Firing properties of accessory olfactory bulb mitral/tufted cells in response to urine delivered to the vomeronasal organ of gray short-tailed opossums.
In comparison with many mammals, there is limited knowledge of the role of pheromones in conspecific communication in the gray short-tailed opossum. Here we report that mitral/tufted (M/T) cells of the accessory olfactory bulb (AOB) of male opossums responded to female urine but not to male urine with two distinct patterns: excitation followed by inhibition or inhibition. Either pattern could be mimicked by application of guanosine 5'-O-3-thiotriphosphate and blocked by guanosine 5'-O-2-thiodiphosphate, indicating that the response of neurons in this pathway is through a G-protein-coupled receptor mechanism. In addition, the inhibitor of phospholipase C (PLC), U73122, significantly blocked urine-induced responses. Male and female urine were ineffective as stimuli for M/T cells in the AOB of female opossums. These results indicate that urine of diestrous females contains a pheromone that directly stimulates vomeronasal neurons through activation of PLC by G-protein-coupled receptor mechanisms and that the response to urine is sexually dimorphic.
Zhang
Jing-Ji
JJ
Department of Anatomy and Cell Biology, 450 Clarkson Avenue, Brooklyn, NY 11203, USA. jingji.zhang@downstate.edu
Huang
Guang-Zhe
GZ
Halpern
Mimi
M
D000818:Animals; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004963:Estrenes / Q000494:pharmacology; D005260:Female; D008297:Male; D008839:Microelectrodes; D009830:Olfactory Bulb / Q000502:physiology*; D009893:Opossums / Q000502:physiology*; D011760:Pyrrolidinones / Q000494:pharmacology; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors; D014556:Urine; D019147:Vomeronasal Organ / Q000502:physiology*
D004791:Enzyme Inhibitors; D004963:Estrenes; D011760:Pyrrolidinones; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D010738:Type C Phospholipases