Implants of estradiol conjugated to bovine serum albumin in the male rat medial preoptic area promote copulatory behavior.
The expression of mating behavior in male rats is dependent on estrogen-responsive neurons in the medial preoptic area (MPO). Previous reports showed that mating is attenuated if the aromatization of testosterone to estradiol (E2) is blocked in the MPO and that mating is maintained by MPO E2 implants. However, the mechanisms by which E2 exerts its action are not fully understood. It had been thought that E2 acted exclusively by binding to nuclear estrogen receptors to exert it effects; however, recent reports suggest that E2 also binds to membrane-associated receptors activating downstream intracellular cascade responses. In this study, we aimed to determine if an action of E2 at the cell surface is sufficient to support mating behavior. Therefore, either vehicle, E2, or E2 conjugated to bovine serum albumin (BSA-E2: a complex of E2 and a large protein that will not cross the plasma membrane, thereby restricting the action of E2 to cell surface signaling) was chronically administered bilaterally to the MPO of castrated, dihydrotestosterone-treated male rats. Mating behavior was supported by MPO BSA-E2 implants, suggesting that E2 operates in the MPO via a cell surface mechanism to facilitate male rat mating behavior.
Huddleston
Gloria G
GG
Department of Biology, Georgia State University, Atlanta, GA 30302-4010, USA.
Paisley
Jacquelyn C
JC
Graham
Sean
S
Grober
Matthew S
MS
Clancy
Andrew N
AN
D000818:Animals; D002417:Cattle; D003307:Copulation / Q000187:drug effects / Q000502:physiology*; D004343:Drug Implants; D004958:Estradiol / Q000008:administration & dosage*; D004966:Estrogens, Conjugated (USP) / Q000008:administration & dosage*; D005260:Female; D008297:Male; D011301:Preoptic Area / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012710:Serum Albumin, Bovine / Q000008:administration & dosage* / Q000502:physiology
D004343:Drug Implants; D004966:Estrogens, Conjugated (USP); D012710:Serum Albumin, Bovine; D004958:Estradiol