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Biol Reprod

Title:		Vomeronasal organ removal blocks pheromonal induction of estrus in gray short-tailed opossums (Monodelphis domestica)
Author(s):		Jackson LM; Harder JD;
Address:		"Department of Zoology, Ohio State University, Columbus 43210, USA"
Journal Title:		Biol Reprod
Year:		1996
Volume:		54
Issue:		2
Page Number:		506 - 512
DOI:		10.1095/biolreprod54.2.506
ISSN/ISBN:		0006-3363 (Print) 0006-3363 (Linking)
Abstract:		"Estrus is induced in female gray short-tailed opossums (Monodelphis domestica) by exposure to male chemical signals (pheromones). Isolated females remain anestrous, but direct exposure to a male or his scent-marked cage induces estrus within 4-6 days. The objective of this study was to investigate the importance of the vomeronasal organ in detection of and response to estrus-inducing pheromones. The vomeronasal organ was surgically removed through the palate from 8 females (VNX); 5 females (SHAM) underwent sham surgeries in which the vomeronasal organ was exposed but not removed. After a 10-day recovery period, females were placed into male scent-marked cages. Body weight and urogenital sinus cytology were monitored throughout the experiment. All females were anesthetized and perfused with 4% paraformaldehyde 12-13 days after initial pheromone exposure. Vomeronasal organ ablation was evaluated histologically in decalcified snouts. In addition, deafferentation of the accessory olfactory bulb was confirmed by use of a lectin stain specific for the vomeronasal nerve and the glomerular layer of the bulb. All females classified as completely VNX (n = 5) remained anestrous throughout the pheromonal exposure. Incompletely VNX females (n = 2) and all SHAM animals exhibited estrus within 7 days of pheromone stimulation. At perfusion, the mean uterine weight (280.71 +/- 95.6 mg/85 g BW) of SHAM females was greater (p < 0.05) than that of unresponsive, VNX females (133.33 +/- 31.14 mg/85 g). This study demonstrates that the vomeronasal organ is an essential component for transduction of male pheromones required for induction of estrus in a marsupial species"
Keywords:		Animals;Animals Denervation *Estrus Female Male *Nasal Septum Olfactory Bulb/anatomy & histology/physiology/surgery Olfactory Pathways/*physiology/surgery Opossums/*physiology Organ Size Pheromones/*pharmacology Uterus/anatomy & histology;
Notes:		"MedlineJackson, L M Harder, J D eng Research Support, Non-U.S. Gov't 1996/02/01 Biol Reprod. 1996 Feb; 54(2):506-12. doi: 10.1095/biolreprod54.2.506"