Tea et al 2025 - data summary

This data set was generated to address a knowledge gap concerning the types of serotonin receptors involved in serotonergic activation of the hypothalamic-pituitary-interrenal (HPI) axis in fishes. Activation of the HPI axis leads to production of the glucocorticoid stress hormone, cortisol. Using rainbow trout (Oncorhynchus mykiss) as our study species, we detected 5htr1a, 5htr2 and 5htr4 transcripts in all three tissues of the HPI axis by real-time RT-PCR. Administration of serotonin in vivo to cannulated rainbow trout evoked a cortisol response, although in the absence of an increase in crf transcript abundance or circulating ACTH. Recognizing that the HPI axis tissues are complex, we used an in vitro head kidney preparation to more fully explore the role of serotonin receptors in cortisol production by interrenal cells. Our data suggest that of the three receptor types we investigated, only 5-HT4 receptors stimulate cortisol production.