Role of Previous Parasite Exposure in Routine Metabolic Rate and Brain Serotonin Dynamics Following Acute Infection
Society for Experimental Biology Annual Conference / Seville, Spain
Hosts incur energetic and often fitness-related costs from harboring parasites. Parasite infection typically stimulates an immune response in the host, the energetic cost of which creates a potential tradeoff between immediate survival and body condition, foraging, reproduction and other important processes. However, this response varies greatly among and within hosts, depending on the pathogenicity of the parasite, the condition of the host, and ambient environmental conditions. While studies often focus on the longterm costs of host infection, we know little about how host energetics are altered during and immediately following parasite exposure, and the relative importance of acute and long-term infection costs to the host’s energy budget. Here, we examined the effects of a braininfecting microsporidian parasite (Pseudoloma neurophilia) on its fish host (the zebrafish, Danio rerio). We measured how the acute infection process alters metabolic rate in naive versus previously infected hosts, and whether these effects are accompanied by changes in brain neurochemistry (particularly serotonergic activity). We found that routine metabolic rate increased with long term infection, but did not change with acute infection. However, serotonergic activity exhibited varying responses to infection depending on previous parasite exposure. Following acute infection, previously naïve fish reduced brainstem serotonin concentrations while hosts with a long-term infection show increased serotonin levels, suggesting that the acute perturbation of a host´s first parasite encounter can obstruct serotonin function. This work provides us with a better understanding on how hosts modulate their energetic response to infection depending on their previous infection history.
Nadler, Lauren E.; Le Midttun, Helene; Killen, Shaun S.; Vindas, Marco A.; Øverli, Øyvind; and Johansen, Ida B., "Role of Previous Parasite Exposure in Routine Metabolic Rate and Brain Serotonin Dynamics Following Acute Infection" (2019). Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures. 744.