title: Exposure to female pheromones stimulates a specific type of neuronal population in the male but not female magnocellular division of the medial preoptic nucleus (MPN mag) of the Syrian hamster.
abstract: The magnocellular division of the medial preoptic area (MPN mag) integrates pheromonal and hormonal signals to play a critical role in the expression of male typical sex behavior. The MPN mag contains two morphologically distinct neuronal populations; the percentage of each type within the nucleus is sex specific. Males have more neurons with a single nucleolus whereas females have more with multiple nucleoli. To determine which neuronal subtype mediates pheromonal induction of copulation, tissue from male and female hamsters exposed to female pheromones was immunolabeled for the immediate early protein (EGR-1). Subsequently the tissue was counterstained and the number of ERG-1 neurons with one or two nuclei was determined. The results indicate that pheromones stimulate neurons with single nucleoli in males but fail to stimulate either neuronal subtype in females suggesting that synaptic input to the MPN mag is sexually differentiated.
authors.affiliation: Lehigh University, Dept of Biological Sciences, United States. Electronic address: jms5@lehigh.edu.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Swann
authors.forename: Holly A
authors.initials: HA
authors.lastname: Richendrfer
authors.forename: Lindsay
authors.initials: L
authors.lastname: Dawson
authors.forename: Elana
authors.initials: E
authors.lastname: Nack
authors.forename: Jack
authors.initials: J
authors.lastname: Whylings
authors.forename: Tim
authors.initials: T
authors.lastname: Garelick
mesh_terms: D000818:Animals; D006224:Cricetinae; D000072237:ERG1 Potassium Channel; D051638:Ether-A-Go-Go Potassium Channels / Q000378:metabolism; D005260:Female; D008297:Male; D008647:Mesocricetus; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D009928:Organ Specificity / Q000187:drug effects; D011301:Preoptic Area / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D012724:Sex Attractants / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D013268:Stimulation, Chemical
chemical_list: D000072237:ERG1 Potassium Channel; D051638:Ether-A-Go-Go Potassium Channels; D012724:Sex Attractants
keywords: 3rd ventricle; BST; BSTpi; BSTpm; Bed nucleus of the stria terminalis; Bed nucleus of the stria terminalis posterior intermediate subdivision; Bed nucleus of the stria terminalis posterior medial subdivision; EGR-1; Fornix; HVS; Hamster vaginal secretions; IIIv; MPN mag; MPOA; Magnocellular division of the medial preoptic nucleus; Mating behavior; Me; MeA; MeP; Medial nucleus of the amygdala; Medial nucleus of the amygdala anterior subdivision; Medial nucleus of the amygdala posterior subdivision; Medial preoptic area; Nucleolus; Optic tract; Sex differences; Stereology; Stria medullaris; f; ot; sm