Stress increases susceptibility to pentylenetetrazole-induced seizures in adult zebrafish.

Stress is the body's reaction to any change that requires adaptive responses. In various organisms, stress is a seizure-related comorbidity. Despite the exposure to stressors eliciting aversive behaviors in zebrafish, there are no data showing whether stress potentiates epileptic seizures in this species. Here, we investigated whether a previous exposure to an intense acute stressor positively modulates the susceptibility to seizures in pentylenetetrazole (PTZ)-challenged zebrafish. The conspecific alarm substance (CAS) was used to elicit aversive responses (3.5 mL/L for 5 min), observed by increased bottom dwelling and erratic movements. Then, fish were immediately exposed to 7.5 mM PTZ for 10 min to induce seizure-like behaviors. Stress increased the seizure intensity, the number of clonic-like seizure behaviors (score 4), as well as facilitated the occurrence of score 4 episodes by decreasing the latency in which fish reached the score 4. Moreover, fish with heightened anxiety showed increased susceptibility to PTZ, since positive correlations between anxiety- and seizure-like behaviors were found. Overall, since CAS also increased whole-body cortisol levels in zebrafish, our novel findings show a prominent response to PTZ-induced seizures in previously stressed zebrafish. Moreover, we reinforce the growing utility of zebrafish models to assess seizure-related comorbidities aiming to elucidate how stress can affect epileptic seizures in vertebrates. Copyright © 2020 Elsevier Inc. All rights reserved.

Citation

Julia Canzian, Francini Franscescon, Talise E Müller, Flavia V Stefanello, Thiele P Souza, Luiz V Rosa, Denis B Rosemberg. Stress increases susceptibility to pentylenetetrazole-induced seizures in adult zebrafish. Epilepsy & behavior : E&B. 2021 Jan;114(Pt A):107557

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PMID: 33243678

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