Biology subjects

Quintana, L. A.

Publications and source records attributed to Quintana, L. A..

3 recordsLinked to original sources

bioRxiv2025

One More Lap: Environmental Modulation of Small-Scale Exploration in Weakly Electric Fish

Animals actively explore their surroundings to efficiently obtain resources, relying on the sensory modalities available to them. In South American weakly electric fish, self-generated electric organ discharges (EODs) create a short-range "sensory bubble" that, together with locomotion, supports exploration. This behavior relies on the coordinated modulation of spatial movement and electromotor activity, reflected in changes in EOD rate (EODr). However, how these components are engaged in natural contexts, and which conditions are sufficient to elicit exploration, remain poorly understood. Here, we examined how environmental and contextual factors modulate exploratory behavior in Gymnotus omarorum by combining a minimalistic laboratory assay with multi-day recordings in a seminatural arena. In laboratory tanks, freely moving fish showed minimal locomotor activity, which increased only when darkness and a novel electrosensory stimulus co-occurred, indicating strong context dependence and gating by chronobiological and motivational factors. By contrast, under seminatural conditions preserving natural light and temperature cycles, fish exhibited robust nocturnal rhythms in both locomotor activity and EODr. Chronobiological analysis revealed that the electrosensory rhythm consistently preceded the locomotor rhythm, with individual phase differences correlated across behaviors. These results show that exploration is a temporally organized behavior arising from coordinated modulation of sensory and motor systems. By linking electrosensory activity, locomotion, and circadian timing under ecologically relevant conditions, this study provides insight into how animals regulate sensory sampling and movement during exploration. Summary statementExploration in Gymnotus omarorum is a temporally organized behavior arising from coordinated circadian modulation of electrosensory activity and locomotion.

animal behavior and cognition↗

bioRxiv2025

Seasonal plasticity in neuroendocrine mechanisms relevant to year-round territorial aggression in a wild teleost fish

Animals experience cyclical environmental changes, such as seasons, that require physiological adjustments to support different behaviors. Although many behaviors occur only during specific periods, some species, like Gymnotus omarorum, display territorial aggression year-round, making them valuable models to study seasonal plasticity in the mechanisms maintaining stable behavioral outputs. G. omarorum is a teleost fish in which neuroestrogens have been shown to play a key role in non-breeding aggression. Here, we quantified circulating hormone levels and gene expression in the social behavior network of wild breeding and non-breeding individuals. During the non-breeding season, both sexes exhibited elevated circulating androgen levels, providing potential substrates for local estrogen synthesis. Consistently, brain aromatase and estrogen receptor expression were also upregulated, suggesting an increased capacity for local estrogen synthesis and signaling. Our findings provide the first evidence in a teleost of seasonal plasticity in the mechanisms underlying territorial aggression. Comparisons with birds and mammals reveal both shared and lineage-specific strategies, highlighting common endocrine principles while revealing the evolutionary diversity of solutions to maintain a stable behavioral phenotype across changing seasonal contexts.

neuroscience↗

bioRxiv2020

The estrogenic pathway modulates non-breeding female aggression in a teleost fish

Aggressive behaviors are widespread among animals and are critical in the competition for resources. The physiological mechanisms underlying aggression have mostly been examined in breeding males, in which gonadal androgens, acting in part through their aromatization to estrogens, have a key role. There are two alternative models that contribute to further understanding hormonal mechanisms underlying aggression: aggression displayed in the non-breeding season, when gonadal steroids are low, and female aggression. In this study we approach, for the first time, the modulatory role of estrogens and androgens upon non-breeding aggression in a wild female teleost fish. We characterized female aggression in the weakly electric fish Gymnotus omarorum and carried out acute treatments 1 h prior to agonistic encounters with either an aromatase inhibitor or an antagonist of androgen receptors. Aromatase inhibition caused a strong distortion of aggressive behavior whereas anti-androgen treatment had no effect on behavior. Territorial non-breeding aggression in female G. omarorum is robust and depended on rapid estrogen actions to maintain high levels of aggression, and ultimately reach conflict resolution from which dominant/subordinate status emerged. Our results taken together with our own reports in males and the contributions from non-breeding aggression in bird and mammal models, suggest a conserved strategy involving fast-acting estrogens in the control of this behavior across species. In addition, further analysis of female non-breeding aggression may shed light on potential sexual differences in the fine tuning of social behaviors. HighlightsO_LIFemale Gymnotus omarorum displayed robust territorial aggression in lab settings. C_LIO_LIAcute treatment with aromatase inhibitor lowered aggression levels. C_LIO_LIAromatase inhibition increased first attack latency and decreased conflict resolution. C_LIO_LIAcute treatment with anti-androgens showed no effects. C_LIO_LIThis is the first report of estrogens underlying teleost non-breeding female aggression. C_LI

animal behavior and cognition↗