Biology subjects

Amo, L.

Publications and source records attributed to Amo, L..

5 recordsLinked to original sources

bioRxiv2025

The common kestrel Falco tinnunculus is attracted to the scent of voles

Although the study of the role of olfaction in avian foraging is providing exciting results, whether olfaction is involved in the detection of prey by raptors is still understudied. Here, we present the results of a study aimed to assess whether the common kestrel (Falco tinnunculus) is attracted to the scent of the cues that common voles (Microtus arvalis) use to mark their territory. In an experimental study in captivity we released kestrels in an aviary containing two trays, one tray containing vole scent and one unscented tray. Results show that kestrels are attracted to the vole chemical cues as a greater number of kestrels paid the first visit to the vole-scented tray. Furthermore, the kestrels visited significantly more often the vole scented tray than the control tray. Therefore, our results show that common kestrels are able to use chemical cues emitted by their prey for foraging.

animal behavior and cognition↗

bioRxiv2025

Dual role of GABAB receptor in oligodendrocyte function and immune modulation in experimental multiple sclerosis

GABAB receptors (GABABR) mediate the actions of the inhibitory neurotransmitter GABA in the central nervous system, regulating key processes such as synaptic activity, interneuron communication and excitation-inhibition balance in the brain. Recent studies using the GABABR agonist baclofen have revealed a critical role for these receptors in promoting oligodendroglial differentiation in both health and disease, highlighting their potential as therapeutic targets in demyelinating diseases such as multiple sclerosis (MS). In this study, we identify a dual role for oligodendroglial GABABR in experimental autoimmune encephalomyelitis (EAE), an animal model of MS. Conditional deletion of the GABAB1 subunit in NG2+ cells ameliorates acute disease symptoms while inducing an immune-like phenotype in oligodendrocytes. This immunomodulatory role is further supported by pharmacological activation of GABABR in oligodendrocytes, which reduces the expression of MHC class II in these cells. Notably, baclofen treatment after EAE symptom onset attenuates the course of the disease while enhancing oligodendrocyte progenitor cell differentiation and suppressing T cell infiltration into demyelinating lesions. Moreover, prophylactic baclofen administration delays disease onset and further decreases immune cell recruitment into the spinal cord, underscoring its potent immunomodulatory effect. These data demonstrate that GABABR signaling exerts context-dependent effects on both oligodendrocyte lineage progression and neuroinflammatory responses. Importantly, these compelling findings validate baclofen, a drug already approved for MS-associated spasticity, as a promising candidate for therapies targeting both inflammation and remyelination, advancing our understanding of glial-immune interactions in demyelinating diseases and supporting the translational potential of GABABR modulation in MS.

neuroscience↗

bioRxiv2024

Activated NK cells with a predominance of inhibitory receptors and a decidual-like phenotype expand after autologous HSCT in children with tumors.

Early immune reconstitution after autologous hematopoietic stem cell transplantation (autoHSCT) is associated with a better outcome in a variety of cancers. NK cells constitute the first lymphocyte subset to recover in the blood after autoHSCT. We have in-depth characterized them in pediatric patients with different tumors and found that, immediately after autoHSCT, NK cells transiently acquired a decidual-like phenotype, were more immature and activated, and exhibited an increased expression of inhibitory receptors, while activating receptors levels were diminished. This activated and decidual-like phenotype was characterized by increased CD56, CD9, CD49a, CD151, CD38, HLA-DR and CD55 expression. We also determined plasma levels of several cytokines and found that their concentrations were associated with the observed changes in NK cells phenotype. In vitro experiments, including flow cytometry and single-cell RNA sequencing (scRNA-seq), recapitulated the changes observed in NK cells early after autoHSCT. Specifically, results revealed that the combination of IL-15 and TGF-{beta} induced, at least partially, this distinctive phenotype on NK cells after autoHSCT. Finally, we have observed a positive correlation between relapse and the percentage of CD56dim NK cells shortly after autoHSCT in our cohort of pediatric patients. Altogether, our work is of relevance to understand the physiopathology of NK cells during the immune system reconstitution after autoHSCT in children and potentially help in the management of these patients.

immunology↗

bioRxiv2022

Assessing behavioral sex differences to chemical cues of predation risk while provisioning nestlings in a hole-nesting bird

Birds can assess nest predation risk and adjust their parental activity accordingly. Risk taking behavior should be related to investment in reproduction as well as to confidence in parenthood that often differ between sexes. In those cases, sexual differences in risk taking behavior may be expected. For example, in blue tits, females invest more time and energy than males in nest-building, egg laying and incubation. Furthermore, confidence in parenthood is supposed to be higher for females, as extrapair paternity is common in this species. Therefore, the reproductive value of nestlings may be higher for females than for males and the former may assume greater risks to ensure nestling growth and maximize their reproductive success. We examined potential sexual differences in the risk assumed by parents in relation to perceived risk of predation inside the nest cavity, where predation risk perception may be higher. We increased perceived predation risk by adding predator chemical cues inside blue tit (Cyanistes caeruleus) nest-boxes, and we tested whether female and male parents differed in the risk assumed when taking care of nestlings. Females and males did not differ in the risk assumed in response to perceived predation risk. However, females reduced time devoted to nest sanitation activities when predator chemical cues were detected inside the nest-box, likely as an anti-predatory strategy to minimize their own risk of predation. Therefore, these results add to the evidence that birds can detect chemical cues of predators inside the nest cavity and suggest that the behavioral response to an increase in risk of predation perceived through olfactory cues is not sex-dependent in blue tit.

animal behavior and cognition↗

bioRxiv2022

House sparrows do not exhibit a preference for the scent of potential partners with different MHC-I allele numbers and genetic distances

MHC genes play a fundamental role in immune recognition of pathogens and parasites. Therefore, females may increase offspring heterozygosity and genetic diversity by selecting MHC genetically compatible or heterozygous males. In birds, several studies suggest that MHC genes play a role in mate choice, and recent evidence suggest that olfaction may play a role in such discrimination. Previous studies indicated that house sparrow females with low allelic diversity prefer males with higher diversity in MHC-I alleles. Here, we directly explored whether both house sparrow females and males could estimate by scent the number in MHC amino acid and functional variants as well as the level of MHC-I similarity or dissimilarity of potential partners. Our results show that neither females nor males exhibit a preference related to the number of MHC-I amino acid variants or functional variants or in relation to MHC amino acid or functional similarity of potential partners, suggesting that MHC-I is not detected through olfaction. Further studies are needed to understand the mechanisms responsible for MHC-I based mate discrimination in birds.

animal behavior and cognition↗