The hedonic impact of cleaner-client fish interactions is mediated by the opioid system.

According to the 'incentive salience hypothesis' reward processing involves two main components, including the motivation to obtain a reward (i.e. incentive salience or 'wanting') and the hedonic pleasure felt during its consumption (i.

Social status in zebrafish modulates the behavioral response to 5-HT2C receptor agonists and antagonists.

The effects of previous social experiences on social behavior have been demonstrated across species both in cooperative and competitive contexts. In dominance-subordinate hierarchies, differences across social ranks have been observed in many different mechanisms. Dominance hierarchies interfere in defensive behavior, where subordinate animals present a greater defensive behavior, regarding potential threats ("anxiety-like behavior"), than dominant animals.

Roles of the 5-HT1A receptor in zebrafish responses to potential threat and in sociality.

Background: Anxiety is a normal emotion representing a reaction to potential danger, whereas fear can be defined as a reaction to real, explicit danger. Anxiety-like behavior in animal models has been associated with differences in the serotonergic system.

Aims: To understand the roles of the 5-HT1A receptor in zebrafish anxiety-like behavior and sociality.

Alternative protocol for the histological preparation of animal tissues.

This study presents an alternative protocol that employs low-cost options to produce high-quality histology slides. The method is easily reproducible using recyclable materials, such as discarded blister packages, and simple adaptations, such as substituting a digital microscopy camera for a smartphone camera. Additionally, we provide a reliable method for setting image scale bars using office software and the open-access software ImageJ/Fiji.

Cryopreserved sperm does not affect larval ontogeny and quality in Rhamdia quelen.

Fish sperm cryopreservation is an important technique for optimizing juvenile production in aquaculture stations and laboratories and contributing to the conservation of endangered species. Despite its benefits, the cryopreservation process can cause cellular damage, affecting spermatozoa quality and offspring viability. This study aimed to evaluate the larval development of jundiá Rhamdia quelen originating from cryopreserved sperm.

Anxiolytic-Like Effect of Chrysin on Female Zebrafish is Likely Mediated by α Subunits of γ-Aminobutyric Acid A Receptors.

Chrysin (5,7-dihydroxyflavone) is a natural flavonoid with potential anxiolytic-like effects in preclinical models. Acute treatment with this molecule (0-10 mg/kg) produced a biphasic dose-response in the zebrafish light/dark test (LDT), with anxiolytic-like effects at low doses and anxiogenic-like effects at high doses. Chrysin (1 mg/kg) decreased anxiety-like behavior in the zebrafish novel tank test but did not prevent the anxiogenic effects of acute stress.

Biocultural Aspects of Mental Distress: Expanding the Biomedical Model Towards an Integrative Biopsychosocial Understanding of Disorder.

To produce a theoretical approach about the relations between neuroscience and psychopathology that expands beyond the biomedical model to include a non-reductionist, enactive, and biocultural perspective. An integrative review, drawing from the biocultural approach from Anthropology, is used to produce examples from epigenetics, neuroplasticity, and functional neuroanatomy. A biocultural approach points to a brain that is highly plastic, reinforcing a much more complex model in which biological vulnerabilities and the historical-cultural environment co-construct each other.

Repeated exposure to ethanol alters memory acquisition and neurotransmission parameters in zebrafish brain.

Alcohol is widely consumed worldwide and its abuse can cause cognitive dysfunction, affecting memory and learning due to several neurophysiological changes. An imbalance in several neurotransmitters, including the cholinergic and glutamatergic systems, have been implicated in these effects. Zebrafish are sensitive to alcohol, respond to reward stimuli, and tolerate and exhibit withdrawal behaviors.

Activation of NOS-cGMP pathways promotes stress-induced sensitization of behavioral responses in zebrafish.

Nitric oxide (NO) is a molecule involved in plasticity across levels and systems. The role of NOergic pathways in stress-induced sensitization (SIS) of behavioral responses, in which a particular stressor triggers a state of hyper-responsiveness to other stressors after an incubation period, was assessed in adult zebrafish. In this model, adult zebrafish acutely exposed to a fear-inducing conspecific alarm substance (CAS) and left undisturbed for an incubation period show increased anxiety-like behavior 24 h after exposure.

Fish personality: meta-theoretical issues, personality dimensions, and applications to neuroscience and psychopathology.

While the field of personality neuroscience has extensively focused on humans and, in a few cases, primates and rodents, a wide range of research on fish personality has emerged in the last decades. This research is focused mainly on the ecological and evolutionary causes of individual differences and also aimed less extensively at proximal mechanisms (e.g.

Social investigation and social novelty in zebrafish: Roles of salience and novelty.

Social preference tests can be used to analyze variables that influence and modify social behaviors, and to investigate effects of substances such as medications, drugs, and hormones. They may become important tools for finding a valid model to study neuropsychiatric changes and to study human neurodevelopmental processes that have been impaired by social events. While a preference for conspecifics has been shown for different species, social novelty has been used as a model for anxiety-like behavior in rodents.

Oogenesis and in vitro reproduction of the twospot astyanax Astyanax bimaculatus (Linnaeus, 1758) exposed to conspecific alarm substance.

Stress situations can be essential to trigger reproduction in fish; however, it may also inhibit it. One of those situations involves the release of the conspecific alarm substance (CAS), a natural stressor, into the water by specific fish epidermal cells after a predator attack. Little is known about the effects of that substance on fish reproduction.

Biocultural psychopathology as a new epistemology for mental disorders.

Psychopathology has been criticized for decades for its reliance on a brain-centred and over-reductionist approach which views mental disorders as disease-like natural kinds. While criticisms of brain-centred psychopathologies abound, these criticisms sometimes ignore important advances in the neurosciences which view the brain as embodied, embedded, extended and enactive, and as fundamentally plastic. A new onto-epistemology for mental disorders is proposed, focusing on a biocultural model, in which human brains are understood as embodied and embedded in ecosocial niches, and with which individuals enact particular transactions characterized by circular causality.

Roles of the 5-HT2C receptor on zebrafish sociality.

Serotonin (5-HT) receptors have been implicated in social behavior in vertebrates. Zebrafish (Danio rerio) have been increasingly being used behavioral neuroscience to study the neurobiological correlates of behavior, including sociality. Nonetheless, the role of 5-HT receptors in different social functions were not yet studied in this species.

Social Stress Increases Anxiety-Like Behavior Equally in Male and Female Zebrafish.

Zebrafish anxiety-like behavior was assessed in the novel tank test after the formation of dominant-subordinate hierarchies. Ten pairs of animals were subjected to dyadic interactions for 5 days, and compared with control animals. After this period, a clear dominance hierarchy was established across all dyads, irrespective of sex.

5-HT2C agonists and antagonists block different components of behavioral responses to potential, distal, and proximal threat in zebrafish.

Serotonin (5-HT) receptors have been implicated in responses to aversive stimuli in mammals and fish, but its precise role is still unknown. Moreover, since at least seven families of 5-HT receptors exist in vertebrates, the role of specific receptors is still debated. Aversive stimuli can be classified as indicators of proximal, distal, or potential threat, initiating responses that are appropriate for each of these threat levels.

Open Practical Laboratories in the Neurosciences: An outreach program for neuroscience communication in middle schools.

The Open Practical Laboratory in the Neurosciences is an outreach program that seeks to improve the knowledge of the neurosciences by elementary school students and to promote better attitudes in relation to neuroscience, science in general, and scientists. It consists in practical and demonstration activities on the theme of the neurosciences. This outreach strategy was applied in four public schools in a municipality in Southeastern Pará, Brazil characterized by low performance in educational reviews in Brazil.

Embryonic development of the fire-eye-tetra (Characiformes: Characidae).

This study describes the embryonic development of Moenkhausia oligolepis in laboratory conditions. After fertilization, the embryos were collected every 10 min up to 2 h, then every 20 min up to 4 h, and afterwards every 30 min until hatching. The fertilized eggs of M.

Chrysin, but not flavone backbone, decreases anxiety-like behavior in animal screens.

Chrysin (5,7-dihydroxyflavone), a nutraceutical flavonoid present in diverse plants, has a backbone structure shared with the flavone backbone, with additional hydroxyl groups that confers its antioxidant properties and effects at the GABA receptor complex. However, whether these effects are due to the hydroxyl groups is unknown. Here we report the effects of chrysin or the flavone backbone (1 mg/kg) in rats subjected to the elevated plus-maze and the locomotor activity test, as well as in the zebrafish evaluated in light/dark model.

Seminal characterization of the Amazonian fire-eye tetra (Günther, 1864).

The seminal characteristics of Moenkhausia oligolepis are described. Three males were induced with a single dose of carp pituitary. Semen was collected 6 h after induction, and diluted in dibasic sodium phosphate extender solution.

Dopamine and serotonin mediate the impact of stress on cleaner fish cooperative behavior.

Stress is known to modulate behavioral responses and rapid decision-making processes, especially under challenging contexts which often occur in social and cooperative interactions. Here, we evaluated the effects of acute stress on cooperative behavior of the Indo-Pacific cleaner wrasse (Labroides dimidiatus) and the implications of pre-treatment with monoaminergic compounds: the selective serotonin reuptake inhibitor - fluoxetine, the 5-HT receptor antagonist - WAY-100,635, the D receptor agonist - SKF-38393, and the D receptor antagonist - SCH-23390. We demonstrated that stress decreased the predisposal to interact and increased cortisol levels in cleaners, which are alleviated by fluoxetine and the dopaminergic D antagonist.

A model to study orienting responses in zebrafish, and applications towards the emotion-cognition interaction.

Orienting responses (ORs) are whole-organism reflexes that are elicited by innocuous stimuli, and which decrease in magnitude after stimulus repetition. ORs represent relatively simple responses that can be used to study attentional processes, and are modulated by the organism's state, including arousal and activation levels, as well as by emotional processes. Here we describe a simple method to study ORs in zebrafish, a model organism increasingly being used in behavioural neuroscience.

NOS-2 participates in the behavioral effects of ethanol withdrawal in zebrafish.

Nitric oxide has been implicated in symptoms of ethanol withdrawal in animal models. Zebrafish have been used as models to study neurobehavioral effects of ethanol (EtOH) withdrawal, but the mechanisms associated with these effects are not yet clear. Adult zebrafish were treated with 1% EtOH for 20 min per day for 8 days, injected with the nitric oxide synthase 2 (NOS-2) inhibitor aminoguanidine (50 mg/kg), and allowed to experience withdrawal (WD) in their hometanks for 7 days.