPLAY

neuroscience↗