Toadfish
People
Lead PI
Assistant Professor
“Currently looking for an enthusiastic and hardworking Ph.D. student”
Undergraduate Students
2011–present
2012
2011–present
2012
2012
2012
Former Graduate Students
Former Lab Members: Research Assistants
Fall 2006–August 2007
Summer 2008
August 2008–Spring 2009
Summer 2009
Former Lab Members: Undergraduate Students
2006–2007
2009–2010
2009–2010
2009–2010
2010–2011
2011–2012
Lea Medeiros
Research Statement
My current research investigates how the stress response, and in particular cortisol, plays a role in mediating changes in transcription, binding and functional responsiveness of the serotonin subtype 1A (5-HT1A) receptor in the Gulf toadfish, Opsanus beta. The 5-HT1A receptor plays an important role in maintaining the homeostatic balance between serotonin and cortisol by stimulating the release of cortisol from the interrenal cells when bound by serotonin. In mammals, there is a classical negative feedback loop whereby high levels of cortisol downregulate expression of the 5-HT1A receptor to decrease the release of cortisol in response to chronically elevated plasma cortisol. I am interested in seeing if this system exists in the Gulf toadfish, and also how the changes effected by cortisol are mediated. My long term goal is to relate changes in circulating levels of cortisol, serotonin and the 5-HT1A receptor to changes in reproductive activity. Additionally, because antidepressants are known to affect the 5-HT1A receptor, I am interested in how antidepressants may be upsetting the natural balance between the three (cortisol, serotonin and the 5-HT1A receptor) in a way that affects reproduction. As the Gulf toadfish exhibit very predictable and obvious reproductive behaviors I hope they will prove to be an excellent animal to study this complicated system
Alex Frere
Research Statement
Toadfish tolerate stress well. As we methodically stress our fish in the lab, their biochemistry begins to alter. Their cortisol levels elevate and they change their nitrogenous waste from strictly ammonia to a combination of mostly urea with ammonia as well. This predator avoidance technique utilizes both the glucocorticoid pathway and the serotonin receptor, 5-HT-2A. My work in our lab revolves around determining exactly what role the 5-HT-2A receptor plays in this complex loop, and how stress affects its ability to perform this role. Currently, I am characterizing the pharmacology of the 5-HT-2A receptor so that later we can establish which stressors alter its baseline mRNA expression, binding kinetics and function and how. Varying the amount of stress and the type of stressor should also provide interesting results. Toadfish elevate their stress in response to a variety of stimuli including sound and alpha-beta dominance-like interactions. Using these as novel stressors will hopefully provide us with more information on how 5-HT-2A functions, as little is known about its action other than that it is heavily involved in many serious human conditions such as anxiety, depression, anorexia, and a form of violent suicide.
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