Bonato, M. | Search bioRxiv

bioRxiv2025

Acute particulate matter (PM10) exposure selectively triggers behavioral alterations in the presymptomatic Experimental Autoimmune Encephalomyelitis (EAE) mouse model of Multiple Sclerosis

Multiple Sclerosis (MS) is a chronic disease of the Central Nervous System, where neuroinflammation and autoimmune response against myelin lead to functional impairments, cognitive and psychiatric symptoms. Exposure to air pollution - in particular to peaks of particulate matter (PM) - has been associated with an increase of hospital admissions for MS onset and relapses and exacerbated neuroinflammation in MS patients. Here, in the MOG35-55-induced experimental autoimmune encephalomyelitis (EAE) mouse model of MS, we tested the hypothesis that exposure to PM10 might influence the disease course and severity in individuals with a predisposing background. Short-term PM10 exposures - occurring either before immunization or during the pre-symptomatic phase - did not modify disease manifestation in EAE mice, as assessed by clinical and neuropathological analyses. Yet, presymptomatic EAE - but not healthy - mice selectively showed increased disinhibited, risk-taking and novelty-seeking behaviors early after being exposed to PM10. These data show a selective vulnerability of immunologically primed mice toward the effects of PM10, occurring before the emergence of overt motor impairment and presenting as specific behavioral alterations.

neuroscience↗

bioRxiv2023

Susceptibility to multitasking in chronic stroke is associated to damage of the multiple demand system and leads to lateralized visuospatial deficits

Functional impairment after stroke is related to the amount of brain damage but there is no strict correspondence between lesion and magnitude of the deficit or its recovery. Theoretical constructs such as cognitive or brain reserve have been invoked as unspecific protective factors to explain this mismatch. Here, we consider the opposite point of view, that is the instances in which this protection is lost or overturned. Several studies have shown - in domains encompassing sensory, motor, and cognitive deficits - that paradigms in which the inherent processing limits of the brain are stressed (e.g., by introducing multitasking and attentional load), are indeed capable to unveil the presence of deficits that are otherwise missed. We administered a computerized multitasking paradigm to a sample of 46 consecutive patients with first-ever unilateral subacute to chronic stroke and no sign of lateralized spatial-attentional disorders according to established diagnostic tests. We then used cluster analysis to classify patients, in a purely data-driven manner, according to their multivariate pattern of performance across different conditions (e.g., single- vs dual-tasking, ipsi- vs. contra-lesional stimuli). This enabled us to identify, within a group of putatively spared patients, a cluster of individuals presenting with stark contralesional biases of spatial awareness exclusively in conditions of concurrent attentional load, i.e. a phenotype characterised by high susceptibility to multitasking. This construct was also captured by a latent factor obtained from principal component analysis, providing a continuous susceptibility index across the whole sample. In spite of similar lesion volume, patients in the high susceptibility cluster presented worse performance in activities of daily living and neuropsychological tests evaluating domain-general abilities spanning attention, executive functions, and reasoning. Multivariate predictive modeling based on lesions location and structural disconnections revealed distinctive correlates of high sensitivity to multitasking in the Multiple-Demand (MD) System, a network of frontal and fronto-parietal areas subserving domain general processes. Damage in these areas may critically interact with domain-specific ones (e.g., devoted to spatial attention), resulting in subtle, but significant difficulties for patients in everyday life situations. In conclusion, the construct of susceptibility to multitasking has the promising potential to provide us a better understanding of what marks the passage, after brain damage, to clinically visible deficits. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=113 SRC="FIGDIR/small/561866v1_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@a1bc89org.highwire.dtl.DTLVardef@60cfedorg.highwire.dtl.DTLVardef@1f2ed85org.highwire.dtl.DTLVardef@1c7e5ec_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2022

Experimental evidence that animal societies vary in size due to sex differences in cooperation

Cooperative breeding societies allow the costs of reproduction to be shared. However, as groups become larger, such benefits often decrease and competition increases. This is predicted to select for an optimal group size, yet variation in groups is a ubiquitous feature of cooperative breeding animals. Here we experimentally established groups (ngroups=96) of cooperative breeding ostriches, Struthio camelus, with different numbers of males and females and manipulated the potential for cooperation over incubation. There was a clear optimal group size for males. Their reproductive success was maximized in groups with four or more females and no other males, irrespective of cooperation over incubation. Conversely, female reproductive success was strongly dependent on the benefits of cooperating over incubation, being maximized in groups with either many males or many females. In intermediate sized groups, both male and female reproductive success was reduced by sexual conflict over the timing of mating and incubation. Our experiments show that sex differences in the opposing forces of cooperation and competition can explain why variation in cooperative groups is widespread.

evolutionary biology↗