Browsing by Author "Silva, Bryon"

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    Genetic sex of enteric neurons enables ovarian relaxin to gate maternal gut plasticity
    (2026) Silva, Bryon; Tsakani, Edisona; Kontopoulos, Alexandros; De, Joydeep; Gaspar, Pedro; Hiridjee, Alya; Rosselli, Camila; Juan-Sanz, Jaime De; Campusano Astorga, Jorge Mauricio; Treiber, Christoph D.; Waddel, Scott; Miguel-Aliaga, Irene; Hadjieconomou, Dafni
    Animals must align intestinal plasticity and feeding with reproductive state, yet the checkpointthat gates these adaptations is unknown. Here we show that an ovary-to-enteric-neuron axisgates the onset of maternal gut plasticity in Drosophila. Genetic sex establishes endocrinecompetence in a subset of enteric neurons via the sex determination pathway, enabling femalespecific expression of the relaxin-family receptor Lgr3. After mating, steroid signallingincreases Lgr3 receptor expression, priming these neurons for reproductive adaptation. Onceoocytes mature fully, follicle cells secrete the relaxin-like hormone dILP8, which activatesLgr3 to trigger gut enlargement and increased feeding. Disrupting the sex determinationpathway in enteric neurons, Lgr3, or ovarian dILP8 prevents gut enlargement and reducesfeeding. Thus, genetic sex establishes competence, steroid signalling primes it, and ovarianrelaxin triggers it, defining a maternal intestinal plasticity checkpoint that ensures gutadaptations initiate only once reproduction is underway and energy demands peak. Ourfindings delineate an ovary-to-enteric-neuron axis that couples reproductive state to maternalgut plasticity.
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    Muscarinic ACh receptors contribute to aversive olfactory learning in drosophila
    (2015) Silva, Bryon; Molina Fernández, Claudia; Ugalde, María Beatriz; Tognarelli, Eduardo I.; Angel, Cristian; Campusano Astorga, Jorge Mauricio
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    Serotonin Receptors Expressed in Drosophila Mushroom Bodies Differentially Modulate Larval Locomotion
    (2014) Silva, Bryon; Goles, Nicolas I.; Varas, Rodrigo; Campusano, Jorge M.
    Drosophila melanogaster has been successfully used as a simple model to study the cellular and molecular mechanisms underlying behaviors, including the generation of motor programs. Thus, it has been shown that, as in vertebrates, CNS biogenic amines (BA) including serotonin (5HT) participate in motor control in Drosophila. Several evidence show that BA systems innervate an important association area in the insect brain previously associated to the planning and/or execution of motor programs, the Mushroom Bodies (MB). The main objective of this work is to evaluate the contribution of 5HT and its receptors expressed in MB to motor behavior in fly larva. Locomotion was evaluated using an automated tracking system, in Drosophila larvae (3rd-instar) exposed to drugs that affect the serotonergic neuronal transmission: alpha-methyl-L-dopa, MDMA and fluoxetine. In addition, animals expressing mutations in the 5HT biosynthetic enzymes or in any of the previously identified receptors for this amine (5HT(1A)R, 5HT(1B)R, 5HT(2)R and 5HT(7)R) were evaluated in their locomotion. Finally, RNAi directed to the Drosophila 5HT receptor transcripts were expressed in MB and the effect of this manipulation on motor behavior was assessed. Data obtained in the mutants and in animals exposed to the serotonergic drugs, suggest that 5HT systems are important regulators of motor programs in fly larvae. Studies carried out in animals pan-neuronally expressing the RNAi for each of the serotonergic receptors, support this idea and further suggest that CNS 5HT pathways play a role in motor control. Moreover, animals expressing an RNAi for 5HT(1B)R, 5HT(2)R and 5HT(7)R in MB show increased motor behavior, while no effect is observed when the RNAi for 5HT(1A)R is expressed in this region. Thus, our data suggest that CNS 5HT systems are involved in motor control, and that 5HT receptors expressed in MB differentially modulate motor programs in fly larvae.