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UNDERESTIMATED SENSE. “Our olfactory sense is well developed, even if it has often been underestimated.” https://peerj.com/preprints/27908/ View in LinkedIn

CLASSIC ODORANTS. “Pheromones are the same in all sexually mature males, for example, of a species. It is the consistency in these molecules between individual males in a population which allows them to be identified as a pheromone. Some males may produce more of the pheromone and thus may be more attractive to females: well-fed male voles with high testosterone levels produce more pheromone.” https://lnkd.in/drx5_4e View in LinkedIn

CONDITIONS PRECEDENT. “While, typically, pheromones do not need to be learnt, if development is interfered with by an experimenter, previously invisible dependencies can be revealed. For example, honeybee workers need early exposure to queen mandibular pheromone in order to be attracted to it when they attend the queen as older workers.” https://lnkd.in/drx5_4e View in LinkedIn

PRIMED WHEN LOADED. “Male Agrotis moths do not respond to female sex pheromone for up to 24 hours after mating. Even though pheromone still stimulates the olfactory sensory neurons in the male moth’s antennae, the brain response is blocked until enough time has elapsed for the male to have replenished his accessory protein stores to go with his sperm. Male hamsters only respond to female pheromone if they are well fed, giving them sufficiently high blood testosterone levels in their hypothalamus.” https://lnkd.in/drx5_4e View in LinkedIn

NUANCED RESPONSES. “Pheromones elicit stereotyped behavioural and/or physiological responses but these are modulated by context, time of day, and many other factors including the receiver’s genetics, age, sex, hormonal state, dominance status, and recent experience.” https://lnkd.in/drx5_4e View in LinkedIn

GENES STIMULATED. “Sex pheromones in the urine of dominant male Mozambique tilapia (Oreochromis mossambicus) deter subordinate males, attract females and prime ovulation in females. Two steroid glucuronates (5β-pregnane-3α,17α,20β-triol 3-glucuronate and its 20α-epimer) are produced in large quantities by dominants and are the most potent urinary odorants to females. They act via (a) specific and common olfactory receptor(s) on the females’ endocrine axis, stimulating production and release of 17,20β-P, the major oocyte maturation-inducing hormone in teleost fishes. This leads to the ripening of the oocytes and (likely) synchronizes spawning.” https://lnkd.in/drx5_4e View in LinkedIn

THE FLY IN THE OINTMENT. “Male tilapia sex pheromones have multiple effects.” https://lnkd.in/drx5_4e View in LinkedIn

PHYSIOLOGICAL PRIMERS. “Many bioassays measure a behavioural response as in the silk moth or the suckling of a rabbit pup in response to the rabbit mammary pheromone, 2-methylbut-2-enal. Other pheromones need different kinds of bioassays as they have physiological (‘primer’) effects. Many pheromones, such as male tilapia urinary pheromones and honeybee alarm pheromone, have both immediate ‘releaser’ effects and longer lasting primer effects. In the honey bee this is reflected in changes in gene activity in the bee’s antennal lobe. For many hours after exposure to alarm pheromone, honeybees are more likely to attack intruders.” https://lnkd.in/drx5_4e View in LinkedIn

BIOASSAY REQUIRED. “Butenandt used the wing fluttering response of the male silk moth as the bioassay to track the female sex pheromone activity in his solvent fractionations and to later confirm that the synthesized molecule, bombykol, was indeed the pheromone. Such bioassays, repeatable experiments designed to measure a biological response, are still an essential part of pheromone identification. Without this systematic approach, no claim that a molecule or combination of molecules is a pheromone is credible.” https://lnkd.in/drx5_4e View in LinkedIn

DOPING MIXTURE. “Many pheromones, perhaps most, consist of a particular combination of molecules, not a single molecule.” https://lnkd.in/drx5_4e View in LinkedIn