Biology subjects

Gal, C.

Publications and source records attributed to Gal, C..

3 recordsLinked to original sources

bioRxiv2026

Glycosaminoglycan presentation-dependent regulation of glial responses by Orion during Drosophila neuronal pruning

Neuronal pruning refines neural circuits by eliminating unnecessary connections to ensure proper nervous system function. In Drosophila mushroom body gamma-neuron remodeling, the chemokine-like protein Orion is required for astrocyte infiltration and phagocytosis. This study investigated whether glial responses depend on how Orion is presented. We found that Orion interacts with glycosaminoglycans (GAG) associated to proteoglycans, which are essential for proper axon pruning. Tethering Orion to the gamma-neuron plasma membrane, mimicking glycosaminoglycan binding, was sufficient to induce astrocyte infiltration into axon bundles. However, membrane-bound Orion alone could not efficiently support phagocytosis, which additionally requires a soluble and mobile Orion pool. We also identified exosomes carrying GAG-bound Orion as potential mediators of neuronal remodeling. These findings provide the first evidence that glial infiltration can be uncoupled from phagocytosis, demonstrating that the mode of Orion presentation regulates distinct glial mechanisms during neuronal remodeling.

neuroscience↗

bioRxiv2023

Randomness impacts specific priors building, visual exploration, and perception in object recognition

1.Recognising objects is a vital skill on which humans heavily rely to respond quickly and adaptively to their environment. Yet, we lack understanding on the role visual information sampling plays in this process, and its relation to the individuals priors. To bridge this gap, the eye-movements of 18 adult participants were recorded during a free-viewing object-recognition task using Dots stimuli (Moca et al., 2011). Participants viewed the stimuli in one of three orders: from most visible to least (Descending), least visible to most (Ascending) or in a randomised order (Random). This dictated the strength of their priors along the experiment. Adding to Moca et al.s original finding that visibility order influenced participants recognition performance and visual exploration, we found that while orders allowing for stronger priors generally led participants to visually sample more informative locations, this was not the case of Random participants. Indeed, they appeared to behave naively, and their use of specific object-related priors seemed fully impaired, while they seemed to maintain the ability to use general task-related priors to guide their exploration. These findings have important implications for our understanding of perception, which appears markedly subjective even at the basic level of visual sampling and object perception.

neuroscience↗

bioRxiv2020

DREAM represses distinct targets by cooperating with different THAP domain proteins

The DREAM (DP, Retinoblastoma [Rb]-like, E2F, and MuvB) complex controls cellular quiescence by repressing cell cycle and other genes, but its mechanism of action is unclear. Here we demonstrate that two C. elegans THAP domain proteins, LIN-15B and LIN-36, co-localize with DREAM and function by different mechanisms for repression of distinct sets of targets. LIN-36 represses classical cell cycle targets by promoting DREAM binding and gene body enrichment of H2A.Z, and we find that DREAM subunit EFL-1/E2F is specific for LIN-36 targets. In contrast, LIN-15B represses germline specific targets in the soma by facilitating H3K9me2 promoter marking. We further find that LIN-36 and LIN-15B differently regulate DREAM binding. In humans, THAP proteins have been implicated in cell cycle regulation by poorly understood mechanisms. We propose that THAP domain proteins are key mediators of Rb/DREAM function.

genomics↗