Biology subjects

Gallego, J.

Publications and source records attributed to Gallego, J..

5 recordsLinked to original sources

bioRxiv2026

Mafb-lineage activation of a short polyalanine (+5) PHOX2B mutation produces severe respiratory dysfunction with preserved postnatal weight gain among survivors in a mouse model of congenital central hypoventilation syndrome

Rationale: Congenital central hypoventilation syndrome (CCHS) is most commonly caused by polyalanine repeat mutations in PHOX2B. The in vivo consequences of the short five-alanine expansion and the contribution of specific hindbrain lineages to the resulting respiratory phenotype remain poorly understood. Objectives: To characterize the neonatal phenotype caused by the Phox2b25Ala/+ mutation and determine the contribution of the MafB lineage associated with the r5-r6 hindbrain territory. Methods: We generated a conditional Phox2b25Ala allele and studied mice with constitutive or MafB-lineage activation. Neonatal survival, growth, gastric milk content, ventilation, and hypercapnic responses were assessed in vivo. Respiratory-network activity and responses to extracellular acidification were recorded in E18.5 isolated brainstem-spinal cord preparations, and retrotrapezoid nucleus (RTN) development was examined histologically. Measurements and Main Results: Constitutive Phox2b25Ala/+ pups exhibited high neonatal mortality, markedly impaired weight gain, reduced gastric milk scores, hypoventilation, increased apnea time, and blunted ventilatory responses to CO2. Embryonic preparations showed a slower respiratory rhythm, an impaired response to acidification, and severe RTN dysgenesis. Activation of the mutant allele in the MafB lineage was also associated with severe respiratory dysfunction, RTN dysgenesis, and early neonatal mortality. In contrast, postnatal weight gain was preserved among surviving MafB-lineage mutants, and the reduction in gastric milk scores was significantly attenuated compared with constitutive mutants. Conclusions: A short PHOX2B polyalanine expansion reproduces major respiratory features of CCHS in mice. Activating the mutant allele in the MafB lineage is sufficient to cause severe respiratory dysfunction and neonatal mortality, whereas postnatal weight gain is preserved among survivors.

neuroscience↗

bioRxiv2026

Individual Bird Identification by Modeling Temporal Structure in Bioacoustic Embeddings

O_LIIdentifying individual animals from vocalizations is an emerging research area in computational bioacoustics. This non-invasive approach reduces reliance on physical capture and tagging for wildlife monitoring. Recent advances in this area leverage deep learning and bioacoustic foundation models adapted from species-level classifiers. However, these models typically rely on fixed-window inputs and may not fully capture temporal structure across extended or complex songs, which can contain information relevant to individual discrimination. C_LIO_LIHere, we evaluate whether modeling sequences of pretrained bioacoustic embeddings improves acoustic individual identification. We developed a framework that integrates transfer-learned spectrotemporal representations from BirdNET with a lightweight long short-term memory network. Unlike static baselines that use either the first embedding or an average over all embeddings, our approach processes time-ordered embedding sequences, allowing the classifier to use information distributed across multiple windows. C_LIO_LIWe evaluated the system using 87,865 vocalizations from 352 individuals across seven species. We used four publicly available vocalization datasets with individual-level labels, covering durations from 0.76 s (short calls) to 27.6 s (prolonged songs). Across five random seeds with stratified partitions, the framework achieved mean test accuracies between 93.9% and 98.3% and macro-F1 scores ranging from 93.2% to 98.3%, without data augmentation. The clearest gains over the strongest static baseline were observed for the great tit and the great spotted kiwi, reaching +1.3 and +2.8 percentage points, respectively. C_LIO_LIOur results indicate that the contribution of temporal sequence modeling depends on vocalization structure, rather than providing uniform evidence that chronological order drives performance. The benefit of recurrent aggregation was limited or absent for short calls but evident for long vocalizations with multiple informative windows. By combining bioacoustic foundation models with lightweight recurrent modeling, this approach provides a scalable, CPU-efficient tool for autonomous wildlife monitoring, particularly for species with extended or structurally complex vocalizations. C_LI

ecology↗

bioRxiv2023

Low-intensity pulsed ultrasound stimulation (LIPUS) modulates microglial activation following intracortical microelectrode implantation.

Microglia are important players in surveillance and repair of the brain. Their activation mediates neuroinflammation caused by intracortical microelectrode implantation, which impedes the application of intracortical brain-computer interfaces (BCIs). While low-intensity pulsed ultrasound stimulation (LIPUS) can attenuate microglial activation, its potential to modulate the microglia-mediated neuroinflammation and enhance the bio-integration of microelectrodes remains insufficiently explored. We found that LIPUS increased microglia migration speed from 0.59{+/-}0.04 to 1.35{+/-}0.07 {micro}m/hr on day 1 and enhanced microglia expansion area from 44.50{+/-}6.86 to 93.15{+/-}8.77 {micro}m2/min on day 7, indicating improved tissue healing and surveillance. Furthermore, LIPUS reduced microglial activation by 17% on day 6, vessel-associated microglia ratio from 70.67{+/-}6.15 to 40.43{+/-}3.87% on day 7, and vessel diameter by 20% on day 28. Additionally, microglial coverage of the microelectrode was reduced by 50% in week 1, indicating better tissue-microelectrode integration. These data reveal that LIPUS helps resolve neuroinflammation around chronic intracortical microelectrodes.

bioengineering↗

bioRxiv2023

Effects of phase encoding direction on test-retest reliability of human functional connectome

The majority of human connectome studies in the literature based on functional magnetic resonance imaging (fMRI) data use either an anterior-to-posterior (AP) or a posterior-to-anterior (PA) phase encoding direction. However, whether and how phase encoding direction would affect test-retest reliability of functional connectome is unclear. Here, in a sample of healthy subjects with two sessions of fMRI scans separated by 12 weeks (two runs per session, one with AP, the other with PA), we tested the influence of phase encoding direction on global and nodal connectivity in the constructed brain networks. All data underwent the state-of-the-art Human Connectome Project (HCP) pipeline to correct for phase-encoding-related distortions before entering analysis. We found that at the global level, the PA scans showed significantly higher intraclass correlation coefficients (ICCs) for global connectivity compared with AP scans, which was particularly prominent when using the Seitzman-300 atlas (versus the CAB-NP-718 atlas). At the nodal level, regions most strongly affected by phase encoding direction were consistently mapped to the cingulate cortex and temporal lobe, with significantly higher ICCs during PA scans compared with AP scans, regardless of atlas. Further, we demonstrated that the observed reliability differences between phase encoding directions may relate to a similar effect on the reliability of temporal signal-to-noise ratio (tSNR) in the same regions (that PA scans were associated with higher reliability of tSNR than AP scans). Averaging the connectivity outcome from the AP and PA scans could slightly, but overall have limited value to boost the ICCs. These results were largely replicated in an independent, public dataset from the HCP-Early Psychosis (HCP-EP) study with a similar design but a much shorter scan session interval. Our findings suggest that phase encoding direction has significant effects on the reliability of connectomic estimates in fMRI studies. We urge that these effects need to be carefully considered in future neuroimaging designs, especially in longitudinal studies such as those related to neurodevelopment or clinical intervention.

neuroscience↗

bioRxiv2020

Long-term (1990-2019) monitoring of tropical moist forests dynamics

Accurate characterization of the tropical moist forests changes is needed to support conservation policies and to better quantify their contribution to global carbon fluxes. We document - at pantropical scale - the extent of these forests and their changes (degradation, deforestation and recovery) over the last three decades. We estimate that 17% of the tropical moist forests have disappeared since 1990 with a remaining area of 1060 million ha in 2019, from which 8.5% are degraded. Our study underlines the importance of the degradation process in such ecosystems, in particular as precursor of deforestation and in the recent increase of the tropical moist forest disturbances. Without reduction of the present disturbance rates, undisturbed forests will disappear entirely in large tropical humid regions by 2050. Our study suggests reinforcing actions to prevent the first disturbance scar that leads to forest clearance in 45% of the cases.

ecology↗