Rabbit pheromone

In rabbits, the as yet unidentified maternal signal during lactation has analogous properties in guiding the reliable orientation of suckling, mainly via MOS input (Hudson and Distel, 1986 Schaal et al., unpubl.). Minor fractions may still function as flag contributors, exemplified by the attractiveness of proestrous elephant urine. Male responses show that intact urine is conspicuously more attractive in comparison with the pure insect mammal pheromone (9.) presented in water (Rasmussen et al., 1996). 

Goodrich B.S. and Myktowycz R. (1972). Individual and sex-differences in chemical composition of pheromone-like substances from skin giands of rabbit. J Mammal 53, 540-548. 

Hudson R. and Distel H. (1986). Pheromonal release of suckling in rabbits does not depend on the vomeronasal organ. Physiol Behav 37, 123-129. 

Keil W. and von Stralendorff E (1990). A behavioral bioassay for analysis of rabbit nipple-search pheromone. Physiol Behav 47, 525-530. 

Nakielny, S., Campbell, D. G., and Cohen, P. (1992b). MAP kinase kinase from rabbit skeletal muscle a novel dual specificity enzyme showing homology to yeast protein kinases involved in pheromone-dependent signal transduction. FEBS Lett. 308 183-189. 

Schaal, B., Coureaud, G., Langlois, D., Ginies, C., Semon, E. and Perrier, G. (2003) Chemical and behavioural characterization of the rabbit mammary pheromone. Nature 424, 68-72. 

Psychobiological functions of the mammary pheromone in newborn rabbits... 

To sum up, 2MB2 emitted in milk by female rabbits meets the five criteria proposed by Beauchamp et al. (1976) to define a pheromone in the case of mammals. As rabbit milk releases neonatal behavior after full ejection, but not when collected from the mammary tract below the nipples (from the tubes or alveolae), 2MB2 is probably produced de novo in the distal part of the mammary apparatus (Moncomble, Coureaud, Quennedey, Langlois, Perrier, Brossut and Schaal 2005). Accordingly, the active compound carried in milk was named mammary pheromone (MP). 

Pheromones have been classified as a function of their effect. Those triggering immediate behavioral effects were termed releasing pheromones, while those altering slower processes of physiological or developmental nature were termed priming pheromones (Wilson and Bossert 1963). The rabbit MP has a clear releasing function but recent data also show that it has another function that cannot be termed priming in the classical sense. 

Coureaud, G. (2001) Olfactory regulation of sucking in newborn rabbit Ethological and chemical characterization of a pheromonal signal. PhD Thesis, University of Paris. 

Coureaud, G., Montigny, D., Dewas, M., Moncomble, A.S., Patris, P. and Schaal, S. (2005) A sensitive period for pheromone-induced odour learning in newborn rabbits. 29th International Ethological Conference, Budapest, Hungary, 20-27 August. 

Coureaud, G., Rodel, H.G., Kurz, C., von Holst, D. and Schaal, B. (2006b) Age-related changes in the processing of the rabbit mammary pheromone comparison in domestic and wild pups. 17th Congress of the European Chemoreception Research Organisation, Granada, Spain, and Chem. Senses 31, 274 (abstract online). 

Gonzalez-Mariscal, G., Chirino, R. and Hudson, R. (1994) Prolactin stimulates emission of nipple pheromone in ovariectomized New Zealand white rabbits. Biol. Reprod. 50, 373-376. 

Hudson, R. and Distel H. (1983) Nipple location by newborn rabbits behavioural evidence for pheromonal guidance. Behaviour 85, 260-275. 

Hudson, R. and Distel, H. (1984) Nipple-search pheromone in rabbits dependence on season and reproductive state. J. Comp. Physiol. A 155, 13-17. 

Montigny, D., Coureaud, G. and Schaal, B. (2006) Newborn rabbit response to the mammary pheromone From automatism to prandial control. Physiol. Behav. 89, 742-749. 

Rabbit Nipple-Search Pheromone Versus Rabbit Mammary Pheromone Revisited... 

In conclusion, the reliable, functionally vital and stereotyped nature of the pups response to the chemical signal governing nipple-search behaviour would seem to qualify this as a true mammalian releasing pheromone (Beauchamp, Doty, Moulton and Mugford 1976) and particularly as it appears to be species-specific rabbit pups fail to respond to lactating cats, rats, guinea pigs or even hares with nipple-search behaviour or nipple attachment (Muller 1978 Hudson 1985 own observations). 

Coureaud, Langlois, Sicard, and Schaal (2004) Newborn rabbit responsiveness to the mammary pheromone is concentration dependent. Chem. Senses 294, 341-350. 

Hudson, R., Gonzalez-Mariscal, G. and Beyer, C. (1990) Chin marking behavior, sexual receptivity, and pheromone emission in steroid-treated, ovariectomized rabbits. Hormones Behav. 24, 1-13. 

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