An immunohistochemical study on the distribution of vasotocin neurons in the brain of two weakly electric fish, Gymnotus omarorum and Brachyhypopomus gauderio

Pouso, Paula; Radmilovich, Milka; Silva, Ana C.

doi:10.1016/j.tice.2017.02.003

Cited by 21 publications

(34 citation statements)

References 68 publications

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“…After behavioural experiments animals were sacrificed by overdose of 2-phenoxy-ethanol (3.75 µg/mL; Sigma P-1126). Immediately after, brains were dissected on ice and transverse cryo-sections (50 µm) were obtained in rostro-caudal direction until POA was identified following the anatomical landmarks and coordinates established for this species 86 and for other gymnotiform species 87 . Four 250 µm sections were isolated (11.9 ± 0.9 mg).…”

Section: Animalsmentioning

confidence: 99%

Brain transcriptomics of agonistic behaviour in the weakly electric fish Gymnotus omarorum, a wild teleost model of non-breeding aggression

Eastman

Valiño

Radío

et al. 2020

Sci Rep

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Differences in social status are often mediated by agonistic encounters between competitors. Robust literature has examined social status-dependent brain gene expression profiles across vertebrates, yet social status and reproductive state are often confounded. it has therefore been challenging to identify the neuromolecular mechanisms underlying social status independent of reproductive state. Weakly electric fish, Gymnotus omarorum, display territorial aggression and social dominance independent of reproductive state. We use wild-derived G. omarorum males to conduct a transcriptomic analysis of non-breeding social dominance relationships. After allowing paired rivals to establish a dominance hierarchy, we profiled the transcriptomes of brain sections containing the preoptic area (region involved in regulating aggressive behaviour) in dominant and subordinate individuals. We identified 16 differentially expressed genes (FDR < 0.05) and numerous genes that co-varied with behavioural traits. We also compared our results with previous reports of differential gene expression in other teleost species. overall, our study establishes G. omarorum as a powerful model system for understanding the neuromolecular bases of social status independent of reproductive state.

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Section: Animalsmentioning

confidence: 99%

Brain transcriptomics of agonistic behaviour in the weakly electric fish Gymnotus omarorum, a wild teleost model of non-breeding aggression

Eastman

Valiño

Radío

et al. 2020

Sci Rep

Self Cite

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“…These neuropeptide systems have also been associated with social status; for example, dominance is related with a distinctive distribution of AVP receptors within the social brain (Cooper et al, 2005 ; Filby et al, 2010 ; Lema et al, 2015 ). Furthermore, a differential pattern of activation of AVT/AVP neurons between dominants and subordinates has been reported in different vertebrates (Ferris et al, 1989 ; Larson et al, 2006 ; Greenwood et al, 2008 ; Hattori and Wilczynski, 2009 ; Godwin and Thompson, 2012 ; Qiao et al, 2014 ; Lema et al, 2015 ; Teles et al, 2016 ; Terranova et al, 2016 ; Pouso et al, 2017 ). Pharmacological manipulations have also contributed indirect evidence for status-dependent actions of these neuropeptides (Goodson and Bass, 2000 ; Backström and Winberg, 2009 ), although there are few studies that explore these actions by comparing the same treatments on both dominants and subordinates (Semsar et al, 2001 ; Goodson et al, 2009 ; Huffman et al, 2015 ).…”

Section: Introductionmentioning

confidence: 98%

Status-Dependent Vasotocin Modulation of Dominance and Subordination in the Weakly Electric Fish Gymnotus omarorum

Perrone

Silva

2018

Front. Behav. Neurosci.

106

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Dominant-subordinate status emerges from agonistic encounters. The weakly electric fish, Gymnotus omarorum, displays a clear-cut example of non-breeding territorial aggression. The asymmetry in the behavior of dominants and subordinates is outstanding. Dominants are highly aggressive and subordinates signal submission in a precise sequence of locomotor and electric traits: retreating, decreasing their electric organ discharge rate, and emitting transient electric signals. The hypothalamic neuropeptide arginine-vasotocin (AVT) and its mammalian homolog arginine-vasopressin, are key modulators of social behavior, known to adapt their actions to different contexts. By analyzing the effects of pharmacological manipulations of the AVT system in both dominants and subordinates, we show evidence of distinct status-dependent actions of AVT. We demonstrate an endogenous effect of AVT on dominants' aggression levels: blocking the V1a AVT receptor induced a significant decrease in dominants' attack rate. AVT administered to subordinates enhanced the expression of the electric signals of submission, without affecting subordinates' locomotor displays. This study contributes a clear example of status-dependent AVT modulation of agonistic behavior in teleosts, and reveals distinctive activation patterns of the AVT system between dominants and subordinates.

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“…This node of the social brain has a well-documented role in aggressive behavior (1,(94)(95)(96)(97). Moreover, it has already been shown that preoptic area neuropeptides have a status-dependent role in the modulation of non-breeding aggression in G. omarorum (70,98). The analysis of local brain synthesis of estrogens and androgens in this region regulating non-breeding aggression is currently underway.…”

Section: Non-gonadal Estrogens Modulate Non-breeding Agonistic Behaviormentioning

confidence: 99%

A Teleost Fish Model to Understand Hormonal Mechanisms of Non-breeding Territorial Behavior

2020

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Aggressive behaviors occurring dissociated from the breeding season encourage the search of non-gonadal underlying regulatory mechanisms. Brain estrogen has been shown to be a key modulator of this behavior in bird and mammal species, and it remains to be understood if this is a common mechanism across vertebrates. This review focuses on the contributions of Gymnotus omarorum, the first teleost species in which estrogenic modulation of non-breeding aggression has been demonstrated. Gymnotus omarorum displays year-long aggression, which has been well characterized in the non-breeding season. In the natural habitat, territory size is independent of sex and determined by body size. During the breeding season, on the other hand, territory size no longer correlates to body size, but rather to circulating estrogens and gonadosomatic index in females, and 11-ketotestosterone in males. The hormonal mechanisms underlying non-breeding aggression have been explored in dyadic encounters in lab settings. Males and females display robust aggressive contests, whose outcome depends only on body size asymmetry. This agonistic behavior is independent of gonadal hormones and fast acting androgens. Nevertheless, it is dependent on fast acting estrogenic action, as acute aromatase blockers affect aggression engagement, intensity, and outcome. Transcriptomic profiling in the preoptic area region shows non-breeding individuals express aromatase and other steroidogenic enzyme transcripts. This teleost model reveals there is a role of brain estrogen in the control of non-breeding aggression which seems to be common among distant vertebrate species.

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An immunohistochemical study on the distribution of vasotocin neurons in the brain of two weakly electric fish, Gymnotus omarorum and Brachyhypopomus gauderio

Cited by 21 publications

References 68 publications

Brain transcriptomics of agonistic behaviour in the weakly electric fish Gymnotus omarorum, a wild teleost model of non-breeding aggression

Brain transcriptomics of agonistic behaviour in the weakly electric fish Gymnotus omarorum, a wild teleost model of non-breeding aggression

Status-Dependent Vasotocin Modulation of Dominance and Subordination in the Weakly Electric Fish Gymnotus omarorum

A Teleost Fish Model to Understand Hormonal Mechanisms of Non-breeding Territorial Behavior

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