The selective serotonin reuptake inhibitor fluoxetine increases spontaneous afferent firing, but not mechanonociceptive sensitization, in octopus
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Serotonin is a widely studied modulator of neural plasticity. Here we investigate the effect of fluoxetine, a selective serotonin reuptake inhibitor, on short-term, peripheral nociceptive plasticity in the neurologically complex invertebrate, octopus. After crush injury to isolated mantle (body wall) tissue, application of 10 nM fluoxetine increased spontaneous firing in crushed preparations, but had a minimal effect on mechanosensory sensitization. Effects largely did not persist after washout. We suggest that transiently elevated, endogenous serotonin may help promote initiation of longer-term plasticity of nociceptive afferents and drive immediate and spontaneous behaviors aimed at protecting wounds and escaping dangerous situations.
KeywordsSSRI Fluoxetine Octopus Nociceptive sensitization Injury
Central nervous system
Fluoxetine (in solution, 10 nM in ASW)
Peripheral nervous system
Selective serotonin reuptake inhibitor
We thank members of the Crook Lab for assisting with animal care, and Peyman Bastani and Robert Dasmarinus for conducting additional data analysis. Funding was provided from a DRC Grant from SF State, and from start-up funds to RJC, and an NIH MBRS-RISE (R25-GM059298) to PVP.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no competing interests.
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