Coordination of hamster lordosis and flank marking behavior: role of arginine vasopressin within the medial preoptic-anterior hypothalamus.
The role of arginine vasopressin (AVP) within the medial preoptic area-anterior hypothalamus (MPOA-AH) in the neural coordination of lordosis and flank marking was investigated. AVP, but not saline, microinjected into the MPOA-AH of ovariectomized hamsters not given hormone replacement therapy stimulated high levels of flank marking when tested with a sexually experienced male, or when tested alone. In contrast, AVP microinjected into the MPOA-AH of ovariectomized hamsters given estradiol benzoate (EB) and progesterone did not stimulate flank marking or inhibit lordosis during tests with a sexually experienced male. However these same females exhibited high levels of flank marking in response to AVP when tested alone. A second experiment demonstrated that progesterone was not required for inhibition of AVP-induced flank marking in ovariectomized females given EB replacement and tested with sexually experienced males. The present study provides no evidence that AVP acts within the MPOA-AH to inhibit hamster lordosis, but demonstrates that ovarian hormones and male social contact block the induction of flank marking by AVP microinjected into the MPOA-AH. These data suggest that one component in the neural coordination of lordosis and flank marking is inhibition of the response of the MPOA-AH to AVP.
Albers
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HE
Department of Biology, Georgia State University, Atlanta 30303.
Rawls
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D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology*; D006224:Cricetinae; D004958:Estradiol / Q000494:pharmacology* / Q000502:physiology; D005260:Female; D007031:Hypothalamus / Q000187:drug effects / Q000502:physiology*; D007032:Hypothalamus, Anterior / Q000187:drug effects / Q000502:physiology; D010052:Ovariectomy; D011187:Posture; D011301:Preoptic Area / Q000187:drug effects / Q000502:physiology; D011374:Progesterone / Q000494:pharmacology* / Q000502:physiology; D012726:Sexual Behavior, Animal / Q000187:drug effects / Q000502:physiology*
D001127:Arginine Vasopressin; D011374:Progesterone; D004958:Estradiol