Biology subjects

Arroyo, B.

Publications and source records attributed to Arroyo, B..

6 recordsLinked to original sources

bioRxiv2025

Identifying the exposure of taxonomic, functional, and phylogenetic diversity of steppe birds to renewable energy developments

Biodiversity is globally threatened by human impacts including land use transformation and climate change. Global warming has prompted a rapid transition from fossil fuels to cleaner energy sources such as photovoltaic (PV) energy. However, utility-scale PV plants demand vast areas and can lead to conflicts with biodiversity conservation, making strategic planning essential. We evaluate the spatial overlap between conservation priorities and PV infrastructure using steppe birds--a highly threatened bird group occurring in lands potentially suitable for PV plants--as a model. First, we quantified and mapped taxonomic (TD), functional (FD), and phylogenetic diversity (PD) of 26 species across a main stronghold for European steppe birds (mainland Spain and Balearic Islands) to identify prioritization scenarios that best preserved all steppe bird diversity facets (TD, FD, and PD), and steppe birds of conservation concern. Next, we generated a diversity hotspot map based on the combination of TD, FD, and PD and overlapped with existing PV infrastructure to determine: (1) exposure areas (high diversity hotspots with high PV occupancy), and (2) no-go areas (high diversity hotspots with low/null PV occupancy). We found that the prioritization scenario combining TD+FD+PD retained 68.5% of TD, 75.5% of FD, 59.7% of PD, and 62.8% of areas with species of conservation concern, providing a more balanced representation across biodiversity facets than other prioritization scenarios. PV infrastructure currently occurs in 53.1% of high diversity hotspot cells. Overall, exposure areas (7.2% of the study area) were mainly concentrated in Central, Southern, and Northwestern Spain, while no-go areas (19.9% of the study area) were concentrated in Northern, Central, and Central-Western Spain. Our methodology is adaptable to other species, communities and regions, offering a robust framework for balancing development projects with biodiversity conservation. As the transition to renewable energy accelerates, including biodiversity in energy planning is crucial for preventing irreversible ecological losses.

ecology↗

bioRxiv2025

The Crunchometer: A Low-Cost, Open-Source Acoustic Analysis of Feeding Microstructure

Elucidating the neuronal circuits that govern appetite requires precise, high-resolution monitoring of the microstructure of solid food consumption, a need unmet by existing tools, which are either costly or lack the temporal resolution to align feeding events with neuronal activity. To overcome this, we developed the Crunchometer, a low-cost, open-source acoustic system that uses computational algorithms to generate high-resolution feeding ethograms from the sounds produced during solid food consumption. Validation across energy states (hunger/satiety) confirmed its sensitivity to changes in feeding microstructure, and the system reliably detected semaglutide-induced suppression of intake and reduced preference for a high-fat diet. Leveraging its seamless integration with in vivo recordings in freely behaving mice, we paired the Crunchometer with lateral hypothalamus (LH) electrophysiology to identify "meal-related" neurons that track entire meals rather than individual bouts. Calcium imaging further revealed that distinct subsets of LH GABAergic and glutamatergic neurons were tuned to feeding only, to licking only, or to both behaviors. Thus, LH neuronal ensembles differentially encode the consumption of solid food versus liquid sucrose. These findings demonstrate that the Crunchometer is a robust, accessible platform for dissecting the neural correlates of feeding behavior at the resolution of a single bite. Significance statementThe Crunchometer is a low-cost, open-source technology that democratizes feeding analysis, enabling the precise dissection of neuronal circuits involved in appetite to advance therapies for obesity and eating disorders.

neuroscience↗

bioRxiv2024

Effects of N361 Glycosylation on Epidermal Growth Factor Receptor Biological Function

Epidermal growth factor receptor (EGFR) is a transmembrane tyrosine kinase that is frequently modified by glycosylation post-translationally. In cancer, EGFR amplifications and hotspot mutations such as L858R that promote proliferation have been detected in a significant fraction of non-small cell lung carcinomas and breast adenocarcinomas. Molecular dynamic simulations suggested that glycosylation at asparagine residue 361 (N361) promotes dimerization and ligand binding. We stably expressed glycosylation-deficient mutant EGFR N361A, with or without the oncogenic mutation L858R. Immunofluorescence and flow cytometry demonstrated that the mutants were each well expressed at the cell membrane. N361A decreased proliferation relative to wild-type EGFR as well as decreased sensitivity to ligands. Proximity ligation assays measuring co-localization of EGFR with its binding partner HER2 in cells revealed that N361A mutations increased co-localization. N361A, located near the binding interface for the EGFR inhibitor necitumumab, desensitized cells expressing the oncogenic EGFR L858R to antibody-based inhibition. These findings underline the critical relevance of post-translational modifications on oncogene function. SIGNIFICANCEEGFR transduces signals from growth factors into cell proliferation and is frequently hyperactivated in tumors. Glycosylation of EGFR at N361 regulates EGFR dimerization, growth factor stimulation of proliferative signaling, and susceptibility to targeted inhibition. Insights into EGFR glycosylation may expand therapeutic opportunities to benefit cancer patients.

cancer biology↗

bioRxiv2024

The flow of reward information through neuronal ensembles in the accumbens

Reward information flows through neuronal ensembles in the nucleus accumbens shell (NAcSh), influencing decision-making. We investigated this phenomenon by training rats in a self-guided probabilistic choice task while recording single-unit activity in the NAcSh. We found that rats dynamically adapted their choices based on an internal representation of reward likelihood. Neuronal ensembles in the NAcSh act as dynamic modules to process different aspects of reward-guided behavior. Ensembles dynamically change composition and functional connections throughout reinforcement learning. The NAcSh forms a highly connected network with a heavy-tailed distribution and neuronal hubs, facilitating efficient reward information flow. Reward delivery evokes higher mutual information between ensembles and unifies network activity, while omission leads to less synchronization. Our recordings shed light on how reward information propagates through dynamically changing ensembles of neurons in the NAcSh. These functional ensembles exhibit flexible membership, dropping in and out and even shrinking in number as the rat learns to obtain (energy) rewards in an ever-changing environment. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=189 HEIGHT=200 SRC="FIGDIR/small/580379v2_ufig1.gif" ALT="Figure 1"> View larger version (37K): org.highwire.dtl.DTLVardef@1e870org.highwire.dtl.DTLVardef@1434c90org.highwire.dtl.DTLVardef@157971aorg.highwire.dtl.DTLVardef@1812ca6_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2023

Tesofensine, a novel antiobesity drug, silences GABAergic hypothalamic neurons

Obesity is a major global health epidemic that has adverse effects on both the people affected as well as the cost to society. Several anti-obesity drugs that target GLP-1 receptors have recently come to the market. Here we describe the effects of tesofensine, a novel anti-obesity drug that acts as a triple monoamine neurotransmitter reuptake inhibitor. We investigated its effects on weight loss and underlying neuronal mechanisms in mice and rats using various techniques. These include behavioral tasks, DeepLabCut videotaped analysis, electrophysiological ensemble recordings, optogenetic activation, and chemogenetic silencing of GABAergic neurons in the Lateral Hypothalamus (LH). We found that tesofensine induced greater weight loss in obese than lean rats, which was associated with changes in LH ensemble activity. In Vgat-ChR2 and Vgat-IRES-cre transgenic mice, we found for the first time that tesofensine inhibited a subset of LH GABAergic neurons, reducing their ability to promote feeding behavior, and chemogenetically silencing them enhanced tesofensines food-suppressing effects. Unlike phentermine, a dopaminergic appetite suppressant, tesofensine causes few, if any, head-weaving stereotypy at therapeutic doses. Most importantly, we found that tesofensine prolonged the weight loss induced by 5-HTP, a serotonin precursor, and blocked the body weight rebound that often occurs after weight loss. Behavioral studies on rats with the tastant sucrose indicated that tesofensines appetite suppressant effects are independent of taste aversion and do not directly affect the perception of sweetness or palatability of sucrose. In summary, our data provide new insights into the effects of tesofensine on weight loss and the underlying neuronal mechanisms, suggesting that tesofensine may be an effective treatment for obesity and that it may be a valuable adjunct to other appetite suppressants to prevent body weight rebound.

neuroscience↗

bioRxiv2023

Use of linear features by red-legged partridges in an intensive agricultural landscape: implications for landscape management in farmland

Current agricultural practices and change are the major cause of biodiversity loss. An important change associated with the intensification of agriculture in the last 50 years is the spatial homogenization of the landscape with substantial loss of such biodiversity-rich elements as seminatural linear features (hedgerows, field margins, grassy strips, etc.). In Europe, some management prescriptions serve to increase heterogeneity by the creation of these seminatural linear features which are not being used primarily for agricultural production. However, these elements are not equal in their support for biodiversity according to their structure and composition. The aim of this study is to determine the importance of landscape heterogeneity and specifically linear features on the spatial distribution of red-legged partridges, a small game species in decline in Europe. Through GPS-monitoring of adult birds, we first assess home range size throughout the year and during the breeding season, in relation to breeding status and to linear features (seminatural linear vegetation and tracks-roads for human traffic) density. Then, we focus on habitat selection during the breeding period in relation to linear features. We found that linear elements shape the use of space by red-legged partridges according to their reproductive status. Traffic routes and seminatural features structured by both herbaceous and woody cover, negatively influenced home range size. Further, breeding birds select linear elements with herbaceous cover while non-breeders select linear elements with woody cover, underlining the different needs of birds according to their breeding status. All birds selected areas near tracks, but non-breeders seemed to avoid roads. This study shows the importance for this species of the linear components that structure the agricultural landscape. We propose recommendations to promote the presence of the red-legged partridge in this agricultural environment but also of the biodiversity in general.

ecology↗