Male pheromone protein components activate female vomeronasal neurons in the salamander Plethodon shermani.
BACKGROUND
The mental gland pheromone of male Plethodon salamanders contains two main protein components: a 22 kDa protein named Plethodon Receptivity Factor (PRF) and a 7 kDa protein named Plethodon Modulating Factor (PMF), respectively. Each protein component individually has opposing effects on female courtship behavior, with PRF shortening and PMF lengthening courtship. In this study, we test the hypothesis that PRF or PMF individually activate vomeronasal neurons. The agmatine-uptake technique was used to visualize chemosensory neurons that were activated by each protein component individually.


RESULTS
Vomeronasal neurons exposed to agmatine in saline did not demonstrate significant labeling. However, a population of vomeronasal neurons was labeled following exposure to either PRF or PMF. When expressed as a percent of control level labeled cells, PRF labeled more neurons than did PMF. These percentages for PRF and PMF, added together, parallel the percentage of labeled vomeronasal neurons when females are exposed to the whole pheromone.


CONCLUSIONS
This study suggests that two specific populations of female vomeronasal neurons are responsible for responding to each of the two components of the male pheromone mixture. These two neural populations, therefore, could express different receptors which, in turn, transmit different information to the brain, thus accounting for the different female behavior elicited by each pheromone component.
Department of Cell Biology, University of Oklahoma Health Sciences Center, 940 S,L, Young Boulevard, Oklahoma City, OK 73104, USA. celeste-wirsig@ouhsc.edu
Celeste R
CR
Wirsig-Wiechmann
Lynne D
LD
Houck
Jessica M
JM
Wood
Pamela W
PW
Feldhoff
Richard C
RC
Feldhoff
D000818:Animals; D002628:Chemoreceptor Cells / Q000187:drug effects / Q000502:physiology; D005260:Female; D008297:Male; D009833:Olfactory Pathways / Q000187:drug effects / Q000502:physiology; D018034:Olfactory Receptor Neurons / Q000187:drug effects / Q000502:physiology*; D011506:Proteins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D012724:Sex Attractants / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D012726:Sexual Behavior, Animal / Q000187:drug effects / Q000502:physiology; D012903:Smell / Q000187:drug effects / Q000502:physiology*; D014562:Caudata / Q000033:anatomy & histology / Q000502:physiology*; D019147:Vomeronasal Organ / Q000187:drug effects / Q000502:physiology*
C121545:PRF protein, Plethodon jordani; D011506:Proteins; D012724:Sex Attractants