Nongenomic cortisol signaling in fish

Area of Science:

• Endocrinology
• Animal Physiology
• Cell Signaling

Background:

• Glucocorticoids, like cortisol in teleosts, are vital for stress adaptation by mobilizing energy substrates.
• Cortisol's genomic effects via the glucocorticoid receptor (GR) are well-studied, but rapid, non-genomic actions are less understood.
• Non-genomic effects occur rapidly (seconds to minutes) and are independent of transcription and translation.

Purpose of the Study:

• To investigate the rapid, non-genomic signaling pathways activated by cortisol in teleosts.
• To identify the elusive membrane receptors responsible for initiating these rapid cortisol responses.
• To clarify the physiological implications of these rapid signaling events on acute stress adaptation.

Main Methods:

• Review of existing literature on cortisol signaling in teleosts.
• Analysis of studies investigating rapid cellular responses to cortisol.
• Examination of evidence for GR and other potential membrane receptors in non-genomic signaling.

Main Results:

• Cortisol triggers rapid cellular effects independent of gene expression.
• The precise membrane receptors mediating these non-genomic effects are not definitively identified.
• Potential mechanisms include membrane-bound GR, novel receptors, or altered membrane biophysics.

Conclusions:

• Teleost cells exhibit rapid, non-genomic responses to cortisol.
• Multiple signaling pathways are likely involved, but the initiating receptors require further investigation.
• Understanding these rapid pathways is crucial for a complete picture of acute stress adaptation in fish.